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Is this normal or is the mandrel bearing shot?
Posted: Thu Feb 23, 2017 10:29 pm
by hearsedriver
Ive got a lot of slop in the mandrel bearing as shown in this video:
https://www.youtube.com/watch?v=THzwHVRGnCQ
Is this normal? The mandrel spins freely when the gate is closed. Im trying to diagnose why the machine bogs down to a stop when I place the reproducer on a cylinder. Im really thinking there is too much pressure on the half nut but, I dont see an adjustment unless the metal plate that holds the nut needs to be shimmed? Thanks
Re: Is this normal or is the mandrel bearing shot?
Posted: Fri Feb 24, 2017 3:43 am
by Lucius1958
Was that video taken with the gate open?
I have to support the mandrel on my Standard B when I close the gate, because of the same slop; and it is a well preserved original.
Bill
Re: Is this normal or is the mandrel bearing shot?
Posted: Fri Feb 24, 2017 6:13 am
by hearsedriver
Yes bill. The gate was open. Sounds like it is normal.
Re: Is this normal or is the mandrel bearing shot?
Posted: Fri Feb 24, 2017 6:11 pm
by Phonofreak
The early Model A and B Edisons must have the endgate closed in order for it to run true.
Harvey Kravitz
Re: Is this normal or is the mandrel bearing shot?
Posted: Sat Feb 25, 2017 5:14 pm
by JerryVan
That is not a bearing. It's simply a support to keep the mandrel from falling off the phonograph when you open the gate. The "bearings" are the end pins, one in the gate & the other at the pulley end, that support and align the mandrel shaft. In other words, what you have is totally normal.
Re: Is this normal or is the mandrel bearing shot?
Posted: Sun Feb 26, 2017 2:02 am
by Lucius1958
Curiously enough, my Home A has no center bearing either, but has far less 'slop'. This is probably due to the length of the mandrel shaft compared to the Standard.
Bill
Re: Is this normal or is the mandrel bearing shot?
Posted: Sat Mar 18, 2017 12:52 am
by tomb
Most of my standard As and Bs have a lot of play, only a couple of them are close when I shut the end gate. I thought it was from usages. Maybe Edison built some play in. I agree with you bill the homes seem to have a lot less play but the end stays seated better. If I was over one hundred ( not too far off) I bet I would have a lot of play in my connections but the miracles of medicine... Tom B
Re: Is this normal or is the mandrel bearing shot?
Posted: Mon Mar 20, 2017 1:48 pm
by JerryVan
tomb wrote:Most of my standard As and Bs have a lot of play, only a couple of them are close when I shut the end gate. I thought it was from usages. Maybe Edison built some play in. I agree with you bill the homes seem to have a lot less play but the end stays seated better. If I was over one hundred ( not too far off) I bet I would have a lot of play in my connections but the miracles of medicine... Tom B
If your mandrels have lots of play when the endgate is shut, then adjust the bearing/s. They're supposed to have minimal play, just enough to allow free rotation of the mandrel and not anything more. Edison didn't "build in" the play, he provided an adjustment to minimize it.
Re: Is this normal or is the mandrel bearing shot?
Posted: Wed Mar 22, 2017 8:55 am
by Wes K
There is an adjustment you can do that will keep the mandrel shaft from dropping so far that it has to be picked up to close the end gate.
It has to do with how the mandrel is positioned left-to-right and the position of the drive gear to the left of the support.
Re: Is this normal or is the mandrel bearing shot?
Posted: Thu Mar 23, 2017 5:06 am
by Lucius1958
Wes K wrote:There is an adjustment you can do that will keep the mandrel shaft from dropping so far that it has to be picked up to close the end gate.
It has to do with how the mandrel is positioned left-to-right and the position of the drive gear to the left of the support.
We would appreciate any information on these adjustments, including photos.
Bill