I have this old machine I'm working on in my spare time. When I say old,
it's really old, probably pre-1920. It has two shafts which had gears
fixed to them by pinning. The shafts were drilled and the gears were
drilled but the holes didn't line up so they just took thin pin stock
and banged it in so it bent but jammed in there "good enough".

Now I took it all apart and don't want to replicate the bent pin trick.

I'm thinking of temporarily fixing the gear to the shaft somehow, setting
it up in the mill, and drilling straight through with a 1/4" drill and
then just push through a 1/4" roll pin. I can't really figure out how to
fix the gear onto the shaft temporarily, though. Ideas?

PS I'm open to other solutions, but I think a set screw might slip ..

Grant

--
Posted via a free Usenet account from http://www.teranews.com

"Grant Erwin" wrote in message
.. .
I have this old machine I'm working on in my spare time. When I say old,
it's really old, probably pre-1920. It has two shafts which had gears
fixed to them by pinning. The shafts were drilled and the gears were
drilled but the holes didn't line up so they just took thin pin stock
and banged it in so it bent but jammed in there "good enough".

Now I took it all apart and don't want to replicate the bent pin trick.

I'm thinking of temporarily fixing the gear to the shaft somehow, setting
it up in the mill, and drilling straight through with a 1/4" drill and
then just push through a 1/4" roll pin. I can't really figure out how to
fix the gear onto the shaft temporarily, though. Ideas?

PS I'm open to other solutions, but I think a set screw might slip ..

If hot melt glue is strong enough, that should do it. If not I'd try some
other glue that breaks down with heat. Cyanoacrylate may be the trick.

However, I'd avoid the roll pin. It doesn't have a lot of shear strength.
I'd go for a solid pin.

--
Ed Huntress

"Grant Erwin" wrote in message
.. .
I have this old machine I'm working on in my spare time. When I say old,
it's really old, probably pre-1920. It has two shafts which had gears
fixed to them by pinning. The shafts were drilled and the gears were
drilled but the holes didn't line up so they just took thin pin stock
and banged it in so it bent but jammed in there "good enough".

Now I took it all apart and don't want to replicate the bent pin trick.

I'm thinking of temporarily fixing the gear to the shaft somehow, setting
it up in the mill, and drilling straight through with a 1/4" drill and
then just push through a 1/4" roll pin. I can't really figure out how to
fix the gear onto the shaft temporarily, though. Ideas?

PS I'm open to other solutions, but I think a set screw might slip ..

Loctite? Heat to remove the gears after drilling.

On Sun, 09 Dec 2007 13:26:57 -0800, Grant Erwin wrote:

I have this old machine I'm working on in my spare time. When I say old,
it's really old, probably pre-1920. It has two shafts which had gears
fixed to them by pinning. The shafts were drilled and the gears were
drilled but the holes didn't line up so they just took thin pin stock
and banged it in so it bent but jammed in there "good enough".

Now I took it all apart and don't want to replicate the bent pin trick.

I'm thinking of temporarily fixing the gear to the shaft somehow,
setting it up in the mill, and drilling straight through with a 1/4"
drill and then just push through a 1/4" roll pin. I can't really figure
out how to fix the gear onto the shaft temporarily, though. Ideas?

PS I'm open to other solutions, but I think a set screw might slip ..

Grant

Before you "repair" that "screwup", you may want to make sure that the
machine wasn't designed correctly in the first place, then made a victim
of poor maintenance.

Not knowing what the rest of the story is I can't say, but are you sure
that the shaft, gears and pins weren't right from the factory, then made
wrong by some major maintenance that put some _other_ pieces in the wrong
spots? Could the shaft have been put in backwards, or it's locating
hardware put in wrong, or the shafts that it runs against done wrong,
etc.?

--
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com

Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html

"Tim Wescott" wrote: (clip) are you sure
that the shaft, gears and pins weren't right from the factory, then made
wrong by some major maintenance that put some _other_ pieces in the wrong
spots? (clip)
^^^^^^^^^^^^^^^^^^^^^
The simplest possibility is that the gears are 180 degrees around from where
they should be. When a gear or collar is pinned to the shaft, the hole
doesn't line up in both positions.

Beyond that, I suggest lining things up as well as you can, and then reaming
for the next larger size taper pin. The reamer will line things up, so
there will be no need to position the gears.

On Sun, 09 Dec 2007 13:26:57 -0800, Grant Erwin
wrote:

I have this old machine I'm working on in my spare time. When I say old,
it's really old, probably pre-1920. It has two shafts which had gears
fixed to them by pinning. The shafts were drilled and the gears were
drilled but the holes didn't line up so they just took thin pin stock
and banged it in so it bent but jammed in there "good enough".

Now I took it all apart and don't want to replicate the bent pin trick.

I'm thinking of temporarily fixing the gear to the shaft somehow, setting
it up in the mill, and drilling straight through with a 1/4" drill and
then just push through a 1/4" roll pin. I can't really figure out how to
fix the gear onto the shaft temporarily, though. Ideas?

