[GTFreeFlyer]

I thought this could be a good place to post feeds and speeds that work well with the Momus machine.

I don't have any data of my own yet as I just got the machine running, but I will post when I have some data. For now, I need some data to save me from mistakes

Material
Tool type, size, material and #flutes.
Spindle RPM
Cutting depth
Feed rate
Climb or conventional cut
Anything else?

[GTFreeFlyer]

Alright, first data

Material - 6061 Alum
Tool - Endmill, Carbide TiCN, .25 dia, 2 flute, upcut
Spindle RPM - 8600
Cutting depth - .75 (side cutting with .010 material removal each pass)
Feed rate - 4, 6 and 8 ipm.
Climb cut
Notes: 4 and 6 ipm worked nice, ejecting thin and wispy "hair-like" chips with a nice shiny surface finish, although I've seen better. At 8 ipm, tool edges grabbed the aluminum and took the carriage along for a ride. I think I almost broke my E-stop button. I hope that thing will stand up to the abuse of my learning curve over the next few months

[SpeedyDad]

Carbon Fiber

I've achieved good results running the following:
12ipm
.040 cut depth
Diamond (or diamond-like) coated bits
High RPM

[BobWarfield]

4 and 6 IPM is really too slow a feed. The cutter will probably rub and that'll produce a decent finish, but a shorter tool life. I wouldn't try to go much slower than 8 IPM. To understand this "rubbing" phenomenon, the diagrams here may be helpful:

CNC Milling Chiploads, Surface Speed, and Other Concepts

Incidentally, also on that page is a brief discussion of radial chip thinning, which causes very light cuts (0.010" width of cut) to make it worse if you don't speed up the feedrate.

A more ideal feedrate for aluminum with that cutter, depth of cut, and width of cut is actually 38 IPM. Not clear if that router is up to that, but that's what the cutter numbers call for.

The grabbing at higher feedrates could be from several sources. If you're climb milling, that wants to pull the cutter along. A good CNC can resist that can use climb milling to advantage, but you could try conventional milling and see if you get better results. That's all described in the feeds and speeds tutorial the first link is a part of.

Last thing, the grabbing may also be the onset of what's called "Built Up Edge". Aluminum likes to weld itself to the cutter if you give it half a chance. If you plan to cut much aluminum, check out this article from my blog:

10 Tips for CNC Router Aluminum Cutting Success « CNCCookbook CNC Blog CNCCookbook CNC Blog

Cheers,

BW

[ger21]

My machine is much bigger than a momus, but probably less rigid.
I cut some 3/4" thick 6061 the other day.
Using this Onsrud bit,
10,000 rpm
60ipm
.015 depth per pass ( due to lack of rigidity)
climb cut
dry
Spindle is a PC 690 with Super-PID

[GTFreeFlyer]

Looking for Momus machine suggested feeds and speeds for engraving.

I did some engraving today in wood and plastic and realized I had no idea what I was doing. I just ran it at full RPM, 100 IPM, and .030 cutting depth with a 30 degree v-bit.

It worked, but I don't know if this was bad for the bit or not. I guess not broken bits means that was good.

Aluminum will be next. Suggestions?