Re: [Emc-users] Accuracy stability of those AMT103 capacitive encoders
On Thu, Mar 04, 2010 at 12:48:37PM -0600, Jon Elson wrote: On the CUI encoder, the differential driver is made in a little heat shrink blob on a cable accessory. So, you buy the standard encoder and then also buy the $7 differential driver cable. This is not the best way to do things, but it at least gets the diff. driver within a foot of the encoder. Grateful thanks, Jon. There's more information on what the cable can do in your paragraph than in their entire product datasheet. Erik -- Ahead warp factor one, Mr. Sulu. -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] mux
I don't know of a limit. I would guess the limit is the processor's capability. I think the limit is 16 currently. Regards, Alex -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Very cheapHardinge CNC lathe
(I have just realised why nobody ever responds to my questions, my main email address isn't subscribed, but if I reply then Gmail uses the subscribed address. There was originally a little more advenced warning about this auction) Hardinge CNC lathe + Tooling, £130 at the moment. Auction closes in 2 hours. Located in my home town (Basildon,UK) I don't have the space but I do have an auction login, so could bid if anyone wants it. http://www.ppauctions.com/online/index.php?a=1002b=37601 (Does anyone want to mention it on IRC? I don't seem to be able to log in from work) -- atp -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Hobbing
(This is one of potentially several reposts of questions that never made it to the list due to operator error) I am unsatisfied with the results of my attempts at gear-milling. I think this stems partly from me not knowing which of the three cutters I have is for what tooth count, or what the addendum and dedendum is meant to be for each cutter. I have decided that as a set of milling cutters comprises about 6 cutters at £10-£20 each, a hobbing cutter which will make any size of gear seems like a good plan. Hobbing, as you almost certainly know, involves rotating a hob and the work on not-quite-right-angles axes in a fixed ratio. Some parts of that are very easy with an EMC-controlled CNC machine (mine is one of these one of these, convertulated) http://www.amadeal.co.uk/acatalog/CX23A-750_Multi-Purpose_Lathe_Milling_Machine.html I have an encoder on the lathe spindle and it is a simple matter of connecting that to the rotary table in HAL to keep them geared together permanently at any arbitrary ratio. (there is even an encoder_ratio module for this sort of thing, but that isn't exactly right for what I want) However, the stepper-driven rotary table tops out at 5rpm. I can swap the motor for a servo, and that gets me 17rpm. The lathe and milling spindles don't really like doing less than 200rpm. I want to cut 12-tooth pinions, and that really isn't enough overhead for the rotary axis to catch up and synch. It is also a major change to the control box wiring and the software setup to swap to servo motor. However here are advantages, and I have all the parts. Holding the rotary axis at the correct angle to a hob held in the milling head is difficult. (though obviously doable) clamping it to the table at an angle to the lathe spindle is easy, but then I can only make gears of one diameter. It would be nice to be able to rotate the milling head. There is presently no facilty to do that, but there is a joint between two castings where the facility could be added. I am thinking of making a faster rotary axis using an ER32 collet holder I have on a 3/4 ground shaft and some taper roller bearings. I would drive that with a spare stepper I have, at about 10:1 ratio. (or one of the little servos) I can't believe that there are very large rotating forces on a gear during hobbing, I think it is probably largely balanced. If I do make this rotary axis, then I can either mount it at an angle to the milling spindle, or at an angle to the lathe spindle. In the latter case I would need a vertical slide, but I do have a spare compound slide that the CNC machine no longer uses. In either case I would need a compound feed on the two translational axes, or the offset angle will mean that the gear moves down the axis of the hob, giving a very slight second-order helix angle (if I am visualising it right) Modifying the milling head to tilt avoids this problem. The lathe spindle already has an encoder, the milling spindle is still waiting. Ideally I would make a hobbing head to clamp to the lathe saddle to cut gears held in the lathe spindle, with a nice powerful servo motor and encoder just like a real gear hobbing machine. But if I had a suitable servo motor like that it would already be my lathe headstock motor. So, rambling over, does anyone have any ideas for ways of arranging the shafts and slides that I have not thought of yet? (one idea has just occurred to me, I could mount a flexible coupling in the milling or lathes spindle. mount a secondary pair of bearings elsewhere, and put the hob on that to get the required angle). I think my favourite so far is a combination of new, faster rotary spindle holding the gear mounted on a vertical slide on the lathe saddle, with the hob in the lathe spindle. -- atp -- atp -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Closed-Loop Spindle Control.
