Attached is a pic of a test piece I cut out tonight on my DIY machine. 10mm 2F endmill at a full depth of 24mm, followed by a contour same depth with a 3F taking off 0.4mm finishing run. The little red area is where my machine will chatter. Feels like its the whole machine bumping around. Even when the cut is a light pass.

I have tried every way I can think of to find where this chatter is? Its kind of on the diagonal axis between X and Y in direction. Honestly, I have swung and twisted and pulled in every direction and when I find something that I think might be loose?? Nope. It is still there. I think even with a tiny 6mm endmill it is enough to hear the chatter but not so evident in the work. So I can actually climb cut with this machine quite well, except in that one direction - or almost the opposite. It sometimes sounds worse than it is on the workpiece.

I dunno, I wasnt going to write on here about it. Its a DIY machine. I guess if someone has an idea on something I can address that is new, well thats what it is all about huh?

I am about to build a new steel frame and sit a cast T slot table on it in the next 12 months. The frame will be pretty heavy as it needs to hold the 600kg cast table off the floor. I still think it might be no different.

Oh, yes I do know I can decrease my workload, but it would be nice to sort this - kind of a challenge.

Thoughts?