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Need this splined pulley but on bigger shaft

madmachinst

Stainless
Joined
Jan 15, 2007
Location
Central FL
OK this is a splined pulley from the V2XT BP Series one machine 1991.
IMG_20210729_203104601[1].jpg
It's a taper lock bushing. This can be seen clearer from here.
IMG_20210729_203401702.jpg
As a few of you know, the ballscrew pulley ( servo shaft) and that pulley are not in align by say about 1/2" I can't just move that pulley out by 1/2" on the shaft because then the pulley will barely have any servo shaft in it. I was thinking servo shaft is 5/8" diameter and even has a key slot in it and threaded hole in end. How about I make an extension with a 3/32" wall thickness that has a bore 5/8" and use the lathe to broach a keyway in there. Then I can make that shaft as long as need be. Now the OD of this thing will be 13/16" or .8125".
A.)Would be a miracle if there was a replacement taper lock bushing that goes in that pulley instead of the existing one that accommodates 13/16" bore. B.) Any suggestions other than a taper lock bushing what could get that New shaft mounted to the splined pulley? C.) Maybe the pulley can be bored out for that intent and purpose if need be? D.) Wondering how I can chuck that thing up and not on the rims.
Thanks
 
Than you everybody for all the amazing help. Idea popped up in my head, instead of collet, use expanding mandrel like we all have had to make at some time or another for holding stuff on the lathe. The extended shaft .8125" diam can have on the end that goes in the splined pulley ( O.D. 1.858 splines 30 degrees apart) a spreader screw. Forget about that collet. Gonna have to mount a test indicator to my mill's quill to figure out the taper in side that splined pulley. Thinking aluminum for that shaft extension will work just fine. We talking .972" diam on the skinny end. Fat tapered end like 1.2" Suggestions for spreader screw anyone or will plain old countersunk screw work? Any reason this shouldn't work?
 
Was it not in alignment when new?

Can other end be moved?

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This thing was new in 1991. Bought it in 2012 for scrap metal value. Fired it up 1st time and saddle slammed into column ( instead of just cleaning switch I tore it apart) 1st retrofit Dugong drivers and Mach 3, closed loop to servo drivers worked but like eh....... New retrofit machmotion system closed loop to motion controller, self tuning AC brushless servos but needed to make adapter plates for servos. This was when pulleyts went out of alignment, cause not enough shaft sticking in the box that holds the belts and pulleys together. Reason this bothers me is that when I was trying to set steps per inch ( no backlash all going same direction) I was getting values all over the place +/-.005". Thing has NSK ballscrews and axial/radial bearings. Worked precisely during previous retrofit with crappier electronics, but the servos then were original SEM DC servos without newly designed adapter plates. Other end can not be moved.
IMG_20210729_203045423[1].jpg
Here is the other end.

edit. I might be able to put some kind of spacers/washers on the other end of that pulley pictured above and replace that lock nut. Tomorrow will take closer look and pics.
 
Can you get that H series pully with a built in hub and not a taper lock bushing? The hub will give you more ability to move pulley out from motor.
 
Can you get that H series pully with a built in hub and not a taper lock bushing? The hub will give you more ability to move pulley out from motor.

problem is motor shaft not long enough. I don't want that pulley just holding on to say last 1/4" of servo shaft. Hence need for extension. Servo mounting plate like 1/2" thick and I can't bring it down to say 1/8" thick.
 
Or...

Buy another same size pulley with larger hole.

Make an interface hub that fits shaft od on one end and new pulley ID on other end.
Length as needed

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Or use original pulley and make something like this but on a larger scale.
89382752_615159519217199_7948743631664316416_n (1).jpg

I wonder, if I start using a hex bar instead of round bar. Keep track of which chuck jaw goes on which flat, will that give me better than .001" concentricity when I flip the part over for boring the back?
 
Moving the ballscrew pulley is out of the question.

here is my idea
K2g7Oaz.jpg

fJ6hURB.png

Taper hopefully precisely follows contour withinside the pulley and the expansion part is pretty clear. Bottom pic shows the bore and there will be a keyway in there to work with the servo shaft keyway. Screw that expands the face will also pull the shaft into the servo shaft as the servo is threaded for a 10-24 screw. Maybe use a 10-24 with flat head and big washer to draw it all tight and then the countersunk head to spread the serrations later?
 








 
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