What's new
What's new
By:
Advanced search…

Removing stuck taper pin on pinon gear

JWPage

JWPage

Aluminum
Joined
Apr 12, 2010
Location
Northern California, USA
I am in the middle of disassembling the apron on my 16" SB. And I can't seem to remove the pin holding the pinon gear. (This is the one on the right side when looking from the back of the apron)

I can see a pin (assume that it is tapered) one side is flush with the gear, the over side seems to have a mushroomed (rivot looking) end.

Trying to knock out from the flush side, I am getting no where. :willy_nilly:

Then I thought maybe it's suppose to be knocked out from the other side, which means I would have to grind off the mushroomed head off.

My question is, "Is this the way it was meant to work?" Am I missing something?

Thanks in advance.
 
Try the other side with a center punch
You need to hit the small end of the taper pin

Dave
 
I understand that there is a pin that comes out, it just appears that the small end was hit with a riviting bucking bar, and mushroomed over. my guess would be to prevent the pin from falling out.

My question is, was this standard proceedure, in the manufacture on the lathe?
 
The use of tapered pins was standard on SB lathes. Mushroomed pins are abused. I recommend filing the mushroomed portion off, then carefully measure both pin ends to find the small one. That's the end you drive. Unfortunately, it sounds as if someone really pounded the he*# out of it, in which case it could be a real bear to get out. Hope this helps somewhat,Ed

p.s. Tapered pins were never 'peened' to prevent their falling out. Installing a new pin requires a hammer tap after the pin is pushed home.
 
Removing stuck taper pin

JWPage,
Back in the day-------- Long time ago ------- I worked for NCR (National Cash Register). They held everything together with tapered pins and we found removing them to be a real hassel at times.
Never use a center punch when working with tapered pins.
We had all kinds of punches for working with tapered pins.
None of the punches were pointed like a center punch.
All punches were fround flat on the end.
Most of them were either round or square or rectangler (sp)
and a flat end.
I believe the best thing for you to do now is file or grind the pin flat and flush with the hub that it is through. Polish it as smooth as you can and then "set it" with a hammer and a punch.
This should show you the outline of the pin. If this is the small end of the pin, use a punch that is slightly smaller than the dia of the pin outline, line up on the pin and give it a good whack.
No, ou dont understand, I said a good whack.
Sometimes it is a job for two people, one to line up the punch and hold it in place and the other person to whack the punch.
I believe this is where the expression comes from, "When I nod my head, you hit it".
I have even buck up the hub from the other side with a V block.
Good Luck...
Regards Walt...
 
I find a center punch can be very good at starting a taper pin moving. You can't really hit very hard on a springy pin punch without bending or breaking it, where with a center punch can be whacked pretty hard to knock the pin loose and then use the pin punch. Kenny
 
Paychk said:
A center punch would have the effect of swelling the end of the pin, a better choice to start removing a stuck pin would be a starter punch such as these:
Click to expand...

I've been keeping out of this because I haven't had much success with taper pins, but as regards using a centre punch - the advice above seems totally in line with other advice I've seen saying to pop the ends of pins with a centre punch to swell them so they can't fall out.

If a flat punch won't drive it out I guess the only other option is to drill it and collapse it in itself - you need a centre punch then to get your drill started down the centre. My experience of drilling stuck pins is that if you can't get the item to a drill press, you will probably make a mess of it - I successfully drilled the pins for the brake pads on my brothers van (after bending 2 punches and melting a rubber boot trying to use thermal expansion), but the holes were slightly oval at one end afterwards. It's damn near impossible to get perfect with a hand drill.
 
The way I found out the center punch works. When you have tried everything and no joy. Use a center punch to spot for a drill. After you do this a few times and the pin starts out from the blow you will eventually figure out it works. Don't knock it if you haven't tried it. Kenny
 
Pin Punch did it for me

I had a couple of tough ones, and I did break one of my pin punches trying. However, once broken, it was still in good enough shape to get it loose, just a lot shorter. Some light hits with a center punch might be OK, but I agree that it might swell the end a bit if hit too hard (and mine really took some hard whacks with a small sledge). I like the idea of grinding/cleaning it up to be sure that you are hitting the correct end first, so you don't have to be half-hearted when you swing the hammer.
 
