Thread: Machining an Inside Taper

Yes, the offsetting is just to get some side relief

Attachment 198540

Michael

Hi Ray
Bobs photos are what I am talking about. Issue 168 of Model Engineers Workshop shows how to make them. If you can't get a copy I can post out it out to you.

Phil

Get an MT1 or 2 reamer, put it on the T&C grinder and re-grind the taper to what you need.

What, you don't have a T&C grinder? Perfect reason for buying another machine.....

PDW

You can grind little boring bars out of square HSS . I've managed to bore out holes as small as 10mm with this tool . Only light cuts are possible as it will flex. But with patience , anything is possible.

Mike

Originally Posted by morrisman

You can grind little boring bars out of square HSS . I've managed to bore out holes as small as 10mm with this tool . Only light cuts are possible as it will flex. But with patience , anything is possible.

Mike

Same here, Ive got a few of these, & they work well.
I use an off hand grinder to make these with an 8" dia by 1/2" grinding wheel in grade 46 (Coarse) its actually a 38A 46 K ( white Alox fairly soft bond) A J bond or H bond would even act softer & possibly cut cooler & faster.
On the other end of the grinder I have a white Alox grade 60 wheel in 8"' by 1"' for general drill & HSS toolbit sharpening.
regards
Bruce

Hi Ray,
I take it this is for timber handles, if so what about drilling a small hole down it first, then make up a tapered spade bit with the sides sharpened as well with back rake. Instead of a point like spade bits have, just make it a round pilot so it follows the drilled hole. As long as everything was held firmly I couldn't see why it wouldn't work.

If you found it to be a bit hard in the tool, you could always drill the hole with a larger drill so far down to relieve it a bit, but I don't think you would have any problems.

Dave

Hi Dave,

I made a plastic cast of the inside of the Lie Nielsen socket chisels, to be able to measure the taper more accurately and they drill a pilot hole the same diameter as the small end of the taper, not sure how they machine the rest but either step drills then reamers, or maybe a tapered drill like the one BT linked to. Or a reground morse taper drill like PDW suggested

I think the step drill will be quicker and more consistent than a boring bar. Phil, I had a look for MEW168 but last one i've got is 160

Thanks Michael G, Kev, Mike, Rob, Bryan, BT, Phil, Dave, Bruce and everyone, for all the suggestions. I've got enough good ideas to be able to try a few different things.

Welcome back Rob, I hope you had a good trip.

Regards
Ray