I tried setting up closed-loop spindle control last night. It took me a while to figure out why it wasn't working (my encoder had lost the B channel) but during my investigations I found some interesting points. The output of the Hostmot2 PWM block gives 100% duty cycle at +100% and -100% input, though it inverts the direction bit. This is, of course, perfectly sensible. The output of the PID hal component is limited to +/- maxoutput. The effect of this seems to be that if the spindle is faster than setpoint, the PID controller can wind down to the negative limit, which sets the PWM to 100%, which sets the spindle speed to max. One solution would be to wire the PWN direction pin to the spindle direction buttons, but this ia a VFD and that seems unwise. Curiously http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?Closed_Loop_Spindle_Speed_Control seems to address this by using the PID block in a rather unusual way, adding the output of the PID block to the motion.spindle-speed-out pin, so that the output of the PID becomes a correction to the setpoint rather than the actual setpoint (which might explain why he suggests a PGain of zero). The other alternative would be to limit the output of the PID to zero before sending it to the PWM, but then it will tend to take some time to wind up from the negative limit to zero and that seems potentially troublesome. Which way is best? I am coming round to the idea that the documented solution (using motion,spindle-speed-out effectively as a precontroller and the PID as a tuning offset) actually makes a lot of sense, even if it does seem a little unconventional. I suspect it could still get stuck on its negative limit, though? -- atp -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Absolute Encoder Connector - now encoders in general....
Like you guys, I'm interested in using some of these inexpensive encoders. Compared to industrial units, they are a fraction of the price. The casing and wiring is obviously not industrial Nema 12 etc, in nature - no oilproof military connector on the side of the encoder and no bearings... So how do you guys get around these issues?Fashion some type of cover over the back of the motors and run the cable through a grommet? How could you use one of these encoders for a spindle encoder? Make up a two bearing support system with a stub shaft that the encoder can hang off of? I haven't heard much about US Digital's cheap encoders. What about Renco encoders? Is the consensus that those are ok? Dave On 3/4/2010 6:53 PM, Kirk Wallace wrote: On Thu, 2010-03-04 at 15:13 -0700, John Harris wrote: Hi Kirk, Try Samtec at http://www.samtec.com/documents/webfiles/pdf/FTSH_TH.PDF They only do dual row headers, and they also do ribbon cable connectors to match. You can get free samples if you find your way to their Sudden Service page. I f you can tell me exactly the row and pin count, with SMT or through hole, I may be able to give you the exact part number. Their catalog and web site are tough unless you know your way. John Thanks John. The encoder has a single row of five pins, or as Lawrence noted blades. This connector seems to be the mate for the encoder: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detailname=WM1723-ND I'll give your link a look. -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Accuracy stability of those AMT103 capacitive encoders
On Wed, Mar 3, 2010 at 1:36 PM, Jon Elson el...@pico-systems.com wrote: encoders. He was accelerating at something like 1 rad/sec^2, Holy cow, that's from zero to 100,000 RPM in one second. Can you say what is the application, what power, etc? Is it even realistic? -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Accuracy stability of those AMT103 capacitive encoders
On Friday 05 March 2010, Przemek Klosowski wrote: On Wed, Mar 3, 2010 at 1:36 PM, Jon Elson el...@pico-systems.com wrote: encoders. He was accelerating at something like 1 rad/sec^2, Holy cow, that's from zero to 100,000 RPM in one second. Can you say what is the application, what power, etc? Is it even realistic? Depends on the available power supply. I once saw the AVR-25's (ampex 2 quadruplex video tape machines, state of the art in the 70's) which could go from a stopped head wheel to a sync locked picture in 400 milliseconds, using amplifiers with several hundred volts of headroom for the required 3 phase, 440 hz motor drive. Or it could make pix in 40 milliseconds from a hot, already spinning head wheel. It could at times make the overhead florescent lights blink with its instantaneous power draw of about 25kw for the first 250 milliseconds of the acceleration. But that head wheel was only 2 in diameter, and only had to get to 14,400 rpms with an angular accuracy at any one instant in the 5 microsecond range from where it was supposed to be in order to make a usable picture.. --- --- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- 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) Simon: It's okay to leave them to die. --Serenity -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Closed-Loop Spindle Control.
