[Bdumoit]

Ok,
So i have searched all over and have had little luck. Where do I start? Ok, I have a surfboard shaping machine made by precision shaper. www.precisonshaper.com
I am having an interrupt problem. It runs on Mach3. It has a router cutting tip. It will cut half the board, sometimes a third of the board, then it jerks/interputs. It was fine for 2 months then it started again. Here is the kicker. It runs fine until it hits the EPS foam. When it is cutting the foam is when it starts interrupting. Its never in the same spot. Its very sparatic. The company that built the machine has no Idea why its doing this. We have done everything we can think of. Replaced communication cables, controllers, computers EVERYTHING. I am just a surfboard shaper and not a CNC guru but this is really messing up my business. HELP!

Brock

[bhurts]

I wonder if it's caused by static. It is crazy sounding but could it be static discharging during cuts. Foam has a lot of static. Try wetting the foam before cutting. Or grounding the foam somehow? I've seen ungrounded dust collection hoses discharge large lightning bolts into a router mount periodically during operation.

Ben

[Bdumoit]

Static has been on our list. There are over 50 of these machines world wide but this one and one other is having the problem. I've removed the extractor to try and eliminate the cause but it still does it. It's when the router actually touches the foam. Sometimes right when it touches and sometimes when 3/4 of the foam is cut. It's showing up in our computer as well. Driving me absolutely crazy...... We have tried damn near everything....... Just looking to see if anyone else can think of something that we aren't
Why would the router/ cutting tip cause the motors to freak out periodically. Once it starts it jerks frequently after that........
Good suggestion on wetting the foam though. I'll try that in the morning.

[Al_The_Man]

It sounds a bit like it could be grounding or at least bonding of the gantry the the main earth ground conductor, and ensure the motor frame the same.
Equi-potential bonding is very important, especially for a machine that uses static prone material.
http://www.automation.siemens.com/do.../emv_r.pdf?p=1
Al.

[Bdumoit]

I had an electrician come out and verify everything was grounded and it was. The machine frame, router.... Everything. We were still both scratching our heads.
You may need to further elaborate in the bonding suggestion. Not sure I follow.... I'm a newb to CNC.

[underthetire]

Some high speed spindles actually have a small copper wire brush that grounds the spindle shaft for reasons such as this. I've only seen it on 60k spindles with ceramic bearings, and it was to eliminate micro arching at the cutting edge of the tool.

[Al_The_Man]

What is the nature/technology of the spindle motor, and does it have a controller, if so what type/make? VFD etc.
Al.

[Bdumoit]

It's a Hitachi M12VC router that runs the cutting tool.

[Bdumoit]

There is a controller and it is made by Precision Shaper. The program runs off of mach 3 if that helps.......

[awerby]

Are you leaving the tool path display on in Mach3? I've had problems like that when I've done that, since it uses a lot of resources from the computer. Go into the Diagnostics panel to turn it off, then try again.

[Al_The_Man]

I am not sure how your system is put together, but often with Mach it can get a bit fractured rather than everything being in a single enclosure and fed from a common supply as is the case with a commercial CNC system.
i.e. the supply etc for PC, the spindle, the drives, can be fed from different sources.
Your PC, if a desk top has the P.P. connected to earth ground, so if the systems are fed from different sources the common ground can be separated.
Here is one previous post as an example.
http://www.cnczone.com/forums/phase-...se-issues.html
Al.

[Bdumoit]

I had an electrician come in and verify everything was grounded. I even brought in a big generator and ran the machine just on that power source to rule out dirty power etc........
If the machine doesn't have foam present it runs like a champ. No jerking, no pausing NADA!
I have seen a trend as well over the weekend. It will cut the first half of the board fine. Once it has cut the first half, it hit a homing switch then proceeds to cut the second half. Now, this is when it starts to jerk. It will start to cut the foam and then, it could be on the first cut path or the 12th or 6th. It's sparatic. But it's happening on the second half of the board.
Also, let me back up a little. I got this machine in January and have had trouble for about 2-3 month from that point. Then the problem disappeared then just recently re-appeared.
At this point I'm ready to pull my hair out. It's not like I can sell the damn thing at this point because it doesn't work!
I need a Guru..........

[Bdumoit]

I've read somewhere that variable speed routers can sometimes be a problem when it comes to electrical noise. My communication cables aren't shielded. However this machine was made like the other 53 world wide with no shielding on the stepper motor cables...... I'm shooting in the dark now.
I can see in the G code that it pauses on the screen milliseconds before the motor locks up. Then jumps back into motion, then freezes then moves then freezes. Once the motors jerk, it jerks about 2-5 times then gets going again. Pulling my hair out