Chronometric

[jachenbach]

My Chronometric speedo looks great on the outside, but rather than sweeping smoothly, the needle proceeds upward in discrete jumps. After finding an old post by RichardL I decided to open it and have a look. Looked like new inside, but no way am I going to take that thing apart! Added a drop of Marvel Mystery Oil at shaft ends and put it back in the case. Cable is new and made sure it was lubed and routed properly as well. Maybe it'll smooth out with use as the oil penetrates. If not, I'll send it out to someone who knows these little beasts.

[Greybeard]

A stepping display is correct due to the mechanical mechanism. Modern traditional style speedos have a revolving magnet acting, (very weakly) on an alluminium plate. This allows for a smooth movement.

I found this:
https://www.youtube.com/watch?v=HKYCHu5A-LEdisplay.

And this is the magnet type
https://www.youtube.com/watch?v=yG6-KpkVbsA

[Butch (cb)]

And another thing. If the cable breaks whilst you are in motion the needle sticks at that point.

[Greybeard]

...If the cable breaks whilst you are in motion the needle sticks at that point.

These devices need to have the action rotated to return to zero.

[jachenbach]

Thanks, Greybeard. That video looks just like mine.

[terryg]

"needle proceeds upward in discrete jumps"

The joys of retro!

Digital from an analogue age.