Edison Home Slows and Stops

[jchawner]

Hello.

Several of you have been very generous with your advice on getting an Edison Home Model B refurbished and running. In my last post I described my first attempt to create a new belt which turned out to be way too stiff. After buying belt material online from a phono person, I have made and installed a new belt.

The good news is that the Phonograph works. It'll play music from my one and only reel just fine. The half nut seems to track the lead screw just fine.

The bad news is that the turning of the mandrel eventually slows and stops while playing, never finishing the cylinder. What might cause this?

It's not because the spring has unwound. Lifting the reproducer and giving the mandrel a nudge gets it going again.

I have applied (sparingly) lubricant to the bearings at the end of the mandrel and mandrel shaft, the ring that separates the shaft from the mandrel itself, the carriage rod, and I've ensured the tensioner pulley is turning freely. If I remove the reproducer, the carriage tracks easily along its entire length. It's not the weight of the horn that causes it to slow; it'll slow and stop with just the reproducer. When I lift the lid and watch it run, I don't see anything obviously wrong. All those gears were lubricated as part of the refurb. I did not disassemble the motor or spring.

Can you suggest other things I can look at to get this thing to play a cylinder all the way through? If it does this once, I'll call the project done and put this on a table for display. (It used to sit in my in-laws house.)

Thank you.

[JerryVan]

The first thing to look for is that everything on the upper works spins freely, with zero binding. Try slipping the belt off the mandrel pulley, then giving the mandrel a good spin. See if it coasts to a stop, or if it stops very quickly.

Also, if the half nut exerts even a small amount "extra" pressure on the leadscrew it has the effect of "putting on the brakes". There is a half nut adjustment screw that controls the pressure. It can be a delicate balance between too much, versus not enough pressure. Be sure the leadscrew is well lubricated as well. With the reproducer removed, the carriage engaged, and the motor running, see if at any time the carriage is slightly lifted from the front slide edge. It should not be...

[jchawner]

Thank you, Jerry.

I'll check all those things. On the first one, if the mandrel does stop early what might I look at?

I've read about all the half nut adjustment stuff and how tricky it can be. Which screw is the adjustment screw? I did lube the leadscrew.

I'll update this post with the results of those tests. It'll be a few days.

[JerryVan]

... if the mandrel does stop early what might I look at?

I've read about all the half nut adjustment stuff and how tricky it can be. Which screw is the adjustment screw? I did lube the leadscrew.

If the mandrel drags down quickly, look for the end bearings on it to possibly too snug. There should be just a tiny amount of side-to-side play in the mandrel shaft.

What are you using for lube? It should be very thin oil.

Here is the pressure adjustment screw for the half nut...

Screenshot 2025-10-21 183938.png (215.91 KiB) Viewed 1293 times

[danohallaron]

Just had one today that wouldn't finish a cylinder. I slightly lifted the carriage and it took off. So, it can be several things, as others have suggested. But try lifting up the carriage/reproducer while playing, just slightly. If that removes your drag, it's a carriage/half nut adjustment.

[jchawner]

Thank you all. Here's an update with progress.

I took all the suggestions posted. Lubed the bearings at either end of the mandrel shaft, adjusted the end gate to ensure it wasn't too tight and there was a little back and forth play, lubed the mandrel screw, etc. For lubricant, I'm using Zoom Spout Oiler which was suggested here in response to another of my posts.

Now I can get it to play all the way through with really good volume. However, it does tend to skip at the very beginning of the cylinder and at the end. If I apply just a tiny bit of downward pressure on the half nut, it plays through those skips.

But the main problem is that when I put the cone on the reproducer (it's the original cone), the thing slows and after about 30 seconds. I lift the carriage to ensure it doesn't grind down the cylinder.

My inference is the weight of the cone is putting pressure where the stylus contacts the cylinder. Which is probably bad. But I'm having trouble figuring out how that can be the case because the stylus and reproducer seem to be rigidly held in place and the bit that slides along that rail is also rigid with no adjustments possible - it fits where it fits.

To test that issue (weight of the cone), I just played it with only the reproducer (no cone) and used my finger to provide a little down Force on the reproducer and/or the ring and guess what - it skipped and slowed. But I couldn't see any movement of the reproducer or carriage when I pressed down. Therefore, the reproducer in its natural position must be too low/heavy such that a tiny press by my finger or the cone slows it. Does that make sense? I can feel a little slack on the carriage rod at the end where the reproducer is (not the half nut). I can grab the reproducer ring and push and pull and get about 1 mm of slack meaning that the carriage hole is slightly larger the the diameter of the rod.

Also worth noting, the reproducer is not the original from the Phonograph (its stylus was lost along the way) so I bought a refurbished one off eBay (model C).

Any more helpful advice? All I want to do is get a good video of the thing playing with the cone on for as much of the cylinder as I can. Then this project is done.

Thanks again.

[Marc Hildebrant]

Can you explain what the "cone" is?

I'm not familiar with that phrase.

Marc

[Phono-Phan]

I believe he is referring to the horn.

[JerryVan]

Can you show us a photo of the cone/horn? Or, at least give us some dimensions of it, such as diameter at the "big" end and overall length?

[Phono-Phan]

Can you show us a photo of the cone/horn? Or, at least give us some dimensions of it, such as diameter at the "big" end and overall length?

Maybe he is trying to use a larger horn with no crane?