Re: The Cintimatic Saga

Brad Heuver wrote:

> From: "Brad Heuver" <bheuver@...>
>
> As it now stands, I believe that I'm going to have to let the Cintimatic
> slip through my fingers. I am still looking at salvaging some parts,
> prior to letting it go to the scrapyard. The ballscrews appear to be
> 1.25" dia, and might be retrofittable to my 1960 B'port. They nut moved
> the table on this machine, however, with the screw fixed, so I'm not
> sure of the compatibility. Does anyone know if it would be possible to
> adapt these to a Bridgeport style fixed nut type machine?
> If someone here has a strong interest in the whole machine, its in
> Metro-Detroit, speak up now, as Rick, the owner has found a scrapper who
> will take it out of his shop for free (for the scrap value). Someday
> I'll kick myself for not jumping on this one...

Unless the screws are in bad shape, it would be both a shame and a
wasted opportunity to let a fine set of ballscrews get scrapped. They should be
very easy to pull out. Bridgeport's BOSS series of machines used the same
arrangement. To set it up that way, the motor ends up inside the knee
(or you need to cut a huge hole in the knee, which sounds like a bad idea).
This arrangement avoids whip on the screw, and allows both ends to be
VERY firmly mounted. Yes, if you are starting frm scratch, a good idea!
But, as a retrofit, this could be a difficult way to go. Most likely, the
nut can be removed from the bearing assembly, and mounted to the yoke.
Unless the nut is VERY compact, it won't fit inside the holes in the original
BPT yoke. You could either make a cylindical mounting sleeve that fits
the yoke and holds the nut beside the yoke, or make a completely new
yoke, like I did. I'm not sure I recommend that way, however, because I
had a lot of trouble getting my yoke to hold the nuts at just right spot.
I spent quite a few hours with a surface plate and height gauge, so I have
no idea where I went wrong, but somehow, the nuts came out about .050"
off axis, so I had to pad the whole works so the screws were aligned.
My yoke is a lot more rigid that the original BPT part. In fact, it is so
solid it resricts the Y axis motion, so I have to pull it out someday and
do a little carving on it.

One other comment is that the inside of the Bridgeport knee gets all sorts
of crud dumped into it, so you MUST install a way cover set, and try
to keep the crud from dumping all over the screws. If possible, you
should get screw covers, or make some. The Goretite bellows look
real nice, but I found out they were real expensive, because our shop
at work got a bid on some of those. I've been thinking of making something
with telescoping brass tubes or something like that.

Good luck,

Jon