What does this connect to??

Printable View

11-02-2023, 2:43 PM
Jim Tobias

3 Attachment(s)

What does this connect to??

I bought this is as part of a package of extras from a turner and there was nothing that it would screw into in the group of items. It has male threads. It seems it would screw into some adapter either on the headstock or onto an adapter that goes in a chuck but there is no brand at all so I'm just looking for answers.
The front width is 2" and the back threaded area is 1.58".
It appears to be well made.
Thanks for any help.

Jim
11-02-2023, 2:48 PM
Mel Fulks

I’ve heard them called , “spur centers”
11-02-2023, 2:52 PM
Jim Tobias

Quote:

Originally Posted by Mel Fulks

I’ve heard them called , “spur centers”

Thanks Mel, I know it's a spur center but what I am trying to find out is the identity of the part so I can see what is needed to use it. Hoping to find a brand or maker of the part.
I have searched using many terms(including spur center) but have not found it yet.
11-02-2023, 3:30 PM
Tony Joyce

Based on the second picture, it appears to be grooves rather than threads.
If it is grooved it would clamp into a four jaw chuck. I seen pictures of this configuration, but don't have any for reference.
11-02-2023, 4:22 PM
Bill Howatt

I'd say you are right, Tony. It isn't a Oneway or Nova but it may well grip enough in any jaws that are close to its diameter when almost closed. I use my Oneway but I can't say it's my go to spur drive but it does allow the chuck to stay on the lathe.
11-02-2023, 5:20 PM
Bruce Page

Pic 2 looks like a standard 60* thread to me.
11-02-2023, 5:24 PM
Tony Joyce

Quote:

Originally Posted by Bruce Page

Pic 2 looks like a standard 60* thread to me.

If it is in fact a thread why doesn't the first and last "thread" have a starting taper or bevel? They would not be parallel would they?
11-02-2023, 9:34 PM
Jim Tobias

Tony,
I looked at it closely after seeing your response and you are right......it is a series of parallel grooves. Not threads. I guess I was just expecting that it was threads. I hope it is hard steel as I would worry about damaging the grooves when "cranking" down to secure it in a chuck. Am I overly concerned?
Thanks for all the responses,
Jim
11-02-2023, 9:57 PM
Tony Joyce

Quote:

Originally Posted by Jim Tobias

Tony,
I looked at it closely after seeing your response and you are right......it is a series of parallel grooves. Not threads. I guess I was just expecting that it was threads. I hope it is hard steel as I would worry about damaging the grooves when "cranking" down to secure it in a chuck. Am I overly concerned?
Thanks for all the responses,
Jim

No experience with one, but I would presume it was designed to take the pressure.
11-02-2023, 11:22 PM
Sam Force

I believe the jaws on my one-way stronghold chuck would hit right into that spur center as they have the parallel groves on the inside
11-03-2023, 12:43 AM
mike calabrese

Quote:

Originally Posted by Tony Joyce

Based on the second picture, it appears to be grooves rather than threads.
If it is grooved it would clamp into a four jaw chuck. I seen pictures of this configuration, but don't have any for reference.

Yup I agree those are not threads and here is a related video on the subject, different than your center but the idea is the same
calabrese55
https://www.youtube.com/watch?v=c3Ocgiwhv78

https://www.youtube.com/watch?v=tpSkLJfsXmA
https://www.youtube.com/watch?v=LYLwMjZhcXs
11-03-2023, 10:19 AM
Bill Howatt

Quote:

Originally Posted by Sam Force

I believe the jaws on my one-way stronghold chuck would hit right into that spur center as they have the parallel groves on the inside

I measured the grooves in the #2 jaws on my Stronghold and the peaks are about 2.4mm apart, center of peak to center of next peak, roughly just under 0.1". Talon #2 are the same. So if the groove troughs on the spur are that size it would fit.
11-03-2023, 1:16 PM
Larry Litwin

Quote:

Originally Posted by Jim Tobias

I bought this is as part of a package of extras from a turner and there was nothing that it would screw into in the group of items. It has male threads. It seems it would screw into some adapter either on the headstock or onto an adapter that goes in a chuck but there is no brand at all so I'm just looking for answers.
The front width is 2" and the back threaded area is 1.58".
It appears to be well made.
Thanks for any help.
Jim

Is the center point fixed or does it move with pressure? This looks like a steb center to me. Releasing tailstock pressure slightly disengages the drive spurs while keeping the tuening centered on the point so you don't have to stop the lathe to stop the turning to check something. Adding pressure re-engauges the drive spurs. If it's not that, then I'd guess just a simple drive center.