Grinding gash on long endmills

[J&RMachine]

I was just wondering how most shops grind the gash on long endmills such as 2" diameter x 12" long 6 flute. A cincinnatti # 2 spindle will not go up high enough to do this.

Jim

[cb1]

we do it by hand grinding.
lots of fun

[J&RMachine]

Thanks for the reply.

I talked to a guy that grinds tooling for a living and he also said that he grinds these by hand. He actually said that he grinds most gashes by hand even on the shorter endmills. For me doing it by hand just doesn't come out as nice as using a machine.

I have a little shop here at home that I actually started to regrind the endmills that we use where I work. I just ground these in the evenings and on weekends.

I had an old covel cutter grinder with worn out spindle bearings that I paid $35.00 for. So I mounted a small index head off to the side of the table. Then I mounted a surface grinder spindle to the top of the wheel head which allowed me to grind the gash on a very long endmill. Now I actually do more machining than grinding in my home shop and a few years ago, I bought a cnc mill. To make room for it, the old covel had to go and now I kind of miss it. I still have two cincinnati #2s but they just won't grind the gash on those long endmills like the old covel would.

[Cyclotronguy]

I'm not the best at offhand grinding; so I let the endmill overhang the back of the table.

Cyclotronguy

[pvromano]

It sounds like your grinding with the cutter verticaly,try reversing a dish wheel on your spindle and seting it up horizontaly on in the index head. Then grind straight into the end face to the center.

[Cyclotronguy]

Just got a 6 jaw chuck for the 50 NMTB workhead... no longer limited by the small dia capacity of 5C or ER-40 collets for such things. Have done as you suggested.... thanks!

Cyclotronguy