What is this weird tapered shaft?

**Gearbreaker** · 11-17-2019, 02:55 PM

I have aquired a coil winding machine on which there is a tapered shaft. I need to buy an adapter to change it to an ER collet holder but I cannot figure out the taper type. It is 1.2" long, the small diameter is .57 and the large is .625. Does anyone know what this is? I cannot find anything that matches this taper on the internet. Thanks in advance.

**Rob F.** · 11-17-2019, 03:04 PM

Tapered pin?
McMaster-Carr

Jacobs taper?

**tdmidget** · 11-17-2019, 03:06 PM

Don't suppose you'd share useful stuff like who made the machine, origin, etc?

**Gearbreaker** · 11-17-2019, 03:15 PM

I would certainly supply the machine information but unfortunately it has no markings.

**Rob F.** · 11-17-2019, 03:17 PM

Pictures then?

**Gearbreaker** · 11-17-2019, 03:25 PM

I don't see a provision for uploading pics. How can I do this?

**Larry Dickman** · 11-17-2019, 03:28 PM

this little icon on the toobar

**Gearbreaker** · 11-17-2019, 03:34 PM

Thank you. I am currently on an android so the icon isn't here. I will post a pic as soon as I can get to a PC.

**Gearbreaker** · 11-17-2019, 03:41 PM

Here is the pic. Hopefully it comes through. It is the lower shaft with the cap screw sticking out of it.

**eKretz** · 11-17-2019, 04:27 PM

How sure are you on those dimensions? They don't match up with anything near as I can tell. About 0.550" taper per foot or 1:22 ratio, so doesn't match with anything that I'm familiar with.

**Gearbreaker** · 11-17-2019, 04:33 PM

I measured with a caliper. I'll double check them and let you know but I believe the measurements to be pretty close.

**twin staged** · 11-17-2019, 04:45 PM

Unless I’m reading this wrong you it sounds close to jacobs taper #33 but that’s only about 1 inch long. Lots of tapers fall within .050 ish of this

**Gearbreaker** · 11-17-2019, 05:21 PM

I don't think it is necessary to use the entire shaft so that may be the key. The shaft is one piece all of the way through so it is a part custom made by the company for the application. The nut is simply a jack nut to remove the holder from the tapered shaft. Interesting that the entire shaft with the threads is close to 2". I will attach some closeup pics. I will also measure the shaft diameter one inch from the end.

**Clive603** · 11-17-2019, 05:22 PM

If 40 + year old memory is correct the somewhat similar coil winder we had in the electronics lab had a taper shaft and with a variety of carriers to suit different sizes of ferrite and other material cores. Certainly not a standard taper. Just whatever the designer felt would work for the job. I think ours was a bit smaller diameter but taper was probably similar.

Clive

**Gearbreaker** · 11-17-2019, 05:23 PM

Originally Posted by Gearbreaker

I measured with a caliper. I'll double check them and let you know but I believe the measurements to be pretty close.

Checked dimensions and they are pretty accurate.

**Gearbreaker** · 11-17-2019, 05:29 PM

Originally Posted by Clive603

If 40 + year old memory is correct the somewhat similar coil winder we had in the electronics lab had a taper shaft and with a variety of carriers to suit different sizes of ferrite and other material cores. Certainly not a standard taper. Just whatever the designer felt would work for the job. I think ours was a bit smaller diameter but taper was probably similar.

Clive

I'd bet this is supposed to be the same setup but I got no adapters with the machine. I figure with a collet adapter I can fit the coil forms onto a simple custom machined holder locked in a collet. If I get desperate enough I could always turn the shaft down to eliminate the taper but I'd rather not.

**awander** · 11-17-2019, 06:07 PM

It might be a "Standard Dental Taper", such as is used on dental polishing lathes.

Darned if I can find the specs on that taper, though...

Or maybe a B16 Taper:

**Gearbreaker** · 11-17-2019, 07:19 PM

Originally Posted by awander

It might be a "Standard Dental Taper", such as is used on dental polishing lathes.

Darned if I can find the specs on that taper, though...

Or maybe a B16 Taper:

That B16 sure looks promising. If I am figuring right, by the time you do the math the difference front to back is only.03". I am under the impression that the B tapers are metric based and the machine appears to have been made overseas so it would make sense. So far, I think that B16 is the best bet. I'll try to find the dental equipment dimensions too.

**eKretz** · 11-17-2019, 10:24 PM

Unless your measurements are off, the B16 would be a sloppy fit. You might be best served making your own adapter.

**L Vanice** · 11-17-2019, 10:48 PM

Originally Posted by awander

It might be a "Standard Dental Taper", such as is used on dental polishing lathes.

Darned if I can find the specs on that taper, though...

Or maybe a B16 Taper:

ABB (Baldor) catalog for polishing lathes says, "True-running chucks
Made to close-tolerance specifications, keeps vibration to an absolute minimum. All chuck guaranteed to match ABB lathes andother make with standard tapered shaft. Mounting hole 0.370" tapered 0.250 per foot."

Catalog is here. See page 16. https://www.baldor.com/mvc/DownloadC...les/9AKK107348

Larry