Here we go with another chatter thread

First, I know…“search”. Second, I have since I got it in May or June. I’ve done everything…EVERYTHING! It acts like it’s almost a pot setting issue as it comes and goes, but is almost always consistent along the X axis when further out on the Y axis from machine home. Everything has been checked multiple times. Still…chatter. I’m planning the linear z upgrade soon, but after the sign I’m working on now, I’m not even sure that would solve it. Tonight I have a sign for my mom that is being carved. Terrible chatter on straight x axis cut while along the y axis about the 7" range. The straight cut along the x when closer to the y axis machine zero is fine. I put my hand on the router, the z axis, the carrier that slides across the x axis and it calms the chatter down. But I’m sure not going to sit and do that. There is absolutely nothing loose, or too tight on it. Everything else is properly adjusted. What the hell could it be!!! This has been a recurring problem since I’ve had this thing. It’s the 1000m version if that matters. https://discuss-assets.s3.amazonaws.com/original/3X/c/b/cb528afa2945271f729f982ad63ac6197cbedeeb.MOV

This is at about .25" on the y axis. X travel is fine, zero chatter.

If this is a true statement, then the only other option is that you are cutting too aggressively.

https://discuss-assets.s3.amazonaws.com/original/3X/f/0/f00e87d23c838847b7c99e99f8166a10ecb02cae.MOV

This is along the x at about the y 7" mark

@LarryM doesn’t matter the settings. I can run at 40ipm, 15ipm plunge and .01" depth per pass with a 1/16" and it does it the same as 55ipm, 15 plunge, .02" depth per pass.

Next thing would be a worn out mill.

It has done it since the beginning, and it was a brand new router. I’ve taken it off and fully inspected it, nothing wrong with it.

If it did it along both the x and y, then I could understand a issue with router, or possibly being too aggressive, assuming I hadn’t checked or played with either potential issue. It’s driving me nuts.

From the video you have some obvious vibration of the router. Something is not tight enough, or your frame is not rigid enough.

Have you checked the tightness of the frame screws?

Checked every screw on the machine. Everything else as well. That’s why this is driving me insane.

Does the chatter only show up when you’re carving? If you do an air cut, does the same thing happen?

No. I have my G30 set towards the back right corner and when I hit it from G28, it zooms right over with no issue.

Really has all the symptoms of a feed or depth of cut issue. Can you give more details about the end mill, feed, and depth of cut?

Could be your system reach a harmonic frequency at that certain point?

May be a stupid question but, Have you tried another bit? it could be slightly bent causing the wobble when cutting.

What is your belt tension?

First, thank you to everyone offering suggestions.
I have actually ordered a 3/4" bit to surface the waste board, but a machinist square says it’s flat right now. In the video is it .02" depth per pass. Does the same at .01" per pass though, that’s why I’ve been thinking it’s not the depth. The spindle to waste board is perfectly perpendicular, the base of the pocket is smooth, with no lines indicating otherwise.
Using a 1/16" downcut Kyocera. This one is probably a bit dull after looking close to the letters after the carve was complete, not sure if that would matter.

Haven’t re-enforced the Y rails YET, mainly due to the fast I was going to wait on that until I upgrade to the linear Z, and get lifted Y end plates.

Belt tension is 3.9lbs all around. When I set it originally after the initial first few hours of use, I set it to 4.2lbs. So, they have stretched a bit. I want to do the upgrade to the wider belts, and at first thought I couldn’t since I have the newer steppers with the pulleys that are secured…but I’ve seen this week where I can remove the pulleys without damaging the stepper shaft. So, new wider belts and pulleys are very soon to be ordered.

Did you caliper the actual cut to ensure it’s cutting what you want?

Just did. Set it at .035" total depth and it’s measuring between .034-.036 best my shaky hands can tell.

Try halving your feed rate and see if the issue persists. I think you’re moving too fast for that shall of a bit.

@PhilJohnson not yet. All I’ve used is easel so far. Been so busy with stuff I haven’t had much time to mess with f engrave yet. Going to try to mess with it and UGS this week though.

1 Like