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Edison home question...
Posted: Tue Mar 25, 2025 9:51 pm
by ewomack
Hello, I have an Edison home machine that I posted about here some years ago. Then I took a (far too long) break from it. Why? I don't know.
After looking at it again, I noticed that the carriage feed doesn't sit perfectly on top of the feed screw. It's a little off towards the back (see photo). This is what it looks like with the carriage fully down. Shouldn't that sit flat on top of the feed screw? I should see if that varies as it glides across the feed screw as well to check for other problems.
If it should sit flat, how do I fix that? I know there is a V-shaped device to the right of the photograph that adjusts the angle, I'm guessing that I need to mess with that for a bit?
Thank you!
Re: Edison home question...
Posted: Wed Mar 26, 2025 12:30 am
by tomb
The two screws on top can adjust the tracking a little bit. loosen them up, gently push down on the shaft to align it then tighten it up. I had to modify a small screwdriver to properly fit some of those screws. I do not remember if it was for those screws though.
Re: Edison home question...
Posted: Sun Apr 06, 2025 11:43 am
by ewomack
tomb wrote: Wed Mar 26, 2025 12:30 am
The two screws on top can adjust the tracking a little bit. loosen them up, gently push down on the shaft to align it then tighten it up. I had to modify a small screwdriver to properly fit some of those screws. I do not remember if it was for those screws though.
Thank you, that helped align things and the top piece now fits perfectly into the bottom piece. After doing this and making a few more adjustments, the machine played half way through a cylinder, the furthest it has ever managed. It still bogs down after about 15 seconds, with or without a cylinder loaded, for reasons I still can't determine. I also think I may have some kind of gearing problem with the 2 to minute 4 minute adjuster mechanism. When set to 4 minute, the mandrill has a pretty hard time rotating. Here are photos of the mechanism in each position (sorry, I could not get these pictures to align properly despite rotating them a few times before uploading):
I did also realize that the cylinder I've used for testing has some material missing from the inside. I don't know if that would make a difference, but I'm guessing a non-damaged cylinder (I have a few) would be far better to use.
Re: Edison home question...
Posted: Sun Apr 06, 2025 3:04 pm
by JerryVan
Have you oiled anything? The leadscrew needs a light coating of oil. Also needs a bit of oil at each end of the leadscrew, especially when geared for 4 minute records, since the mandrel shaft is spinning within the leadscrew at double the speed of the leadscrew itself. Any drag between the two will bog things down. Also, a thin coat of oil on the rod that the carriage slides on
Re: Edison home question...
Posted: Wed Apr 23, 2025 12:08 am
by tomb
the screw in the middle adjusts the tension on the ½ screw on the cylinder. That is a touchy adjustment at times with some machines. It is the screw on top of the !/2 nut set in that will raise and lower the pressure on the cylinder. Every thing must be lined up and straight. It playing around with those adjustments and they can drive you nuts. Two screws hold it to the shaft the next screw is the adjustment screw then the two screws that hold the half nut on. I would try to align the whole thing up then adjust the cylinder tension which is the center screw.
Re: Edison home question...
Posted: Wed Apr 23, 2025 5:00 am
by JohnM
The part on the carriage that engages the feed-screw is called a ‘half-nut’.
Re: Edison home question...
Posted: Wed Apr 23, 2025 9:15 am
by paradroid1793
I've had to replace the half nut on a similar machine. It takes patience and a lot of revising. Too much and the reproducer isn't able to make contact. Too little and the tracking doesn't work. If you adjust it near-perfect and still cannot play through a cylinder there may be a problem with the gears located under the bedplate.
Re: Edison home question...
Posted: Wed Apr 23, 2025 10:53 am
by drh
"It still bogs down after about 15 seconds, with or without a cylinder loaded, for reasons I still can't determine."
Bogs down how? If the machine still runs but the carriage stops and just clicks, you may have the half nut reversed. They're directional. I had that problem with my Triumph back during the COVID lockdowns and fixed it with the help of advice from here on the forum. I wrote it up in an article, with video of how the problem manifested, here:
https://www.tnt-audio.com/vintage/trium ... ity_e.html
Re: Edison home question...
Posted: Wed Apr 23, 2025 12:02 pm
by JerryVan
How far are you winding it up? Many times, people who are new to wind-up phonographs do not wind them up enough to complete a record.