Re: [Emc-users] Increase Damping

[Jeshua Lacock]

On May 20, 2012, at 7:08 PM, Jon Elson wrote:

> Jeshua Lacock wrote:
>> Actually, I really have only been using open-loop mode.
>> 
> Since we had confusion here, open loop means LinuxCNC does not see movement
> when you move the motors.

Hi Jon,

That is correct.

>> But as soon as I try closed loop mode, I get a ton of noise and the drive is 
>> super jittery. It starts nearly stable but seems to run away until it 
>> faults. When I say run away it becomes increasingly jittery.
>> 
> So, reduce P, and reduce I and D proportionally.  You can reduce P to 
> 1.0 and I and D to zero
> to start out, and then increase P just until you get movement.  Make 
> sure it is moving the right
> way to null out error, then increase P in modest steps until you get 
> controlled movement.
> Error will remain a bit large at this point.  Then, increase P until you 
> get some vibrations,
> and add a bit of D to improve stability.

Thank you so much for this! I was starting with the default settings in the 
.ini file.

Putting these numbers in immediately made the drive stable - even in closed 
loop which is now what I am tuning.

I was able to get the P up to 150. I can add some D, but it seems that it only 
makes the drive more jittery without decreasing the error.

Can you tell me what exactly is the goal? Do I want the P as high was possible 
while keeping it stable? In other words, why not just leave P at 50 or 100 and 
be done with it?

> And, it may be that you are having feedback from the G320 drive's PWM 
> outputs to
> the encoder cables.  This may be what is causing the "increasingly 
> jittery" effect.
> Do you have shielded encoder cables?

Yes. Do the shields need to be grounded to be useful?

> Are you using US Digital encoders that
> are known to be noise sensitive?  

Not on this first axis I am trying to tune. It is a Renco. My other two axises 
are US Digital, but those will be replaced by CUI AMT102 encoders when I get 
around to installing the new much more powerful motors for the other 2 axises.

> You may need to use shielded motor power
> cables as well.  The G320 has no filtering on the outputs, so whatever your
> DC supply voltage is, that is being chopped at 20 KHz by the G320, producing
> ~70 V pulses with 100 ns risetime edges continuously on the motor wires.
> That's why I put an LC filter on the output of all my drives to prevent this
> type of interference.

I just went ahead and ordered some differential encoder/decoders just to be 
safe. Due to the size of the machine they are pretty long cables, I would guess 
around 15 feet.

Also, I routed my motor power lines as separately as I could. My encoders exit 
the machine on the left side and the power on the right.

>> The sample .ini file uses two different values for 2 different axises.
>> 
>> When you say low P settings, what would you start with? And what I and D is 
>> good to start with?
>> 
>> Also, what would you consider small steps to increase for P, I and D?
>> 
> You can go as low as 1.0 for P, and zero for I and D.  You can leave I 
> zero all the time, but
> as you raise P, you will need some D.  Too much D can be disastrous.  It 
> takes instantaneous
> following error and compares it to the following error last servo 
> period.  This can have
> large fluctuations due to the position quantization of the encoder PLUS 
> the time
> quantization (sampling) of the encoder reading.  So, there is a HUGE 
> amount of noise
> in this D term at 1/2 the sampling rate.  So, you want to use just 
> enough D to help
> smooth out the response.  I usually increase D by 20% steps when I don't 
> know what
> to expect, and maybe 50% when I have a good idea where I will run into 
> instability.
> Have the E-stop button handy.  Don't worry about I during tuning, it has 
> minimal
> effect on stability.  D is more sensitive.  I typically find D needs to 
> be between 5 - 10%
> of P, not sure if this number applies as much to the G320/USC setups.
> A rough set of number I use when testing the Gecko Interface board with an

What is the goal with I once P and D are good?

> old G320 drive and small motor is :
> MAX_VELOCITY =  1.20
> MAX_ACCELERATION =  20.0
> PID_MAX_VEL =  1.25
> BACKLASH = 0.000
> INPUT_SCALE =   4000
> OUTPUT_SCALE = 1.000
> MIN_LIMIT = -10.0
> MAX_LIMIT = 10.0
> FERROR = 0.0100
> MIN_FERROR = 0.05
> DEADBAND = 0.0007
> P =  200
> I =  2
> D =5
> BIAS = 0
> FF0 =  0
> FF1 =  1.2
> FF2 =  0.0045

Interesting, I can't seem to get D anywhere near that high. With P at 150 or 
200, it gets real jittery with a D of over 0.5.