PS I'm open to other solutions, but I think a set screw might slip ..

Grant

If it's a decent fit, blue Loctite -- Loctite #242. Car parts stores
carry it. It will hold well enough for drilling, a bit of heat will
pop it loose. The red stuff #271 is stronger, but it can be tougher
to get loose.

Tim Wescott wrote:

On Sun, 09 Dec 2007 13:26:57 -0800, Grant Erwin wrote:


I have this old machine I'm working on in my spare time. When I say old,
it's really old, probably pre-1920. It has two shafts which had gears
fixed to them by pinning. The shafts were drilled and the gears were
drilled but the holes didn't line up so they just took thin pin stock
and banged it in so it bent but jammed in there "good enough".

Now I took it all apart and don't want to replicate the bent pin trick.

I'm thinking of temporarily fixing the gear to the shaft somehow,
setting it up in the mill, and drilling straight through with a 1/4"
drill and then just push through a 1/4" roll pin. I can't really figure
out how to fix the gear onto the shaft temporarily, though. Ideas?

PS I'm open to other solutions, but I think a set screw might slip ..

Grant


Before you "repair" that "screwup", you may want to make sure that the
machine wasn't designed correctly in the first place, then made a victim
of poor maintenance.

Not knowing what the rest of the story is I can't say, but are you sure
that the shaft, gears and pins weren't right from the factory, then made
wrong by some major maintenance that put some _other_ pieces in the wrong
spots? Could the shaft have been put in backwards, or it's locating
hardware put in wrong, or the shafts that it runs against done wrong,
etc.?


Hear ya, but this can only go together one way .. - GWE

--
Posted via a free Usenet account from http://www.teranews.com

"Don Foreman" wrote: (clip) The red stuff #271 is stronger, but it can be
tougher
to get loose.
^^^^^^^^^^^^^^^^^^^
If you are going to drill it and pin it. why would you need to get it loose?

Leo Lichtman wrote:

"Don Foreman" wrote: (clip) The red stuff #271 is stronger, but it can be
tougher

to get loose.

^^^^^^^^^^^^^^^^^^^
If you are going to drill it and pin it. why would you need to get it loose?

To assemble it. You have to take the gear off, stick the shaft through a
bearing, and put the gear back on.

Grant

--
Posted via a free Usenet account from http://www.teranews.com

"Grant Erwin" wrote in message
.. .
I have this old machine I'm working on in my spare time. When I say old,
it's really old, probably pre-1920. It has two shafts which had gears
fixed to them by pinning. The shafts were drilled and the gears were
drilled but the holes didn't line up so they just took thin pin stock
and banged it in so it bent but jammed in there "good enough".
snip

Weld it on with a good BAP with a MiG.

Tom Gardner wrote:
"Grant Erwin" wrote in message
.. .
I have this old machine I'm working on in my spare time. When I say old,
it's really old, probably pre-1920. It has two shafts which had gears
fixed to them by pinning. The shafts were drilled and the gears were
drilled but the holes didn't line up so they just took thin pin stock
and banged it in so it bent but jammed in there "good enough".
snip

Weld it on with a good BAP with a MiG.


Loctite? You can always heat it afterwards, to get it off.

On Dec 9, 4:26 pm, Grant Erwin wrote:
...
I'm thinking of temporarily fixing the gear to the shaft somehow, setting
it up in the mill, and drilling straight through with a 1/4" drill and
then just push through a 1/4" roll pin. I can't really figure out how to
fix the gear onto the shaft temporarily, though. Ideas?
Grant

One way to manage the Straight Through part is to rest the exit hole
on a center facing upwards under the spindle, with the drill stop set
just short of it.

On Dec 9, 1:26 pm, Grant Erwin wrote:
I have ... two shafts which had gears
fixed to them by pinning.

I'm thinking of temporarily fixing the gear to the shaft somehow, setting
it up in the mill, and drilling

Hand-reaming for a taper pin would be easiest, but if you want to
hold both in a mill, can you make a clamp? Bore a through hole
in scrap for the shaft, widen the hole half-through for the pinion
collar-part, hacksaw a slot, fit the shaft/gear and close the
mill vise on the scrap so as to close the saw kerf and hold
it all still. It sometimes helps to kerf across so the two diameters
are independent (and use a mill vise with some flexibility
in the moving jaw, or put a rocker scrap against that jaw).

Grant Erwin wrote:

I have this old machine I'm working on in my spare time. When I say old,
it's really old, probably pre-1920. It has two shafts which had gears
fixed to them by pinning. The shafts were drilled and the gears were
drilled but the holes didn't line up so they just took thin pin stock
and banged it in so it bent but jammed in there "good enough".


Superglue breaks down at 250F or so. I super glued some shimstock to a gib
and it proved too thin. A bit of time in the oven at 250F and the shim came
off.

Wes