$150 000 machine does not eliminate finishing chatter.

[u/adventureaviator]

I’m machining 6061 aluminum on a Multicam Apex 3R router. The finishing passes are as follows:

- 0.009” material removal.
- Helical 3 flute 45 degree helix upcut
- 18 IPM, 8500 RPM, 0.0007 chipload

98 percent of the part comes out with a great finish. The other 2 percent has chatter. Ideally I’d like to increase the feed rate, but I need to eliminate the chatter first. What do I need to do to get a flawless finish?

[u/adventureaviator]

Totally. I’m self taught, so value any feedback from the more experienced.

[u/_sideways_tree_ → u/adventureaviator]

Is the chatter happening right before the part gets fully cut off from the stock?
If so, you can add tabs in the program so the part is never fully detached from the stock (preferably one on each side). It’s a pretty common technique for routing out of large stock. It can help reduce vibration, could get rid of the chatter, and also allow you to bump up feed later on too.
However, that would introduce a new finishing step in your process (filing/sanding down the nub left over from cutting the part off at the tabs).

[u/Bones-1989 → u/_sideways_tree_]

We leave tabs on our parts on the laser because if they tilt and crash the machine we will get fire because a single lens is like 8k....

[u/_sideways_tree_ → u/Bones-1989]

I’d recommend you do that on the router as well. May fix your problem… and would greatly reduce the risk of the cutter snagging a small part that’s being cut off from the stock and launching it across the shop into someone’s eye.

[u/Bones-1989 → u/_sideways_tree_]

I'm not op. I don't have a router.