On Fri, Mar 5, 2010 at 5:25 AM, Andy Pugh a...@andypugh.fsnet.co.uk wrote: I tried setting up closed-loop spindle control last night. It took me a while to figure out why it wasn't working (my encoder had lost the B channel) but during my investigations I found some interesting points. The output of the Hostmot2 PWM block gives 100% duty cycle at +100% and -100% input, though it inverts the direction bit. This is, of course, perfectly sensible. The output of the PID hal component is limited to +/- maxoutput. The effect of this seems to be that if the spindle is faster than setpoint, the PID controller can wind down to the negative limit, which sets the PWM to 100%, which sets the spindle speed to max. One solution would be to wire the PWN direction pin to the spindle direction buttons, but this ia a VFD and that seems unwise. Curiously http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?Closed_Loop_Spindle_Speed_Control seems to address this by using the PID block in a rather unusual way, adding the output of the PID block to the motion.spindle-speed-out pin, so that the output of the PID becomes a correction to the setpoint rather than the actual setpoint (which might explain why he suggests a PGain of zero). The other alternative would be to limit the output of the PID to zero before sending it to the PWM, but then it will tend to take some time to wind up from the negative limit to zero and that seems potentially troublesome. If you limit the PID outut to only values of zero or above, then the dir line of the PWM would never switch which would make the winding down to the negative limit problem go away since it could never window down to anything less then zero. Maybe a safer way to do it, instead of limiting the PID output to zero, since it may be undetermined what the dir line does when you are at zero, is to wire the PWM dir output line to the PWM enable line so that if the dir line ever sends the spindle in a negative direction it turns off the PWM effectively setting the PWM output to zero for any PWM value that is negative or zero. Which way is best? I am coming round to the idea that the documented solution (using motion,spindle-speed-out effectively as a precontroller and the PID as a tuning offset) actually makes a lot of sense, even if it does seem a little unconventional. I suspect it could still get stuck on its negative limit, though? -- atp I'm the original author of that wiki page, glad you found it useful. It's an awful way to use the PID, but it works ok especially if you have a very non-linear speed controller like the one I cobbled together for my mill. I believe you are correct, if you set the spindle speed to zero, the integral output of the PID will quickly go negative, which summed to the motion-spindle-speed-out which is zero, will make the PWM go into a negative value and in your case start speeding up the spindle again and very quickly be stuck at full speed. Lawrence -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Hobbing
On Fri, 2010-03-05 at 13:23 +, Andy Pugh wrote: ... snip I am unsatisfied with the results of my attempts at gear-milling. I think this stems partly from me not knowing which of the three cutters I have is for what tooth count, or what the addendum and dedendum is meant to be for each cutter. I have decided that as a set of milling cutters comprises about 6 cutters at £10-£20 each, a hobbing cutter which will make any size of gear seems like a good plan. I haven't cut any gears yet, but my plan is to use the rack form gear cutter to cut all gear sizes for a particular pitch. https://www.travers.com/Default.asp (Click on Keyword Search box, click Guest, search for involute, their search and descriptions are pretty weak) or http://www1.mscdirect.com/cgi/nnsrhm (search involute, or invoute 14-1/2 for 14 1/2 degree pressure angle) (Other links welcomed, Number 1 cutters seem to be the rack form) The hobbing motion can be replicated, except you only cut one section of tooth width, one tooth at a time (actually the slot between two teeth). The gear blank is mounted to a rotary axis. The gear cutter is mounted in the spindle. The coordinated motion of the rotary and cross feed will mimic the motion of a rack tooth engaging the gear as it rotates for the entry an exit of one tooth slot. The process would need to be repeated to cut the width of the gear, then repeated for each slot. The problems with trying to replicate hobbing with CNC rotary axes are, the rotary encoders would need to be very high resolution, feedback and command control very tight, and data throughput high enough to keep up. I think it has been stated before that current systems aren't up to the task. I think it would be great to have someone try, but I think the odds are against any success. -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Emc-gcode throughput
Kirk Wallace wrote: On Thu, 2010-03-04 at 20:52 -0600, Jon Elson wrote: ... snip more resources than a 3-axis program, but the super-hard stuff they usually make these parts out of are not machined at high feed rates. A ... snip This one's pretty quick: http://www.youtube.com/watch?v=0LCaRqQ8Qf8 That workpiece is almost certainly aluminum. That is a whole different ballpark than Inconel and other turbine blade materials. I *THINK* the original request had to do with turbine blade machining. Jon -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Absolute Encoder Connector - now encoders in general....
