Hi I am experiencing problems when routing. Please see attached picture. It is the same fault on all parts I make. Just where the router enters the material it is a slightly "radius". Any suggestions to what might cause this? SAVE_20170607_091023 by Cncstar posted Jun 7, 2017 at 9:03 AM
Need more info to help, what machine do you have, what programs you using, material, bit size type, feed, speed, depth of cut (DOC)... Just based on the pic and a guess, you have too aggressive of a plunge into the material and this is causing the bit to chatter out and enlarge the hole.. but without knowing anything else this is just a guess. If you have a belt drive system maybe the belts are not tight enough. or your Z has too much flex (reduce the DOC)
If you are using SketchUcam, turn on ramping. Same in any other software, ramp into the work instead of plunging. Milling bits are very bad at plunging, yes, even end cutting bits. I think Gary is right, your plunge (+ some looseness somewhere) is causing this. Is the bit center cutting? How fast are you plunging? What software are you using? What machine is it? Belt drive? are they tight enough? Screw drive? antibacklash nuts adjusted properly? What spindle? has it got runout? loose bearings?
