Aluminum 3D?

[applik]

Can it be done? Had a guy ask if we could do a relief design maybe 1/8" deep into some 3/8 aluminum. I did a search but it seems most all the threads are about cutting shapes. I'm just curious if anyone has done this or will it work?
thanks,
Shari

[scott_smith]

You’ll need to take it slow and shallow. Attached are some small V-Carved (not 3D) aluminum parts I’ve cut. Just used a carbide 90* bit. The machine marks will be harder to remove than wood. I remember the artwork you had at the Phoenix camp a few years back so I know if you do it it’ll look awesome!

Scott

4783

[paco]

Brady Watson did a water pump impeller once. It sure can be done! I'll see if I can remember the thread.

I would look for the shortest ball end cutter I could find. Typical ball end carving tools are 1/2" CEL or more. Those may break easily or flex in such hard material as aluminum. I remember seeing a 1 O-flute ball end tool bit from Onsrud... for aluminum. I would do a search toward the metal cutting tools also.

A raster rough would surely be worth unless it's very shallow and/or small.

[jamesgilliam]

Shari, Although I have not tried to cut aluminum on the shopbot myself, I did in my machine shop days cut it quite often. For bits I would suggest ball end mills from a local machine shop tool supplier. Rutland Tools is a good source. After breaking a couple expensive bits when I first got the bot, I switched over to end mills for all of my cutting. Have not had one break on me in over 6 years, and they cost less. You do have to contend with limited geometry offered, but me not being a production shop I can live with the lower feed rates.

[applik]

If it can be done, I'll give it a try. Any ideas on stepover for 1/8" deep? I found some cutting speeds of .8 to 1.2 with a z of .1 to .2. I think I have an 1/8" tbn end mill
with a cut length of 1/2 and a 1/4" shank. So I could try that maybe. But I'll have to order a flexible air thing. Will let you know how it comes out. I tried a link in one of Brady's posts about the pump but it said under construction. Maybe he'll see this and pop in with some additional 3D words of wisdom.
Scott - that was back when I was using that darn CW machine. Now I'm a true botter! I love being able to put a rough sawn 150 lb alligator slab on the table and carve away. And it makes the shop smell good too. ;)
thanks guys for your input,
Shari

[knight_toolworks]

myself I would not trying it with cut3d. it does not give you a depth of cut choice. so if the deepest 3d cut is 1/4" it will try that in one pass. that may be way too much in aluminum.

[gabepari]

In Cut3d you can assign a "pass" depth for each tool. Wouldn't this limit the maximum depth of cut?

Gabe

[knight_toolworks]

no that only works for cutouts and roughing from what I have found. the finish pass is full depth no matter what.

[applik]

I'm using Artcam Pro so I can pick all the various settings I'd need. If we're only talking a 1/8" depth, would 8% stepover do it?
later,
Shari

[jamesgilliam]

Shari, If you are running a spindle, and assuming you are using the 1/8" bit you described earlier, 8% stepover is about 0.010". If the finish needs to be fairly smooth you may want to drop the stepover to about 5%.

[applik]

James,
I only have a Mwk router but I'll try the 5% on the little sample of aly he gave us and see how that goes. Still waiting on the air nozzle to arrive. I have a feeling this is going to be cost prohibitive to the customer for the actual size of relief he wants. Not to mention I don't want to be carving on aly for 3 days running.
thanks again,
Shari

[eaglesplsh]

I cut aluminum and brass a lot, so I thought I'd chime in with another important detail that you should consider...

You have to pick the right aluminum alloy for CNC machining or you'll never have a chance of getting a good part. Just like cutting oak is different from cutting pine, some aluminum is soft and stretchy while some is harder and more brittle. Most wood router speeds are too high to machine a lot of the softer alloys - the heat will melt the chips to the end of your bit and in the groove of your cut.

I'd recommend trying 6061 or 6063 - there both commonly available and relatively cheap. They give me clean cuts with crisp corners - which are usually too sharp to handle, so you may have to buff/polish them down.

Hope that helps.
Russ

[twhaley]

here is a logo i cut out of 1/8 inch alum. i cut it with a 1/8 endmill. the piece is 12 inches long and 4 inches tall. i cut 1/16 of an inch deep. the cut speed was set to .5 and i steped down three times. it took about 4 hours to cut. i have a makita router on a shopbot buddy. here is a pic of the finished logo.
4784

[mikek]

Shari, a friend of mine with a PRT Alpha cuts 1/4" aluminum in one pass at .6 to .7 IPS. They use CRC 03410 TrueTapTM Foamy Foaming Cutting Fluid sprayed on the surface being cut. The cool tool didn't work well for them. Without TrueTap they break bits. A bit (1/4" O flute) will last about a day and a half cutting 8 hours a day. Should work with a 1/8" or 1/4" ball end mill with very small stepover for good detail. your ideas on feed and z step sound good.