Hogging steel question

Finishing pass, no more than .005 on the side, climb milling. Conventional milling tends to pack chips onto the surface.
 
If the machine will allow it always climb. On a manual machine this is often not practical so do what works best.
 
I never used a end mill that large on my PM25. She just won't take it, i.e., not rigid enough. I never used anything larger than a 3/8" end mill in my machine, and if I had to do what you are doing, I'd use a rougher to reduce the loading on the mill for the initial passes. Then a four-flute for the finish passes.

The PM25 is a great machine. If you don't try to overpower it. :)

EDIT: Using a 3/8" rougher, I'd take half-width passes with it. But that's just me, as I don't like to push my machines too hard and wear them out prematurely. :)
 
You should have a VERY ridged machine/set-up when using a Carbide end mill. Or you will just be asking for trouble. And probably destroy the Carbide cutting edges. I would not buy Carbide end mills. Instead, if you want something other than regular HSS, I would take a look at Cobalt. I have a 8 flute 1/2” Cobalt that I grab first and is still good and sharp after several years!!! As for roughing, maybe try one of the corn cob end mill cutters. And don’t try any climb milling unless it’s a VERY light cut and everything is tight. Or it could be unsafe with your type of milling machine…Good Luck & be SAFE...Dave.
 
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12bolts said:
I would just use a slitting saw and keep the resulting waste for another purpose apart from swarf

Cheers Phil
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Have you (well, does anyone) have any specific recommendation for a slitting blade ( and arbor)? How many tpi? What material? Thickness? Vendor? Sensible price? That is good for steel?

Thanks.

-Bill
 
Bill Kahn said:
Have you (well, does anyone) have any specific recommendation for a slitting blade ( and arbor)? How many tpi? What material? Thickness? Vendor? Sensible price? That is good for steel?

Thanks.

-Bill
Click to expand...
There are lots of different slitting saws and arbors. Pick one that will do the job at hand and perhaps also serve for other jobs in your shop. There are too many variations in machines, projects, and preferences to give a good answer to your question beyond "there are plenty of useful tools out there to do what you want to do." With slitting saws, do your homework and learn about speeds and feeds with the purpose of achieving a reasonable chip load per tooth, which is important.
 
I've found that my PM25 has problems going slow enough to run a 2 1/2" slitting saw. there's not enough torque to carry it through the cut, I have to hand feed it about .001 per rev. if that much. Otherwise it catches and stalls. That's at whatever its slowest speed is. Any faster is too many surface feet per minute.
 
12bolts said:
I would just use a slitting saw and keep the resulting waste for another purpose apart from swarf

Cheers Phil
Click to expand...
OP here. Thank you. It is a bit of a pain given my HF 4x6, but some jury rig part holding and got the bulk of the notch cut out horizontally and finished up vertically by hand. In terms of speed, this is the way to go.

But, in terms of easy, figured out a better way. Using this https://www.ebay.com/itm/5-8-Solid-...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649 end mill, with .5" in and .15" down at 2000rpm and the slowest x-feed my PM25 could go (about .003"/sec (.2"/min)) just let her run. Way slow. But I can putter around the shop while it makes the dust-like sharf. Seems to work both directions (at that speed I guess makes sense)). And, yes, I tried a full .5" depth and even at that slow speed, would not work.

Oh, and thanks to an earlier poster on needing to retram. Yup. Stalling the machine and cracking a 3/4" carbide end mill. (Yes, I wear eye protection if any machine is running (or I am exerting force)) got my attention. And when I went to check, the tram was .01" out over 18". Now is back to .001" over 18".

Thanks for all the advice.

-Bill
 
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