Hold downs

[jrw]

How much side pressure is required for the hold down rollers on the y axis. That is, the manuel states slight side pressure? With good contact on the rails should they be able to be turned by hand without moving the carraige, or should they be tighter. The reason for my question is I am getting a bit of chatter when I do smaller radius cuts 4" or smaller. I have moved the Z as close to the pinion side of the carraige as I can, and that helped alot but I am shooting for perfect. Any Ideas. I have taken steps to make sure everything is aligned (square) as good as I can get.

[jay tomaka]

jay the truth is the shopbot is not a silent running machine. it chatters doing certain moves in my case circular cuts esp small ones like you have mention. one thing that will reduce the noise is reduce your speeds. the chatter is normal though so basically accept it and forget it it is not harming your machine. heavy shaking and grinding is another story but what you sound like you have is a normal running shopbot. merry christmas

[davidallen]

you should not be able to turn the wheels without moving the carriage. on the older PRT (not the angle iron model) the support wheels wear 'tracks' in the corners and will need to be adjusted after wear in.

I'm assuming that the 'chatter' you're talking about is the quality of the router cut and not noise? if so, your cut speed may be too high. you may also want to look at the direction of cut. a roughing pass should be downhill while the finish pass should be uphill. I routinely cut small radius curves, though not full circles, with no problems.

da