gcode resetting my surface zero to Z-0.200"

Re: gcode resetting my surface zero to Z-0.200"

Postby Mr.Chips » Mon Apr 15, 2019 11:46 pm

The material is printed 3/4” MDF.
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Re: gcode resetting my surface zero to Z-0.200"

Postby wmgeorge » Mon Apr 15, 2019 11:48 pm

GME wrote:
wmgeorge wrote:1. What material are you cutting those designs into? Looks like cloth but it can't be.


2. Were there any settings on those Stepper Drivers that needed to be set or re-set?


Bill,

They just use 1/4W current set resistors. No other settings.

Gary


Well I am out of ideas. Unless its the BoB? Or his computer parallel port not able to keep up with the tiny movements? I am assuming its the same computer he has had for the past ten years or so. The Gecko drive at least the 210 has micro stepping jumpers to set however so I wonder? https://www.geckodrive.com/support/step ... ev-16.html And Of course Assuming is bad for troubleshooting. :P
Last edited by wmgeorge on Mon Apr 15, 2019 11:57 pm, edited 1 time in total.
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Re: gcode resetting my surface zero to Z-0.200"

Postby Mr.Chips » Mon Apr 15, 2019 11:56 pm

This is feedback to Gecko, when he mentioned to half the IPM all the way around.

I ran it twice one at 17.5 IPM XY 2.5 IPM z. router speed 3.5. it returned to 0.0012” at the surface at end of run. , 0.000” at start, well within my error Z axis setting. The cut was perfect.

Based on that I ran it again at 35 IPM XY and 5 IPM Z. Router speed 4.5. It returned to +0.235” at the surface at end of run. 0.000” At
T start. Again cut was progressively deeper. Thought a faster router speed would offset the faster speed

Voltage measured at PS was 49.6VDC

You mentioned Motor Tuning, I attached motor details.

In a return email I sent him the below attachment and screen shots of Motor Tunins screens.
The one where everything was slowed down cut perfect. Based on that I thought raising the speeds back to what they were and speeding up the router would work but not. Deep cutting.

Hager
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D67F84AE-154B-41D7-AAC9-F551929A532B.jpeg
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Re: gcode resetting my surface zero to Z-0.200"

Postby wmgeorge » Tue Apr 16, 2019 12:00 am

Mr.Chips wrote:This is feedback to Gecko, when he mentioned to half the IPM all the way around.

I ran it twice one at 17.5 IPM XY 2.5 IPM z. router speed 3.5. it returned to 0.0012” at the surface at end of run. , 0.000” at start, well within my error Z axis setting. The cut was perfect.

Based on that I ran it again at 35 IPM XY and 5 IPM Z. Router speed 4.5. It returned to +0.235” at the surface at end of run. 0.000” At
T start. Again cut was progressively deeper. Thought a faster router speed would offset the faster speed

Voltage measured at PS was 49.6VDC

You mentioned Motor Tuning, I attached motor details.

In a return email I sent him the below attachment and screen shots of Motor Tunins screens.
The one where everything was slowed down cut perfect. Based on that I thought raising the speeds back to what they were and speeding up the router would work but not. Deep cutting.

Hager


Your parallel port or the BoB can not keep the pulse rate up to do the tiny, tiny movements without missing steps.
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Re: gcode resetting my surface zero to Z-0.200"

Postby Mr.Chips » Tue Apr 16, 2019 12:05 am

Gecko reply

The fact that it is happening in a progressive fashion means that the axis is slipping over time, likely losing steps on a reversal. When you command it to go up it misses a few steps because it is either:



a.) Underpowered or running with a failing power supply, or
b.) Being told to accelerate too quickly.


Those two options are not mutually exclusive and (b) could be a symptom of (a). Can you increase your acceleration time so that you run the motor extremely lax? The problem is likely power supply related, though, so if you have a spare supply you could try that would help immensely in troubleshooting.

R
He hasn’t replied back since I sent him the motor settings and the last photo.
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Re: gcode resetting my surface zero to Z-0.200"

Postby Mr.Chips » Tue Apr 16, 2019 12:20 am

I talked to Gecko on the phone he really feels it’s a PS going bad, even though the voltage is OK probally the amps are low, and drivers need amps to deliver torque, that’s why slowing it down helped.

That could be the reason I had the problem all of the sudden.

More as it happens.
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Re: gcode resetting my surface zero to Z-0.200"

Postby GME » Tue Apr 16, 2019 12:46 am

Mr.Chips wrote:I talked to Gecko on the phone he really feels it’s a PS going bad, even though the voltage is OK probally the amps are low, and drivers need amps to deliver torque, that’s why slowing it down helped.

That could be the reason I had the problem all of the sudden.

More as it happens.



A power supply going bad never occurred to me, but I have never had one go bad. I guess replacing it can't hurt (except in the pocketbook).