>> When the error spikes, wouldn't that also indicate that it needs more gain 
>> and or damping

Re: [Emc-users] A rose by any name? [Was: Not so custom]

[Mark Wendt]

On 05/21/2012 01:40 AM, Mike Bennett wrote:
> I faced the same issue a couple of years ago.  The company I work for was 
> called FDS so this was used in all the class names we created.  We were sold 
> and now trade under a new name.  I decided to stick with FDS in existing and 
> new code as this would be less confusing.
>
> Mike
>
Feminine Deodorant Spray?  ;-)

Mark

--
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Increase Damping

[andy pugh]

On 21 May 2012 09:26, Jeshua Lacock  wrote:
> Can you tell me what exactly is the goal? Do I want the P as high was 
> possible while keeping it stable?

The goal is the best achievable stable servo response. The PID terms
need to be whatever achieves this, but the target is very much in
terms of machine behaviour, not any targets in the tuning numbers.

If D isn't helping, then don't use it. But you can try negative
numbers too. The systems I work on frequently have a simple P or PI
controller, and many of the PID controls have D set to zero.

-- 
atp
If you can't fix it, you don't own it.
http://www.ifixit.com/Manifesto

--
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Power and data cables for CNC

[gene heskett]

On Monday, May 21, 2012 05:20:52 AM Rafael Skodlar did opine:

> On 05/20/2012 12:12 PM, Dave wrote:
> > On 5/20/2012 12:40 PM, Rafael Skodlar wrote:
> >> I wonder what kind of power and data cables would you recommend for
> >> use in X-Y-Z CNC about 1.2mx1m size? Besides power, it's not clear
> >> to me how many data lines for sensors, encoders, motor control, etc.
> >> are needed in general.
> >> 
> >> Is it preferable to carry power and handful of control signals to the
> >> circuit on the gantry and preprocess some functions there or have
> >> everything wired into the central box? That would dictate the number
> >> of wires in the cable needed and what kind you need to buy.
> >> 
> >> Would cable carrier from McMaster-Carr # 55835K432 be sufficient?
> >> 
> >> Thanks,
> > 
> > Figure out what cables you need to move back and forth and then choose
> > the carrier.  Jamming cables into a cable carrier is not a good idea.
> 
> I'm well familiar with flexing and shielding issues in general since
> early HP plotter days. I was hoping to get a simple answer based on real
> life experience, get this or that cable with x number of shielded and
> stranded or twisted wires ;-) That's why I mentioned size as that would
> give one an idea of motor sizes and other requirements.
> 
> Is it better to have one cable with x number of wires to take care of
> all needs or a number of smaller cables (y) with x/y wires?
> 
> > If you don't do some figuring before you know what you are going to
> > carry, you will either have too much, or not enough space.   Guessing
> > usually doesn't work out nearly as well.
> 
> Agree, and that's why I tried to see what others are doing on this issue
> as it seem to be poorly documented in general. I try to capture this
> from numerous pictures but wires seem to generate little interest in
> general.
> 
> > As an alternative supplier; Igus sells direct in the US.
> > http://www.igus.com/default.asp?c=us&L=en
> > 
> > Dave
> 
> Links are always encouraging. However, I'm still struggling with the
> variety of cables mentioned on Igus site: data cable, bus cable, servo
> cable, control cable. Lots of homework ahead I guess, and that's before
> the experiment can begin.
> 
> Thanks guys,

I use separate cables, with my smaller machines the biggest motors are 425 
oz nema 23's.  Clark Wire & Cable in Chicago imports a lookalike of 
Belden's Star-Quad cable, intended for very low noise microphone wiring, in 
24 gage, its 4 wires twisted, with a 98% shield braided on top of that.  I 
used it in 1000' spools at the tv station.  Several of them.



Ultra flexible, fairly limp, 50 feet or so in 25' pieces has followed me 
home over the years.  I use it for all the 4 wire motors, and as encoder to 
C1G, but ran out and had to use some 4 wire shack ribbon for the lathes 
spindle control.  But I don't have any of it in cable trackage.  Despite 
that I haven't damaged any of it, ever.  And 24 gage seems to be plenty, 
with one motor wired bipolar parallel at 4.2 amps working just fine on 
about 5 feet of it.  It seems to hold up well, Vactra and Sunflower oil or 
ACE cutting oil have not seemed to have effected the jacket yet and some it 
it has been in service for almost a decade.  Susan may have some in a 
heavier gage for higher current usages if you call & ask.  That cable, and 
her 7559 video cable I've used several miles of are the best cables I have 
dealt with as a BC engineer, far less 'fixing' required over time even when 
being drug around on the studios concrete floor for years.

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: 
If you explain so clearly that nobody can misunderstand, somebody will.

