Re: [Emc-users] Spindle position, direction and Index with only one channel.
On Fri, Nov 23, 2012 at 11:21 AM, andy pugh bodge...@gmail.com wrote: The bidirectional sensors are for start-stop applications where it is important to retain crank-synch even during rock-back when the engine stops. We need to inject fuel on the very first available TDC to meet the start-time targets. OK, but there's very little consequence if the engine controls get it wrong, correct? it'd just keep turning over and fire on another TDC. Whereas rigid tapping would go quite wrong if it was off by a revolution. -- Keep yourself connected to Go Parallel: DESIGN Expert tips on starting your parallel project right. http://goparallel.sourceforge.net ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On 27 November 2012 20:21, Przemek Klosowski przemek.klosow...@gmail.com wrote: OK, but there's very little consequence if the engine controls get it wrong, correct? it'd just keep turning over and fire on another TDC. Whereas rigid tapping would go quite wrong if it was off by a revolution. No, as long as it is exactly one rev, it's all fine in the case of rigid tapping. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Keep yourself connected to Go Parallel: DESIGN Expert tips on starting your parallel project right. http://goparallel.sourceforge.net ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
andy pugh wrote: On 27 November 2012 20:21, Przemek Klosowski przemek.klosow...@gmail.com wrote: OK, but there's very little consequence if the engine controls get it wrong, correct? it'd just keep turning over and fire on another TDC. Whereas rigid tapping would go quite wrong if it was off by a revolution. No, as long as it is exactly one rev, it's all fine in the case of rigid tapping. Not if the tap is buried in the workpiece at the time! This happens every time the tap reaches full depth, the spindle is reversed and the tap is brought out in sync with the thread. If it even looses a couple teeth (depending on tooth count/ rev) it will break the tap or maul the workpiece. If it misses the index pulse (the missing tooth) that is pretty benign, but if there is a loss of one or more teeth at reversal, that would be bad. My specific concern with this whole scheme is if the reversal happens right over the missing tooth, you CANNOT compute your way out of it by timing alone. It seems impossible to detect the difference between the time between tooth crossings right at reversal and know whether that contained the missing tooth or not. Maybe you can do it by always maintaining the count up/down and knowing when the next tooth is the missing one, but that incurs a jump when you were going forward, say, and the next tooth should be the missing one, and then you detect the first tooth showing the pulse width that indicates the reverse direction. Suddenly, you have to shift the spindle position by two teeth. If the encoder has pretty high resolution, that doesn't represent a lot of degrees, but if it has a fairly low tooth count, then it does. Jon -- Keep yourself connected to Go Parallel: INSIGHTS What's next for parallel hardware, programming and related areas? Interviews and blogs by thought leaders keep you ahead of the curve. http://goparallel.sourceforge.net ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
well gene i agree the mopar sensor is junk but these are 19 bucks like i said :) http://compare.ebay.com/like/181031267122?var=lvltyp=AllFixedPriceItemTypesvar=sbar On Sat, Nov 24, 2012 at 12:49 AM, Gene Heskett ghesk...@wdtv.com wrote: On Saturday 24 November 2012 00:38:21 jeremy youngs did opine: actually accuracy is needed as it has to pick up thta position on fire up :) it is also to note that several reversible sensors of identical or similar design are found everywhere on autos. this is not a dissertation just point to the larger world. i think andy is trying to feel whether we are interested in a simple one channel encoder with parts store availability and not discern how autos work. I for one would love to be able to use a 15 dollar locally (globally?) available crank sensor and not have to wait to ship or find it discontinued Let me assure you that the very high failure rate crank sensor in a mopar engine is far from a 15 dollar part. I have replaced a few of them in Jeeps in particular, and have never paid less than $80 US for one from N.A.P.A. I have not noted any of them lasting much past the 50,000 mile mark, with replacements apparently not good for much past 10,000 miles. When the 3rd one got funkity, requiring several restarts to bring her home from work, 15k miles after its last replacement, she said screw it and changed the paint and vin, but its still a Jeep. Now its newer and white, but I don't believe the red one had yet hit the 100k mark. Some folks never learn, heck I was slow too, replacing Dee's mopar/mitsubishi vans twice before I swore off. Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene is up! Pray: To ask that the laws of the universe be annulled in behalf of a single petitioner confessedly unworthy. -- Ambrose Bierce -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- jeremy youngs -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
