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.
--
EA



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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 : http://www.icscuttingtools.com/catalog/page_281.pdf jsw
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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!
--
EA



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rect

this

given

80"

limited, so

staggered

mill.

practical and

it.

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.
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On 6/20/2013 11:02, Existential Angst wrote:

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

--
Steve Walker
snipped-for-privacy@frontierbrain.com (remove brain when replying)
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On Thu, 20 Jun 2013 11:02:37 -0400, "Existential Angst"

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.
--

-JN-

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On Friday, 21 June 2013 17:14:47 UTC+1, J. Nielsen wrote:

One thing about staggered teeth, it halves the feedrate.
DanP
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