--
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] A rose by any name? [Was: Not so custom]

[charles green]

all acronyms are ultimately counterproductive, because of such conflicts for 
example.  projects should be designated by number in the order of creation, or 
something like that.  take a hint from the borg in such matters.

--- On Sun, 5/20/12, Viesturs Lācis  wrote:

> From: Viesturs Lācis 
> Subject: Re: [Emc-users] A rose by any name? [Was: Not so custom]
> To: "Enhanced Machine Controller (EMC)" 
> Date: Sunday, May 20, 2012, 11:48 PM
> 2012/5/21 Dave :
> > On 5/20/2012 6:13 PM, gene heskett wrote:
> >> On Sunday, May 20, 2012 06:11:51 PM charles green
> did opine:
> >>
> >> I am used to linuxcnc now, so lets not repaint the
> train again please.
> >>
> > I agree.
> >
> > I also don't see any sense in going into the source
> code and changing
> > all references of "emc" to something else.
> >
> 
> I think that this is a question to our board - what was the
> agreement
> about the rebranding.
> Was the agreement only about name, which is represented to
> public, or
> was the agreement about not using those three letters
> _anywhere_,
> which IMHO includes also source code of the application.
> 
> I do agree that messing up the code by leaving "emc" and
> now
> substitute it with "linuxcnc" in new code would be wrong
> approach.
> On the other hand, I am in favor of replacing "emc"
> throughout the code.
> 
> Could somebody from the board comment on this side of the
> agreement?
> Is it allowed to use "emc" in the source code?
> 
> -- 
> Viesturs
> 
> If you can't fix it, you don't own it.
> http://www.ifixit.com/Manifesto
> 
> --
> Live Security Virtual Conference
> Exclusive live event will cover all the ways today's
> security and 
> threat landscape has changed and how IT managers can
> respond. Discussions 
> will include endpoint security, mobile security and the
> latest in malware 
> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
> 

--
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] A rose by any name? [Was: Not so custom]

[Mike Bennett]

Good old Wikipedia :-)

Factory Data Systems actually, now part of Qube Global Software.

Mike

On 21 May 2012 10:05, Mark Wendt  wrote:

> On 05/21/2012 01:40 AM, Mike Bennett wrote:
> > I faced the same issue a couple of years ago.  The company I work for
> was called FDS so this was used in all the class names we created.  We were
> sold and now trade under a new name.  I decided to stick with FDS in
> existing and new code as this would be less confusing.
> >
> > Mike
> >
> Feminine Deodorant Spray?  ;-)
>
> Mark
>
>
> --
> Live Security Virtual Conference
> Exclusive live event will cover all the ways today's security and
> threat landscape has changed and how IT managers can respond. Discussions
> will include endpoint security, mobile security and the latest in malware
> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>
--
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Power and data cables for CNC

[dave]

On Sun, 20 May 2012 20:57:06 -0700
Rafael Skodlar  wrote:

> On 05/20/2012 12:12 PM, Dave wrote:
> > On 5/20/2012 12:40 PM, Rafael Skodlar wrote:
> >> I wonder what kind of power and data cables would you recommend
> >> for use in X-Y-Z CNC about 1.2mx1m size? Besides power, it's not
> >> clear to me how many data lines for sensors, encoders, motor
> >> control, etc. are needed in general.
> >>
> >> Is it preferable to carry power and handful of control signals to
> >> the circuit on the gantry and preprocess some functions there or
> >> have everything wired into the central box? That would dictate the
> >> number of wires in the cable needed and what kind you need to buy.
> >>
> >> Would cable carrier from McMaster-Carr # 55835K432 be sufficient?
> >>
> >> Thanks,
> >>
> >>
> >
> > Figure out what cables you need to move back and forth and then
> > choose the carrier.  Jamming cables into a cable carrier is not a
> > good idea.
> 
> I'm well familiar with flexing and shielding issues in general since 
> early HP plotter days. I was hoping to get a simple answer based on
> real life experience, get this or that cable with x number of
> shielded and stranded or twisted wires ;-) That's why I mentioned
> size as that would give one an idea of motor sizes and other
> requirements.
> 
> Is it better to have one cable with x number of wires to take care of 
> all needs or a number of smaller cables (y) with x/y wires?
> 
> > If you don't do some figuring before you know what you are going to
> > carry, you will either have too much, or not enough space.
> > Guessing usually doesn't work out nearly as well.
> >
> 
> Agree, and that's why I tried to see what others are doing on this
> issue as it seem to be poorly documented in general. I try to capture
> this from numerous pictures but wires seem to generate little
> interest in general.
> 
> > As an alternative supplier; Igus sells direct in the US.
> > http://www.igus.com/default.asp?c=us&L=en
> >
> > Dave
> >
> 
> Links are always encouraging. However, I'm still struggling with the 
> variety of cables mentioned on Igus site: data cable, bus cable,
> servo cable, control cable. Lots of homework ahead I guess, and
> that's before the experiment can begin.
> 
> Thanks guys,
> 

