Old Becker no. 3 Mill - help with spindle taper

Hi all. First time posting in the forum, but I've been lurking here quite a bit over the years.
I just bought my first mill- a Reed Prentice Becker No.3. It's a neat little machine and I got it for a pretty good price (or so i thought...)

I knew collets would be kind of difficult to find, but it came with a few so I was ok with waiting for some 3B's to pop up on ebay. Luckily, i found two collets within a week of having the machine set up in my garage, but when I got the first one in the mail yesterday I was in for a surprise... IT DIDN'T FIT! The small end wouldn't even make it past the taper in the spindle nose. I double checked the collet dimensions on hardinge's website and it's definitely as advertised, and was made for this machine, but it's just too big.

I went back and did the sharpie test on the collets that came with the machine, and immediately started kicking myself because none of them truly fit the taper (only about 1/8" of contact). It looks like at some point in the machine's lifetime the spindle was either reground or replaced. Either that, or it takes different collets than what my research suggests? Does anybody have any more info i may not know about? The drawbar is threaded differently from the 3B collet as well

I have a buddy a few states over who has offered to turn my spindle to fit r8's for a reasonable price if i send it to him (assuming there's enough material to take off). Is there any reason i should second guess this approach? I trust him to do a good job (he's been machining professionally for a long time) but I have a gut feeling that tells me I'm over looking something. I'm wide open to suggestions if anyone has any other ideas for solutions

Thanks for reading!

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Highly likely to be B&S taper and the collets obviously are not for that spindle taper - just someone's half ass "work around"

Say dia at sharpie smear and then find what B&S is near that

Then you will finally have some useful data to base R8 decision on

Machine Tool Shanks (Tapers)

How about a 2AB, it is an 1/8" smaller in diameter.

Maybe try this. If you can, on your draw bar, measure the TPI and the diameter and reference against this source. That may narrow it down to a few collets and then you can figure it out from there.

Collet Dimensions - Transwiki

I did some more digging and after looking closer at pictures of the No.3, i realized the head is totally different from the one on mine. Mine looks more like a 3vg head, but on a no3 body. This suggests that it might actually be a brown and sharpe #10 taper (so you may be right) inside the spindle, but that doesn't explain the initial short taper right at the nose. Maybe somebody reamed it out? There's also this pdf i found which mentions a collet adapter. It could be the short taper was meant to mate with the adapter somehow, but i don't see any geometry on the adapter which might allow this (unless that bushing thing is part of it)
http://vintagemachinery.org/pubs/2524/17967.pdf

Good idea on the thread tpi. I'll try that as soon as i get home

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The old ancient No. 3 Becker mill we had at one time, had a no. 4 Morse taper in the spindle. A No. 10 B & S would not seat in the taper. Of course, the spindle was soft and probably reworked to a MT over the years. I do recall a Reed Prentice jig mill that had a special collet taper. May of been a no. 3, I don't remember. Dad and I looked at one back in the day and decided not to buy it. We just wanted it to complement the big No. 5 R-P jig mill we had back then. It had a NMTB 50 taper spindle. It was a spin off of a Becker mill.

Would it be worth making a Cero Safe or epoxy casting of the spindle end to have, hold, and measure?

Amazing - just happen to have the scan from 1901 - says it is B&S #8

WdTom- I like the idea of cerro safe but something about pouring hot metal in the spindle bugs me. Have you tried it before? Seems pretty safe but my gut is telling me to be cautious.

4GSR - cool that you used to have one! I took a closer look last night and i don't think it's a mt4 or bs10. The "new" 3B collet i got won't fit and the small end is 0.89ish. Good to know there's extra meat there if i want to bore it out though.

Jonoder - thanks for the scan! The spindle/ head in the picture looks different from mine, but i remember reading somewhere yesterday that they switched to a different design later which could be retrofitted to older machines. It could be that mine has the newer head. Any reason why the spindles would be a different taper?

It's not the most precise method, but i just had the idea to 3d print a few tapers in the range I'm looking at and see which is closest to fitting. BS8 may very well be the one im looking for based on the diameter of the sharpie line i made on the old collets. If i can get one close id feel more confident ordering something on Ebay to confirm it. If i start the printer as soon as i get home they'll be done late this evening. Hopefully I'll have some good news tomorrow

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Wow! An B & S No. 8 taper. I have never seen anything in the past 50 years with that taper on it. No. 7 and 9, yes. That is a very rare bird for sure. You will definitely have to make your own arbors for sure. Ken

4GSR said:

Wow! An B & S No. 8 taper. I have never seen anything in the past 50 years with that taper on it. No. 7 and 9, yes. That is a very rare bird for sure. You will definitely have to make your own arbors for sure. Ken

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For fun I looked in the 1923 P&W Small Tools & Gages catalog to see if there were any B&S 8 cutter shanks - none

Interesting... a no. 8 B&S taper. Never heard or seen one either. Obviously it didn't go over too well, as there isn't a listing for one in that P&W catalog by 1923. Looked at some of my old paper, and found nothing listed for a #8. Rare bird indeed.

jdleach said:

Interesting... a no. 8 B&S taper. Never heard or seen one either. Obviously it didn't go over too well, as there isn't a listing for one in that P&W catalog by 1923. Looked at some of my old paper, and found nothing listed for a #8. Rare bird indeed.

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Yeah this is gonna be a real adventure for sure. I bought this thing to learn, so that's exactly what I'll get. I'm about to learn a lot about cutting tapers on the lathe for sure [emoji16]

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Rather than make a bunch of tapered shanks that may fit and may not, I would take the spindle out and set up in the lathe and cut a R-8 taper in the spindle. The spindle on mine was not harden and apparently was modified to a No. 4 MT at one time in life. My old mill is long gone to scrapper heaven, reborn into widgets of today. Ken

The spindle on mine was not harden

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The two Cincinnati spindles I altered from 12 and 14 B&S to NMTB 50 were just tough, not hard

TreDanger said:

WdTom- I like the idea of cerro safe but something about pouring hot metal in the spindle bugs me. Have you tried it before? Seems pretty safe but my gut is telling me to be cautious.

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The stuff has such a low melting point that your spindle has probably seen higher operating temperatures. The stuff melts in boiling water.

Steve