Plunge Milling

[binzer]

Has anyone plunge milled before? I have a part I would like to try roughing out by plunge milling its alum 6061 t6 , it is 4.562 thick 7" wide and 14.250 long. I need to leave .250 walls and .500 thick on the bottom like a box. Any suggestions on what type of cutter ,speeds and feeds and is there a gibbs pluggin for this?

Thanks

[cadman]

Yes, Gibbs has a Plunge Roughing plug-in. Can't help with tooling recommendations but there are insert cutters made specifically for plunge roughing. You should be able to find something by Iscar, Kenametal, Ingersol, etc... and they'll also have starting points for speeds & feeds.

[binzer]

Well I contacted Seco on this and they recommend cavity milling with a 2" dia 3 tooth cutter. Its about a $1,000 for the whole coolant thru setup. If it works out right it will save 1 hour per part on run time. I will find out tommorrow.

[cadman]

Plunge roughing is supposed to be a fast way to rough large cavities with minimal stress on the machine. Keep us posted what on what kind of results you get.

[dertsap]

a udrill works excellent for fast removal of material in pockets , they can handle the interupted cut vey well in steel , so in aluminum there should be no stopping it , a the sfm will be quite high in aluminum with the proper insert

[binzer]

Ok the update we used the cavity mill seco R220.97-02.00 with coolant thru. We ran it at 5000 rpm at 108 ipm .200 deep by 1.4 step over passes. The old way we used 3 diffrent roughing endmills. So we got rid of those 3 plus 2 drills and the face mill to cut the top. The only problem was when the cutter got about 3" into the part the chips would not escape and would get caught between the part and the cutter, that was some bangin noise. So we hooked up a air line to the coolant line to blast the chips out worked great so that problem solved. The final time the old way was 2:31:20 the new time minus the cutters and drills with the new mill, 1:25.49.

[cadman]

Knocking off almost an hour of roughing with one tool, impressive.

[binzer]

Actually after fine tuning today its down to 56:28 everything is running good no wear on inserts yet after 8 parts. Lots of chips thou.