On 05/12/17 17:52, Bob La Londe wrote:
I've been playing with the idea of making a taper attachment for
PM1440 for a while, but because most of the stuff I do is within the
range of the compound I have just been using that.Â* Well, a buddy of
mine asked me to make some longer tapers yesterday and he's willing to
pay a fair rate, so I move that up to "next project" status.

I don't really want to remove the back splash from the lathe, so here
is my thought.Â* Put the pivot support near the head with the pivot
center as close to exactly halfway between the bed and the splash
guard.Â* The back not the one over the chuck.Â* Then make two or three
swing ends. Maybe one at about 8 inches for short steep tapers, one at
20 inches,and one at the full end of the bed for really long tapers.Â*
My thought is that both ends of the linear rail can be held in a pinch
collar so the swing end can just be machined straight.Â* Loosen the
collars.Â* Adjust the position, and lock it in place.Â* I know it may be
a bit fiddley, but nothing a brass hammer can't be used to adjust.Â* If
I need to use a different swing end bracket I can unbolt the collar
from the bracket it is on, remove the linear rod and replace it with a
longer or shorter one, and slide the collar and mount on to line up
with the desired swing end bracket.Â* The best part is that as long as
I record everything in my notebook I don't have to make everything at
once.Â* Just the part I need right now.Â* I could of course just use 1
swing end bracket, and have three sets of mounting holes, but I think
if I have to do much of this work I'd like to leave the brackets in
place, and just remove the bracket on the cross slide and the linear
rail and its mounts when not in use.Â* It would make setups much faster
when I need it, and I don't think the adjustable and pivot brackets
would be in the way when the rail is off.Â* They might catch some
chips, but that's about it.


What is the diameter of the material and length of the taper. I made a
fixture some years ago to turn a long taper on 1/4" material over about
8" without a normal taper turning attachment and it worked great, some
details here http://www.metal-arts.co.uk/jacks/index.html . It could be
adapted for larger material but relied on the flexibility of the rod so
may not scale up much.