Boss pulley question

[Sparky_NY]

I just got a V2E3 with boss 8 control, it is a servo system.

The axis drives use timing belt pulleys with taper bushings inside. I believe these same taper bushed pulleys are used on many bridgeport cnc's.

I want to see if I can get new bushings for a smaller shaft size and reuse the existing belt drive setup with new motors. The OEM servos are 5/8 shafts and I want to go to 1/2. I suppose I could bush them down but would rather just buy new tapered bushings to use in the existing pulleys.

Any idea who made these pulleys/bushings for bridgeport? That way I can track down smaller shaft size bushings.

[mactec54]

They are not a special Bridgeport part you can get the taper lock bush from any good Industrial supply

[Sparky_NY]

Originally Posted by mactec54 They are not a special Bridgeport part you can get the taper lock bush from any good Industrial supply

I figured they were a purchased part by bridgeport but there are many different makes out there, Browning, Dodge, Boston Gear and others, not interchangeable. I am hoping someone has found a compatible brand and size.

Searching the net, it appears the standard taper lock is a QD type, totally different, the one on the BP has no keyway and is 2 piece, the tapered bushing with a fine thread on the end and a threaded collar that screws on and has 3 allen screws to pull the bushing tight into the bore. The screws are NOT at the edge of the bushing like on the QD type bushing. Its closer to what is known as a "split taper" bushing but still different.

I looked extensively online at different pulleys with tapered bushing systems, none are the type in the Bridgeport I have. Mine are 2 piece bushings which mount by the threaded collar pulling the bushing tight into the pulley and 3 screws that lock that threaded collar against the face of the pulley. (not into threaded holes)

Perhaps the V2E3 used a different system than the other Bridgeports? I pulled all 3 motors today and they all have the same pulleys.

[mactec54]

They did have some different taper locks but most on the machines like your one had the QD type taper lock I have some that came off a V2E3 & they have the QD taper lock
You have the round tooth belt on your machine I know the TC-22 etc have the type that you have, The QD taper lock you can get them with or without a key, I know you can get them I will try & find were they are

[Sparky_NY]

The belts are standard H series belts, 3/4 wide, for example the Z is a 270H075. The bushings are radically different than a QD bushing, I am very familiar with those. I have looked at Gates, browning, boston gear, and others and not seen one that looks close.

The bushing is 2 pieces! A tapered bushing threaded on the end and a seperate threaded collar that pulls the busing in to lock it. One locked, there are 3 screws that tighten against the face of the pulley to prevent the threaded collar from loosening. Those screws do NOT go into tapped holes, just tighten against the face of the pulley. There is also a single tiny setscrew that locks it into a slot (much like a keyway but threaded) to also prevent the collar from loosening.

Again, its not even close to a standard QD bushing. I will try and get a pic posted tommorrow.

[mactec54]

I know the taper lock you have is nothing like the QD taper lock we just used some the same as your one but they have a 1.5 bore,They were for Bridgeport spindle motor I just have to find were we got them

[TOTALLYRC]

Originally Posted by Sparky_NY The belts are standard H series belts, 3/4 wide, for example the Z is a 270H075. The bushings are radically different than a QD bushing, I am very familiar with those. I have looked at Gates, browning, boston gear, and others and not seen one that looks close. The bushing is 2 pieces! A tapered bushing threaded on the end and a seperate threaded collar that pulls the busing in to lock it. One locked, there are 3 screws that tighten against the face of the pulley to prevent the threaded collar from loosening. Those screws do NOT go into tapped holes, just tighten against the face of the pulley. There is also a single tiny setscrew that locks it into a slot (much like a keyway but threaded) to also prevent the collar from loosening. Again, its not even close to a standard QD bushing. I will try and get a pic posted tomorrow.

What you have described is identical to the ones on my BTC-1.
I don't have any other info than that but just wanted you to know that you are not alone in "weird" taper lock land.

By the way they are actually a very nice and do a great job of holding the stuff together.

Mike

[Sparky_NY]

I am getting bad feelings there is a thin wall 5/8 x 1/2 reducing sleeve in my future.

[mactec54]

What would you make just the bushing for when you could make the whole thing, it will not work as well if you just make a bushing

The attched photo is one that is used for bearings this is similar to what you have

[mactec54]

This is another Taper Lock sleeve that might work for you

[Sparky_NY]

Because of the pain adapting the old pulleys to the smaller stepper shafts I was going to use, and other things, I have changed the game plan.

I am going to reuse the original servos and buy new servo drives, reuse the original BP power supply and run it under mach control.