Author Topic: Issue with slave motor when running gcode  (Read 2840 times)

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Offline O.Wright

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Issue with slave motor when running gcode
« on: February 20, 2018, 03:37:07 PM »
Hi,

Forum newbie here, any help is appreciated. I have a CNC plasma running off mach3 that has been working great for the past couple years. I recently purchased a CNC router secondhand and am having trouble getting the slaved motor to respond to gcode (whether a loaded file or manual input). The strange thing is everything works great if I am jogging the machine. Since the machine responds to jog inputs properly, I am lead to believe it is a mach3 settings issue causing the slave to not respond to gcode (I could be completely wrong though).

Everything in the control box seems to be wired correctly and is tight.
- MKX-IV breakout
- JMC 2DM860 drivers


Settings in Mach3 that I can rule out:
- Angular motion is unchecked
- ports/pins are configured correctly according to the manuals included
- A is slaved to Y
- A/Y motors are tuned identically

Looking to see if anyone has had the same issue or if any guidance through trouble shooting could be provided. If I didn't provide enough information please let me know what I am missing so I can add it.

Thanks

Owen



Offline TOTALLYRC

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Re: Issue with slave motor when running gcode
« Reply #1 on: February 20, 2018, 08:54:40 PM »
Look in the manual and see if the motion controller supports slaved axis.

Mike.

We never have the time or money to do it right the first time, but we somehow manage to do it twice and then spend the money to get it right.

Online joeaverage

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Re: Issue with slave motor when running gcode
« Reply #2 on: February 20, 2018, 10:31:33 PM »
Hi,
there is a thread running on the main board which is remarkably similar, the same controller that apparently
wont slave another motor.

http://www.machsupport.com/forum/index.php/topic,36619.msg251297.html#msg251297

Craig
My wife left with my best friend...
     and I miss him!

Offline O.Wright

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Re: Issue with slave motor when running gcode
« Reply #3 on: February 21, 2018, 05:08:06 PM »
Look in the manual and see if the motion controller supports slaved axis.

Mike.



Hey Mike, thanks for the suggestion. After looking through the manual I don't actually see anything specifically about slaved axis support. I was under the impression slaving was on the mach3 end of things as the board does have A axis output, everything is hooked up and does jog fine. I could be missing something though.

Hi,
there is a thread running on the main board which is remarkably similar, the same controller that apparently
wont slave another motor.

http://www.machsupport.com/forum/index.php/topic,36619.msg251297.html#msg251297

Craig

Hi Craig, thanks for the reply! I've read through that thread a few times and was hoping to take something away from it, but it seems like Olavi is experiences random coordinate changes, motor direction changes and homing issues. Although his motor function stopping is similar, my motors will always work when I am jogging the machine. The slaved motor is completely unresponsive to gcode.

I have contacted Alex He through email with no response. I think I am going to nip this in the bud before I start experiencing more issues by replacing the motion card to something proven. I saw the post you made listing reputable cards, need to do a little bit of research. My only concern is that once I purchase and install a new board I'll experience the same issues if it is a mach3 problem.

The only thing I am confused about is why this is only occurring when trying to run gcode. I've triple checked my Mach3 settings but wanted others opinions in case I missed something, as that does happen more often than I'd like to admit. If anyone has any mach3 related suggestions I could try they will be greatly appreciated.

Thanks

Online joeaverage

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Re: Issue with slave motor when running gcode
« Reply #4 on: February 22, 2018, 01:08:38 AM »
Hi,
I'm pretty scathing of poorly performing/supported Chinese made boards. Those people who buy them and then insist others help them fix all the
problems with them are on a hiding to nowhere.

I'm sure that you've seen enough posts to know that even good controllers can be challenging enough without buying a whole bunch more problems
with a dodgy board.

If you stick to the manufacturers on my list you wont go wrong. You may at some point realize that board B actually has a feature that you didn't appreciate
when you bought board A....but at least board A wont let you down.

Craig
My wife left with my best friend...
     and I miss him!

Offline O.Wright

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Re: Issue with slave motor when running gcode
« Reply #5 on: February 22, 2018, 01:28:44 AM »
Hi,
I'm pretty scathing of poorly performing/supported Chinese made boards. Those people who buy them and then insist others help them fix all the
problems with them are on a hiding to nowhere.

I'm sure that you've seen enough posts to know that even good controllers can be challenging enough without buying a whole bunch more problems
with a dodgy board.

If you stick to the manufacturers on my list you wont go wrong. You may at some point realize that board B actually has a feature that you didn't appreciate
when you bought board A....but at least board A wont let you down.

Craig

Absolutely agree! I originally made a post because I thought I may have missed something in Mach3 using a USB controller instead of a parallel port like my other machine. Just wanted to cover my bases before throwing money at a problem. Unfortunately it just seems like the dll file is not co-operating with Mach3 for whatever reason. I'll have to do some research to find a fitting replacement for the mkx-iv. There may be a few follow up posts seeking advice there. Lots of good information so far on the forum, thank you for contributing so much.

Owen

Online joeaverage

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Re: Issue with slave motor when running gcode
« Reply #6 on: February 22, 2018, 01:43:35 AM »
Hi,
one of the more popular choices is the UC100, its been around for a long time, just beware that there are swags of Chinese knockoffs of that particular board.
If you go to buy something buy off the manufacturer direct or their nominated distributor. Don't get ripped!

Craig
My wife left with my best friend...
     and I miss him!

Offline O.Wright

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Re: Issue with slave motor when running gcode
« Reply #7 on: February 27, 2018, 06:39:08 PM »
Hi Guys,

I think I've decided on replacing the mkx-iv with a PMDX-424. I would prefer to continue using Mach 3 and fired off an email for compatibility but have a feeling if I want to use this board I will have to switch to mach 4. The board seems like a good choice and all around package with some room for expansion in the future.

Anyways, I just thought I would update the thread for future trouble shooting searches. My system was severely under powered. When speaking with a distributor for motion control boards he hinted that the motors may draw more power when following g-code than when under jogging conditions. Although I don't completely understand why that would be the case, it would make sense. Either way, I will confirm once I receive the new power supply. Even if the power supply fixes the issue I am still looking to change the motion control card as I want something reliable and just works.

Thanks again for the help, looking forwards to getting this thing going!

Online joeaverage

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Re: Issue with slave motor when running gcode
« Reply #8 on: February 27, 2018, 06:53:39 PM »
Hi,
the PMDX-424 is a great board and has plugins for both Mach4 and Mach4, take your pick.

When Gcode is running there are often lots of short high acceleration moves running imediately
after one another. High acceleration=high current.

Craig
My wife left with my best friend...
     and I miss him!

Offline O.Wright

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Re: Issue with slave motor when running gcode
« Reply #9 on: March 01, 2018, 01:23:32 AM »
Hi Craig,

Unfortunately Steve over at PMDX replied today saying that the PMDX-424 is a mach 4 specific board. Although I didn't want to increase the learning curve by switching to mach 4 it looks pretty awesome! I will probably get a package deal from PMDX with the board and mach 4. Really excited about the program even after a day of reading up. Now the only issue is I have to wait for everything to get here!

Definitely makes sense why that slave motor wasn't operating during Gcode then. I am relieved to have made some progress trouble shooting and appreciate the help.