APT Boring Heads

[Peter N]

Peter

Don't know about APT but might have a Lushington no 2 spare in the next week if you're interested.

Charles

Thank you Charles, definitely interested. I'll drop you a mail later on, and I've still got to pop over some time to get those change gears.

Peter

[ralphe]

I have been using an APT head with an R8 shaft for a few years. It has worked nicely for me.

[kap pullen]

Detent backlash??

I don't know what you are getting at?

Quote
"I have a horrible cheap import boring head that has the detent groove in the micrometer adjuster so badly machined there is around 0.015" backlash in it."

All boring heads and slides have some backlash.

You have to keep the backlash in the same direction to get accurate readings on most mechanisns without ball screws, or hardened, ground, and lapped threads.

Set the gib to give slight "drag" on the screw so the slide dosen't move from vibration and cylindrical forces.

When using a boring head, I will save .015" for finish cuts, and take 1/3 of that, in three cuts, checking between each cut to achieve accurate size.

Setting an indicator to monitor movement will help. Set the indicator at "O"
at the high point, or low point, of the slide as it is rotated by, by hand.

Tool "spring" is a big problem in fiddly little boring bars, and big ones.

Kap

[viking]

I have a APT boring head with integral R8 shank and it is a nice piece except as others have noted the graduations on the dial are really small and closely spaced. I guess I should follow the advice of others and keep a magnifing glass handy.

[outback]

APT boring heads

I have two APT boring heads. One holds 3/8 shank boring bars and the other holds 5/8 boring bars. I did some work on the dovetail gib of the 3/8 boring head. Don't remember now what I did but it works great now. The 5/8 head worked well right out of the box. Both heads have R-8 shanks.

I also have a 3" boring head purchased from ENCO. Holds 3/4 shank boring bars and the head has an R-8 shank. It is made in Taiwan and is darn good head for around $80.
Jim