Replacing a Pot Metal Bearing in an Edison Standard D

[Jerry B.]

I don't remember reading that Edison did not use "soft metals" but it sure could be true. I don't know why they would make that claim because I've seen the use of pot metal on the upper pulley end of Gem mandrels and several models had pot metal lower belt pulleys. These parts generally did not have nearly the number of failures due to swelling like mandrel bearings. I suspect they did swell but it was not critical like a mandrel bushing. Jerry

[phonogfp]

Agreed, Jerry. The lower pulleys for post-1900 Homes are notorious for swelling.

George P.

[Jerry B.]

Has anyone ever damaged the casting as a result of breaking up the pot metal bushing? If I were concerned about damaging the cast iron, I would employ a long skinny saw blade and make a few cuts into the pot metal and then break it up. I'd like to hear from others that have done this repair. Jerry Blais

[Lucius1958]

I don't remember reading that Edison did not use "soft metals" but it sure could be true. I don't know why they would make that claim because I've seen the use of pot metal on the upper pulley end of Gem mandrels and several models had pot metal lower belt pulleys. These parts generally did not have nearly the number of failures due to swelling like mandrel bearings. I suspect they did swell but it was not critical like a mandrel bushing. Jerry

As I recollect, the claim, "No soft metal or composition" was made in the product descriptions (at least for the Home) in The Phonograph and How to Use It (1900)…

Bill

[VintageTechnologies]

Has anyone ever damaged the casting as a result of breaking up the pot metal bushing? If I were concerned about damaging the cast iron, I would employ a long skinny saw blade and make a few cuts into the pot metal and then break it up. I'd like to hear from others that have done this repair. Jerry Blais

Jerry, I certainly would be nervous about breaking a stanchion on a brittle casting. Read what I posted yesterday on another thread about removing the pot metal bearing in a Home machine -- http://forum.talkingmachine.info/viewto ... =7&t=17872

[Jerry B.]

I've worked on about ten pot metal bushings of which probably six were Standards and I've never broken a casting. I read your post about the possibility of breaking the cast iron pushing support and wondered if anyone has ever damaged the support. I appreciate your concerns and that's why I asked the question. Thanks, Jerry

[VintageTechnologies]

I've worked on about ten pot metal bushings of which probably six were Standards and I've never broken a casting. I read your post about the possibility of breaking the cast iron pushing support and wondered if anyone has ever damaged the support. I appreciate your concerns and that's why I asked the question. Thanks, Jerry

Jerry, as a former machinist I have some experience with cast iron and will say that it can vary in composition, have lots of impurities with internal flaws, be granular and brittle and snap like a pretzel. I once did some destructive testing on an Edison DD bedplate that was in such bad condition that it was heading for the trash can anyway; I though it was particularly poor quality. As a friend joked, "cast from machine shop floor sweepings du jour". As a result of my observations, I decided to devise a method to extract swollen bushings without tapping or cutting at all. Maybe it isn't necessary, but if saves a single instance of heartbreak, it will have been worth it.

[phonojim]

See this 2011 post about the use of muriatic acid for this purpose:

http://forum.talkingmachine.info/viewto ... cid#p32301

[Jerry B.]

Yesterday I worked on a D Standard that had a home made brass bushing. The whole assembly was tight so I decided to replace with a modern bushing made for the Standard. The home made bushing did not want to tap out easily. My solution was to take an old hack saw blade and wearing safety glasses, cut about a 3" piece of the blade and then cut it horizontally so it fit into the hole in the casting. While wearing leather gloves I cut through the bushing the long way and it tapped out easily. Jerry

[edisonplayer]

I remember when I bought my Triumph E from Jerry Donnell.The machine was in the stairwell off his upstairs bathroom.When it was taken out the mandrel was frozen up.Jerry slathered oil and grease on the bearing in hopes it would free up.When I had Tim Fabrizio work on the Triumph one of the thing he did was put in a new bushing.edisonplayer