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1

Show"N"Tell ( What you have made with your CNC machine.) / ISO 30 Tool holder tray

« on: April 23, 2016, 11:53:31 AM »

I designed and built a couple of these to use with out 4x4 CNC router with a ATC.  This one does not have the rubber edging around the holes yet.  I used a 1/16" wall rubber channel I found at an auto glass shop.  Usually used on glass or plastic windows.  Powder Coated after assembly.
Assembled with 6-32 press in flushnuts and screws, but pop rivet or screws and nuts would work as well.

James

2

General Mach Discussion / Positioning errors and out of round holes

« on: February 06, 2016, 05:55:19 PM »

Hello all
  At work we have a new 4x4 cnc router for about 3 months now and have not got it up and running properly.  It was basically a fire sale price to good to pass up.  This is a HD machine with a 5hp HSD tool change spindle and a 6 place finger style changer rack.
It is a servo drive machine with all Delta products in it.  I am guessing it got stuck in a warehouse and never got inspected or run.  We had to replace the controller card and one of the X axis servo motors. 
  We finally got everything working on it but with the type of work we do in it we are seeing position errors after the programs are run.  We are cutting 2mm alum sheet to be used in computer enclosures.  This requires a lot of parts and small holes for fasteners.  I generally run a 1/8" bit to cut anywhere from 3.25-6.35mm holes in the sheet to be used as hold downs for the parts before they are cut out.  This can add up to several hundred holes.   At the original acceleration setting in Mach3 I was getting about a .5mm out of round condition on holes under 10mm and after runing the program and returning to zero it would be off 2-4mm from my original start point that I would mark on the sheet.  But if I was cutting larger holes or parts without the rapid movements like in the smaller holes then I did not see the positioning errors.  I have tried turning down the acceleration rate in the Motor Tuning for the X and Y and it had reduced the error but not completely.  I can do a REF all Home and GOTO Zero and it will return to the original zero setting but that not practical.
  Any help here would be greatly appreciated.

James 

PS - here is a test cut I did,  the small holes were all out of round but the larger ones were fine.