Gear selector drum detent

[saluki42]

Hi there, I have a question relating to the detent mechanism for the gear selector drum fitted to the 1930s hand change gear boxes. Is this just a ball and spring affair with an end cap or is it a spring load plunger with the same end cap.
If its the ball does anybody know the diameter and if plunger any dimensions or photos would be a great help.

Thanks in advance

Chris

[Doug]

Plunger. Should be able to rustle up some dimensions.

-Doug

[Doug]

Info on the plunger:



Full size PDF

And a photo.



Note that while my drawing shows the spring with both ends closed (that is just the way my template model is), three gearboxes that I sampled all had the same rate spring cut from a longer one to the length shown in the drawing. So they only had one closed end. Apparently another example of Douglas repurposing old inventory, and cutting one or two out of a longer spring. Also the tip of the plunger is a truncated cone, and not spherical as you might expect. This was the best of the three, the other two being battered and worn down, indicating they were not hard enough for the job in hand.

-Doug



[fix typo.  fix link to PDF. 02Mar22 -Doug]

[saluki42]

As usual Doug thank you very much for that I'll got on the lathe and get that sorted.

One further question though, regarding the kick start spring, where abouts would the free end of the spring be anchored, I assume onto one of the inner cover bolts but which one?

Chris