Taper Pins

Drilling always worked best for us on the stubborn ones. We use a drill about half the diameter of the large end of the taper pin. Spot the hole on the large end. Drill from the large end about half-way through the diameter of the shaft. Turn it over and drill about 1/8" deep from the small end. Heat lightly with a propane torch. Place a steel punch in the hole on the small end and use a 5 lb hammer so that it will not "bounce" on the punch. One good hit usually pops it right out. Steve
 
Any pin or rivet can be removed easily if you can get a suitable hole nearly through it, but not all the way. A punch down the hole hit with a big hammer will stretch and pull out the tightest pin. There is no chance of swelling the pin tighter. I learned this about 1965 from the installation instructions for lower ball joints on a 1957 Oldsmobile. I think the originals must have been frozen before installation as they were extremely tight and impossible to drive out the normal way.
 
FWIW the following quote is from Cincinnati Bickford "Instruction Book and Parts Catalog for the Super-service Radial", Booklet R18-a, 1938:

"Taper pins, such as are used to pin collars on shafts etc., should always be removed in this manner. Use a piece of soft brass on the small end of the pin and hit it a sharp blow with a hammer. Ordinarily, one blow will loosen it and it can be readily removed. Never attempt to remove one of these pins with a steel punch. A steel punch will upset the end of the pin and destroy the pin hole. Next to lack of oil and failure to keep machine tools clean, more damage has resulted from the use of steel punches on taper pins than from any other source. ..."
 
file the ends flush, heat with propane to 500 degrees or so, then cool, apply some gun blue or steel blue to find the small end, drill to 1/4 or 1/2 depth for the punch, then use a 32 ball peen.

Steve
 
"I believe this is where the expression comes from, "When I nod my head, you hit it".
I have even buck up the hub from the other side with a V block."

One of my favorite expressions walt. You should see the grins when I use that
at work these days!

+1 on backing the part up with a SOLID block of some kind when attacking pins
like this - or any other kind of pin that's stubborn.

I just went though a bout with a straight pin holding a back gear to a cone
pulley for a lathe. Wasn't until I had an extra pair of hands holding the
pulley down hard to a steel block that I started to budge it at all. If the
part bounces when you hit the punch, go back and re-think the setup.
 
On my 16" the ends of the taper pins were already upset and wouldn't fit back through the hole. You could see the ends were mushroomed and bent a little before I even touched them. On most pins I needed to drill out the center of the pin from both sides to get it moving. Then the pins almost fell out. Inside the gearbox & apron, it was easier for me to get a long drill in there than a file or cutoff device. I did damage the taper hole, but becasue I only drilled halfway through from both sides, the damage was in the center of the shaft, where it didn't matter to me.

Different strokes for different folks.
 
You must log in or register to reply here.

Similar threads

K
Jammed half nut cam lever
Replies
8
Views
302
animal12
A
K
WTB: South Bend 11" quick-change drive gear / banjo gear
Replies
4
Views
324
Koreth
K
L
Machining a Famco #1 Arbor Press pinon gear
2
Replies
26
Views
704
Lugnut262
L
4
Apron removal from a Clausing 6300
Replies
11
Views
235
Richard King
Richard King
Savedbygrace77
van norman caliper calibration pin stuck in hole - how to remove?
Replies
2
Views
130
Dan from Oakland
D








 

ABOUT PRACTICAL MACHINIST

With more than 10.6 million unique visitors over the last year, Practical Machinist is the most visited site for metalworking professionals. Practical Machinist is the easiest way to learn new techniques, get answers quickly and discuss common challenges with your peers. Register for the world’s largest manufacturing technology forum for free today to stay in the know.

Learn more about us.

STAY CONNECTED

Facebook Instagram YouTube LinkedIn Pinterest Twitter Tiktok

Register Become a forum member. Register today.

Sign Up Sign up for our e-newsletter.

© 2024 Copyright Practicalmachinist.com. All Rights reserved.

Back
Top