Question on engraving aluminium

My Taylor Hobson Model A engraver has two speeds, 5500 and 11000 rpm. The manual recommends the higher speed for aluminium, though I have had good results using the lower speed and feeding slowly. I think you would need to feed very slowly indeed if your machine can only reach 1600 rpm.

Mike

Thanks Mike

It is a Chester champion mill with CNC fitted and yes slow spindle speed, could you let me know what type of cutter you would use, would a 20 degree cutter or slightly wider say 45 degree cutter be OK?

Adrian

See:

Not made this unit, but it sounds as if it should be an ideal long-term solution for you.

David

Thanks David, but unfortunately just after short term fix.

Cheers

Adrian

Bodge time!

If you have a dremeloid and a little ingenuity, you can mount it next to the millhead - after all, it doesn't have to be inline with the spindle, just parallel to it - and for engraving, even roughly parallel is enough.

One tip, the up position should be a little higher than normal as a dremeloid will typically have a bit of lengthwise slop.

-- Peter Fairbrother

Adrian

I don't claim to be an expert on engraving, but for soft materials like alumium I usually use cutters with an included angle of 30 or 40 degrees, truncated according to the required width of the lettering. For the small stuff I do, handwheel dials and the like, I usually engrave 6-8 thou deep.

HTH

Mike

I get great results milling 5mm high text in 6082 with a carbide 1.2mm ball nose, 3500rpm, 60mm per min, 0.2mm per pass. Usually 2 passes gives me a good engraving that polishes up very well. I use paraffin as coolant/lubricant gently brushing it on whilst clearing any chips.

I found these settings quite quickly but still break cutters if the work isn't exactly level.

I tried a 45 deg V bit but I get the impression that these work best at very high rpm's, the finish isn't a patch on the ball nose's at 3500rpm.

Thanks to you both for the replies, it will give me some thing to try out.

Adrian