Edison Home Phonograph Slows Down

[alessandrotnt]

Hello everyone. I know that this topic has already been addressed but I'm going to ask more specific questions here.

So let me explain first.

I have a 2 minute model B Edison Home Phonograph which slows down and eventually stops before reaching the end of a 2 min cylinder.

I did some tests as follows:

1) wind it up with 25 turns

2) with the belt removed the motor and gears below the chassis runs well for about 11.30 minutes and gradually stops at 12.30 minutes

3) wind up again with 25 turns

4)now with the belt on but the carriage lifted it runs well for 10 minutes and gradually stops at 11 minutes. So with the additional load of pulley and mandrel it loses around 1.30 minutes.

Now my consideration is that, as far as I know, this running time "unloaded" (no reproducer and horn to move) should be fine. So the motor and gears shall be fine, I hope.

I noticed 3 things I'd like to have comments from yout expertise:

1) the feedskrew has some "ruined parts" which, if the half-nut is too lose, makes it jump and not proceeding anymore. So I had to increase the pressure of the half nut and now there are no jumps anymore but for sure this causes more resistance.

2)the brass wheel of the belt tensioner below the case is not able to rotate with the moving belt. So this is causing additional resistance but it does not seems much to my eye. But for sure this should turn with the belt, correct?

3) when I start the motor, it takes a short while to start (1 sec?). I saw on some youtube videos some other motors which have a very quick setup time after they are released , mine seems a little bit too slow.

And I also have a final question: what is the max number of crank turns the home phonograph can whitstand? On mine I never go beyond 25 as the crank gets quite hard, but I heard people doing even 35 turns...


Thank you all for your support!

[gramophoneshane]

The brass wheel of the tensioner must turn, otherwise it will act like a brake on the belt, which probably explains the delay you're experiencing with the top works starting.
A chemical reaction occurs between the brass wheel and the iron pin it rotates on, which forms a green waxy verdigris that needs to be removed.
I use gasoline to degrease motors, but the degreaser of your choice should work in removing the verdigris allowing the wheel to rotate.
Once clean apply a very small amount of oil to the centre and it shouldn't give you any trouble after that.

As for winding the spring, I wind my machines fully so have never counted how many rotations I make, but it sounds like the amount you're winding yours should be plenty to play a couple 2 minute cylinders.

[Jerry B.]

For starters the brass wheel on the belt tensioner needs to spin. With the belt off get some oil at the center of the wheel where it spins on the shaft. I don't own a B Home but if there is an adjustment screw for feed screw tension a quarter turn is a gross amount. If you get the belt tension wheel oiled and all other oil points above and below deck oiled you should play. If not, at some point, you've got to consider a weak spring. Please report back & good luck!

Jerry B.

[pallophotophone]

If the machine was mine and if ½ nut was worn or rusty, I'd replace it before it could damage the feed screw. Inexpensive insurance when compared to a feedscrew / mandrel replacement !

[FellowCollector]

If you’re able to post some pictures or better a video it would be more helpful in diagnosing the problem.

As mentioned the belt idler pulley must rotate freely. I ALWAYS bypass the idler pulley on all of my cylinder phonographs as it’s not necessary if your belt is made and fits properly.

You mentioned that the feed screw is compromised a bit but exerting more tension from the feed nut helps. I would consider cleaning the feed screw with Evapo Rust found at hardware stores. It should clean the threads a bit. If the threads are compromised by injury then the rust treatment won’t help.

[MisterOpera]

I would suggest buying a new ½ nut. This would help, and as said before, you don't want to damage the feed screw.
Another thing that happened to me years ago, was that the spring was fatigued It would play about a ½ of a record, and then slow and stop. I replaced the spring with a new one and the problem was solved!

[FellowCollector]

I must be missing something here. The original post indicates that the feed screw "has some ruined parts". I don't see where it mentions the half nut is not functioning properly but when loose makes it jump. So maybe tightening the feed nut?

1) the feedskrew has some "ruined parts" which, if the half-nut is too lose, makes it jump and not proceeding anymore. So I had to increase the pressure of the half nut and now there are no jumps anymore but for sure this causes more resistance.

[52089]

You should also be sure that the feedscrew is lubricated properly. A drop or 2 of light oil like sewing machine oil spread evenly across will do nicely. Heavier weight oil will definitely slow the machine down.

[alessandrotnt]

I must be missing something here. The original post indicates that the feed screw "has some ruined parts". I don't see where it mentions the half nut is not functioning properly but when loose makes it jump. So maybe tightening the feed nut?

1) the feedskrew has some "ruined parts" which, if the half-nut is too lose, makes it jump and not proceeding anymore. So I had to increase the pressure of the half nut and now there are no jumps anymore but for sure this causes more resistance.

Hello! Thanks for your answers!

Indeed this is correct. The half nut is in perfect conditions, the issues are on the feed screw bar.. I suppose that this was removed in the past, ruining it or something fall on it. I think this is an intrinsic weakness of the home model, since it is well exposed to any damage. The standard has a better implementation for this.


Anyway.. it seems I need to focus on the "green grease" which seems to stuck the belt tensioner to properly run over the belt.

My question is: I already tried to remove the pulley but it seems to be stuck and I don't want (at least for now) to disassemble everything.

I may try to remove the belt tensioner, unscrewing it from the holes on the pulley.. do you think this may work or I must Need to remove the pulley first?

Many thanks to everyone!

[AmberolaAndy]

I would suggest buying a new ½ nut. This would help, and as said before, you don't want to damage the feed screw.
Another thing that happened to me years ago, was that the spring was fatigued It would play about a ½ of a record, and then slow and stop. I replaced the spring with a new one and the problem was solved!

I highly recommend the half nut being replaced. I fussed with my Triumph nearly the whole month of June and the half nut being worn out was a huge culprit of the issues it had.