Diagnosing a faulty platform escapement.

[clockboy]

Another update the ships clock.. It was fiddle day today to find out why one of the  platform escapements was not running. This is how I diagnosed the fault. Assembled the spare movement after repairing one of the old springs. Then I test the train of wheels no fault found but the platform refuses to run. The next stage of analysis was to identify what part of the platform was at fault so I removed the hairspring assembly and low and behold the escape wheel would not turn.. This was the area I suspected yesterday. Removed the pallets assembly and still no action under microscope found the bushing that supports the escape wheel was badly worn and was binding. (See first pic)

The bushing hole required was 0.28mm and I used a french clock “Bouchon” see some on my desk in the second pic. The hole for the bushing was 0.80mm. The hole for the bushing was made with a small cutting broach. I used my staking tool to push the bushing in and I used my Seitz jeweling tool to adjust the end shake. 

It is now on my bench running just fine.

Next job try to refurbish the dial

 

 

 

 

Edited June 10, 2022 by clockboy

[oldhippy]

Well done. A very common problem with clock platforms when they are not fully jeweled.

[RichardHarris123]

Well done indeed, far beyond my level of expertise. 

[transporter]

Without reading the full explanation I would of said check the depthing of the escape  wheel to the third/fourth wheel,I’ve has exactly the same problem with a French drum cylinder movement and found the depthing to be incorrect due to large screw holes on the platform itself.

[oldhippy]

Getting the depth correct from the  contrite wheel to the escape wheel is vital. Always a good thing is to mark the platform before you remove it. Many movements also have a depthing screw for the contrite wheel before removing the screw take note of how many turns it takes to unscrew it form its plate.  

[clockboy]

This is the adjuster screw I think you are referring too. I did fiddle with it to get the best performance..

 

 

 

Edited June 11, 2022 by clockboy

[oldhippy]

Yes that's it. 

[clockboy]

3 hours ago, oldhippy said:

Yes that's it. 

Yes it alters the about of mesh.