Maybe someone else can jump in here, but the feedrate used seem way way too slow for normal cutting. I haven't done much V carving, but shouldn't the feedrate be closer to 200-250 ipm in MDF with a regular wood router?

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Re: gcode resetting my surface zero to Z-0.200"

Postby wmgeorge » Tue Apr 16, 2019 12:53 am

I have no idea what size motors he has but with my NEMA34s I can run that file at least at 120 ipm maybe a lot faster but V carving has a lot of detail, if you go too fast you may not get it all, but I never have tried.
I am wondering if he has ever checked for loose or poor connections to the PS? That could cause it to lose power.
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Re: gcode resetting my surface zero to Z-0.200"

Postby GME » Tue Apr 16, 2019 1:30 am

wmgeorge wrote:I have no idea what size motors he has but with my NEMA34s I can run that file at least at 120 ipm maybe a lot faster but V carving has a lot of detail, if you go too fast you may not get it all, but I never have tried.
I am wondering if he has ever checked for loose or poor connections to the PS? That could cause it to lose power.



NEMA 24s, if I recall correctly. I agree that checking for loose connections is a good idea. Not much vibration to cause them to loosen, though. It has been running for 10 years after all.

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Re: gcode resetting my surface zero to Z-0.200"

Postby TReischl » Tue Apr 16, 2019 1:43 am

wmgeorge wrote:I have no idea what size motors he has but with my NEMA34s I can run that file at least at 120 ipm maybe a lot faster but V carving has a lot of detail, if you go too fast you may not get it all, but I never have tried.
I am wondering if he has ever checked for loose or poor connections to the PS? That could cause it to lose power.


The only reason you would not "get it all" is because the acceleration would be overcome by the mechanics. The pulses go out but the machine cannot physically respond, so steps are lost. Same thing as if you were to clamp your axis in position and then make a movement command. The command would go out alright, but the motor would not be able to move. As far as the control is concerned the move happened. Steppers as we all know are not a closed loop system as a general rule. Mr Chips certainly are not.

I run my machine at 250-300 IPM doing detailed vcarving and 3d work. An incredible amount of small tiny steps. I do not lose steps.

Edit: If the machine is doing a lot of tiny steps without significant change in direction it will accelerate to programmed feedrate. If it has significant direction changes then it will not be able to achieve targeted feedrate. This can be observed by programming a smooth curve over a few inches. Even though there are an incredible amount of small moves the machine will accelerate to programmed feedrate.
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Re: gcode resetting my surface zero to Z-0.200"

Postby wmgeorge » Tue Apr 16, 2019 2:46 am

You may have it set ar 250 ipm but doing VCarve detail your measured true speed will be much below that. He is running
4.5 ipm, when he cuts the speed in half it works fine. If you read the rest of the posts you will see this file with a lot of detail
is the one that is giving him the losing steps (suspected) problem.

BTW I have never tried VCarve file or 3D file faster than what I said. Maybe just for fun when I get back in town I will? After all I nave a new modern control system, should not be an issue.
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Re: gcode resetting my surface zero to Z-0.200"

Postby wmgeorge » Tue Apr 16, 2019 3:33 am

Sure if you run too fast your going to lose steps. It just depends on the machine, and how far are you willing to go to risk screwing up your project. If you have not tested your machine,... with that file.
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Re: gcode resetting my surface zero to Z-0.200"

Postby Mr.Chips » Tue Apr 16, 2019 6:46 am

So it’s loosing steps.
I thought about increasing the Z axis stepper motor from the current nema 23 425 oz in unit to a larger one. Marcus at Gecko said the 251X drivers could take up to a stepper up to 50V 3.5A, but I can’t find a larger stepper that has that low Amp. The Gecko 251X’s are single stepper drivers. Could I use a nema 34 stepper with its own driver?

This afternoon Marcus mentioned Z axis motor tuning but hesitated to recommend settings. I changed the Z tuning from, velocity of 70.02 to 34.498 and acc from 5 to 3, and G’s from 0.01295 to 0.00777.

I reran a portion of the file at the original 35 IPM XY and 5 IPM Z. The results were acceptable see attachment. Seems I got lucky.

I checked all the electrical connections none found loose. Have yet to check the amp output of the driver PS, it should be 48 VDC and 7.3 amps.

So I may have found a work around, but think a larger Z stepper would also help, comments?

Thanks
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Re: gcode resetting my surface zero to Z-0.200"

Postby ger21 » Tue Apr 16, 2019 12:48 pm

Sure if you run too fast your going to lose steps.


If your machine is setup properly, you should never lose steps.
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Re: gcode resetting my surface zero to Z-0.200"

Postby ger21 » Tue Apr 16, 2019 12:50 pm

So I may have found a work around, but think a larger Z stepper would also help, comments?


It won't help if you have a bad power supply. You should be able to cut much faster with the motors you have.
You have a problem, and it's not the motors.
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