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  #11  
Old 02-16-2012, 06:09 PM
Jerry Stanek jerry_stanek is offline
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I had the same problem with the proximity switches triggering until I move the switch ground to a different ground post. Haven't had a problem now for a year.
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  #12  
Old 02-16-2012, 06:33 PM
David B Jacquot Brett1970 is offline
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i don't run anything else in the shop when the bot is going. The bot is on it's own breaker, as is my dust collector, and my vacuum hold down. Any power lines going to the bot itself, are not zip tied to the motor wires, i kept them seperate to eliminate cross talk. I don't ramp in to any cuts, and i cut my melamine and ply in 2 passes. I followed the rule of depth of cut max = 1.5 bit diameter. I'm over just a touch on the melamine, at .405 but that's just to make sure i am cutting all the way through it.

I've had it cut 15 sheets with no issue, other times it's only 2 - 3 sheets before it acts up.
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  #13  
Old 02-16-2012, 07:10 PM
Greg S fredtoo is offline
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"My system is grounded, starting at the breaker box in the house."

How far is that? Are you maybe looking at a ground loop or GPR (ground potential rise). Try moving that ground over to one of your local outlets or maybe disconnect it temporarily and run a test cut. Too may grounds can, if at different potentials, can cause BIG problems.
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  #14  
Old 02-16-2012, 07:10 PM
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Gary Campbell, ShopBot Tools garyc is offline
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David...
Try cutting a few sheets with your speeds set at half of what you now cut at. When all is good your cut speeds are near the max for the machine. Add some dust, wear and tear and a partially dull bit and max speeds must be reduced.

Have you dropped out the motors and cleaned the racks lately? have you done a free wheel motion test of all axes? How about pinion replacement? Many that cut sheetgoods fairly steady forget to dissassemble the z axis motion parts to clean and lube. Out of sight is not out of mind when cutting aggressively.
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  #15  
Old 02-16-2012, 07:24 PM
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Ron Moorehead ron_moorehead is offline
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A couple of days ago, I got a switch proxy warning (input 4) and the shopbot shut down. I checked all my wiring and took apart the emergency stop switch, and found all the wires tight. The wire were tight at the connector on the circuit board. I was still having the same problem. I put jumpers on the input for the emergency stop thinking I my have a bad cable, still had the problem. I finally figure out that I was running the Z into it's end stops and stalling out the motor. You get the same fault warning as a proxy switch. Repositioned my work so I would not run into the end stop and everything worked fine. I have a PRT Alpha and I only run it at about 2 ips. I also heard the grinding noise just before she would stop.
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  #16  
Old 04-09-2012, 09:38 PM
David B Jacquot Brett1970 is offline
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I dropped my cut speeds from 4 inches a second to 3.5 i ran off 20 sheets with zero issues. now today, it's doing the same damn thing, ruined 2 sheets in a row. First time was on the Z axis as it was cutting. Wasn't as severe as before. The last time was a pronounced grind. This time, it's more like it hit a speed bump, just a quick THUNK sound, first sheet i lost position. it did it right before it went to plunge, and it lost position on the Z by 1/4". the next time it did it, it was on the X axis while cutting, heard a thunk, and lost position by 1/8th inch.

I am positive i have no ground loop in my grounding system. The length of my ground from box to machine is no more than 16 feet. much shorter than if i hit the ground in the nearest outlet by alot.

I am so frustrated and sick of losing money on ruined materials i am at my wit's end. if i slow this thing down any further, i might as well get out the hand router.
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  #17  
Old 04-09-2012, 09:59 PM
Bruce Taylor bruce_taylor is offline
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David,
I can relate to the frustration of ruined material and time. How many sheets out of the bit? What are you using for a bit. 3.5 ips still sounds a bit fast. You are loosing steps which implies to me that you may be pushing a bit hard still. I know you don't want to here that but give a little more info on rpm cutter wear etc and what you changed after the first sheet was ruined. I use a reference point to zero to incase of loss of position or loss of power so I can re zero my position if I have an issue that might help. What is the recommended feed and speed from the dealer for your bit selection. Is cut quality acceptable? I would really like to help you resolve the issue. Anything else you can tell us about the variables would help .
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  #18  
Old 04-09-2012, 10:18 PM
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Gary Campbell, ShopBot Tools garyc is offline
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David...
In most of the cases that I have seen or heard a quick "thunk" as you describe, the cause was static. Do you have your dust collection hose grounded? Is there a bare wire run inside the dust hose? Is it grounded on the end away from the machine? Is the dust foot alligator clip attached to it?
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  #19  
Old 04-09-2012, 11:18 PM
David B Jacquot Brett1970 is offline
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i have it all grounded per the guide i found on here. I think i've covered my grounding before but i will go over it again in case i haven't. ground starts at the breaker box, goes to control box, then to Aluminum X rail, from here it splits off - one leg goes through my wiring looms, and is attached to the X car, then through my wire chain, and is attached to the side of the plate the spindle is attached to. The other leg from the X rail, goes over and connects to the other X rail. From there, it goes to the base of my dust collector. Then from the base, it goes to the stranded bare wire that goes through the dust collector hose, to the dust skirt. I also have a wire through the plastic on the dust hose, and it's connected to the ground back at the base of the dust collector too.

Using a 1/4 double flute full carbide bit, cutting birch plywood. cut quality is fine, i have maybe 10 sheets on that bit. i usually get around 25 sheets before i swap it. Cutting in .375 deep passes. Jog speed of machine is whatever factory setting is. Pc is optimized to bare bones, no internet, defragged, etc. The other stuff i was cutting was black melamine, using a 1/4 compression bit, same speeds, but .4 max depth of cut per pass, and had no issues. I switch to ply and it all goes to **** : /
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  #20  
Old 04-11-2012, 11:27 PM
David B Jacquot Brett1970 is offline
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i adjusted the motors, cleaned all the tracks, even the Z greased everything, etc. Still get the grinding noise, and have to hit the stop before it ruins a sheet. Then start over, cut again... sigh. won't be much longer before i just sell it to fix the problem.
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