Has anyone on list used a stepper as an encoder like this: http://home.clear.net.nz/pages/joecolquitt/stepper_as_encoder.html James On Sat, 2012-11-24 at 19:01 -0500, jeremy youngs wrote: well gene i agree the mopar sensor is junk but these are 19 bucks like i said :) http://compare.ebay.com/like/181031267122?var=lvltyp=AllFixedPriceItemTypesvar=sbar On Sat, Nov 24, 2012 at 12:49 AM, Gene Heskett ghesk...@wdtv.com wrote: On Saturday 24 November 2012 00:38:21 jeremy youngs did opine: actually accuracy is needed as it has to pick up thta position on fire up :) it is also to note that several reversible sensors of identical or similar design are found everywhere on autos. this is not a dissertation just point to the larger world. i think andy is trying to feel whether we are interested in a simple one channel encoder with parts store availability and not discern how autos work. I for one would love to be able to use a 15 dollar locally (globally?) available crank sensor and not have to wait to ship or find it discontinued Let me assure you that the very high failure rate crank sensor in a mopar engine is far from a 15 dollar part. I have replaced a few of them in Jeeps in particular, and have never paid less than $80 US for one from N.A.P.A. I have not noted any of them lasting much past the 50,000 mile mark, with replacements apparently not good for much past 10,000 miles. When the 3rd one got funkity, requiring several restarts to bring her home from work, 15k miles after its last replacement, she said screw it and changed the paint and vin, but its still a Jeep. Now its newer and white, but I don't believe the red one had yet hit the 100k mark. Some folks never learn, heck I was slow too, replacing Dee's mopar/mitsubishi vans twice before I swore off. Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene is up! Pray: To ask that the laws of the universe be annulled in behalf of a single petitioner confessedly unworthy. -- Ambrose Bierce -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On Saturday 24 November 2012 20:39:45 jeremy youngs did opine: well gene i agree the mopar sensor is junk but these are 19 bucks like i said :) http://compare.ebay.com/like/181031267122?var=lvltyp=AllFixedPriceItem Typesvar=sbar So mopar is as usual, ripping people off. And have been doing it since the K car days, if not before. I personally decided it was time I got the hell out of the mopar business, even if Mitsubishi was actually making it when a fuel filter, hidden inside the right side frame rail under the passengers seat, cost me $513.67 to get it replaced. The local dealer had already sealed his fate the 2nd time I took it in for what should have been a $50 repair max, a noisy fan belt tensioner that needed a new bearing, and when they were done it needed $3000 worth of work in the body shop. Claimed it was that way (a passenger door everything but ripped out by the roots) when I brought it in. I guess that extra $450 was retribution for getting it to limp into their shop lot, but before I gave them the keys the last time, I went around it with my camera, taking pix from both sides all 4 corners showing that there was no body damage. And they saw me doing it. Bastards. With it running, and even the dashboard was temporarily working, I right quick changed the paint, and vin, but that was a short experiment. That v-dub Jetta was the most expensive to fix, paranoid car I ever owned, so now there has been a Toy Rav-4 in the drive for about 3 years. Stick the key in the switch and drive it. Gas it when its empty, and change the oil at 5k intervals. Whats not to like? And now we are for sure off topic. Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene is up! Your sister swims out to meet troop ships. -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On Saturday 24 November 2012 21:05:58 James Boulton did opine: Has anyone on list used a stepper as an encoder like this: http://home.clear.net.nz/pages/joecolquitt/stepper_as_encoder.html James I breadboarded a similar circuit, feeding the coils of a small 24v stepper into a comparator with a very slight hysteresis, perhaps 5mv of feedback so that stopped the status was still known. On the scope, it appeared to work quite well at speeds even slower than I might turn the shaft with a 2 spinner knob. I was going to use it as a pendant to drive the mill, but it seems as if I have miss-placed my round tuit. pcb for the lm339's and 4 motors have been occupying a box in the basement for about 2 years now. I was going to mount them on a box so x was on the right side, y was on the front, with z and (a|b|c) on the top. Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene is up! Excellent day for drinking heavily. Spike the office water cooler. -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On 23 November 2012 04:04, Gene Heskett ghesk...@wdtv.com wrote: To buy the crank code-wheel new is not that cheap ($100) but there ought to be many in the junkyards now. The correct pickups are less likely to exist, but those are $17. Since the requirement is that its ferrous, I seen no reason that can't be a milling machine project. The target wheels we have on our engines are _not_ ferrous. They are a magnetic track and the crank sensor has no internal magnet. (I can't find that actual sensor on the Allegro site). Having said that, ebay has many trigger wheels at quite low prices which could work, though most seem to be quite low-resolution. http://www.ebay.com/itm/261124381577 You can see the one I have in my drawer at the bottom of this picture here: http://images.sklepy24.pl/87078282/3668/large/kolo-pasowe-walu-korbowego-1-8-tdci-dayco.jpg You can just about make out the magnetic track. (There are two parts there, 6B319A and 6B319B) -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On Friday 23 November 2012 09:14:56 andy pugh did opine: On 23 November 2012 04:04, Gene Heskett ghesk...