I've used shielded CAT5 with no problems for encoder cables. I usually
buy 50' patch cables and cut them up. Seems to be the cheapest way to
get there. SO in two conductor works well for servo power. I suppose it
also comes in 4 conductor for 3 phase. Of course, there is no
shielding. ;-(

Dave

--
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Power and data cables for CNC

[Dave]

On 5/20/2012 11:57 PM, Rafael Skodlar wrote:
> On 05/20/2012 12:12 PM, Dave wrote:
>
>> On 5/20/2012 12:40 PM, Rafael Skodlar wrote:
>>  
>>> I wonder what kind of power and data cables would you recommend for use
>>> in X-Y-Z CNC about 1.2mx1m size? Besides power, it's not clear to me how
>>> many data lines for sensors, encoders, motor control, etc. are needed in
>>> general.
>>>
>>> Is it preferable to carry power and handful of control signals to the
>>> circuit on the gantry and preprocess some functions there or have
>>> everything wired into the central box? That would dictate the number of
>>> wires in the cable needed and what kind you need to buy.
>>>
>>> Would cable carrier from McMaster-Carr # 55835K432 be sufficient?
>>>
>>> Thanks,
>>>
>>>
>>>
>> Figure out what cables you need to move back and forth and then choose
>> the carrier.  Jamming cables into a cable carrier is not a good idea.
>>  
> I'm well familiar with flexing and shielding issues in general since
> early HP plotter days. I was hoping to get a simple answer based on real
> life experience, get this or that cable with x number of shielded and
> stranded or twisted wires ;-) That's why I mentioned size as that would
> give one an idea of motor sizes and other requirements.
>
> Is it better to have one cable with x number of wires to take care of
> all needs or a number of smaller cables (y) with x/y wires?
>
>
>> If you don't do some figuring before you know what you are going to carry,
>> you will either have too much, or not enough space.   Guessing usually
>> doesn't work out nearly as well.
>>
>>  
> Agree, and that's why I tried to see what others are doing on this issue
> as it seem to be poorly documented in general. I try to capture this
> from numerous pictures but wires seem to generate little interest in
> general.
>
>
>> As an alternative supplier; Igus sells direct in the US.
>> http://www.igus.com/default.asp?c=us&L=en
>>
>> Dave
>>
>>  
> Links are always encouraging. However, I'm still struggling with the
> variety of cables mentioned on Igus site: data cable, bus cable, servo
> cable, control cable. Lots of homework ahead I guess, and that's before
> the experiment can begin.
>
> Thanks guys,
>
>


I tend to sketch things out on paper in order to maintain my sanity.
Generally, motor power cables and encoder feedback cables are 
separate.   If you buy a commercial brushless servo motor setup, they 
always (so far) come with a
Servo power cable that is shielded, and an encoder cable that is also 
shielded.   If you have a gantry machine, you will probably want limit 
switches and perhaps a home switch on the gantry slide.  I would run 
another cable for that.So that is three cables
- two of which need to be run all the way to the gantry motor 
location.The other motors, if they move, will also need an energy 
chain tied to them.  It all depends on how your machine is designed.

If you are just going to use your machine once a week or even a couple 
of times per week, I'd probably go cheap and try and use Cat 5 patch 
cables for your signal wires and perhaps your encoders (you can get 
shielded cat 5 flex cable).

If you are going to make money off your machine on a frequent basis, buy 
the better cables as normal flex cable will eventually break.  (Actually 
they all eventually break, but some last a lot longer than others)

Dave



--
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Power and data cables for CNC

[samco]

we have used stranded shielded cat 5 with good results.

