Assuming your lathe has an mt2 spindle taper, the usual approach is to put the mt2 blank in that with a drawbar to hold it in. Another way is to buy an mt2 female to parallel adapter (rdg have these I think?), hold the blank in that again with a drawbar, and hold the adapter in the 4 jaw to get it dead on centre. This is assuming that the blank has a threaded hole in the small end for a drawbar? If not, and it has a tang, then it isn't really suitable for a boring head which will need to be positively held in the spindle of whatever machine you are using it in.

I have done this several times now. using the taper in teh lathe mandrel gives the best possible result.

If your lathe is like mine with an MT3 taper, invest in an MT3-2 adaptor. Use a drawbar (even if it is improvised from studding) as otherwise it WILL slip while you are threading it (don't ask how I know this).

Neil

Gareth,

I've just bought a 3 – 2 morse taper for my lathe to machine a similar item its open ended so that I can use a draw bar to hold it, I bought it from Arceuro and found it to be very cheap but of high quality.

Martin P

> Why is using studding for a drawbar "improvising"?

Because a proper drawbar should be made from a blank finished on a centreless grinder, turned between centres, have milled threads, and polished to perfection, before being matched to its hand-scraped nut and washer.

Seriously? Because I have found that cheap studding doesn't like being done up (reasonably tight) and loosened again and the threads go bad and strip. The stainless stuff is OK.

Neil

I remember a drawbar design in mew a few years ago recommending high tensile steel! If you tightened that up to anywhere near the steel yield strength you'd never get the taper out again! I've never had a problem with studding stripping used for draw bars or tee bolts, though I tend to get the stainless stuff now as it's better finished.o

I used the stainless stuff for my grinder leadscrews and its been fine.The cheaper stuff I have used for bearing pullers and random clamps and, like bonsai trees, it doesn't flourish under my care.

neil

My understanding is that the grip is from the fit of the morse taper parts and the drawbar is only there to pull the tapers together and as an insurance against shock loads. As such the draw bar should not be over tightened? The draw bars I have are either home made ( MS) or from studding. They seem OK but am I running a risk here?

Neil I'm still curious about your avatar – what the heck is it? Please put me out of my misery!

Norman

Apart from one draw bar that came with the 2" face mill, my other ones have been made by cutting the heads off two old bolts, and welding them together. Ian S C