@wdtv.com wrote: To buy the crank code-wheel new is not that cheap ($100) but there ought to be many in the junkyards now. The correct pickups are less likely to exist, but those are $17. Since the requirement is that its ferrous, I seen no reason that can't be a milling machine project. The target wheels we have on our engines are _not_ ferrous. They are a magnetic track and the crank sensor has no internal magnet. (I can't find that actual sensor on the Allegro site). For a hall sensor to work, there must be a magnetic field for it to sense. Generally that requires a ferrous material. It can be magnetized, or a bias magnet in the sensor can make a soft iron toothed wheel work. Not all steels are magnetic though, as you can check by trying to pick up with a magnet, an exhaust valve from one of the engines Ford has been making since 1955. :) Its 'austenitic'(sp). You would have to warm that valve back up to near melting, and let it cool slowly in order for it to regain its magnetic properties as it cools below its 'curie' point temperature. Having said that, ebay has many trigger wheels at quite low prices which could work, though most seem to be quite low-resolution. http://www.ebay.com/itm/261124381577 You can see the one I have in my drawer at the bottom of this picture here: http://images.sklepy24.pl/87078282/3668/large/kolo-pasowe-walu-korboweg o-1-8-tdci-dayco.jpg You can just about make out the magnetic track. (There are two parts there, 6B319A and 6B319B) Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene is up! No foreign coins. -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
Seems to me a resolver would be the best choice for position on start up. Velocity could be derived also. A resolver on the cam and crank could tell you the next piston to reach tdc. On Nov 23, 2012 8:30 AM, Gene Heskett ghesk...@wdtv.com wrote: On Friday 23 November 2012 09:14:56 andy pugh did opine: On 23 November 2012 04:04, Gene Heskett ghesk...@wdtv.com wrote: To buy the crank code-wheel new is not that cheap ($100) but there ought to be many in the junkyards now. The correct pickups are less likely to exist, but those are $17. Since the requirement is that its ferrous, I seen no reason that can't be a milling machine project. The target wheels we have on our engines are _not_ ferrous. They are a magnetic track and the crank sensor has no internal magnet. (I can't find that actual sensor on the Allegro site). For a hall sensor to work, there must be a magnetic field for it to sense. Generally that requires a ferrous material. It can be magnetized, or a bias magnet in the sensor can make a soft iron toothed wheel work. Not all steels are magnetic though, as you can check by trying to pick up with a magnet, an exhaust valve from one of the engines Ford has been making since 1955. :) Its 'austenitic'(sp). You would have to warm that valve back up to near melting, and let it cool slowly in order for it to regain its magnetic properties as it cools below its 'curie' point temperature. Having said that, ebay has many trigger wheels at quite low prices which could work, though most seem to be quite low-resolution. http://www.ebay.com/itm/261124381577 You can see the one I have in my drawer at the bottom of this picture here: http://images.sklepy24.pl/87078282/3668/large/kolo-pasowe-walu-korboweg o-1-8-tdci-dayco.jpg You can just about make out the magnetic track. (There are two parts there, 6B319A and 6B319B) Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene is up! No foreign coins. -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On 23 November 2012 14:26, Gene Heskett ghesk...@wdtv.com wrote: The target wheels we have on our engines are _not_ ferrous. They are a magnetic track and the crank sensor has no internal magnet. (I can't find that actual sensor on the Allegro site). For a hall sensor to work, there must be a magnetic field for it to sense. Yes, there is a ring of non-ferrous magnetic plastic stuff (like very thick cassette tape) round the periphery. Basically just like this stuff: http://www.machine-dro.co.uk/high-accuracy-magnetic-linear-tape.html But applied to the disc prior to the the pattern being applied. Not all steels are magnetic though Yes, I know. I have a PhD in ferrous metallurgy. I've lost interest. Everyone with an opinon seems to think this is a bad idea. I have no need for it, so I won't bother. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On 23 November 2012 15:22, Stuart Stevenson stus...@gmail.com wrote: Seems to me a resolver would be the best choice for position on start up. This is the car industry. Cost is everything. They probably use the one-wire sensor purely to save the extra wire and connectors that a quadrature sensor would need. If you save $1 on a million cars you can afford quite a lot of up-front software and development. I think that the position is stored in system memory for next time the engine is started, but ffinding the index on the first start of the trip isn't a huge hardship anyway. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
not everyone andy :) 15 yrs as an auto tech im actually understanding of what you are trying to do. however i do not have an immediate application to justify your time :( but thanx for sharing. I have wondered why machines dont follow the same stategy as autos involving rotational positioning -- jeremy youngs -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
Car engines are unidirectional Unless you fit a Bolinder or other boat engine The reverse detection is probably only an error signal Dave Caroline -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
transmissions , differentials and wheels are not :) On Fri, Nov 23, 2012 at 11:09 AM, Dave Caroline dave.thearchiv...@gmail.com wrote: Car engines are unidirectional Unless you fit a Bolinder or other boat engine The reverse detection is probably only an error signal Dave Caroline -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- jeremy youngs -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On 23 November 2012 16:09, Dave Caroline dave.thearchiv...@gmail.com wrote: Car engines are unidirectional Unless you fit a Bolinder or other boat engine The reverse detection is probably only an error signal I thought I explained this already? The bidirectional sensors are for start-stop applications where it is important to retain crank-synch even during rock-back when the engine stops. We need to inject fuel on the very first available TDC to meet the start-time targets. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