sam

On Mon, 21 May 2012 08:12:55 -0700
 dave  wrote:
> On Sun, 20 May 2012 20:57:06 -0700
> Rafael Skodlar  wrote:
> 
> > On 05/20/2012 12:12 PM, Dave wrote:
> > > On 5/20/2012 12:40 PM, Rafael Skodlar wrote:
> > >> I wonder what kind of power and data cables would you recommend
> > >> for use in X-Y-Z CNC about 1.2mx1m size? Besides power, it's not
> > >> clear to me how many data lines for sensors, encoders, motor
> > >> control, etc. are needed in general.
> > >>
> > >> Is it preferable to carry power and handful of control signals to
> > >> the circuit on the gantry and preprocess some functions there or
> > >> have everything wired into the central box? That would dictate the
> > >> number of wires in the cable needed and what kind you need to buy.
> > >>
> > >> Would cable carrier from McMaster-Carr # 55835K432 be sufficient?
> > >>
> > >> Thanks,
> > >>
> > >>
> > >
> > > Figure out what cables you need to move back and forth and then
> > > choose the carrier.  Jamming cables into a cable carrier is not a
> > > good idea.
> > 
> > I'm well familiar with flexing and shielding issues in general since 
> > early HP plotter days. I was hoping to get a simple answer based on
> > real life experience, get this or that cable with x number of
> > shielded and stranded or twisted wires ;-) That's why I mentioned
> > size as that would give one an idea of motor sizes and other
> > requirements.
> > 
> > Is it better to have one cable with x number of wires to take care of 
> > all needs or a number of smaller cables (y) with x/y wires?
> > 
> > > If you don't do some figuring before you know what you are going to
> > > carry, you will either have too much, or not enough space.
> > > Guessing usually doesn't work out nearly as well.
> > >
> > 
> > Agree, and that's why I tried to see what others are doing on this
> > issue as it seem to be poorly documented in general. I try to capture
> > this from numerous pictures but wires seem to generate little
> > interest in general.
> > 
> > > As an alternative supplier; Igus sells direct in the US.
> > > http://www.igus.com/default.asp?c=us&L=en
> > >
> > > Dave
> > >
> > 
> > Links are always encouraging. However, I'm still struggling with the 
> > variety of cables mentioned on Igus site: data cable, bus cable,
> > servo cable, control cable. Lots of homework ahead I guess, and
> > that's before the experiment can begin.
> > 
> > Thanks guys,
> > 
> 
> I've used shielded CAT5 with no problems for encoder cables. I usually
> buy 50' patch cables and cut them up. Seems to be the cheapest way to
> get there. SO in two conductor works well for servo power. I suppose it
> also comes in 4 conductor for 3 phase. Of course, there is no
> shielding. ;-(
> 
> Dave
> 
> --
> Live Security Virtual Conference
> Exclusive live event will cover all the ways today's security and 
> threat landscape has changed and how IT managers can respond. Discussions 
> will include endpoint security, mobile security and the latest in malware 
> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users


--
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Power and data cables for CNC

[Jon Elson]

Rafael Skodlar wrote:
> On 05/20/2012 12:12 PM, Dave wrote:
>   
>> On 5/20/2012 12:40 PM, Rafael Skodlar wrote:
>> 
>>> I wonder what kind of power and data cables would you recommend for use
>>> in X-Y-Z CNC about 1.2mx1m size? Besides power, it's not clear to me how
>>> many data lines for sensors, encoders, motor control, etc. are needed in
>>> general.
>>>   
> I'm well familiar with flexing and shielding issues in general since 
> early HP plotter days. I was hoping to get a simple answer based on real 
> life experience, get this or that cable with x number of shielded and 
> stranded or twisted wires ;-) That's why I mentioned size as that would 
> give one an idea of motor sizes and other requirements.
>
> Is it better to have one cable with x number of wires to take care of 
> all needs or a number of smaller cables (y) with x/y wires?
>   
With non-filtered motor drives, it is pretty important to NOT put 
encoder or other signal-level
wires in the same cable as the motor wires.  I usually separate encoder, 
home/limit sensors
and motors on 3 cables per axis, even though my motor drives ARE filtered.
A plain quadrature encoder needs 4 wires, if it has index then 5.  If 
differential,
then 6 or 8 wires.  If brushless motors are used, those usually need 
Hall sensors,
add 4 more wires.  Stepper motors need a minimum of 4 wires, brush servos
need 2 plus maybe a safety ground, brushless would need 3 plus ground.

You can check the catalogs for the number and size of the wire strands.  
The more fine
wires there are, the better the cable will handle flexing.  The good 
stuff has #36 AWG
or finer strands, thinner than hair.

