The Talking Machine Forum — For All Antique Phonographs & Recordings

Hi everyone

I'm currently in the middle of my first rebuild which involves replacing the mainspring on a small tabletop Columbia. Projects been so far so good, new spring has been successfully wrestled into the barrel and packed with grease (using just a standard wheel bearing grease and some gear oil). I hit an unexpected road block however in that I can't seem to get the new spring to hold tension for more than a few seconds before it releases. Again it is a brand new spring, no fractures whatsoever, so my only hypothesis is that (see photo) the inner end of the spring is not getting a good enough hold on the main barrel shaft. It is the same pear-shaped hole and hook connection as on the other end of the spring.
Given the tight quarters making getting a good look at how it connects unfeasible, what should I do? Do I have to pull the spring out again and then make that connection before I wind it into the barrel?


Thanks

Colin

Check to see if the hook on the shaft has sufficient space to engage the spring... if that makes sense. I have had to use a Dremel to open up the space on the hook to accommodate a new spring because the new spring was slightly thicker than the old one.

Having successfully installed quite a few mainsprings in the phonographs in my collection over many years I will offer my own personal advice.

I'll presume that the arbor hook is in fine condition so that it will catch and hold the inner end of the spring. If not then consider following Curt's advice above.

Before installing any mainspring into its barrel what I do is get either of the following:

1) a heavy set of needle nose pliers
2) 2 straight blade screwdrivers

With either of these in hand(s) I carefully bend and shape the end of the mainspring (the first "revolution" around the arbor) making a fairly tight circular shape so that I have almost a perfect "O" on the very end of the spring. The circular end must be made so that it will just barely slip over the arbor (shaft) and its hook and ASSURE that there is plenty of room for the hook to catch the hole in spring successfully. This works for me every time.

Good luck.

Doug

This has happened to me before--but did you perchance install the spring backwards?

I've done that a few times with results ranging from underwhelming to explosive.

Sounds to me that it's the outer end that's not hooked. If it were the inner end you would never get the slightest bit of tension, but you say you get tension that will slip after a few seconds.