I, too, find this thread interesting. -- dos centavos -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
you did i was just saying that there are many similar systems requiring racking and a carte blanche statement would not apply :) nor the probably an error statement which is pure speculation not based in experience On Fri, Nov 23, 2012 at 11:21 AM, andy pugh bodge...@gmail.com wrote: On 23 November 2012 16:09, Dave Caroline dave.thearchiv...@gmail.com wrote: Car engines are unidirectional Unless you fit a Bolinder or other boat engine The reverse detection is probably only an error signal I thought I explained this already? The bidirectional sensors are for start-stop applications where it is important to retain crank-synch even during rock-back when the engine stops. We need to inject fuel on the very first available TDC to meet the start-time targets. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- jeremy youngs -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On Fri, Nov 23, 2012 at 4:21 PM, andy pugh bodge...@gmail.com wrote: On 23 November 2012 16:09, Dave Caroline dave.thearchiv...@gmail.com wrote: Car engines are unidirectional Unless you fit a Bolinder or other boat engine The reverse detection is probably only an error signal I thought I explained this already? The error I talking about is the rocking back due to compression at stop, accuracy hardly needed, I know it is a count/angle while off. to jeremy youngs gearbox/transmission none you stop and reverse the engine http://worcestervista.com/index.php/mechanics/bolinder-engines/ Dave Caroline -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
actually accuracy is needed as it has to pick up thta position on fire up :) it is also to note that several reversible sensors of identical or similar design are found everywhere on autos. this is not a dissertation just point to the larger world. i think andy is trying to feel whether we are interested in a simple one channel encoder with parts store availability and not discern how autos work. I for one would love to be able to use a 15 dollar locally (globally?) available crank sensor and not have to wait to ship or find it discontinued -- jeremy youngs -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
Stuart Stevenson wrote: Seems to me a resolver would be the best choice for position on start up. Velocity could be derived also. A resolver on the cam and crank could tell you the next piston to reach tdc You check the price on a resolver, lately? The problem is a wound-rotor brushless resolver is pretty expensive to make. The bigger they are, the more expensive, too. Variable reluctance resolvers are cheaper, as there are no windings on the rotor, and so can be made arbitrarily large. but, those have multiple poles/rev, and so you don't get absolute crank position at power-on. So, from a cost standpoint, alone, I don't think the auto makers are going to go to a resolver over a cheap solid state sensor. One absolute sensor on the cam would be all you'd need, they have plenty of resolution. Jon -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
Sounds like this could be a major move forward. I'm not wed to the full quadrature concept. This sounds like it is almost an absolute encoder? Or close? I've got to get back to working on an SSI absolute encoder interface now that I am back home. Julian was working on a SSI interface on the support forum using a Mesa 5i25 board, but it doesn't show that it was completed. I spent two weeks in Mexico and one in China starting up some machine cells for an Automotive OEM. It was not a vacation as we worked a lot of hours with no days off. But the weather was really nice. Neither the China or the Mexico plants had a heating or cooling system as the weather is very mild in both locations. Cold is 50 degrees F and hot is 80 degrees F. I could get used to that! :-) Now I find it is a little difficult dealing with 34F/1C and 30 mph winds in Indiana, USA, after enjoying the nice weather in Mexico and China! Dave On 11/23/2012 10:51 AM, andy pugh wrote: On 23 November 2012 14:26, Gene Heskettghesk...@wdtv.com wrote: The target wheels we have on our engines are _not_ ferrous. They are a magnetic track and the crank sensor has no internal magnet. (I can't find that actual sensor on the Allegro site). For a hall sensor to work, there must be a magnetic field for it to sense. Yes, there is a ring of non-ferrous magnetic plastic stuff (like very thick cassette tape) round the periphery. Basically just like this stuff: http://www.machine-dro.co.uk/high-accuracy-magnetic-linear-tape.html But applied to the disc prior to the the pattern being applied. Not all steels are magnetic though Yes, I know. I have a PhD in ferrous metallurgy. I've lost interest. Everyone with an opinon seems to think this is a bad idea. I have no need for it, so I won't bother. -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
Interestingly, this sort of sensor would have been helpful on my latest problem with the lathe spindle Z pulse encoder I wanted to run on a pulley at 3x the spindle rate, presuming there was software support for it. In my case the pulse length accounting would have had to have been in the 7i33 firmware though. Being able to count a backwards pulse as backwards would have allowed me to accurately ignore every third pulse in software, regardless of rock back or other spindle changes in direction. Scott On Fri, Nov 23, 2012 at 2:00 PM, Jon Elson el...@pico-systems.com wrote: Stuart Stevenson wrote: Seems to me a resolver would be the best choice for position on start up. Velocity could be derived also. A resolver on the cam and crank could tell you the next piston to reach tdc You check the price on a resolver, lately? The problem is a wound-rotor brushless resolver is pretty expensive to make. The bigger they are, the more expensive, too. Variable reluctance resolvers are cheaper, as there are no windings on the rotor, and so can be made arbitrarily large. but, those have multiple poles/rev, and so you don't get absolute crank position at power-on. So, from a cost standpoint, alone, I don't think the auto makers are going to go to a resolver over a cheap solid state sensor. One absolute sensor on the cam would be all you'd need, they have plenty of resolution. Jon -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
