Custom T-slot cutter

I'm slotting, and then enlarging the ID of a 1/2 x 1" x 1/8 wall alum rect tube with a 1/4" T-slot cutter (about .235 x .563). The nominal ID of this tube is .25 x .75, and I am enlarging it to about .320 x .760. Any given roughing or finish "cycle" will require 4 passes -- which add up on 80" tubing. This is being done on a gantry mill, flood coolant pressure is limited, so chip removal is a bit of an issue.

Would it be prohibitive to have a .320 x .760 custom cutter made? 1/4 T-slot cutters are anywhere from $30 to $100, in HSS or cobalt, staggered tooth. Haven't seen carbide. Will a custom cutter cut as well as a stock cutter? Will limited chip clearance nix this strategy from the gitgo? Any sources for getting one made?

I won't be doing this forever. When I work out the bugs of the basic design, I will bite the bullet and have this form extruded from a mill. But I will proly be doing this for a while, so if it's at all practical and can make my life less effingly miserable in the meantime, I'd go for it.

Reply to
Existential Angst
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You could have a two flute endmill ground to size. This would give you more chip clearance. If you use a .760 dia. cutter to cut the slot in one pass you might find the slot being cut to be unacceptable. The cutter will be climb cutting on one side and conventional cutting on the other side. This will cause the cutter to deflect. You may find that one side of the slot, the conventional cut side, will have gouges in it. If I was doing this slot I would use a two flute cutter ground to .740 and make two passes. What is the width of the slot that determines the small dia. of the T slot cutter shank? If this dia. is quite small you will get even more cutter deflection. Modifying an endmill to do this job shouldn't be that expensive. I would expect to pay probably 70 bucks for the mod. Eric

Reply to
etpm

Can highly recommend AB Tools:

I've had a custom corner radius and dovetail cutter made by them in solid carbide, the quality and performance was stellar. I'd venture to say, their carbide tipped cutter, made to your specs, will outperform an off the shelf cutter from say, MSC, and if I'm reading your application correctly, do it in one pass?

Jon

Reply to
janders

Except when in the tube, this cutter will have to cut bottom AND top. Can they do that?

This would give you

I hear dat, except the nominal width is .750, being opened up to .760, a very lite cut. The TOP of the cutter will be taking off .045, the bottom will be taking off .025.

What is the width of the slot that

A full 1/2", plenty rigid for this, I would imagine.

Modifying an

If they can make it so that the top will cut, a 2-fl endmill would be nice. Chips are recutting as it is.

Reply to
Existential Angst

Broach?

Reply to
Pete C.

Carbide would be nice, would certainly help the one-pass ambition. Hopefully it won't break the bank. I'll try to call them today.

Reply to
Existential Angst

80" long??
Reply to
Existential Angst

[commercial interrupt]

How do you think they make one of your favorite mechanical devices -- the ring gears for planetary gearsets?

Actually, most of them are made with gear shapers (a generating machine, not a conventional form-cutting shaper). But I've seen straight pull broaches and helical broaches for cutting those gears, and they're typically 12 feet long or so.

We now return you to our regularly scheduled program....

Reply to
Ed Huntress

Ed, Stop this right now! You'll be single-handedly responsible for giving fuknKidding a hyper-chubby.... "Single-handedly" in the manly/metaphoric way, of course, not the literal prison-way.....

Reply to
Existential Angst

You could ask a tool grinder to quote reducing a larger cutter to your spec, such as this TSC 024 which is 0.328 x 0.781 :

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jsw

Reply to
Jim Wilkins

DOOD!!!

I could proly use that, AS IS!! I'd prefer .760, but I can lose .010 on each side, for now. The .328 is fine, proly wouldn't cost much to trim the diam a hair, if need be. Eventually, I'd like to go carbide, if the extrusion stuff gets delayed, but it sure is good to have options.

But I can try this, just to see if one-pass cutting is viable. And $63 is not out of line at all. You know, I wasn't paying attention to decimal-equivalent dimensions.... Had I realized this, I"da bought one of these a while ago! I figgered I was lucky to have the 1/4" cutter work at all. Good lookin out!

Reply to
Existential Angst

One would hope it wouldn't take anywhere near that long a broach to remove the amount of material you're talking about.

Reply to
Pete C.

practical and

A good tool grind shop can easily make a 2 flute tool like that out of an expended 1in endmill.

Oftentimes it's more cost-effective to buy solid material than it is to buy hollow extrusion, something to consider since you are having to mill it anyways.

Reply to
PrecisionmachinisT

Loc-line T fitting, runner hose, feed it into the end of the tube to flush the chips out.

Reply to
Steve Walker

Of course it depends on how many parts you'll have to cut, but I would go for a custom made solid HM cutter. As long as you're not doing full size slotting cuts you can have a larger number of teeth for faster feed. No need for any fancy staggered or helical teeth profile. And since you'll plunge in sideways you just need a few degrees of backward taper on top & bottom to keep the cutter from smearing.

Reply to
J. Nielsen

Ayup. And put it in the Far End...so you flush out the chips already cut...not push them forward and keep cutting them over and over again.

Reply to
Gunner Asch

These guys can make a custom cutter for you. Great service Every time.

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Reply to
Cross-Slide

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