Recondition ? , a 29-4 Bell Crank Lever .

[nylonRigging]

hey as Metal and welding not my forte, 'Question'  ? , 
Have you, or anyone you know ? . Welded a Bead to the surface on the ( both top and bottom side ) , of ( worn/flattened ) , radius tip of the Bell crank Lever ? .  To then just resurface back to Spec. roundness again .

I bought an aftermarket Bell feed Lever replacement part . I got it all working and getting a solid 6-SPI threw 5-stack of 1000 den. nylon . And that not bad for a 105 year old 29-4 .
The 'generic' aftermarket Bell Lever that is sold , ( did need some resurfacing on the outside of Round Loop )  at bottom of the forks , as the loops wall thickness was bigger than old factory part, to get it to 'rock back and forth' and align correct . Also was needed for the 2 factory mount screws, to pass-by outside wall of the loop to remount it  .

I got the aftermarket part functioning great in the machine , BUT ... I Really want to keep and replace back, the original 'factory #'s part '  Bell Lever back into the old 29 again if possible . So if I can get an opinion as to weld bead to the old metal part, that would be great .

.....thanks
-

-

Edited November 22, 2019 by nylonRigging

[dikman]

I haven't done that particular part but I don't see any reason that it couldn't be done.

[RockyAussie]

I did once have a old friend build one up for me using the brazing method and it held up well for years. Machining was just a file and fine wet and dry by hand and eye.

[nylonRigging]

1 hour ago, RockyAussie said:

I did once have a old friend build one up for me using the brazing method and it held up well for years. Machining was just a file and fine wet and dry by hand and eye.

I really want to get it done good . The old factory parts had a good hard surface tempering to last, so that was my concern about Brazing  . sounds like Brazing might work OK also if it hard enough surface and bond to last .

Welding Rod and Wire can be had in different hardness, but laying down a tiny clean precision bead is where i need to find a real craftsman . the area to build-on is small and no place to be practicing skills.
-

[dikman]

Ahh, but that's the beauty of doing something like that as, within reason, it doesn't have to be a perfect, neat job because it's going to be ground down. Someone broke an extractor lug off my Uberti 1866 while (helpfully) removing a stuck boolit so not knowing any better () I built up a blob of weld and slowly ground and filed it until it was a good fit. Still working and saved me a heap of $.

[Wizcrafts]

I've bronze brazed to build up the worn puck on a 29-?, then used files and Emory cloth to bring it down to the best fit in the ring, then polished it on a buffer with green buffing compound. It lasted for a few years and never lost its stitch length (5/inch) as long as I owned it. That was a long time ago, in a land far far away.

[chrisash]

I found this file a couple of years ago that may well assist you though for a K13 http://needlebar.org/main/restoration/Singer29K13.doc

[Gunnarsson]

There's a few pictures of someone building the wear back up with silver brazing on Facebook. Not sure if you need to be logged on or member of the right group to see it, but give it a try, interesting pics anyway. https://www.facebook.com/media/set/?set=oa.1612557675430105&type=3 

Silver brazing may wear faster than the original steel, but on the other hand when that happens it can just be built back up again when you have the tools for it. Old machines require some maintainance anyway.
I know there has been bronze brazing rods meant for wear protection available, i.e. brazing bronze that resists wear very good. Not sure if there's any of that around any more, or if everyone has gone for hardfacing by welding instead. Another minimum wear version could be silver brazing pieces of high speed steel onto the worn area and grinding that to the correct shape. HSS retains it hardness after reaching welding/brazing temperatures, unlike ordinary carbon steel (that may become too hard and brittle, or quite soft, depending on temperature reached and cooldown rate).

[CowboyBob]

We have always brazed them with bronze rod & they holdup for a long time.

[jimi]

Yes, can be done but takes a lot of filing and fitting, easier to get a new one because your motion ring will probably be worn also. So when you eventually get it in and working you might get 5 spi in a spot where it has less wear but when you turn it towards you normally that is where the ring is worn most, your stitches might drop again??