Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

An overhead view of the gearbox as it is at the Mo' showing the chain back to the drive sprocket on the bogie, modifications to the gearbox side plates are next on the agenda to give better clearance for the drive chain

In the last week I've made further progress on the gearbox ...

Modified the gear housing and made up the cab front plate to cover the gears and provide somewhere for the gear shift lever to mount to at a later stage, modified the plywood chassis to allow for clearance of the chain. Finally made up a pattern for the boige to mount on giving this an offset so the franes are clear of the chain drive.

After much thought I (and trial and error) decided on the method to engage drive... found a Meccano Dog Clutch set and using the primary gear bored this out at 7.00 then turned up a spacer shaft including the taper so this mated up with the gear wheel, turned down the shaft by 0.25 of a mil just enough to give a gap where the gear change fork plate will run

Next turned up a holder for the Dog Clutch counter bored this to slide on the spacer shaft so this can bolt through to hold in place. Test fitted and silver soldered this all up as two separate units Drilled and taped a 10BA securing bolt – then tested the completed item.