Help identifying taper pin

[Shotgun]

I was making some turning tool holders for my CXA QCTP a couple days ago. To get the tool slot perfectly aligned, I decided to cut it on the lathe. I mounted the ER32 collet chuck-block with a 1/2" carbide endmill on the spindle, and the work-in-progress toolholder on the toolpost. Figured a couple passes, and I'd have my slot.

Except, at the end of the cut, the endmill broke through, and the carriage jerked. Then I noticed that there was a 1/4" space between the carriage and measure dial. Tore it down yesterday to find that the crossfeed is held from pushing out toward the operator by a pinned gear on the inside. The pin sheared when the endmill broke through. The fatigue pattern tells me that this break was long in the making.

Best I can tell from, this pin goes from .178 to .192 over the .850 diameter for the gear. I installed a B&S taper pin once in the distant past, but that is the extent of my taper pin experience. I know there are a ridiculous number of "standards" given how seldom taper pins are used, and I don't even know where to start to determine which standard (if any), this 80yr old Sebastian lathe followed. I'm thinking my best bet is to find a modern standard that is just a tiny bit larger.

But, how would I go about that?

 

[rabler]

That sounds like 1:60 which is unusual. Imperial tends to 1:48, metric to 1:50. See McMaster's taper pin page. They also sell matching taper reamers.

 

[MyLilMule]

All taper pins have the same taper, 1/4" per foot. The different "number" taper pins just land somewhere on that taper.

This link should give you some useful information. Taper pins are often ground flat to the surface they are in after it had been seated properly.

Just find one where the big end is slightly larger than your largest hole. In your case, probably a #2. If you have an Ace Hardware near you, they have these in the hardware isle.

Taper Pins

Taper Pins For use as an aid in hole alignment, taper pins are made of steel, with 18-8 stainless steel available upon request. The standard taper is 1/4

www.almabolt.com

 

[Doug Gray]

I think this is close

McMaster-Carr

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Dang I type slow, three people beat me to the punch