Jon

--
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Increase Damping

[Jon Elson]

Jeshua Lacock wrote:
> Putting these numbers in immediately made the drive stable - even in closed 
> loop which is now what I am tuning.
>
> I was able to get the P up to 150. I can add some D, but it seems that it 
> only makes the drive more jittery without decreasing the error.
>   
Well, then lower the D until the loop is stable.  At some point, too 
LITTLE D will also
start to make it jittery, there should be a valley where it is good.
> Can you tell me what exactly is the goal? Do I want the P as high was 
> possible while keeping it stable? In other words, why not just leave P at 50 
> or 100 and be done with it?
>
>   
Yes, sure.  Once you have good, stable response where the following 
error is fairly low
in the cruise portion of a move, then apply FF1 to make the error nearly 
zero there,
then add tiny amounts of FF2 to reduce the error in the accel/decel 
ramps.  You should
be able to get the error quite small, although with your encoder 
resolution (I'm
guessing from some numbers you gave before that it is about 2000 
counts/inch)
you may not be able to get below .002" or so under all conditions.  That's
probably OK for a router, and already less than the overall accuracy and 
backlash
of the mechanical part.
>> And, it may be that you are having feedback from the G320 drive's PWM 
>> outputs to
>> the encoder cables.  This may be what is causing the "increasingly 
>> jittery" effect.
>> Do you have shielded encoder cables?
>> 
>
> Yes. Do the shields need to be grounded to be useful?
>
>   
Of course.  You should ground the shield at the control end only, so 
either the
USC or the Gecko interface.
>> Are you using US Digital encoders that
>> are known to be noise sensitive?  
>> 
>
> Not on this first axis I am trying to tune. It is a Renco. My other two 
> axises are US Digital, but those will be replaced by CUI AMT102 encoders when 
> I get around to installing the new much more powerful motors for the other 2 
> axises.
>
>   
Hmmm, the AMT encoders have a lag in responding to acceleration, but it 
isn't
as bad as I originally thought.  It seems to help to use less than the 
maximum
resolution the encoder can provide.
> I just went ahead and ordered some differential encoder/decoders just to be 
> safe. Due to the size of the machine they are pretty long cables, I would 
> guess around 15 feet.
>   
OK, that's a good plan.
> Also, I routed my motor power lines as separately as I could. My encoders 
> exit the machine on the left side and the power on the right.
>   
That should also help, although shielded encoder cables can be routed 
next to motor cables
in most cases.  At least with my drives, that is fine, but they have the 
filters on the output.
>
> What is the goal with I once P and D are good?
>   
Well, that's the problem.  I works great in a steady-state system, but 
CNC never is
steady-state for long.  It looks back in time at the average error over 
some period
and applies a correction.  But, as soon as the axis reverses, the 
correction is
now in the wrong direction!  There are a bunch of other places where I 
also fails,
such as the change from accel to cruise to decel, or when the cutter is 
cutting vs.
out of the cut.  So, I would not work very hard with tuning I, and use it
sparingly.  If you want, you can try setting I to 10% of P and see how 
it works.
But, if the other params (P, D, FF1 and FF2) have reduced error to a good
minimum, then the I term really has no error to work on, and is benign.
> Interesting, I can't seem to get D anywhere near that high. With P at 150 or 
> 200, it gets real jittery with a D of over 0.5.
>   
Well, this all depends on INPUT_SCALE, motor response and inertia, and 
all sorts
of other things, both software and mechanical.  Don't think that your 
numbers should match
mine, as the motor to encoder link is so critical to the whole 
response.  One thing is if
there is any backlash between the motor and the machine part to be 
moved, it really
complicates the tuning.  Whenever the gear, or whatever, taps from one 
side to the
other of the backlash, it creates a big impulse to the system.
> I see. So when I am tuning, I should start out with a modest acceleration 
> factor, then bump it up until I see a spike?
>   
Yes.  If a big spike suddenly appears in a system that was previously 
well-behaved,
that is a strong indication that some limit has just been reached, most 
likely the
current limit if it appears on the accel/decel ramps.  You want to back off
maybe 20% from there to allow cutting forces to be developed.  You don't
want 100% of available torque to be used solely for acceleration.
>
> Yeah, I think the 5:1 gear box will get me somewhere in the same neighborhood 
> as your Bridgeport. 
>
> My motor is definitely not weak though it is a 1125 oz-in Peak 90V/40A.
>   
But, with the Gecko 320 turned all the way up, you only get 562 Oz-In 
since you
can only feed it 20 A.  But, you are less likely to fry such a motor.
> Besides muc

[Emc-users] OT : large cnc

[Roland Jollivet]

One of the better videos of large format CNC for those in want of a nice
bedtime video;

http://www.youtube.com/watch?v=Xn7tsNG6pyo


Regards
Roland
--
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] OT : large cnc

[N. Christopher Perry]

When money is no object  I love the toolchanger!

