"Matty F" wrote in message
oups.com...
The3rd Earl Of Derby wrote:
Matty F wrote:
The3rd Earl Of Derby wrote:

Two pieces of wood to clamp it in the vice.

If I use the bandsaw and the wood comes loose, the bandsaw blade might
jam and break, at some considerable cost and inconvenience and danger.

Then don't use the band saw,use a conventional hack saw.

What, I have an expensive metal bandsaw available and I don't use it?
How long will it take to make 400 cuts through 5/8" rod with a hacksaw?

It's the same problem as shortening or drilling bolts or threaded bar in the
lathe and how to hold them in a 3 jaw chuck. For a bolt with a hex head you
use one loose nut of the same size as the head and grip both at the same
time. For threaded bar you lock two nuts together to act as the 'head' and a
third loose nut further down. You grip on the loose nut and the lower of the
two locked ones. Ideally you want the two locked nuts at the cutting tool
end of the bar because there will be a small amount of chatter between the
bar and the loose nut.

For 400 pieces that's a lot of screwing and unscrewing nuts though. It'll
take longer to put the nuts on than to cut the bar. To save time in the long
run I might be tempted to take two lengths of softwood, put a V groove along
both with a 90 degree chamfering tool, attach those to the vice and use them
as soft jaws to clamp the threaded rod between the V's. You could also put
semicircular grooves with a ball nosed milling cutter, each a couple of mm
less deep than the radius of the rod so the threads can dig in a bit. Once
you've done the first piece you'll have a nice thread indented into the wood
and you can align the other pieces into that. The rod ain't going to go
anywhere with several inches of its length indented hard into wood.
--
Dave Baker
Puma Race Engines
www.pumaracing.co.uk
Camp American engineer minces about for high performance specialist (4,4,7)