bent center arbor

[Carroll Hardin]

The center arbor on a Hamburg American clock is bent-seriously bent. When the spring went, it broke out a barrel tooth and bent the arbor on each side of the lantern pinion. Those bends were corrected but now the hand portion( in front of the plate,which is tapered) has a few bends in it. They are enough so that the motion wheels will bind at one point or more. Try as I may, Have not been successful in straightening this one. This clock is a loss as far as time goes because almost every part was damaged including the ew,. which had every tooth bent. Have that corrected and clock runs fairly well after complete bushing, etc-even had to make a new suspension spring which is a two piece arrangement. I haven't started on the strike side yet. I think most would have passed on this one. Have never seen this amount of damage and wear on a German clock... It belongs to a good client and I just can't give up on it. Please excuse the long speech, but wanted to explain the problem I need help with- that is- how do y0u take multiple bends out of a TAPERED center arbor. My search didn't turn up anything for me. Thank you for any help.

Carroll

 

[Carroll Hardin]

The center arbor on a Hamburg American clock is bent-seriously bent. When the spring went, it broke out a barrel tooth and bent the arbor on each side of the lantern pinion. Those bends were corrected but now the hand portion( in front of the plate,which is tapered) has a few bends in it. They are enough so that the motion wheels will bind at one point or more. Try as I may, Have not been successful in straightening this one. This clock is a loss as far as time goes because almost every part was damaged including the ew,. which had every tooth bent. Have that corrected and clock runs fairly well after complete bushing, etc-even had to make a new suspension spring which is a two piece arrangement. I haven't started on the strike side yet. I think most would have passed on this one. Have never seen this amount of damage and wear on a German clock... It belongs to a good client and I just can't give up on it. Please excuse the long speech, but wanted to explain the problem I need help with- that is- how do y0u take multiple bends out of a TAPERED center arbor. My search didn't turn up anything for me. Thank you for any help.

Carroll

 

[stewart]

Hello Carroll

A technique I use to straighten rounds, tapered or cylindrical is as follows. Using a vise or hammer and brass punch rough the bent shaft into shape, anneal when possible. Then use the equivalent or approximate. On a 6" x 6" x 6" steel anvil (block) I roll the piece to be straightened under a 2" x 2" x 3/4" steel square held in hand over the shaft. All tool surfaces are ground smooth, use heavy hand pressure, roll back and forth (tapers will roll in a circle). I get great results with this method.

Stewart

 

[Peter G Mitchell]

If you have a lathe hold the arbor as near the most cental bend, put a "T" rest against the arbor to sight it, rotate spindle by hand check run out and bend to get the arbor running true, slowly draw the arbor out of the chuck checking for run out and trueing every 1/8'' to 1/4'', do the same from the other end if necessary.
Peter

 

[Carroll Hardin]

Thanks, Stewart and Peter.
Have tried those methods. Will keep trying.


Carroll

 

[Carroll Hardin]

David,

Thank you for thw tip on a front pivot hole, sort of like a steady rest/.
Ive just about got it but would like it a little better.

Carroll