Face Milling techniques & workholding advice needed.

[Moondog]

I have received my Mill (BP Clone) and getting myself acquainted with it...

I want to surface some Alum Plate 450*220*20mm and I am unsure of the best way to do it...Things such as the best holdown method, feed, RPM etc.

I have a 63mm facing head with 4 carbide inserts, T slot holddowns etc.

I tried facing a smaller piece of Alum however it left a very small ridge between the cuts.

I have searched everywhere to see if I could find some articles/tips on this method....

Also, once milled how do you remove the milling marks?... or do I need to..

thanks in advance.

[nervis1]

Have you trammed the head? Reason I ask is I had the same problem with a ridge between cuts a while back. One reason you'll get that is if the face mill is tilted relative to the table. Level from the table, then tram the head to the table.

Fixturing could be done with some toe clamps, or just use t nuts and clamps and move em around in pairs to get the whole plate.

Milling marks from a facing cutter are high art. Don't remove them ...ever.

[Moondog]

Thanks nervis1....

Art work...I'll remember that and look at the swirls in a different light.....

Toe clamps?... what are they...

Trammed the Head'.. is that using a dial indicator?... I know I can adjust the head in one plane becasue of the head rotation but fore and aft adjustment I don't know....

Also..if I start in normal cutting direction should I reverse the feed over the same area of should I proceed to take the next cut (opposite dir) climb feeding?....

sounds like I need a tutorial on this......

[RotarySMP]

http://www.jjjtrain.com/vms/mill_movments_vert_hd.html

[nervis1]

Thanks to Rotary, nice tutorial.

Now that you are square to the table look at a couple big supply catalogs under the work holding catagory. You'll see clamps like mitee bite et. al.

They are designed to stay under the top of the work as they hold so you can work on the whole surface without collision.

[Moondog]

Thanks Rotary...

There are some great articles on that site. Have already benefited from reading it....

Nervis1... I'll have a look for different clamping systems as you recommended.
So much to learn....

[Swede]

Remember that if you are face milling a typical aluminum extrusion to true the surface (extrusions are often +/- 0.010" or worse), the act of clamping the work DOWN can warp the sheet.

For example, let's say you have a 3/8" X 6" X 10" piece you want to face mill. You clamp it heavily to the table, bowing the surface you present to the face mill. The cut itself produces a temporarily true plane, but as soon as it's unclamped, it'll warp back to an untrue state. This action is much more obvious the thinner the piece. Working around this tendency takes persistence, patience, and some imaginative workholding, such as clamping the work on long, thin parallels, applying the clamping pressure through the work and the parallels only, and taking light cuts. Once one side is truly planar, then it can be flipped and heavily clamped.

If you want a truly flat chunk of aluminum plate, go for mic6 jig and fixture plate - great stuff.

As for the face-mill marks - yup, a properly trammed, sharp, quality face mill, will produce art.

[Moondog]

Thanks Swede.

Lots of new things to learn... that's half the fun of it..

Thanks for that advice... didn't think of useing parrallels.

I like the Art work on my pieces... bit like an Artists signature....

I wish facing was as easy as doing timber... over the planer and then thru the thicknesser.... wonder if I could do that with Alum?.....

I must check out that Mic6 plate... I know its not available here, will have to check interstate. Hopefully the Mill will do that for me..

cheers