Hi. Like a lot of folks, I’m seeing the problem where what should be a circle is actually milled as an oval. But it only happens sometimes. I’ve been milling some 6.4 mm circles that will receive a small magnet as part of a box lock.
The circles drilled towards the front of the machine (-Y) are OK – not perfect, but good enough to receive the magnet.
Circles milled 50 mm towards the back of the machine come out as ovals, with the long axis mostly east to west
. This is consistent regardless of where I set up the job on the washboard. It’s not that the ovals happen at some specific physical location; they seem to happen at a relative location to the work origin.
This has me stumped. If it was slippage or backlash or incorrect X,Y increment settings shouldn’t it happen consistently?
Not sure why this would happen this specific way, but it is still probably something to do with some of your v-wheels eccentrics not being tightened quite right, and/or suboptimal belt tension, maybe double check that before anything else? Check ALL of them vwheels.
Thanks, Julien! I’ll give that a try. Fortunately there is a lot of info out there on adjusting v-wheels.
Side note – I put a small dot of white paint on each v-wheel to make the movement more visible. (Probably lots of people have thought of that). They were all tight when I checked two months ago but it looks like a least a couple are now loose.
Just to close out this issue - I went through the tuneup check described elsewhere for circle/oval problems, and found one (of two) set screws, on the Y+ drive pulley, was loose. Tightening it up was enough to solve my circle problem.