Dave wrote: Like you guys, I'm interested in using some of these inexpensive encoders. Compared to industrial units, they are a fraction of the price. The casing and wiring is obviously not industrial Nema 12 etc, in nature - no oilproof military connector on the side of the encoder and no bearings... For the CUI encoder, the motor's bearings are the encoder's bearings. There have been kit encoders for years that work this way. So how do you guys get around these issues?Fashion some type of cover over the back of the motors and run the cable through a grommet? How could you use one of these encoders for a spindle encoder? Make up a two bearing support system with a stub shaft that the encoder can hang off of? That is how you would do it. I haven't heard much about US Digital's cheap encoders. What about Renco encoders? Is the consensus that those are ok? Renco's encoders are fine, and are used inside many name brand motors, such as GL, SEM, Servo Dynamics, etc. They were the first to integrate commutation tracks wth ABZ for brushless motors. They were just bought out by somebody, and their web site was in some disarray and offline for a while. It is now back, and has data on their old models, too. I'd avoid US Digital's economy line. Enough problems have been reported related to noise sensitivity that you just don't need to get into that trouble. Jon -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Emc-gcode throughput
On Fri, 2010-03-05 at 12:17 -0600, Jon Elson wrote: Kirk Wallace wrote: On Thu, 2010-03-04 at 20:52 -0600, Jon Elson wrote: ... snip more resources than a 3-axis program, but the super-hard stuff they usually make these parts out of are not machined at high feed rates. A ... snip This one's pretty quick: http://www.youtube.com/watch?v=0LCaRqQ8Qf8 That workpiece is almost certainly aluminum. That is a whole different ballpark than Inconel and other turbine blade materials. I *THINK* the original request had to do with turbine blade machining. Jon Touche' -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Accuracy stability of those AMT103 capacitive encoders
Przemek Klosowski wrote: On Wed, Mar 3, 2010 at 1:36 PM, Jon Elson el...@pico-systems.com wrote: encoders. He was accelerating at something like 1 rad/sec^2, Holy cow, that's from zero to 100,000 RPM in one second. Can you say what is the application, what power, etc? Is it even realistic? Well, he wasn't going to 100K RPM, but he wanted to go from zero to several thousand RPM in just milliseconds. Yes, it is realistic, and there are actual needs for such stuff. The one I'm familiar with was the old 1/2 computer tape drives. They had to run at constant speed during reading or writing, and the gap between data blocks should be kept as short as possible. So, they had to accelerate from zero to 100 inches/second or more in a few ms. Very light ironless rotor motors were used. The armature was just a bobbin woven with wire, with a solid steel slug in the center that didn't rotate. Shafts were often ceramic, the tape capstan was either magnesium or fiber composite. But, I think trying to do this on a Taig mill with it's tiny leadscrews was not a realistic choice. The motors are Keling size 23 brushless motors, the servo amps are Pico Systems brushless PWM amps. I did not understand the application other than it was a university reasearch project. Jon -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Absolute Encoder Connector - now encoders in general....
