Chattering on X axis

Hi Everybody!

I was wondering if someone could help me troubleshoot the chatter on my X axis. Everything I see it tight, and all the V wheels are tightened down.

This particular cut was with a 1/4" endmill at 45 ipm in some walnut, cutting .7 inches deep (with a ramp) in 8 passes.
But I also had the same issue on the previous cut with an 1/8" endmill cutting only .2 inches deep in 5 passes, at the same speed.

The first pass and plunge into the material works fine, and the bit is supported on all sides. In the attached example, the chatter is happening when moving right to left, but if I were clearing something wider, it would chatter left to right as well.

I’ve checked my belts, and my pulley set screws (my machine is an older model). I do have the upgraded X axis (and X controller). Usually, I do my clearing at a 45 degree raster, but recently changed this was the result. The machine jogs fine.

Try cutting shallower - about .06 per pass - but increasing the speed to around 80 ipm and see if it helps. I will say I had the chatter issue on the X axis too. After about a year I broke a belt and had to replace them. I went from the original 5mm 3GT2 belts to the 5mm 3GT3 belts which are heavier. This really helped with the chatter. Moving to the 9MM belts was probably a better fix but I was too cheap at the time to buy the wider pulleys and belt clips needed. Probably next time…

I suspect this is a combination of wheel friction / belt dynamics relateve to cutting speed/load. Atleast when going right to left in that video.

Do some searching on stiffening your Y-axis rails. I know, sounds crazy because you’re getting chatter in the X direction, but trust me. :wink:

1 Like

Thanks for the feedback. I’ll be doing to testing and playing around today. Already I can see there is some play in the Y axis wherever the X carriage is sitting. I’ll have to dig around and see what I see.