as to the autos variable reluctance is cheap and effective for things that arent too slow as voltage is a function of rpm in them . Hall effects require magnets and collect debris (as does variable reluctance) and are not as robust in my experience. Led/ collector is a fairly robust system with good timing capabilities but works best in the dark. probably the best for our application will be a three wire magneto resistive sensor as it has very little bounce, a static voltage , is not rpm dependant and has excellent response time. just my auto tech .02 -- jeremy youngs -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On Saturday 24 November 2012 00:21:24 andy pugh did opine: On 23 November 2012 14:26, Gene Heskett ghesk...@wdtv.com wrote: The target wheels we have on our engines are _not_ ferrous. They are a magnetic track and the crank sensor has no internal magnet. (I can't find that actual sensor on the Allegro site). For a hall sensor to work, there must be a magnetic field for it to sense. Yes, there is a ring of non-ferrous magnetic plastic stuff (like very thick cassette tape) round the periphery. That is on the bottom disks edge in that pix? I wondered about that, not exactly the right color for freshly made metal. Basically just like this stuff: http://www.machine-dro.co.uk/high-accuracy-magnetic-linear-tape.html But applied to the disc prior to the the pattern being applied. Not all steels are magnetic though Yes, I know. I have a PhD in ferrous metallurgy. Better than my degree from UHK, and certainly 40 years fresher. But the technology does move on and and I wouldn't want to be 'caught out' anymore than you would. Discussion refreshes memories. Particularly mine. :D I've lost interest. Everyone with an opinon seems to think this is a bad idea. I have no need for it, so I won't bother. I wasn't trying to say it was a bad idea Andy, on the contrary I believe it can be made to work quit well with an additional index detector channel. Half a cmos 556 (7556) set for about a 65 u-sec pulse triggered by the leading edge, and a latch to latch the falling edges state and in should be 100% ready to a simple sampling circuit to grab the resultant dir output of the latch. Seems pretty simple, and possibly less error prone than the quadrature decoder we have already. Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene is up! I can hire one half of the working class to kill the other half. -- Jay Gould -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On Saturday 24 November 2012 00:38:21 jeremy youngs did opine: actually accuracy is needed as it has to pick up thta position on fire up :) it is also to note that several reversible sensors of identical or similar design are found everywhere on autos. this is not a dissertation just point to the larger world. i think andy is trying to feel whether we are interested in a simple one channel encoder with parts store availability and not discern how autos work. I for one would love to be able to use a 15 dollar locally (globally?) available crank sensor and not have to wait to ship or find it discontinued Let me assure you that the very high failure rate crank sensor in a mopar engine is far from a 15 dollar part. I have replaced a few of them in Jeeps in particular, and have never paid less than $80 US for one from N.A.P.A. I have not noted any of them lasting much past the 50,000 mile mark, with replacements apparently not good for much past 10,000 miles. When the 3rd one got funkity, requiring several restarts to bring her home from work, 15k miles after its last replacement, she said screw it and changed the paint and vin, but its still a Jeep. Now its newer and white, but I don't believe the red one had yet hit the 100k mark. Some folks never learn, heck I was slow too, replacing Dee's mopar/mitsubishi vans twice before I swore off. Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene is up! Pray: To ask that the laws of the universe be annulled in behalf of a single petitioner confessedly unworthy. -- Ambrose Bierce -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On 22 November 2012 02:32, Gene Heskett ghesk...@wdtv.com wrote: I think it makes sense to do index the same way as engines do, just have a short tooth so there is a pulse missing. But, would that not upset any speed controls? The encoder counter would need to compensate. it isn't too hard, because the counter knows when to not expect a tooth. The system has been used in car engines for decades. That's hundreds of millions of vehicles doing hundreds of millions of revolutions. I can't think of many things that have ever been quite so thoroughly tested. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On 22 November 2012 11:26, Dave Caroline dave.thearchiv...@gmail.com wrote: Current encoder inputs need 50% ratio Some cleaning/retiming required I can't decide if it is a special case of counter mode, or a whole new component. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On 11/22/2012 6:42 AM, andy pugh wrote: On 22 November 2012 11:26, Dave Carolinedave.thearchiv...