Cutting a blind keyway

[RobWilson]

(09-11-2015, 07:04 AM)Pete O Wrote: Thanks Rob, that is perfectly clear. I thought I was being clever by plunging a hole at either end but obviously not.
So when I get another go at it, I will (1) rough it out with a smaller end mill and (2) cut in one direction, withdrawing the tool each time for the return and (3) plunge at the start of the cut just to the depth for that pass.
I'll have to figure out how to set up end stops on my machine, makes sense rather than relying on the dials.
Any suggestion what would be an appropriate size endmill to rough out with for a 1/4" finished size?

Hi Pete 

yeah you got it , I would go 3/16 , 5mm   to rough your slot out , I have some very short flute TC slot mills that  due to being short and rigid cut bang on 1//4 with no ruffing out .  

Long slots for sliding things I go for a woodruff cutter if I can ,like so . 



bags of coolant , lashings of the stuff 



and the result with a good sharp cutter .




So they are worth keeping an eye out for , or make your own (different tread) 








Rob