Loosening a Frozen Mandrel Shaft

[CDBPDX]

Just got a nice Edison Standard D bedplate and top parts but the mandrel shaft is frozen. Seriously frozen. I tried light banging, twisting, turning, heat, oil, liquid wrench, and harsh language, all to no avail. All the other gears were frozen, too, easy to fix, but the mandrel shaft is stubborn. Any tips, tricks, or tutorials available to get this loose?

Thanks! Cliff

[Chuck]

Hi Cliff,

Well I was working on cleaning up a Dictaphone shaving machine last winter which had a mandrel
pulley that was frozen onto the shaft.

I tried everything, and nothing worked.

Finally it busted loose after a couple of days.
I had soaked it with P.B. Blaster, then tapped
on it gently in the lengthwise direction.

What finally got it loose was the application
of a fair bit of heat from a heat gun, along with lots more tapping and plenty more Blaster.

Be patient. As Micamonster says: This is how the damage happens, when we apply too much force.

Let us know how it turns out.

Good luck!

Chuck

[Jerry B.]

If nothing works try:
1- Carefully tap off the mandrel from the shaft using a block of wood between the mandrel and your rubber mallet.
2- Now that the mandrel is off, grab the shaft with vice grips and turn back & forth taking care not to bend the shaft.
3- With the shaft firmly in the grip of the vice grips, tap with a hammer and the shaft will come out of the pot metal bearing. Any marks on the shaft will be hidden under the mandrel when it is re-installed.
4- Remove the pot metal bearing and replace with a brass bushing or roller bearing.
5- Gently tap on the mandrel and you're good for the next hundred years.
*
I've done probably a dozen frozen mandrels over the years and have never damaged a mandrel or broken a casting. Use lubricants to make the job easier and you'll do fine. Jerry Blais

[CDBPDX]

Thanks for the advice. Wish me luck! I've already built a motor for this and I'm kind of anxious to get the top up and running. I've never removed a mandrel from a shaft like this, nor have I ever removed a shaft from the bearing, didn't know what to expect. A pot metal bearing? Who 'da thunk it? Thanks! Cliff

[De Soto Frank]

Eric Reiss's book "The Compleat Talking Machine" (title?) has a good paragraph or two on this...

[CDBPDX]

Eric Reiss's book "The Compleat Talking Machine" (title?) has a good paragraph or two on this...

Found that section - SPECIAL PROBLEMS WITH EDISON PHONOGRAPHS / Pot Metal Mandrel Bearings

Seems I need to gat a brass replacement bearing "available from most suppliers". Any suggestions where I could find a supplier of these bearings?

Thanks! Cliff

[OrthoSean]

Call Ron Sitko, he carries them:

518-371-8549

Sean

[Chuck]

That is very interesting what Jerry B points
out about tapping the mandrel off of the shaft.

I never knew they are just pressed on there, and
that one could reasonably expect to be able to
push the mandrel off of the shaft like that.

If I ever would attempt that, I'd be afraid
of bending the shaft in the process of getting
the mandrel off.

How tightly are those pressed on there?
I suppose it varies depending upon crud, corrosion, stuff like that, right?

Chuck

[CDBPDX]

I got the mandrel off the shaft, the shaft out of the bearing, and the bearing out of the bed plate casting. The mandrel came off with a few taps on a wooden block, as described above. Once the right end of the mandrel cleared the end of the shaft, it came off pretty easy after that.

The shaft came out of the bearing with some effort. Clamped vise grips on the shaft and tapped it with a hammer. There was very little injury to the shaft from this procedure.

The bearing seemed more than willing to shatter apart after a few taps on a chisel. Used steel wool to 'hone' the bearing seat, won't know if that will be sufficient until the new brass bearing arrives from Mr Sitko.

I might actually have a working Standard D phonograph pretty soon!

This is fun! Cliff

[Jerry B.]

I didn't mention that you can resurface the pot metal bearing. It's a temporary fix until the old bearing swells again. I don't recommend this. Jerry