Test Run Amberola Issue

[tarheeltinkerer]

I decided to put the top part of the reproducer in the carriage and run the Amberola 30 to see what would happen. It runs fine until the horn begins to center...then the rear end of the carriage begins to LIFT OFF the knife edge and stops progressing.

Rut roh.

The horn is connected via a spring to the bedplate, and yes, it floats without the reproducer present. The reproducer fits snuggly into the carriage ring. If I don't lock it into place, and just let it rest on the top of the carriage, it works. The horn seems to be bottoming out or something when it comes to center. When the horn was removed for repainting, there were no dents in it suggesting it has bowed out, nor did the horn have any damage to indicate it has become deformed.

I really am at a loss here. With the reproducer in place locked down, if you try to move the carriage manually (feed nut up), it is very stiff in the middle of the carriage rod when the horn would be at its center.

Any ideas about what may be wrong here? I'll try to post a video to demonstrate what I mean tomorrow.

[matty]

I can only think of 2 things.

1. The horn is binding on the reproducer.
When I did mine, I had to run sandpaper over the part of the reproducer where the horn attaches. Being pot metal, it can swell, and I found mine had a tight spot which wouldn't allow the horn to roll freely on the reproducer.

2. You may need felt washers inbetween the bedplate & cabinet mounts.
The top of the bedplate should sit flush with the wood around the top of the cabinet. A while back, someone else was having the same problem, and once he put felt washers 1/8" thick under the bedplate mounts, the problem was solved.
Some 30's seem to have these washers, and others don't. Whether they all started off with them & they've either been lost or eaten away by bugs, I don't know.

Personally, I'd check the horn connection first, and if that doesn't work try the washers.

[tarheeltinkerer]

The horn is bottoming out on the case when the horn is upright attached to the reproducer. Some of the paint is wearing off on the case bottom when I checked. I bought some green "sticky felt" to make the little green felt corners. When I cleaned the brackets, there was no indication of there ever having been washers or anything of this nature on the bedplate brackets.

The underside of the case was separating and I glued the bottom-most piece back...I wonder if something similar has happened to the inside of the case where the horn is touching.

One day I'll work on a phonograph and it will go together as designed and work as it should without issue. One of these days...

[tarheeltinkerer]

Okay, four layers of felt on the brackets, heavily polished the inside of the bell where the reproducer attaches, a little work on the bow of the horn, a tiny piece of felt on the base of the horn, and things seem to be running correctly now. The carriage does not lift off now at center (if it is lifting it is only by a sliver) and the unit runs from end to end of the feed screw without assistance. Now I just need my new governor springs to arrive and hopefully it will run up to speed.

[matty]

I'm glad the felt washers did the trick.
Out of curiousity, did you notice if adding the washers made any difference to the level of motor noise?
I don't have felt washers on mine, and even though the horns not bottoming out, the bedplate is sitting below the cabinet, so I'm wondering if it's worth me putting some in.
If the washers stop the motor resonating through the cabinet even the slightest bit, it will probably be well worth the effort

[tarheeltinkerer]

This I do not know exactly, as I haven't noticed any major noise change. I bought a sheet of felt with glue backing at Michaels craft stores and just cut little pieces off to cover the brackets. I think I may try this instead with rubber to see how that works instead. I'm just happy I solved the problem