Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: Marcin81 on May 23, 2011, 04:35:51 PM
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Hi to all,
I need some help with setting up my mach3 configuration. I read almost every post that I could find on the internet but still can figure it out what's going on. The problem is that when I jog the machine it moves smooth and fast but when I load g code for profiling the motion slows down and motors makes a lot of harsh noise. I tried different motor tuning configuration and also many other settings but no lack at all. Some specifications of my setup:
PC:
Processor: Pentium 4 - 3.2Ghz
Ram memory: 2 Gb DDR2
Cnc
Controller: Tb6560 board
X axis: Nema 34 step motor, 8 micro steps, 16mm screw, pitch 10 mm
Y axis: Nema 23 step motor, 8 micro steps, 16mm screw, pitch 10 mm
Z axis: Nema 23 step motor, 8 micro steps, 16mm screw, pitch 5 mm
Here is the link to short video where you can see and hear what's going on with the machine when jog and when start working on the profile cut.
http://www.youtube.com/watch?v=uwzfqMPyA2Y
I also made screen shots of my mach3 configuration.
Thanks
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Can you attach your xml and also the code you were running in the vid please.
Hood
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Hello Hood,
Thank you very much for replay. Here are the files.
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XML looks fine, can you try a test by using the circular pocket wizard to see how that runs. Also try the Roadrunner and see how that runs.
Hood
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I did that already, and works great. I don't understand this ???
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I'm sorry, circle pocket works fine, but the Roadrunner is very slow and also a lot of noise. Another thing is that when I run the Roadrunner the router almost doesn't move but the motion on the screen move fast.
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It looks like the small moves are causing your problem. Circle test was to see if it was fine with multi axis moves, looked fine in jogging but was just checking. Roadrunner and your code are made up of loads of small lines so thats why I wondered if roadrunner acted the same as your code.
Try dropping your acceleration by half and see if that helps any, can always increase later if it does.
Hood
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Doesn't help. Makes it even worst when I jog. Makes the motors stalling.
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Try changing the Step to Active low on Ports and Pins, Motor Setup, it may be your drives need it that way.
Also maybe worth trying Sherline mode but for that you would have to drop your Velocity and set kernel to 25KHz.
Does the driver test look ok?
Hood
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I changed the step to active low and the jog become very jerky and slow. I lower the velocity and acceleration but didn't helped much. Sherline mode makes router slower but no improvement on running g-code.
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Do your drives have tuning for mid band resonance?
Hood
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I'm sorry, circle pocket works fine, but the Roadrunner is very slow and also a lot of noise. Another thing is that when I run the Roadrunner the router almost doesn't move but the motion on the screen move fast.
Marcin,
Just a thought but the Roadrunner code is in imperial units. If you machine is set-up in metric units the roadrunner image would be only 7mm x 6mm. (you could try putting a G20 at the beginning of the code)
Tweakie.
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Hello,
I added G20 at the beginning of the code but didn't help, is still this same. Regarding the tuning for mid band resonance, I don't know what that is.
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Here is another think. First when I got that machine I had the problem with getting the router to work as the step motors didn't move at all. In one of the posts Tweakie suggested that the old type controllers doesn't work wit the new PC as the printer port voltage is to low and that was it. I bought the buffer board and that worked. But maybe the controller that I have is somehow just not compatible with mach3 ?
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What type of controller board is it ?
Tweakie.
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Toshiba TB6560
Here is the link to ebay page:
http://cgi.ebay.co.uk/CNC-TB6560-3-Axis-Stepper-Motor-Driver-Controller-Board-/250789782935?pt=UK_BOI_Industrial_Automation_Control_ET&hash=item3a643c6597
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I think that your problem is not really a problem.
You should try to build stepper damper, this will eliminate a lot of vibration.
http://www.cnczone.com/forums/stepper_motors_drives/32284-my_take_stepper_damper.html
Jeff
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Hello,
Thank you Jeff for your advice. Gerry from Cnc zone was suggesting this same thing. There is nothing else to try so this must be it. Is there any place that I can but stepper dampers ? Or maybe there is some step motor that comes with some kind of build in steeper dumper inside ?
Thanks,
Marcin
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I just watched the videos from one of the posts. This is just amazing. You are right, that will fix everything. I must to find the way to fix the dumper to the motor. I have no shaft on the back on my motors.
Thanks,
Marcin
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You could ry mounting it to the other end of the screw. Some people have had good results by using a hockey puck, drilling a slightly under size hole and just pressing it onto the shaft.
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Just curious, have heard about dampers getting used but cant recall seeing any when the likes of Geckos are being used. Is the need for the dampers due to the nature of the cheaper drives?
Hood
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Great idea and easy to do. I will try that. Thanks Gerry
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Have you seen this video about stepper damper.
http://www.youtube.com/watch?v=UJjivsVwSsQ
Really impressive what those can do.
Jeff
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Have you seen this video about stepper damper.
http://www.youtube.com/watch?v=UJjivsVwSsQ
Really impressive what those can do.
Jeff
Hey, that's mine. :)
To answer Hood's question, Yes, it's usually the cheaper drives that suffer from resonance. Mine happens to be a Xylotex. A lot of people don't really know they're getting resonance issues until they add dampers, which can double or triple the performance of inexpensive drives.
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Hi to All,
I did try to put some weight on the end of my ball screws today and the router could run the code much faster and the noise was gone. However I think will be better to change this stepper motors for good quality ones as my current ones are from chine. Could someone recommend me good motors that will work with my controller or maybe also new controller. I am looking for good quality as I don't have a lot of time to be fixing this things.
Thanks,
Marcin
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Ger,
thanks for the info, thought that may be the case.
Marcin
Most motors will be made in China anyway, even a lot of drives are made there, some drives good some bad but most motors seem to be reasonable.
I think if it was me I would look at Gecko G540 if your motors fall within the current range of them.
Hood
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Thanks Hood,
This looks like a good deal. I also would like to get new stepper motors but I couldn't see nema34 on gecko website which I need for my x axis. I also heard that keling stuff is very good.
Marcin
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Keling drives are Chinese but they are the better Chinese ones. I have used the 8 Amp versions of these drives and they worked well, not quite as nice as the Gecko G201 and G202 that I have but not far behind. The Chinese drives are massive compared to the Geckos but they do have inbuilt heatsinks which is probably about half the size of the drives. I never needed heatsinks on my G201/202's but I do live in a coldish climate so that may be the reason.
As for the motors, well they too will be Chinese but as mentioned you would be pushed to get anything other than Chinese. Just make sure the motors are suitable for the current capacity of the drives, I think Gecko have some informative documents which should help you.
Hood
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It's usually not the motors causing the resonance, it's the cheap drives. Most people are using chinese steppers these days, as they are about 1/2 the cost of japanese or american made.
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Thank you all for help on this one. Now I know how to fix the problem but I don't know yet what I want to do ;D
Marcin