Help with Capstan Crankshaft Deflection Indicator

Is it possible to turn the dial so that the reading covers the positive and negative movement equally? The picture below shows what I want. The picture with the yellow arrows shows what I have : an anti-clockwise movement from rest position at -18 to full deflection at -5.

Thanks

Dennis

Edited By Dennis WA on 08/04/2020 10:36:01

Is it not easier to set it all up on "one side"

So set it at minus 13 to zero

or minus 12 to plus 1 to ensure contact is maintained

Edited By Ady1 on 08/04/2020 11:10:25

I think you need to remove the bezel, remove the hand, reposition dial and hand. requires watchmaking tools and skills.

Thanks Ady

My problem is that I cannot rotate the dial. How does one do this so as to set the pointer where you want it?

There is a screw in the body, but I have not been able to work out what it does.

Dennis

Bazyle

Thanks for the comments. I have watch and clock tools and repair experience. I cannot get the bezel off without resorting to force, which is not an option!

Dennis

Does the grubscrew lock the bezel and dial so that once set, they cannot be moved accidentally?

If so, slackening the screw should allow the zero position to be adjusted.

Howard

Thanks Howard

Slacking the grub screw was the first thing I tried. No effect. I could not unscrew it from the body either.

I will try and see if the bezel is seized on the body preventing rotation.

Dennis

An even more ridiculous suggestion!. Unknown territory here! "Beyond this point be dragons".

If the screw is gradually tightened would that press on something to release the bezel, perhaps?

Howard

Howard The grub screw provides an adjustable stop for the gear quadrant that meshes with the pinion on the shaft carrying the pointer.

Conclusion: There is no provision for zeroing the pointer with the dial.

I opened the movement after removing the bezel using a sharp blade. It needed a clean and I reset the pointer to rest at +20 and it now goes round to -25 without difficulty. More than enough range for me to check the deflection of crankshaft webs, which indicates a shaft running out of true.

Problem solved!

Dennis