Aluminum engraving

[stsparkia]

Hey guys,
I am having trouble finding speeds and feeds to engrave in 6061 Aluminum. Every time I engrave into it, it comes out very rough. My current feed rate is .75 ips and I am running the spindle at 10,000 rpm with .07 in passes. I need to get this engraving as crisp as possible with an 1/8 inch bit. The one I am currently using is a 4 flute SS Spector DE End Mill. Thank you for your help on this guys. It is greatly appreciated!!

[Brady Watson]

A single spiral-O bit would give you better results than a 4-flute. The geometry of the 4-flute is geared more to milling than engraving & 4-flutes generate a lot more heat & smear, than a single flute tool. The downside of a straight or spiral-O is that you may see some tool marks at the bottom of the kerf, but you should definitely get a better top edge.

I would run a spiral-O at .7 to 1.2 IPS on the XY @ 12,000-15,000 RPM. The use of denatured or 90% rubbing alcohol will help cool the bit and give you a better finish. Lube is not required.

-B

[MogulTx]

I have done a lot of cutting in aluminum. I do thin materials and I have also milled off the ends off some blocks that were incorrrectly milled by a vendor for my business. I would recommend that you consider doing a starting pass (or two) and then a very fine finishing pass, at a faster rate and higher rpm. You could use .025-030 depth (x 2 passes).

You will have to play with it a bit to see what works, but I would probably use .010- .015 as my last pass and 13K RPM, and maybe 1.3IPS... at least give this a try on some scrap and see what you come up with. Taking "less of a bite" with each pass should smooth up your cuts.

And I have used a lot of things for lube. For ease of clean up, I would put some WD-40 on it. You can clean it off with almost any solvent.

Good luck on it.

Let me know if my suggestions help any!