"DoN. Nichols" wrote in message
...
[...]
It is standing on one leg while turning I am a bit concerned about :-)
You put it on a lower surface, and sit down so your foot is more
comfortable. :-)
Yes. Cossack dancing - not my forte...
And remember that you are also *first* using the maximum *belt*
speed reduction to keep the motor's speed up a bit.
The whole thing (Singer, foot pedal etc.) has a certain attraction to it.
A
sort of Kalashnikov feedback. When the time comes I shall explore this
concept.
O.K.
[ ... ]
I somehow asumed that it was not a done thing to bore out the *finished*
pulleys as they make the plain pulleys that *are* meant to be bored to
specs.
Looking at the 57105K3
You mean 57105K33?
Must have clipped it pasting.
That is acetal with an aluminum hub, which
would be too weak to handle that kind of treatment -- or the kind of
loads involved. Steel would be better (and more expensive, of course.
:-) Perhaps Acetal for the smaller end pulley, and steel for the larger
end on the lathe's spindle.
the hub is 7/8" which after boring to 5/8" ID
would
leave walls 1/8" thick. You think that is all right? The 6495K733 is
steel
and has a 1.5" hub.
Put more information about the pulleys. I'm going to have to go
back to McMaster Carr's web site and print out that page.
Or get Explorer 7 or 8 with tabs.
Anyway -- even if pinned, that one is acetal on aluminum. No, go
for the steel -- you get more hub to bore and to hold the setscrews.
The other issue I thought was that using the exisiting Taig step pulley
on
the countershaft together with, say, 6495K713, would lead to an ID
mismatch which could not be corrected by boring alone (this one has a hub
of
only 1/2"). Some sort of bushing for the Taig pulley perhaps?
Or -- start out with a shaft which fits the Taig pulley, and
turn one end down to accept the smaller pulley.
Makes sense.
And you won't want to be stepping up speed to the spindle, so
the larger pulley will be on the spindle, thus with the largest hub
diameter too.
Or -- go for the taper-lock type hubs where you can change hubs
to fit the shaft once you have the right pulley.
Presumably you are referring to something like this: 6495K222. The cost
is
getting up there.
No -- those are cylindrical bores. Look at "57095K11" -- and in
particular "57095K112" which is for a 5/8" shaft. But the problem is
one of finding the right timing pulleys to fit. These are for larger
belts ('H' (heavy) series, not 'L' or 'XL'.)
I thought the 57095K11 is a bushing used with a sprocket, not a pulley per
se. The 6495K222 is used with 6086K14 quick disconnect bushing which is
available with a 5/8" bore. But the bushing and pulley combo is close to
$100.
The small pulley that should match it (L series) is 6495K23. This one is
steel, the bigger one is cast iron.
And I would not worry about boring out the larger pulley to fit.
You'll need means for measuring your bore to know when you are at the
right size -- which probably means making up a sample shaft with a step
0.010" too small, one 0.005" too small, one the right size, and one
about 0.002" too large. Stop before the too large will fit in. And be
sure to remove the setscrews before you start boring. Hold it by the
hub in the 4-jaw, and take a lot of time tuning it to on center before
you start boring.
A telescopic gauge?
[ ... ]
http://www.milesfaster.co.uk/gallery...k/sun-dial.htm
Hmm ... I'll bet that was not made on a lathe, but rather formed
up from stainless steel, and welded into shape. If it were solid enough
to turn on a lathe, the supports probably would not hold it. :-)
But one has to walk before one can run. Also one must consider the size
of
the etching bath, how many gallon bottles of Ferric Chloride one would
need,
The markings on that one were welded onto the stainless steel
surface, not etched into them. As the scale goes up, the production
means must change.
Please! I do not just copy other people's work! Well, not too often. Also,
if you have a hammer suddenly there is an awful lot of nails about.
--
Michael Koblic
Campbell River, BC