Re: [CAD_CAM_EDM_DRO] Re: Bridgeport ballscrew retrofit kits and prices

I had my ballscrews made 1" longer than stock with standard ends. Then I
machined a 1" thick spacer that fits between the machine and the bearing
block which is hollowed out on the inside to fit the pulley. The standard
ballscrews, and ACME screws on my mill, had 4" long sections turned down
to 1" diameter on both ends between the bearing area and the threads.

However, depending on the size pulley you're using you may be able to get
the pulley to fit under the table with a little grinding - my table, due
to the casting, interfered with the pulley by about 1/8" in a couple
places. Also, I'd make the spacer 1.25" thick instead of 1" as the
pulleys I used were 1" thick and it was a little tricky getting
everything fitted without rubbing.

Also, on the Y axis, at least on my mill, it was not necessary to make
the Y ballscrew longer as even at full travel, there's still 3-4" of
unused screw with the stock ACME screws.

I also machined a keyway in the screw for the pulley but ended up using
taper locks that didn't have a keyway but I've never had a problem with
slippage.

Some pictures on my site: <http://www.smidgie.com/928/machineshop>

I put up some additional, unsorted, pictures here:

<http://www.smidgie.com/928/machineshop/CometStuff>

On the handle side I've made a spacer and housing to replace the dial
with a 1" ID encoder. The handle can be retained or replaced with another
spacer.

--C.S.

>Well, that is the problem... The end nut has to hold everything...It
>has to tighten up the bearing pair thru the pulley...This means that
>the pulley now cannot be pinned and probally not even
>taperlocked...This leaves only setscrewing the pulley to the shaft
>after the nut is tightened...For the kind of torque we are talking
>about i am not sure setscrewing will hold up...
>
>
>Also using the standard end does not address how to put a encoder on
>the end of the ballscrew or if you want to put a handle on after the
>pulley like you would like to do...This is why a custom end is so
>desirable.
>
>Wally