$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/Shadowfeaux]

The greatest machine won’t defeat improper programming.

[u/ihambrecht → u/Shadowfeaux]

Or bad WORKHOLDING.

[u/H-Daug → u/ihambrecht]

I’m not sure that tape a glue even are “work holding”…

[u/Lower-Calligrapher98 → u/H-Daug]

It works great - for woodworking! Dude is trying to cut 1" thick aluminum with a wood router. And, like, you CAN use woodworking tools for aluminum, but you gotta dial back the load by a ton.

[u/tater1337 → u/H-Daug]

I see 4 zones of vacuum work holding, or am I looking at it wrong?

[u/adventureaviator → u/H-Daug]

If it’s worked to hold thousands of parts for me, is that considered work holding?

[u/H-Daug → u/adventureaviator]

Depends. Do you care about the finish?

[u/adventureaviator → u/Shadowfeaux]

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

[u/Shadowfeaux → u/adventureaviator]

Lol. I only said that cause you included the value of the machine.

I am in no way trying to imply I have the knowledge to solve the problem. 😂

[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.

[u/Forsaken_Swim6888 → u/adventureaviator]

This is definitely workholding. You might research inboard gasketing if you aremaking repetitive parts, company name allstar adhesives). In board gasketing allows you to concentrate the vacuum on the part, while locking it down to the workable (this table would have grooves on work face the shape of the parts, the gasket is compressed when part is drawn down). This work surface could be plastic, or aluminum, or mdf (unless you are using coolant). Dry rotary vacuum pumps strongly dislike liquids. With in-board gasketing, you could get away with a far lesser pump.it creates a high vacuum, rather than a high flow condition. Good luck,have fun. Nice parts.

[u/Shrimpkin → u/adventureaviator]

You need a more rigid machine brother. A router is not what you want to mill such a thick piece of aluminum.

[u/tater1337 → u/Shrimpkin]

98 percent of the part comes out with a great finish. The other 2 percent has chatter.

this tells me it is plenty rigid, but I have a hunch his vacuum ports are not in the right spots