@gmail.com wrote: Current encoder inputs need 50% ratio Some cleaning/retiming required I can't decide if it is a special case of counter mode, or a whole new component. How does the car controls handle the possible partial reverse rotation of the engine when it stops? Is it just ignored and the timing for TDC is close enough on the next crank that it doesn't matter, then they resync when the missing tooth is found again?? Or do they sense the engine speed going to zero and then accelerating and declare that a reverse rotation instance on an engine stop? Dave -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On Thursday 22 November 2012 09:59:53 andy pugh did opine: On 22 November 2012 11:26, Dave Caroline dave.thearchiv...@gmail.com wrote: Current encoder inputs need 50% ratio Some cleaning/retiming required I can't decide if it is a special case of counter mode, or a whole new component. Because the pulse width is the direction signal, and the rep rate is the speed, that does sound like a whole new component to me. We are, generally speaking used to the quadrature mode, where the condition of one pulse on the given edge of the other, is the direction. This would seem to need a timer counter, that for software convenience sake, would probably need to be married to the BASE_PERIOD. On slower boards, this could be a problem because its pulse widths are a bit noisy if you look at the pdf sheets. For fwd rotation, the tolerance is 38-52 u- secs, while the reverse is 76-104 in duration. The speed part is relatively easy, how many pulses in a SERVO_THREAD interval, which should probably be averaged over several intervals with the lowpass component for slower speeds. For those of us using the D525MW boards which seem to be pretty happy running at 23 to 25 u-secs BASE_THREAD we can probably say that a 1 count or 2 is fwd, and a 4 count is reverse, leaving a don't change deadband at a 3 counts. With finer timing of coarse we can likely get pickier, primarily because if its turning even at .25 rps, it sure isn't going to reverse in one BASE_PERIOD. So I think I would nail the dir to whichever rail, until a very slow speed has been detected. A speed at which its possible it could actually have been told to reverse. Consequently I see the direction detector essentially frozen in place as long as the speed precludes its reversal without using hoover dams output for 20 microseconds to achieve the reversal. In any event, it will need a separate index pulse, used to make sure there have been no missing or extranious(sp) pulses since LinuxCNC tracks windup with very wide counters. I can't code it, not on these machines (I could on a TRS-80 Color Computer, but its clock is 1.79Mhz=max speeds in the 1 rps area, but first I'd have to cobble in a parport write a driver, it doesn't have one), but I think that about covers it. Humm, wierd thought about the reversals. Is anyone here using a big honking frame 56 or bigger stepper to turn a lathe spindle? Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene is up! Behind every great man, there is a woman -- urging him on. -- Harry Mudd, I, Mudd, stardate 4513.3 -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On 22 November 2012 15:36, Gene Heskett ghesk...@wdtv.com wrote: In any event, it will need a separate index pulse, used to make sure there have been no missing or extranious(sp) pulses since LinuxCNC tracks windup with very wide counters. I am not sure this is necessarily true. LinuxCNC only typically _uses_ the index pulse when the spindle is running at a constant, non-zero speed. (this style of encoder is probably not appropriate for homing a servo-driven axis). -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On 22 November 2012 14:55, Dave e...@dc9.tzo.com wrote: How does the car controls handle the possible partial reverse rotation of the engine when it stops? Tracking reverse rotation is the whole point of these direction-sensitive devices. Before stop-start the system would have to wait to see an index to figure out where TDC was. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
or use a cam sensor, either way the controller will figure it in 2 revolutions or less On Thu, Nov 22, 2012 at 10:54 AM, andy pugh bodge...@gmail.com wrote: On 22 November 2012 14:55, Dave e...@dc9.tzo.com wrote: How does the car controls handle the possible partial reverse rotation of the engine when it stops? Tracking reverse rotation is the whole point of these direction-sensitive devices. Before stop-start the system would have to wait to see an index to figure out where TDC was. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- jeremy youngs -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On 22 November 2012 16:11, jeremy youngs jcyoung...@gmail.com wrote: or use a cam sensor, either way the controller will figure it in 2 revolutions or less We currently have a requirement to fire on the second TDC (of a 4-cylinder) That's less than 180 crank degrees. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
andy pugh wrote: On 22 November 2012 11:26, Dave Caroline dave.thearchiv...@gmail.com wrote: Current encoder inputs need 50% ratio Some cleaning/retiming required I can't decide if it is a special case of counter mode, or a whole new component. It actually gets fairly complicated! To handle the missing tooth, you need to have a tracking counter (or whatever) that keeps track of the recent time between pulses, so it knows how long a gap is going to be the missing pulse. When the instantaneous change in velocity is large, like at spindle reversal, then you are likely to miss one of those pulses. So, my guess is it can work well for a lathe spindle running at nearly constant speed, but may not work well at all for rigid tapping. I'd be real skeptical it could work at all in that case. Also, with a range of BASE_PERIOD timings, detecting the 45 vs 90 us pulse width might be a bit tricky. If used on a fast machine with a 20 us BASE_PERIOD or less, it should be fine. Generally, I just don't see the advantage of going to a single sensor/single wire scheme when there are so many potential pitfalls. Anyway, it would take some serious work to make sure this is completely reliable. Most parallel ports have 5 input lines, so that should be enough for the E-stop, limit switches and leaves 3 for a quadrature encoder. One other comment, with a 90 us pulse width from the sensor, and assuming some reserve, so assume pulses should never come faster than every 180 us, that is 5556 pulses/second. If you assume a gear with 100 teeth, that is 55 RPS or RPM. So, this should work on most lathes with up to 100 tooth gears on the spindle, but might be a limitation on small mills. (Well, they might have fewer gear teeth, anyway.) Jon -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On 22 November 2012 20:51, Jon Elson el...