Boring Bar Setup That I Can Use In My Mt#3 And My R8 Mills

[BGHansen]

Pretty sure there's a tubalcain video on the broaching technique on the lathe.

Bruce

 

[CraigB1960]

Pretty sure there's a tubalcain video on the broaching technique on the lathe.

Bruce

There is. Using a lathe for broaching is very similar to broaching with an E-Head shaper mounted to a bridgeport. Just takes a lot longer and it is all manual. It works fine if you broach infrequently, but it takes a lot of time and effort.

If you are going to broach a lot, there is no substitute to buying a broach set and using an arbor or hydraulic press. Or a shaper!

 

[Steve-626]

MT3 taper works in friction mode, whereas an R8 taper needs a drawbar. Because of this, I've never seen a MT3 to R8 adapter and most likely will never...just R8 to MT3

The MT3 tapers that are in the mill drills have a threaded end for a drawbar

3/8" -16

 

[CraigB1960]

The MT3 tapers that are in the mill drills have a threaded end for a drawbar

3/8" -16

That is a specialized application and not part of the morse taper standard. Whereas the R8's standard has the drawbar as it's standard.

My point was Morse Taper is designed as a friction lock, with or without a tang...the R8 taper requires a drawbar. The R8 could not physically fit inside a MT3 taper, so it would be very long and does require a drawbar, so changing tools would be tedious.

There's a reason we don't see a MT3 to R8 holder.

 

[Wreck™Wreck]

There is. Using a lathe for broaching is very similar to broaching with an E-Head shaper mounted to a bridgeport. Just takes a lot longer and it is all manual. It works fine if you broach infrequently, but it takes a lot of time and effort.

If you are going to broach a lot, there is no substitute to buying a broach set and using an arbor or hydraulic press. Or a shaper!

You can't push or pull a broach through a blind hole.

 

[CraigB1960]

You can't push or pull a broach through a blind hole.

The key phase I used was "broach a lot"!

If I was going to do a lot (of blind hole keyway cutting) I would use sinker EDM or a product from this company: http://www.keyseaters.com/index.html

I have had faster results using an end mill to cut the keyway slot and than final shaping with a file than using a lathe with a sharp bit to cut a keyway.

 

[Wreck™Wreck]

I have had to resort to the lathe once or twice in the past and it is a tedious process at best, a sinker EDM is not a hobbyist friendly process however.

 

[CraigB1960]

I have had to resort to the lathe once or twice in the past and it is a tedious process at best, a sinker EDM is not a hobbyist friendly process however.

LOL, never said it was...but as a hobbyist and I had "a lot" of blind keyways to do...I would outsource it to a shop that did. There are folks here that might benefit with that knowledge...only reason I threw it out.

Several of my hobby projects grew into products that I market. I certainly don't machine those parts anymore...I've outsourced it due to volume.