Where are you located? It's possible there is someone local to you.
Hi Everyone,
I run a small cabinet shop and recently purchased a 4x8 CNC router from China (you might have heard a similar tale as the one I'm about to tell before).
It has a lot of quality parts on it. Hiwin rails. Yaskawa servo motors. Run by a Syntec 6MB contoller. It's also a heavy beast at over 4,000lbs.
My issue is, if I slow my cuts down to 60 inches per minute, it cuts "ok". I usually use 1/4 inch spiral carbide bits that feed/speed charts say should run upwards of 180 IPMs. When I run it that high, the cuts are terrible. A 1 inch circle cut in MDF at .0125" deep per pass looks like a choppy oval. I use Aspire as my software program and the machine runs on simple G code.
The biggest thing I see is when it gets to turning a 90 corner, the Y axis always over travels a bit. Even at 160 IPM it can overtravel by .025"
My suspicions are the servos are not in tune, but that's a WAG.
I took the covers off and the belts all some tensioned well enough and the gears are making good contact.
My question is, does anyone do support/consulting work on machines like this? It's a pretty simple setup for someone that knows CNC really well. The support from the manufacturer is zero. I've got no where else to turn as I've got little spare time.
I appreciate any direction you could point me. I'm a paying customer. Just need to get this machine straightened out so I can get back to work.
Thanks!
Brandon
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Where are you located? It's possible there is someone local to you.
Jim Dawson
Sandy, Oregon, USA
I'm in the Kansas City area.
Wow, thank you!
I included a couple of photos that show the cuts at 120 IPM with 1/4 upcut spircal carbide bit. It gets much worse the faster I go.
The spindle is HSK (Photo attached).
X and y axis motors are same - SGM7G-09AFC61 (photo attached).
Hope this answers your questions. Please let me know if there is anything else you need.
Brandon
What control system are you running? It also looks like the machine has never been set up or adjusted. Spindle Hp and max speed?
So this is your controller > https://www.cnczone.com/forums/chine...50812-cnc.html
1000x750 Workbee CNC - Mach4 - PMDX USB - Windows 10 Pro
Hi Brandon, I saw you pictures. They both are spindles'. Well, It doesn't matter. I bet your servo drive is SGD7S-7R6A00A.
I just need some pictures of your abnormal cutting work pieces. According to your description, the phenomenon is motor overshoot.
There are some reasons will cause this problem. Such as rigidity is too low; the inertia ratio is not adequate and so on.
I need you to check one thing. Power on your machine, servo on your motors but don't run any programs. Push and pull the CNC table along X direction and then Y directon serval times. See if you can move the table or not. Tell me the result.
What's more, you'd better prepare a communication cable of mini USB, which is used for adjusting the drive performance in case. And you need to download the tuning softerware of sigmawin+.
Servo system is much more complicated than stepper system. We need some more patience.
It might help to do the push/pull test with a dial indicator on the table to see just how far it moves; also - just for repeatability - you might hang something off the table via a rigged-up pulley or roller or something (the idea being to apply consistent force as you are testing & tuning).
Because you say you already checked it mechanically, I suspect that you will find that the following error at those speeds is something astronomical... and the servo drives' PID loops are turned up just barely enough to make it move.
Looks like this might be the culprit. I rechecked all the gears and belts on the y axis. When the machine is on, the right side servo (as I'm looking at it from the front of the machine) is rock solid. The left side has considerable play in it 1/16" plus forward and back. When I move it back and forth, the gears are engaged and moving, the belt moves, so it seems the servo is letting it move.
Well, I'm keeping my fingers crossed, but I think I might have nailed it.
I went to hook up my computer inside the cabinet to diagnose with the program I downloaded and the #1 Y axis had an error code. When I looked it up, it was one of 5 possibilities and one was possibly a loose wire. I unplugged the wire from the motor itself and plugged it back in. Rebooted the console and not only did the error message go away, my two test cuts are perfect for the first time since I've owned it!
At least now I know where to look if I start getting my cutting issues again.
I feel like a dumb rookie, but I can't thank you all enough for your willingness to help; especially you CNCINDUSTRY. I appreciate your willingness to walk me through potentially more involved issues.
My best to you all,
Brandon
Hi Brandon. Thank you for your feedback.
I need to emphasize one thing before we go: The original servo parameters are critical important. You must backup all of them prior to change any items.
Generally speaking, most of the machines are tested and ensure perfectly state before they go out.
For the servo parameters, they are batch replication from one template. So we temporarily leave them alone.
I need to confirm the mechanical structure first.
According to your description: "the right side servo (as I'm looking at it from the front of the machine) is rock solid. The left side has considerable play in it 1/16" plus forward and back."
Does your machine has double Y-axis? In another word, does the machine has two ballscrews in Y direction? Could you show me the pictures of your CNC table? Have you ever checked the coupling?
Yes, and I would suggest making a paper copy and attaching it to the inside of the machine somewhere convenient... the next time that information is needed, it's possible that whatever file storage media you would use would not be easy to read (um... anybody got a 5.25" floppy drive handy? Well, in 25 years, that USB thumb drive might be in a similar situation...).I need to emphasize one thing before we go: The original servo parameters are critical important. You must backup all of them prior to change any items.
Hello Brandon, it is my pleasure to help you. Don't worry and take it easy, if you make some progress in servo system, you will find it is wonderful for a CNC machine.
As I said serval days ago, servo system is much more complicate, so follow me step by step, little by little. You can reach me at this email:
oossppp@outlook.com
For the problems diagnosing, I need some more detail pictures of the wires' connection.
What is the error code with your #1 Y axis?