On Fri, 2010-03-05 at 10:23 -0500, Dave wrote: Like you guys, I'm interested in using some of these inexpensive encoders. Compared to industrial units, they are a fraction of the price. The casing and wiring is obviously not industrial Nema 12 etc, in nature - no oilproof military connector on the side of the encoder and no bearings... So how do you guys get around these issues?Fashion some type of cover over the back of the motors and run the cable through a grommet? Maybe this? http://search.digikey.com/scripts/DkSearch/dksus.dll?Detailname=APC1069-ND How could you use one of these encoders for a spindle encoder? Make up a two bearing support system with a stub shaft that the encoder can hang off of? I haven't heard much about US Digital's cheap encoders. What about Renco encoders? Is the consensus that those are ok? Dave I think the cheap way to use U. S. Digital encoders is to make your own from their hubs and sensors, which I did for my lathe: http://www.wallacecompany.com/cnc_lathe/HNC/00011-1a.jpg http://www.wallacecompany.com/cnc_lathe/HNC/1-1a.jpg http://www.wallacecompany.com/cnc_lathe/HNC/4-1a.jpg For the axes encoders I made round Delrin covers with an o-ring seal. Then used pressed in brass inserts through the cover for screw terminals. I should install shaft seals, but I haven't gotten round2it. My plan for the AEAT's may be similar. The sensor boards have two tiny plastic pins that are staked to fasten the board. A hot soldering iron tip could soften the staking, and the board pushed out. http://www.wallacecompany.com/machine_shop/EMC2/absolute_encoder/dcp_6877-1a.jpg A shaft, bearings and housing would need to be designed with magnetic fields in mind. Using a screw terminal block on an o-ring sealed circuit board might be a way to go. http://search.digikey.com/scripts/DkSearch/dksus.dll?Detailname=A98336-ND or add a few more terminals and place a differential driver chip on the inside of the board. An SSI hal component is in the works too, unless someone has one already? -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Hobbing
On 5 March 2010 18:10, Kirk Wallace kwall...@wallacecompany.com wrote: The problems with trying to replicate hobbing with CNC rotary axes are, the rotary encoders would need to be very high resolution, feedback and command control very tight, and data throughput high enough to keep up. I think it has been stated before that current systems aren't up to the task. This message was cast into the void some time ago. I reposted it today. I am now well on the way to finishing my fast rotary axis. I guess I will soon know if you are right... -- atp -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Absolute Encoder Connector - now encoders in general....
On Fri, 2010-03-05 at 12:27 -0600, Jon Elson wrote: ... snip I'd avoid US Digital's economy line. Enough problems have been reported related to noise sensitivity that you just don't need to get into that trouble. Jon I would not have had any trouble with mine, if I had followed normal noise reduction practices. Others, of course, may have had different results. -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Analog spindle control HM2
Hello group! I have set up a retrofit 3 axis milling machine with mesa 5i20+7i33+2x7i37 The 3 axes are configured, tuned and works great. Now I want to use the fourth channel on the 7i33 to drive my freq inv. spindle I need a spindle enable signal and a 0-10v signal. In the wiki I found Analog spindle speed control using Mesa 5i20, but this is old stuff not using HM2 driver, and it looks like this: # Set up spindle speed net SpindleOn motion.spindle-on net spindle-rpm-cmd motion.spindle-speed-out setp m5i20.0.dac-03-gain [SPINDLE]DAC_SCALE linksp SpindleOn = m5i20.0.dac-03-enable linksp spindle-rpm-cmd = m5i20.0.dac-03-value setp m5i20.0.dac-03-offset 80 Can somebody help me to put together the right hal code to work with HM2? I have searched the wiki and forums, but cant find it anywhere. Best Regards! Lars Levin -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Analog spindle control HM2
