Hi Ian, Vikki,
So the old grey matter was on track after all. That's encouraging!
As you say Ian, an M6x1 will move about 40 thou per turn. That's
still more refined than Vikki's mallet method. It's probably fiddly
if you knurl it and turn it by hand but I'd leave a hex head for
tools. Using a spanner (aka wrench) it would be ok. A ratchet driven
socket for big changes and a ring spanner for final setting. At 40
thou per turn a 1 thou adjustment is 9 degrees on the nut. You won't
go much smaller than that.
I suppose you could look for a finer thread and tap but I'm now
thinking it's not too bad. Yes, you do have to do any camlock mods
first!
John
--- In 7x12minilathe@..., "wrlabs" <wrlabs@...> wrote:
--- In 7x12minilathe@..., "steam4ian" <fosterscons@>
wrote:
G'day John, Vikki.
I think I may have raised the issue of the coarseness of the LMS
mod..
If you do the mod using a 6mm screw then the thread pitch is
1.0mm.
One turn of the nut/screw moves the TS 1mm or 40thou. Add in
backlash
in the nut, screw and bracket and you are left with a very touchy
adjustment.
Touchier than what I am doing now ?!? Seems it would have to be
an
improvement for the front to back adjustment whatever it was. No
way
that I can see to do that with the stock arrangement other than
screwing
with it until you hit it (been doing that all night :-).
If you put the adjuster in the back access is restricted by the
cam
lock modification. If you put it on the front it risks fouling
the
compound slide.
I may well hold off on that one until, at least, I get the cam
lock in
place and see what I have there.
Lathes like the Southbend (and the Hercuses I know) have screws
on
opposite sides of the TS foot which engage a tongue in the TS
body
(or is it the other way round). Tightening these screws against
each
other gives a very fine adjustment because you use the spring in
the
screws and naturally takes out the backlash.
LOL, at the moment I I'm wishing I had one of those ;-)!
I have looked at an adaption of the the LMS mod to use two nuts
which
tighten against the bracket, the problem is access restrictions
caused by the cam lock.
Here is a case where I would be happy to be proved wrong!
I'm certainly not going to be the one that does it, I don't
think :).
BTW; LMS have again served me well, goods arrived in under 7
working
days from US to Oz.
Done well in getting stuff to me quickly enough too.
I'm been working at getting this under control all evening. I'm
about
at the point where I call it good enough, I think.
Got the DI in the chuck reading zero top and bottom and under
0.001 on
the front and back.
Interestingly, measuring from front of the quill (zero) to the
back I am
off by about 0.003, seems that with the DI reading I shouldn't
have that
?!?
Now to get if off of there and tighten down the SHCS on the bottom
without buggering it :-/. The thought that the Chinese hate us has
occured to me ;-) LOL!
Enough for tonight !
Thanks & take care, Vikki.