N. Christopher Perry

On May 21, 2012, at 13:24, Roland Jollivet  wrote:

> One of the better videos of large format CNC for those in want of a nice
> bedtime video;
> 
> http://www.youtube.com/watch?v=Xn7tsNG6pyo
> 
> 
> Regards
> Roland
> --
> Live Security Virtual Conference
> Exclusive live event will cover all the ways today's security and 
> threat landscape has changed and how IT managers can respond. Discussions 
> will include endpoint security, mobile security and the latest in malware 
> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users

--
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] OT : large cnc

[Dave]

That is quite a machine.

The tool changer and tool storage room is excellent..  Why didn't I 
think of that;   The next time I need a tool changer I will just add a 
full size robot! ;-)

I wonder what they charge for machine time?   It has to be really expensive.

What would be a good guess?

Dave

On 5/21/2012 2:27 PM, N. Christopher Perry wrote:
> When money is no object  I love the toolchanger!
>
> N. Christopher Perry
>
> On May 21, 2012, at 13:24, Roland Jollivet  wrote:
>
>
>> One of the better videos of large format CNC for those in want of a nice
>> bedtime video;
>>
>> http://www.youtube.com/watch?v=Xn7tsNG6pyo
>>
>>
>> Regards
>> Roland
>> --
>> Live Security Virtual Conference
>> Exclusive live event will cover all the ways today's security and
>> threat landscape has changed and how IT managers can respond. Discussions
>> will include endpoint security, mobile security and the latest in malware
>> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
>> ___
>> Emc-users mailing list
>> Emc-users@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/emc-users
>>  
> --
> Live Security Virtual Conference
> Exclusive live event will cover all the ways today's security and
> threat landscape has changed and how IT managers can respond. Discussions
> will include endpoint security, mobile security and the latest in malware
> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>
>


--
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

[Emc-users] Tool Offsets

[Eric H. Johnson]

Hi all,

Per the "Setting Coordinate Systems" thread, I converted from using
coordinate systems (G54-G59.3) and setting the offsets with G10 L2, to using
the offsets specified in the tool table. Mostly it worked without a problem.
The exception is when re-running a program without reloading it. The
beginning of the program will have two lines similar to the following:

T3 M6
G43 H3

If I just rerun, the tool offsets seem to be ignored, but if I do a reload
of the same program it runs fine.

Do I need to add a G43 H0 to the end of the program, is there another
explanation for why the offsets are ignored when rerunning?

Thanks,
Eric



--
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] OT : large cnc

[dave]

On Mon, 21 May 2012 14:27:06 -0400
"N. Christopher Perry"  wrote:

> When money is no object  I love the toolchanger!
> 
> N. Christopher Perry
> 
> On May 21, 2012, at 13:24, Roland Jollivet
>  wrote:
> 
> > One of the better videos of large format CNC for those in want of a
> > nice bedtime video;
> > 
> > http://www.youtube.com/watch?v=Xn7tsNG6pyo
> > 
> > 
> > Regards
> > Roland

Gee Santa. I'd like one for Xmas. 
Really cool way to do internal teeth. 

Dave

ps. even a .1 scale model would do. 


> > --
> > Live Security Virtual Conference
> > Exclusive live event will cover all the ways today's security and 
> > threat landscape has changed and how IT managers can respond.
> > Discussions will include endpoint security, mobile security and the
> > latest in malware threats.
> > http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> > ___ Emc-users mailing
> > list Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
> 
> --
> Live Security Virtual Conference
> Exclusive live event will cover all the ways today's security and 
> threat landscape has changed and how IT managers can respond.
> Discussions will include endpoint security, mobile security and the
> latest in malware threats.
> http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> ___ Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users


--
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] OT : large cnc

[Viesturs Lācis]

2012/5/21 Roland Jollivet :
> One of the better videos of large format CNC for those in want of a nice
> bedtime video;
>
> http://www.youtube.com/watch?v=Xn7tsNG6pyo
>

Holly Molly! Is it 3 storey high?!?
And how do they call those sub-tool-holders? I mean those bigger
things that are at the very bottom shelf for the robot, in which the
actual tools are inserted. For turning or milling they were changing
those. Not to mention that inner teeth cutter. Unfortunately it is
pretty much limited for the diameter of inner gear, but OTOH those
large gears might be harder to do with equipment to cut smaller inner
gears.

-- 
Viesturs

If you can't fix it, you don't own it.
http://www.ifixit.com/Manifesto

--
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] OT : large cnc

[andy pugh]

On 21 May 2012 22:28, Viesturs Lācis  wrote:
> And how do they call those sub-tool-holders?

