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Author Topic: Some advice needed on Motion Control and Drivers  (Read 1011 times)

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Some advice needed on Motion Control and Drivers
« on: August 09, 2017, 01:25:07 PM »
Hello everyone,

First time posting, since I have only used open source software on my CNC's so far, but am now ready to upgrade to Mach3.
My current setup works relatively ok, but I dont trust my electronics (Arduino Grbl + gshield). The arduino inputs are too unstable and it keeps reporting a trigger of the mechanical switches when they are not being pressed.

So, I will invest some money and ditch the arduino+gshield+UGCS software. To replace them, I will buy Mach3 and electonics wich work with both the software and my current steppers (Nema 23/17). I live in Portugal, so my buying options are limited to EU stores, as buying from USA will probably double whatever price I can get because of the import taxes. Here are a couple of options I have found:


Finally, is there anything that Im doing wrong? Do you have any suggestions as to what I should buy in terms of hardware? I have spent some time on Ebay, but buying chinese products seems a risk not worth taking, i want some support in case the components fail.

Thanks in advance for the replys!
Re: Some advice needed on Motion Control and Drivers
« Reply #1 on: August 09, 2017, 07:55:33 PM »
I would be interested in seeing photos of your current control panel and wiring. I have done controls for a very long time and some of the stuff I see on homebuilt CNC and 3d printers I am truly amazed it works at all. Glitches like you describe are nearly always wiring problems.

I use CamBam to program for Mach 3 and a large industrial CNC. A fellow named Karst on the CamBam forum has created a plugin that allows you run GRBL right in CamBam! It looks like he did an awesome job too. You might take a look at CamBam and his plugin.
Re: Some advice needed on Motion Control and Drivers
« Reply #2 on: August 09, 2017, 11:40:39 PM »
Hi,
the cheaper all-in-one board from robotica has two disadvantages
1) the maximum voltage of the drivers is 36V so the steppers will be faily slow, 50V is better,80V is about as
    good as you'll get
2) if one of the driver chips blow up, and they do, and you can't fix it you'll have to replace the whole board.

The multi board combination is better, you can add better drivers later if you want or replace one if it fails.
The motion controller does not have backlash compensation or THC. Have a look at CNCdrive products, they
are advertised and popular in the US but are in fact a Hungarian company, you may get them cheaper than then
the Yanks! The UC100 is cheap and has both Mach3 and Mach4 plugins. The UC100 bigger brothers have up to
5 ports worth of IO but do not have a Mach4 plugin yet but are highly regarded as Mach3 capable.

Craig
My wife left with my best friend...
     and I miss him!
Re: Some advice needed on Motion Control and Drivers
« Reply #3 on: August 10, 2017, 04:17:57 AM »
I would be interested in seeing photos of your current control panel and wiring. I have done controls for a very long time and some of the stuff I see on homebuilt CNC and 3d printers I am truly amazed it works at all. Glitches like you describe are nearly always wiring problems.

I use CamBam to program for Mach 3 and a large industrial CNC. A fellow named Karst on the CamBam forum has created a plugin that allows you run GRBL right in CamBam! It looks like he did an awesome job too. You might take a look at CamBam and his plugin.

Thanks for the input. Yes, my setup is probably not done the correct way. I will try and post it today or tomorrow if I have time. Right now I have disabled all my limit switches, since I cant get the CNC to work enough time without triggrting an alarm when they are on. I think the main issue with my setup is that all the wires go trough the same carrier, both the 5V limit switches and the 380V feeding the spindle.
Re: Some advice needed on Motion Control and Drivers
« Reply #4 on: August 10, 2017, 04:22:06 AM »
Hi,
the cheaper all-in-one board from robotica has two disadvantages
1) the maximum voltage of the drivers is 36V so the steppers will be faily slow, 50V is better,80V is about as
    good as you'll get
2) if one of the driver chips blow up, and they do, and you can't fix it you'll have to replace the whole board.

The multi board combination is better, you can add better drivers later if you want or replace one if it fails.
The motion controller does not have backlash compensation or THC. Have a look at CNCdrive products, they
are advertised and popular in the US but are in fact a Hungarian company, you may get them cheaper than then
the Yanks! The UC100 is cheap and has both Mach3 and Mach4 plugins. The UC100 bigger brothers have up to
5 ports worth of IO but do not have a Mach4 plugin yet but are highly regarded as Mach3 capable.

Craig

Thanks a lot for this awnswer! I hadnt reaaly thought about the problem of replacing the whole board if one of the driver chips blows, it may be a real issue if it happens a lot.
As for the 36V maximum output, I am currently running the motors with 24V input, and the speed is just fine for now, I think that might not be a problem.

I will check the Hungarian boards you mention, thanks for that also!
Re: Some advice needed on Motion Control and Drivers
« Reply #5 on: August 10, 2017, 04:35:38 AM »
Hi,
the driver chips look like Toshiba 6600 or similar, they are good value for money ie cheap but are inclined to go bang.

Higher voltage means more than just speed, it means greater motor torque at moderate speeds. Even low voltages will spin an unloaded
stepper fast but ANY load and it will stall, the same motor with higher voltage will have the torque to accelerate and maintain a load at that speed.

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