Model 6### main plate barrel port brass bushing.

[Fergus]

The parts,



Mark the bridge & bush 180 degrees apart. When we reinstall the bush into the mainplate it will go mark to mark to compensate for the wear.



The bush hole in the bridge is 2.4mm diameter and will act as the jig guide to drill the bush hole





The modified 1.7 dia jewellery drill (Cousins D32405) used to drill the mainplate bush hole. The shank is 2.35mm diameter. After cutting the working section back there is just sufficient flute left to drill 1.5mm deep into the main plate.





Offering up the new bush (Cousins B6837, 0.9x1.4x1.8) to ensure the hole is of the correct diameter for reaming.



The 2 reamers we shall use, 0.99mm & 1.79mm and diameters.



Reaming 1.79mm.



Lightly chamfer the reamed hole.



Pressing in the bush...sorry about the blurred pic. I have a small brass spreader plate atop the bush to prevent damage.



Bush installed flush.



Ream 0.99mm.



Inspect using a 1.0mm dril shank for a tightish hole.



Lightly chamfer the hole.



Trial fit the barrel.



Reinstall the bridge bush, mark to mark.



Fit the bridge.



Check underside.



Disassemble and remove excess bushing from rear using a 2.5mm drill.



Flush.



Clean the bore with a smoothing file.



Reassemble the barrel and bridge to check rear finish.



And there we have it.



This is from a 6119 which I am about to assemble which might appear in the tinkering section.

[jpc3]

Excellent write up, thank you!

[Deleted]

Very nice job. Often overlooked. I bush a lot of movements on the main barrel side. It's where all the power is stored. Doesn't help no bugger gets their watches serviced until they go wrong.