Possibly "Live tooling"

-- 
atp
If you can't fix it, you don't own it.
http://www.ifixit.com/Manifesto

--
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Tool Offsets

[Terry Christophersen]

G49 cancels G43 
Send the machine home at the end of the prog using:
G28G91Z0.0  Y0.0  X0.0
 You should not need to use G49
You must be doing something else wrong

Start of every one of my  progs look like this:

T1M6
G54G90G0XxxYxxS500M3
G43H1Z.1M8   moves the tool down to .1 above the workpiece
blah blah

ends look like this:

G28G91 Z0.0   send the Z home
G28G91Y0.0   send the y home to put in a new part
M30


- Original Message -
From: Eric H. Johnson 
To: 'Enhanced Machine Controller (EMC)' 
Cc: 
Sent: Monday, May 21, 2012 2:51 PM
Subject: [Emc-users] Tool Offsets

Hi all,

Per the "Setting Coordinate Systems" thread, I converted from using
coordinate systems (G54-G59.3) and setting the offsets with G10 L2, to using
the offsets specified in the tool table. Mostly it worked without a problem.
The exception is when re-running a program without reloading it. The
beginning of the program will have two lines similar to the following:

T3 M6
G43 H3

If I just rerun, the tool offsets seem to be ignored, but if I do a reload
of the same program it runs fine.

Do I need to add a G43 H0 to the end of the program, is there another
explanation for why the offsets are ignored when rerunning?

Thanks,
Eric



--
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users


--
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Tool Offsets

[andy pugh]

On 21 May 2012 20:51, Eric H. Johnson  wrote:

> T3 M6
> G43 H3

I never use the H-number, it is only useful for applying the offset of
a non-loaded tool to the loaded tool.
Though I doubt that is your problem.

-- 
atp
If you can't fix it, you don't own it.
http://www.ifixit.com/Manifesto

--
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Tool Offsets

[Terry Christophersen]

>I never use the H-number, it is only useful for applying the offset of

It may be not useful in LinuxCNC but I guarentee you 90% + of the mill
programs in the world use it (Fanuc has to have it) also the Dxx
If you omit the D on Fanuc no offset will be applied to G41,G42

Terry




- Original Message -
From: andy pugh 
To: Enhanced Machine Controller (EMC) 
Cc: 
Sent: Monday, May 21, 2012 5:57 PM
Subject: Re: [Emc-users] Tool Offsets

On 21 May 2012 20:51, Eric H. Johnson  wrote:

> T3 M6
> G43 H3

I never use the H-number, it is only useful for applying the offset of
a non-loaded tool to the loaded tool.
Though I doubt that is your problem.

-- 
atp
If you can't fix it, you don't own it.
http://www.ifixit.com/Manifesto

--
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users


--
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Power and data cables for CNC

[Rafael Skodlar]

On 05/21/2012 09:15 AM, Jon Elson wrote:
> Rafael Skodlar wrote:
>> On 05/20/2012 12:12 PM, Dave wrote:
>>
>>> On 5/20/2012 12:40 PM, Rafael Skodlar wrote:
>>>
 I wonder what kind of power and data cables would you recommend for use
 in X-Y-Z CNC about 1.2mx1m size? Besides power, it's not clear to me how
 many data lines for sensors, encoders, motor control, etc. are needed in
 general.

>> I'm well familiar with flexing and shielding issues in general since
>> early HP plotter days. I was hoping to get a simple answer based on real
>> life experience, get this or that cable with x number of shielded and
>> stranded or twisted wires ;-) That's why I mentioned size as that would
>> give one an idea of motor sizes and other requirements.
>>
>> Is it better to have one cable with x number of wires to take care of
>> all needs or a number of smaller cables (y) with x/y wires?
>>
> With non-filtered motor drives, it is pretty important to NOT put
> encoder or other signal-level
> wires in the same cable as the motor wires.  I usually separate encoder,
> home/limit sensors
> and motors on 3 cables per axis, even though my motor drives ARE filtered.
> A plain quadrature encoder needs 4 wires, if it has index then 5.  If
> differential,
> then 6 or 8 wires.  If brushless motors are used, those usually need
> Hall sensors,
> add 4 more wires.  Stepper motors need a minimum of 4 wires, brush servos
> need 2 plus maybe a safety ground, brushless would need 3 plus ground.
>
> You can check the catalogs for the number and size of the wire strands.
> The more fine
> wires there are, the better the cable will handle flexing.  The good
> stuff has #36 AWG
> or finer strands, thinner than hair.
>
> Jon

Thank you very much for detailed advice to all of you that responded to 
my question. I received enough material to spend a few evenings doing my 
homework. It's much easier to start knowing what others have tried and 
what works in different circumstances.

Using Cat-5 was a surprise to me as it's a bit stiff unless each wire is 
made of even smaller wires, not common in general use.

-- 
Rafael

--
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users