On 05/03/2010 19:08, Lars Levin wrote: # Set up spindle speed net SpindleOn motion.spindle-on net spindle-rpm-cmd motion.spindle-speed-out setp m5i20.0.dac-03-gain [SPINDLE]DAC_SCALE linksp SpindleOn = m5i20.0.dac-03-enable linksp spindle-rpm-cmd = m5i20.0.dac-03-value setp m5i20.0.dac-03-offset 80 Can somebody help me to put together the right hal code to work with HM2? I have searched the wiki and forums, but cant find it anywhere. Best Regards! Lars Levin you will need to run the spindle command out through an ABS to make it always be a posative value (emc outputs a - speed value for m03) then you will have a 0-10v signal for the dac out u may have to reverse the output on the card chanel if its 0- -10v here is my code for my spindle #invert voltage out setp hm2_[HOSTMOT2](BOARD).0.gpio.XXX.invert_output true setp hm2_[HOSTMOT2](BOARD).0.pwmgen.XX.output-type 3 #make spindle pos loadrt abs count=0 #scale spindle speed to volts loadrt scale count=0 addf abs.0 servo-thread addf scale.0 servo-thread #spindle speed gain #hm2 1=10v out #pwm/speed=1/6000rpm=0.0001667 #6k setp scale.0.gain 0.00017 net spindle-abs abs.0.in = motion.spindle-speed-out net spindle-abs-out abs.0.out = scale.0.in net spindle-out scale.0.out = hm2_[HOSTMOT2](BOARD).0.pwmgen.03.value then just link spindle forward, spindle reverse to the IOs you need. this should work i just typed it up quickly for you. rob -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Hobbing
On 05/03/2010 18:10, Kirk Wallace wrote: The problems with trying to replicate hobbing with CNC rotary axes are, the rotary encoders would need to be very high resolution, feedback and command control very tight, and data throughput high enough to keep up. I think it has been stated before that current systems aren't up to the task. I think it would be great to have someone try, but I think the odds are against any success. iv cut gears with just a standard involute gear cuter it works grate, but hobbing it would or should make it alot quicker process. i guess also comes down to how acerate you wish to make these gears etc also. i think if you can overcome your speed problem on rotating the blank like you have said you should be on the way to getting some where close. let the spindle do as it likes (just like in rigid tapping) make the blank follow the spindle nice and close in motion. (we do this with the Z axes in rigid tapping no?) i know some servo drives have the ability to take an exsternal encoder or other source and follow it with out the need of anything else so maybe something to look at too? if you can keep them locked in sync at all times every pass should line up so doing a rerun over the gear should work fine. will be grate to see how you get on if you take this further. good luck, rob -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Absolute Encoder Connector - now encoders in general....
Interesting Kirk, Thanks for the ideas. Considering that new industrial Nema 12 type encoders can easily hit $500-600 each this is something to think about. Dave On 3/5/2010 2:08 PM, Kirk Wallace wrote: On Fri, 2010-03-05 at 10:23 -0500, Dave wrote: Like you guys, I'm interested in using some of these inexpensive encoders. Compared to industrial units, they are a fraction of the price. The casing and wiring is obviously not industrial Nema 12 etc, in nature - no oilproof military connector on the side of the encoder and no bearings... So how do you guys get around these issues?Fashion some type of cover over the back of the motors and run the cable through a grommet? Maybe this? http://search.digikey.com/scripts/DkSearch/dksus.dll?Detailname=APC1069-ND How could you use one of these encoders for a spindle encoder? Make up a two bearing support system with a stub shaft that the encoder can hang off of? I haven't heard much about US Digital's cheap encoders. What about Renco encoders? Is the consensus that those are ok? Dave I think the cheap way to use U. S. Digital encoders is to make your own from their hubs and sensors, which I did for my lathe: http://www.wallacecompany.com/cnc_lathe/HNC/00011-1a.jpg http://www.wallacecompany.com/cnc_lathe/HNC/1-1a.jpg http://www.wallacecompany.com/cnc_lathe/HNC/4-1a.jpg For the axes encoders I made round Delrin covers with an o-ring seal. Then used pressed in brass inserts through the cover for screw terminals. I should install shaft seals, but I haven't gotten round2it. My plan for the AEAT's may be similar. The sensor boards have two tiny plastic pins that are staked to fasten the board. A hot soldering iron tip could soften the staking, and the board pushed out. http://www.wallacecompany.com/machine_shop/EMC2/absolute_encoder/dcp_6877-1a.jpg A shaft, bearings and housing would need to be designed with magnetic fields in mind. Using a screw terminal block on an o-ring sealed circuit board might be a way to go. http://search.digikey.com/scripts/DkSearch/dksus.dll?Detailname=A98336-ND or add a few more terminals and place a differential driver chip on the inside of the board. An SSI hal component is in the works too, unless someone has one already? -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Absolute Encoder Connector - now encoders in general....
