SO3 Machining Aluminum

[Fablicator]

I got my SO3 almost exclusively for aluminum machining.

I'm primarily using it for prototyping 0.125" thick panels from 6061/7075, which I understand should be no problem.

Always guilty of pushing my equipment to the max, I'm also going to make a lot of other complicated aluminum parts, some of which are 3/4" thick, and require tool changes. It will also be fun to see how it handles 3D machining in AL.

For now this is a placeholder for tool info from anyone who already has cut aluminum with their SO3 and dewalt 611. Once my machine arrives I'll be adding my experiences.

Specifically I'm looking for (and going to be posting) about max speeds/feeds and overall depths and expected accuracy/finish.

I've already ordered about a dozen lakeshore carbide end mills (ball, stubs, 1/8. 1/4 etc) as well as the precise bits collets for the Dewalt 611.

[heathenx]

I bought my S03 for just about the same purpose...milling/routing lots of aluminum. I've actually got a job lined up for 1/2" thick 6061 aluminum. It's a very simple job but I can't get to it until my Dewalt DW872 cut-off saw arrives (any day now). I don't want to use a hack saw and square it up in my manual mill anymore. I'm getting lazy.

[CastIrony]

Edward posted some parameters a while ago:

The aluminum was cut with the stock S3 and the stock Dewalt DW611 router. No mods.

I don't remember exactly, but I believe the settings were:
-Depth Pass: 1mm
-Feed Rate: 350mm/min
-Plung Rate: 50ipm
-Bit: 3 Flute, 1/4" End Mill - I had the router speed set to '4' on the dial.

(sorry for the mixed units)

-Edward

So that should give you a general ballpark.

[WillAdams]

FWIW, linked on the wiki: http://www.shapeoko.com/wiki/index.php/ ... Shapeoko_3

[Fablicator]

Thanks,

That video is the entire reason I bought the SO3.

I bought my S03 for just about the same purpose...milling/routing lots of aluminum. I've actually got a job lined up for 1/2" thick 6061 aluminum. It's a very simple job but I can't get to it until my Dewalt DW872 cut-off saw arrives (any day now). I don't want to use a hack saw and square it up in my manual mill anymore. I'm getting lazy.

Can't wait to see the results!

[heathenx]

My chop saw just arrived this morning. Hoping to get to it soon. As for the Shapeoko, I might cut with conservative settings on this job.

[Hans]

With the long cycle times you get from taking small bites, you'd probably see a big difference in run time, finish, and tool life using large axial and short radial engagement with HSM toolpaths. Are people still using MakerCAM or whatever basic 2.5D for aluminum? At the very least, ramp instead of plunging. You'll be able to stay much closer to the machine's limits if the software keeps it from bogging down in a corner and makes smooth paths that grbl won't need to slow down for.

[Fablicator]

With the long cycle times you get from taking small bites, you'd probably see a big difference in run time, finish, and tool life using large axial and short radial engagement with HSM toolpaths. Are people still using MakerCAM or whatever basic 2.5D for aluminum? At the very least, ramp instead of plunging. You'll be able to stay much closer to the machine's limits if the software keeps it from bogging down in a corner and makes smooth paths that grbl won't need to slow down for.

I've been using HSM Works/Fusion 360 to play as much as possible before getting mine. Helical entry and adaptive clearing are all things i'll be using.

[heathenx]

I don't use MakerCAM since I'm not very fond of it. I would say most of the time I use the free HSM Express inside of Inventor 2016 for my 2.5D work, Fusion 360 for my 3D work (although I haven't done any yet) and I just purchased V-Carve Desktop to handle my engraving and bitmap to vector work (among other things). I also have MeshCAM (but generating paths takes forever...but I like having it around).

Sooo...back to my project. It was a 99.9% success. My only mistake was that I zeroed my Z about .003" away from my top surface and then started my gcode. It rapid fed right across my stock without lifting first and I gouged the surface by about .002"-.003". I made that same mistake last week. I'm not sure what I should do to fix that problem in the future. Am I supposed to jog the Z upward before starting a job? Am I supposed to tell HSM Express to lift Z before rapid feeding to the first cut? Need advice. To fix the mistake, I ran into work this evening and faced about .005" off of the top with my manual mill. Problem fixed. Plus, it was the bottom side of the plate, so once it's mounted no one will notice.

Other than that little mistake, my SO3 cut this 1/2" thick piece of 6061 aluminum like it was butter. I ran my settings slow like I said I would. Before cutting my aluminum piece, I cut a prototype out of some scrap oak that I had around the shop. After watching it cut wood I felt very comfortable cutting aluminum. My chips looked good. Nothing smoked. Nothing got hot. It sounded good while cutting. Was my speed and feed right? I haven't the foggiest but it seemed right to me.

10in/min feed rate
1/4" carbide cutter from Carbide 3D (#201)
15,000 spindle speed on the Super PID
Depth per pass: 0.01"
No lubrication
HSM Express/Inventor 2016, Mach3 gcode export
I think it took 24 minutes to cut
I didn't chase it with my vacuum. I just let it cut until it was finished.

...and now some pics...

[Fablicator]

That looks fantastic!!!

Even if that's the max speed, I could probably live with that.

I bet you can do at least 10x that from carbide's numbers.

How is the surface finish and accuracy on the inside of the pockets? Did you do a full depth finishing pass?

I'm still not too familiar with HSM, but I would assume there is a setting to make the first move up to the clearance height.