Grinding a chamfer?

[pp-TG]

Any one here have a good acurate method of grinding a 45deg. chamfer on the end of a 2 flute hss end mill?

Thanks, Travis

[Kevin Taylor]

indexing fixture and a surface grinder an automotive valve grinder has a simple vblock 45 fixture to chanfer the tip of the stem this could be used on HS Good luck Kevin

[Lew Hartswick]

Are you trying to make a V bit or just a point. To get the relief angles on a V
cutter will require some rather complex angle holding fixturing on a grinder.
...lew...

[VWSatOz]

El cheapo way is to drill a hole in a block of steel to take your cutter diameter &hold this at 45 degrees in a vice under a surface grinder wheel ( with the XY tables locked). An end stop is reqd at the top outlet of the hole so screw on a thin finger half accross the hole. Feed in your cutter by hand up the sloped hole so the corners get ground off exactly all equal rotating the cutter gently by hand, slowly bring the Z feed down a few thou at a time. you can slip out the cutter to have a look at waht you have achieved so far. TAKE CARE not to get your fingers ground as well! You then have a centreless cylindrically ground cutter with a flat portion left on the end. Back off the teeth by off-hand grinding up to the witness edges you just created. I have made lots of little tapered plasric mold core pins etc this way for years! You get perfect concentricity & all come out the same size!

[pp-TG]

Thanks guys,

I have tried a few different things and the problem i am running into is because the endmill is spiral fluted even though I grind a 45 on it it does not cut to a 45 because of the spiral is there a formula to take this into consideration or is it a huge guessing game.


Thanks again for any help.

Travis,

[VWSatOz]

Try cyl centreless grind as above with cutter at 45 under a wheel, then backoff by hand, will work with ANY spiral angle, as long as you only back off up to the edge you have just created by Cyl Grind