I really liked browsing through your website. The furnace was nice! I have the holy fear working with propane, so I ask; Did you ever consider using a large TIG welder to create a small Arc oven? The Duty cycle on a Transformer Miller Tig seems to be good enough. or Do you know of someone who does this. It would be great info for me as my Syncrowave Tigs are replaced by (way better) HTP Tigs and I can make use of them for other purposes. L Venter Kirk Wallace wrote: On Fri, 2010-03-05 at 12:27 -0600, Jon Elson wrote: ... snip I'd avoid US Digital's economy line. Enough problems have been reported related to noise sensitivity that you just don't need to get into that trouble. Jon I would not have had any trouble with mine, if I had followed normal noise reduction practices. Others, of course, may have had different results. -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Analog spindle control HM2
robert wrote: here is my code for my spindle #invert voltage out setp hm2_[HOSTMOT2](BOARD).0.gpio.XXX.invert_output true setp hm2_[HOSTMOT2](BOARD).0.pwmgen.XX.output-type 3 #make spindle pos loadrt abs count=0 #scale spindle speed to volts loadrt scale count=0 addf abs.0 servo-thread addf scale.0 servo-thread #spindle speed gain #hm2 1=10v out #pwm/speed=1/6000rpm=0.0001667 #6k setp scale.0.gain 0.00017 net spindle-abs abs.0.in = motion.spindle-speed-out net spindle-abs-out abs.0.out = scale.0.in net spindle-out scale.0.out = hm2_[HOSTMOT2](BOARD).0.pwmgen.03.value The hm2 pwmgen has its own .scale parameter, so you could get rid of the stand-alone scale component and just apply the scale.gain to hm2's pwmgen.scale. http://linuxcnc.org/docs/devel/html/drivers_hostmot2.html#r1_14_2 -- Sebastian Kuzminsky -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Absolute Encoder Connector - now encoders in general....
On Fri, 2010-03-05 at 15:14 -0500, ad...@mmri.us wrote: I really liked browsing through your website. The furnace was nice! I need to melt cast iron, but so far I've only done aluminum. It turns out the homemade refractory I used will melt at iron casting temperatures. So I need to make a new furnace. I have the holy fear working with propane, With practice, I'm finding it becoming much more predicable. I am missing some forearm hair, but my eye brows are fine. http://www.youtube.com/watch?v=u5-xS9sDuLg Propane is interesting, I think because the molecule is short, so the flame is short. My guess is the short flame causes a fairly tight pressure wave that can feed back to the regulator causing an unstable feedback. On propane only, the burner has a bit of a pulse jet sound and can be hard to keep lit. I put a flare and reducer on my propane only burner to get more of a de Laval nozzle http://en.wikipedia.org/wiki/De_Laval_nozzle This helped a lot, I think because the pressure wave is directed to the output side of the burner. I need to do the same for the oil burner. The oil has a much longer flame with a bunch more heat, but needs to be vaporized before it will burn. Currently, I run the propane at idle to get just enough of a flame to vaporize the oil, but the oil does the heavy lifting. Eventually, the walls of the furnace glow orange and I can turn the propane off, but by then the aluminum has been melted and poured. so I ask; Did you ever consider using a large TIG welder to create a small Arc oven? The Duty cycle on a Transformer Miller Tig seems to be good enough. or Do you know of someone who does this. It would be great info for me as my Syncrowave Tigs are replaced by (way better) HTP Tigs and I can make use of them for other purposes. L Venter http://www.youtube.com/watch?v=-6NJuctYgxA http://www.youtube.com/watch?v=hF8sGrdzE3o http://www.youtube.com/watch?v=G43rIx0d5aY I think my Hobart could be useful for an arc furnace, but I've got a bunch of waste oil, and more free oil is coming. I will need to plant a bunch of trees to offset my carbon footprint, but I think trees are pretty huggable, so that's okay. It would be fun to try to melt some cast iron in crucible, but I need to find a source for a crucible that can take the heat. One plan is to, get some Mizzou and cast my own crucibles. http://www.empire-refractory.com/catalog/mizzou-castable-plus.htm but I need to find a local vendor. -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Absolute Encoder Connector
On Fri, 2010-03-05 at 15:16 -0500, Dave wrote: Interesting Kirk, Thanks for the ideas. Considering that new industrial Nema 12 type encoders can easily hit $500-600 each this is something to think about. Dave Well, it turns out the sensor board on my AEAT 6010 encoder board is glued in so it was a bit of a chore to get out. Now I need to wire it up to see if it still works. http://wallacecompany.com/machine_shop/EMC2/absolute_encoder/dcp_6885-1a.jpg -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
