Picking up a little bit of X-axis chatter

I ran a project with a big pocket section the other night and I noticed that I’m getting a lot of x-axis chatter. You can hear it more-so than see it in the video, but in person I can definately tell that the axis is moving as I make x-axis cuts. It’s not resulting in a loss of steps, as the part came out just fine (a little extra sanding though to remove the chatter marks).

It also only happen when I’m making step-over cuts. When the bit is breaking new path (the initial cut at a depth) it does not chatter, but when it’s stepping over, I get the chatter. It also isn’t chattering at all on Y.

Anyone have a suggestion about what my problem is?

The cut in the video was 75ipm, .0625 cut depth with a 1/4" 2-flute down spiral bit.

Finished product is here. As you can see, I didn’t lose steps but did get rough edges on those “X-only” tool paths.

X axis is cutting cross grain and climb milling so you will see more chatter with that combantion. The other thing that can play into this is if you have any back lash in the X axis and you are climb milling. climb milling and back lash don’t play well together.
It is an absolute NO NO in manual milling machines when cutting metal.

Hope this helps

Dave

And I’ll bet you never did any more climb milling in a manual mill again.

Dave

Just be thankful it hit you in the chest and not the eye.

Dave

I climb mill with my manual 8520 all the time? Its pretty standard practice to achieve a better finish if your mill isn’t really clapped out and you have your gibs adjusted properly.

You can get away with climb milling in a manual mill if you WOC is small enough that you don’t run the risk of your end mill grabbing the material and pulling the end mill into work.

As you say you climb mill in a manual mill if the mill is tight.

Dave

I guess that’s the big difference. On a manual mill a climb cut is usually a finishing cut and the DOC is small.

All,

Thank you for the responses. Unfortunately I haven’t had time to work with my x-carve at all this week (life getting in the way) but I’ll be doing another project this weekend hopefully. I’ll try to avoid climb cutting (pretty easy to do with v-carve) and see what happens with the amount of chatter that I get.

im not sure what do you mean here, do you mean when doing climb milling make sure theres no back lash?
also, I did manual milling before, don’t you use climb milling for finishing pass? what do you mean absolute nono?

Because manual milling machines have lead screws that have from a little to quite a bit of backlash it is recommended that climb milling with much depth of cut not be attempted.
A finish cut of just a few thou depth of cut can be done carefully.
CNC routers with belt drive for there axis tend to have some backlash because of belt stretch.