[Cold Fusion]

High helix 2 flute 1/4 carbide end mill. The Z axis was fixed long ago. I've made a good amount of runs in MDF but am out of Lexan right now. I have crashed a couple runs so far but nothing was broken. These were in a fairly deep aluminum cut. The limit of my machine (or maybe my bits?) seems to be about .8 inches deep in a single cut profile in 6061 aluminum. Maybe later on today I'll get some pictures of it.

[gmfoster]

It this forum hosed or is it just me and my system. This is the only new message that I find.

Garry

[metlmunchr]

Cold, are you talking about a 1/4" EM in a slotting type cut at .800 DOC? Or just a light cleanup pass around the edges? Generally about one diameter deep is all you can safely run in a slotting cut per pass, unless there's lots of well aimed coolant to keep the chips blasted out.

[Beezer]

Depending on what edge finish you require on the aluminum wouldn't a solid carbide roughing mill be more suited for cutting aluminum with these machines? I am just curious since they really do allow for a deeper cut and a high feed rate not to mention the chips are much smaller. Anyone tried roughing mills on their system yet?

Carl


Oh I almost forgot to ask.

Cold Fusion what are you using as a speed control for reducing the routers rpm?
I need to get one myself and just wondering what you used.

[Cold Fusion]

This was a series of .08 inch deep passes.

Maybe so but I've never tried it. The Porter Cable router I'm using has a built in electronic speed control system that ranges from 10k to 27k.

[Cold Fusion]

Here are some pictures I took yesterday. For some reason the surface finish looks terrible but it turned out great

[IJ.]

Try a spray of CRC or some light lubricant while it's cutting CF, Just looks like a bit of adhesion/buildup is all!

[Cold Fusion]

Now I remember what happened! The first picture was without an type of lube and with a high chip load. I got smart on the second one and backed it down and gave it a shot of wd40.

On the first picture you can actually count the chips being flung out of the bit. Amazing!

[IJ.]

This is half the battle CF learning a new machine always takes time .
Buscht's post is chock full of good info!
(I've managed a few crashes so guess I'm now a real CNC operator )

[Dan S]

does anyone know if these formulas and table are any good?

http://www.endmill.com/pages/training/spdfeed.htm

[High Seas]

What a Great Find! There's a goldmine of info there - sure hope its good speed/feed data! Thanks Dan. Cheers - Jim

[Cold Fusion]

Finished a real part today! It's an upper swing arm for my rc truck project. Tolerence is good at about .005.

It seems like my carbide end mills have gone through one crash too many though. I'll have to order some more if I want to keep making chips.

[IJ.]

CF: Great stuff !!

I'm sitting here eating lunch while the CNC happily cuts a run of parts !!

Isn't the first "real part" a buzz??

[Cold Fusion]

Yeah, feels good to finally have the machine start paying for itself.

Since I have about 20 different cycles of parts to run that's alot of nervous watching and waiting. Those first runs never go right, even if I do a air run.

The next parts will be the more complicated lower swing arms. I would cut them now but the neighnors need some sleep, unlike me.

[Cold Fusion]

While machining the lower arms the electrical transformer for the neighborhood got struck by lighting. Of course I lost power to everything in the middle of the cycle. Oh well, more paperweights.

I finally did get a good cycle done with no freak accidents. Here are the results.

[IJ.]

CF: Brilliant !!

Funny last night must have been the night for power failures!
We had one here that took out the grid right next to mine! (I was in the middle of a run of small parts and saw the lights all go out)

Have you thought about getting a radiused cutter and taking a finishing cut around the out line of your arms?

[Cold Fusion]

I've considered it. This part is for the prototype truck though so looks are not too important. Maybe a 45 degree .1" chamfer would work on the production arms?

Going out to machine some bearing mounts now. Be done in an hour.

[IJ.]

I was thinking just a plain 2mm radius on all of the edges to give them a "finished" look 45 degree chamfers still look a bit "Proto".
Either that or use a small ball end mill to turn your arms into H beams!

I'm inside for most of today so I'll keep an eye on your progress!
Keep the pics coming.

[Cold Fusion]

I could use a 1/4 ball mill and skim the edges at .01.

The chamfer look is used on many big name arms and looks great. I'll pull up a sample in just a minute.

[Beezer]

CF,
What settings have you found work best for you so far when cutting the aluminum? (ie. spindle speed and i.p.m. travel)

Carl