Tricks to getting a "0" runout motor coupler ?

[T.C.]

Are there any?
Where can I buy one for 5mm to .062 wire that will run true on a SV motor ?
Everyone I try is out enough I can see it doing like an oval pattern.
Is it the motor shaft or the coupler?
T.C.

[Darin Jordan]

Are there any?
Where can I buy one for 5mm to .062 wire that will run true on a SV motor ?
Everyone I try is out enough I can see it doing like an oval pattern.
Is it the motor shaft or the coupler?
T.C.

You can do like I've heard of some with deep pockets do... Have the output shaft bored out to accept the wire or flex, then tapped for a set screw, and forgo the coupler completely!

Otherwise, you need to contact someone like Jeff Wholt or ??? to machine one for you. Steven may know of some that exist...

[befu]

Easy

If your shaft is running true, it is easy. The stock is chucked up in the lathe and all cuts are done at one time without removing it, which means you have to have the motor end out.

You turn the outside, face it and center spot it. Then, drill through with the wire diameter first. Then you drill out the motor shaft size, minus .010+/-. Then you bore the hole to size to get the shaft OD. That is how to do it as accurate as possible with one of the holes being 0.062". Only other way would be to do the motor shaft hole first, bore it, then go in with a center and start the 1/16 hole. All depends on how good you .062 drill is and will it hold a straight line over the length of the coupler.

Instead of a drill bit and boring bar to do the motor shaft, you could also use the appropriate size end mill and bore it while it is in the lathe.

I have had good luck doing it this way.

I really like the idea of boring the motor shaft, never thought of that. Might have to try that one. But you need a big motor shaft as even a 5mm shaft will only give you .067" wall thickness. I do not get into motors that powerful, so oh-well.

Hope this helps!

Brian

[Steven Vaccaro]

Jeff will make one or Ned S will make one. I have his contact info, if you want it pm me.

[Jeff Wohlt]

If it is that far out then someone is not lathing well. You should turn it down slightly first to get true round. Very few are true round until you make it that way.

Always use as short of bit as you can so it stays nice and straight. Line boring with a reamer is also one of the best ways to get true.

Much of what you are doing depends on how well your lathe is adjusted.

[Jeff Wohlt]

Or just get you an OCtura coupler from Steve here.. made by Octura and be done with it.

[T.C.]

Thanks for the tips guy's, I like the boring the motor shaft idea also.
I bet they are hardened and would ya have enough material for a set screws ?
I'll keep at it until I get it figured out.
T.C.

[T.C.]

OK, I found the trick.
Ya put the couplers on a different motor !
I put both couplers on a new out of the box SV27 and both have "0" runout.
I guess the other motor had been dropped as there was a small ding in the endbell when we bought it.
It didn't look like it would have been hit hard enough to put the shaft out.
But it's out almost .032 (at the end of the coupler) as the .062 wire was hitting the .125 stuffing tube on both sides.
Also at the time we bought this motor I was making my own couplers and though the runout problem was my machine work, guess not.
That was the main reason for buying the couplers, no faith in my lathe talents.
This is a good example of why people should never bash a manufacture or vendor when they have problems.
This could have been caused by UPS ?
Now what to do with the motor? Anyone want a slightly used SV27?
T.C.

[T.C.]

Thanks to Jeff Wohlt for sending me some "0" runout couplers.
He makes some good stuff.
T.C.

[Jeff Wohlt]

Thank you for the compliment...I really appreciate it!

[boater76]

I have gotten coupler's from this seller on ebay.

http://myworld.ebay.com/alien_boat/

[T.C.]

Thanks for the tip Boater76
I think I'll stay with Jeff as he has good customer service and a fine product.
T.C.

[sundog]

I have gotten coupler's from this seller on ebay.

http://myworld.ebay.com/alien_boat/

I hope yours were better than what I bought from them. They were the only source of 5mm x 3mm couplers I could find so tried them out, but the couplers were offcenter and the runout couldn't be adjusted completely out. I then got Jeff Wohlt to make me some and they were much better quality. I'll be buying from Jeff in the future. Thanks, Jeff!