Soutbend & Taper Pins!!!

[Phil3]

I am rebuilding (at least trying to) a Southbend 9". I really detest the use of taper pins, which are all over this lathe, and now, one has finally conquered me. It has won the battle...unless someone can help me with a new strategy. This is the tapered pin for the right side (chuck side) bushing that locks the backgear shaft to the bushing. The pin first challenged me by having both ends stuck out of the bushing by an equal amount. Since both ends were slightly peened over (mushroomed), it was not apparent which one was the small or large end. Another person said with the backgear disengaged, the large end of the pin would be staring at me as I stood at the lathe. Taking his word, I pounded away on the small end, only managing to mash that end damn near flat to a .175" diameter. Now, the pin has to dislodge itself AND force a bigger diameter head through the small hole all at the same time, the latter a result of me trying to remove it! The harder you try, the more you make it less likely to come out. I hate these things! I don't know what to do now. I am a novice, and my well of ideas has quickly run dry...unless someone here an other options. These pins are enough to make me not want to see another SB for as long as I live.

- Phil

[Patio]

Hi Phil3
I am a new guy too.
What I did when faced with this problem, not that this is the right way, just my way, is to take my dremel and carfully grind the pin down flat to the surface, on both sides, then it is easy to see which is the larger of the two, and nothing to keep from driving it out.
Worked for me!
Best of luck!

[Russ Hanscom]

Once you have the end of the pin flat, square, flush, there is also the option of center punching and drilling the pin, from the large end, to releave some of the stresses.

Some larger tapered pins actually have a male threaded portion so a nut can be used to pull them out.

[wsippola]

Agreed with the grind flush and punch out with the largest punch that will work. If you can get some support on the back side to help ensure the impact is not absorbed by movement in the shaft, it also helps a lot. I generally like taper pins - as long as they are not driven in too tight, they come out quickly and locate parts very well. Given the hammering this one has seen, drilling it may be required, but I would still try supporting the back first - the support does not even have to be rigid. If you have another set of hands available, holding a larger hammer against the back as close as possible to the pin (but not on it!) will work fine - the inertia of the heavier hammer will help keep the shaft from absorbing the blow.

Wayne

[dly31]

A flush surface (on both sides if needed to verify the small end), a well fitting and heavy backup, a well fitting taper punch made of good steel, and a suitable hammer have never failed to loosen a taper pin for me. The hammer usually is not a problem, good backup and a suitable punch are critical. Switch to a pin punch once the pin moves.

Don Young

[Phil3]

I ground the ends of the taper pin on end pretty flush with the rounded surface of the bushing. This resulted in the pin metal just blending in with the bushing metal...the pin is effectively disappearing. I stopped at this point. All this grinding down also results in some unavoidable hitting of the bushing itself with the dremel. From what I can see and measure, the two pin ends are identical in size. I know they can't be, but from what one can see, there is no way to know which end is the small end. All other steps to drive the pin out can not happen unless I know which end is the small end. Two people have told me which pin end is the small end, and they don't agree. At this point, I feel like I should just grind down both pin ends and the bushing, effectively destroying it, slide it through the headstock so I can see which pin end is tapered, and just make another one...on someone's else's lathe. Sorry for the sarcasm, but seriously frustrated and disillusioned, and obviously over my head with this project.

- Phil

[Patio]

Phil3
I read somewhere that someone had this same problem of not being able to see the pins, he used machinist bluing or Prussian blue depending on who you talk to. Apparently it will run into small cracks. Clean the part really well and apply it to the part, wait a bit, then wipe off with some alcohol or thinner, you should be able to see the line around the pin. I don't think the kind is the spray can will do. I have bought some and found the carrier material kind of thick. Just a thought.

What model of SB lathe do you have, and which pin is it. I have a SB heavy 10, if it easy to see without taking the machine apart, I will look at mine for you.
Don't give up hope, take your time, it will pay in the end. Getting impatient will lead to more problems.
There are a lot of people on here that are a lot smarter than me, that may help. It just takes a little time.

Good luck

[swbrooks60]

A suggestion if you have a steady hand and can drill pretty straight: Use a sharp center punch to punch both ends of the taper pin. Using a drill bit slightly smaller than the diameter of the small end of the taper pin, center it on the punched location and then drill half-way through the pin from both ends. This essnetially weakens then pin enough that a sharp tap with a pin puch will shoot it across the room. If the head is mushroomed, grind it first as was suggested earlier. New taper pins can be found at most Ace Harware stores that I've been in so it should not be a major issue to find one and cut/grind it to fit. Steve

[Phil3]

The lathe is a SB 9, Model A, 4-1/2 foot bed. The blueing idea may help, and will need to find some of that locally. Could use it for other things. If you look at your lathe and the right side bushing, you will see that the pin goes into the bushing, through the shaft hole, and into the other side of the bushing. The offset location of the shaft means that the "thickness" of the bushing material the pin sits in, is not the same at one end of the pin as the other. "Thickness" meaning the amount of metal as measured between the outside of the bushing and interior wall of the shaft hole. At the thin point, this may be only about .15". What I need to know is whether the small end is at the thick side of the bushing or thin. It seems the prevailing thought is that the small end is lodged in the thick part of the bushing.

- Phil

Phil3
I read somewhere that someone had this same problem of not being able to see the pins, he used machinist bluing or Prussian blue depending on who you talk to. Apparently it will run into small cracks. Clean the part really well and apply it to the part, wait a bit, then wipe off with some alcohol or thinner, you should be able to see the line around the pin. I don't think the kind is the spray can will do. I have bought some and found the carrier material kind of thick. Just a thought.

What model of SB lathe do you have, and which pin is it. I have a SB heavy 10, if it easy to see without taking the machine apart, I will look at mine for you.
Don't give up hope, take your time, it will pay in the end. Getting impatient will lead to more problems.
There are a lot of people on here that are a lot smarter than me, that may help. It just takes a little time.

Good luck

[spro]

Phil. The small end is in the thick side of the bushing. The larger end of pin stands "in the face" when the backgear is disengaged. (that's really the only way because it could fall...) When engaged, its small end should be accessable from the back. 1951 S.B. "A"

[spro]

A little more info: It's the same type 9" lathe. For some reason your pin was replaced with one slightly too long. The measurement of the amount the large end of pin stands out and the recess in the smaller hole are equal in this one. (lo-mileage orig) When you hit the extended end it mushroomed and that started the problem. So now with the other side supported well, a small punch should do it fine.

[Phil3]

The pin is out! I took the headstock over to a friend's house (on this forum), and he had it out with just three whacks of the hammer, and a total time of maybe 10 minutes, and most of that was grinding a cheap punch to the proper dimensions. It was almost too easy. I learned some key lessons from this exercise.

1) Proper tools! A short punch that is the proper size is key. The punch I was using was too big and far too long.
2) Proper solid setup. The rotating shaft and pin were prevented from moving by clamping the backgear handle to the headstock. The headstock was backed up by solid aluminum blocks. No movement upon impact by the hammer/punch.

Everything above is what others have told me as well, but when you see those measures put into action, it makes it very real. Thanks all for your suggestions. They were all helpful to this novice.

- Phil