@pico-systems.com wrote: Generally, I just don't see the advantage of going to a single sensor/single wire scheme when there are so many potential pitfalls. The single-wire is just a side-effect of using an encoder wheel that is readily available and has a big centre bore. To buy the crank code-wheel new is not that cheap ($100) but there ought to be many in the junkyards now. The correct pickups are less likely to exist, but those are $17. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On Thursday 22 November 2012 23:03:13 andy pugh did opine: On 22 November 2012 20:51, Jon Elson el...@pico-systems.com wrote: Generally, I just don't see the advantage of going to a single sensor/single wire scheme when there are so many potential pitfalls. The single-wire is just a side-effect of using an encoder wheel that is readily available and has a big centre bore. To buy the crank code-wheel new is not that cheap ($100) but there ought to be many in the junkyards now. The correct pickups are less likely to exist, but those are $17. Since the requirement is that its ferrous, I seen no reason that can't be a milling machine project. Depends on what one thinks his time is worth I suppose. :) Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene is up! It is impossible to enjoy idling thoroughly unless one has plenty of work to do. -- Jerome Klapka Jerome -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
andy pugh wrote: On 22 November 2012 20:51, Jon Elson el...@pico-systems.com wrote: Generally, I just don't see the advantage of going to a single sensor/single wire scheme when there are so many potential pitfalls. The single-wire is just a side-effect of using an encoder wheel that is readily available and has a big centre bore. To buy the crank code-wheel new is not that cheap ($100) but there ought to be many in the junkyards now. The correct pickups are less likely to exist, but those are $17. The Allegro ATS667 series are about $6 each, but you need 3 for a quadrature+index scheme. But, the advantage is you can use any available steel gear on the spindle as the encoder wheel. That's what I did on my Bridgeport, used the existing bull gear inside the head. I made a small dimple in the gear for the index pickup. This turns into a 324 count/rev encoder (81-tooth gear * 4 in quadrature.) Jon -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Spindle position, direction and Index with only one channel.
I have a rather interesting datasheet from Allegro. They have a sensor that detects either a magneic codewheel, or a gear tooth (with a biasing magnet behind the sensor). The neat part is that the pulse width is 45uS in one direction, and 90uS in the other. It is intended for crankshaft sensing, where index is done by a missing tooth. The typical code-wheel is a pressed steel part 100m diameter with a 70mm bore. This is pressed on to a hub with a 30mm bore in the case of the one I have on my desk at the moment. The encoding scheme seems compatible with software/parport sensing, and the form-factor seems ideal for a lathe spindle encoder. I wonder if it is worth adding support to the encoder driver? -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On Wednesday 21 November 2012 16:05:50 andy pugh did opine: I have a rather interesting datasheet from Allegro. They have a sensor that detects either a magneic codewheel, or a gear tooth (with a biasing magnet behind the sensor). The neat part is that the pulse width is 45uS in one direction, and 90uS in the other. It is intended for crankshaft sensing, where index is done by a missing tooth. The typical code-wheel is a pressed steel part 100m diameter with a 70mm bore. This is pressed on to a hub with a 30mm bore in the case of the one I have on my desk at the moment. The encoding scheme seems compatible with software/parport sensing, and the form-factor seems ideal for a lathe spindle encoder. I wonder if it is worth adding support to the encoder driver? A 100mm wheel is a bit large for my small lathe, but probably fine for the 9 and up stuff, and if its quadrature direction sensing too, or 2 sensors could be made so, then it sounds like something that would be a heck of a lot less fuss to install make work. IOW, a great idea Andy. Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene is up! Horace's best ode would not please a young woman as much as the mediocre verses of the young man she is in love with. -- Moore -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
I have used these on a competition robot before. They were set up to detect sprocket teeth. Worked great until the mount got a little loose, then it got ground to dust (the magic smoke leaked out at that point). Ray --J. Ray Mitchell Jr. jrmitche...@gmail.com (818)324-7573 A foolish faith in authority is the worst enemy of truth. - Einstein On Wed, Nov 21, 2012 at 9:53 AM, andy pugh bodge...@gmail.com wrote: I have a rather interesting datasheet from Allegro. They have a sensor that detects either a magneic codewheel, or a gear tooth (with a biasing magnet behind the sensor). The neat part is that the pulse width is 45uS in one direction, and 90uS in the other. It is intended for crankshaft sensing, where index is done by a missing tooth. The typical code-wheel is a pressed steel part 100m diameter with a 70mm bore. This is pressed on to a hub with a 30mm bore in the case of the one I have on my desk at the moment. The encoding scheme seems compatible with software/parport sensing, and the form-factor seems ideal for a lathe spindle encoder. I wonder if it is worth adding support to the encoder driver? -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On 21 November 2012 22:57, Gene Heskett ghesk...@wdtv.com wrote: Ahh, so. Do you have a link so we are on the same page with our thinking? http://www.allegromicro.com/en/Products/Magnetic-Speed-Sensor-ICs/Transmission-Sensor-ICs/ATS692.aspx Am I to understand that turning one way its a 90 degree duty cycle for a single tooths full passage, but its only a 45 degree duty cycle when turning the reverse direction, or some such? There is a single fixed-width pulse for each tooth. And the width of the pulse encodes direction. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On Wednesday 21 November 2012 18:41:41 andy pugh did opine: On 21 November 2012 22:57, Gene Heskett ghesk...@wdtv.com wrote: Ahh, so. Do you have a link so we are on the same page with our thinking? http://www.allegromicro.com/en/Products/Magnetic-Speed-Sensor-ICs/Transm ission-Sensor-ICs/ATS692.aspx Thanks much Andy. Am I to understand that turning one way its a 90 degree duty cycle for a single tooths full passage, but its only a 45 degree duty cycle when turning the reverse direction, or some such? There is a single fixed-width pulse for each tooth. And the width of the pulse encodes direction. An admittedly rather cursory read fails to disclose what diffs there might be between the H L versions, looking to be pretty much interchangeable. Both develop their outputs via a 100 ohm load r in series with the negative lead, which is I assume sufficient to tickle a comparator to develop the real, use it for a parport input signal to LinuxCNC. This would be ideal for either of my machines spindles if limited angular resolution can be tolerated given the available gear teeth in the spindle housing of this toy lathe. And I'd have to use the existing index detector. I'll have to lift the lid on the mill and see if there is room for a 6mm thick (I doubt it very much) ferrous toothed disk to be added. No ferrous gears in that POJ to sense, darn it. And I am thinking that an index for that could be obtained by drilling a 2 or 3mm hole in the added disk and setting a 2nd such device to sense the hole going by. Does that make any sense at all for this teeny mill? I'd also assume Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene is up! Pray to God, but keep rowing to shore. -- Russian Proverb -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
On Wednesday 21 November 2012 21:30:14 andy pugh did opine: On 21 November 2012 23:53, Gene Heskett ghesk...@wdtv.com wrote: And I am thinking that an index for that could be obtained by drilling a 2 or 3mm hole in the added disk and setting a 2nd such device to sense the hole going by. I think it makes sense to do index the same way as engines do, just have a short tooth so there is a pulse missing. But, would that not upset any speed controls? Adding that to the encoder component is on my to-do list. But it's a monotonically lengthening list. Just like my bucket list Andy. :) I will probably never see the bottom if it. Queue a forlorn, exasperated Sigh... Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene is up! We don't believe in rheumatism and true love until after the first attack. -- Marie Ebner von Eschenbach -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
andy pugh wrote: I have a rather interesting datasheet from Allegro. They have a sensor that detects either a magneic codewheel, or a gear tooth (with a biasing magnet behind the sensor). The neat part is that the pulse width is 45uS in one direction, and 90uS in the other. It is intended for crankshaft sensing, where index is done by a missing tooth. The typical code-wheel is a pressed steel part 100m diameter with a 70mm bore. This is pressed on to a hub with a 30mm bore in the case of the one I have on my desk at the moment. The encoding scheme seems compatible with software/parport sensing, and the form-factor seems ideal for a lathe spindle encoder. I wonder if it is worth adding support to the encoder driver? You can rig three Allegro ATS667 or similar gear tooth sensors to many spindles and use traditional quadrature plus index sensing. The A and B sensors need to be adjusted to give the right quadrature phasing, and some kind of once/rev mark (either a peg or a dimple) needs to be made for the index sensor. This has worked very well on my Bridgeport, where a traditional encoder was pretty much impossible to connect. I'm not sure the software sensing of such a sensor as you mention would be completely reliable. Jon -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle position, direction and Index with only one channel.
Gene Heskett wrote: A 100mm wheel is a bit large for my small lathe, but probably fine for the 9 and up stuff, and if its quadrature direction sensing too, or 2 sensors could be made so, then it sounds like something that would be a heck of a lot less fuss to install make work. IOW, a great idea Andy. See http://pico-systems.com/bridge_spindle.html for how I added 3 gear tooth sensors to make a spindle quadrature plus index encoder for my Bridgeport. These sensors have a pair of Hall sensors, and so detect the PASSING of a tooth, not just the presence of the tooth. They really work well. Jon -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
