davey4270
Western Thunderer
This week at Crymlyn A Shop some progress has been made on the Andrew Barclay contract locomotive 1140.
A visit by the A.B. engineer, Mr. Trevor Cousins, solved some of the problems with the frames resulting in a silky smooth running chassis.
The motion bracket, cylinder frames and slide bars have been erected on the L/H engine.
Visible above the slide bars is the front crank pin bearing.
A problem can arise here due to insufficient clearances and the usual remedy is to file the retaining nut wafer thin and hope for sufficient clearance.
Here at Crymlyn A Shop we reduce the size of the brass crank pin bearing to approximately 0.25mm thicker than the coupling rod on all bearings.
The two leading bearings are than filled with solder, drilled through with an 0.80 drill then tapped with a 12BA tap.
Place the retaining washer over the crank pin and between the wheel face and the coupling rod as a spacer and fit the adapted bearing with the flange to the outside and tighten with a pair of serrated tweezers.
The tweezers will slip before the thread strips. Just ensure that the reduced face of the bearing is square and not at an angle which could cause the crank pin to tilt on tightening producing a slight eccentricity.
Should you strip the soldered thread, simply repeat the process and don't overtighten.
Our foreman is just visible behind the rear wheelset.
A visit by the A.B. engineer, Mr. Trevor Cousins, solved some of the problems with the frames resulting in a silky smooth running chassis.
The motion bracket, cylinder frames and slide bars have been erected on the L/H engine.
Visible above the slide bars is the front crank pin bearing.
A problem can arise here due to insufficient clearances and the usual remedy is to file the retaining nut wafer thin and hope for sufficient clearance.
Here at Crymlyn A Shop we reduce the size of the brass crank pin bearing to approximately 0.25mm thicker than the coupling rod on all bearings.
The two leading bearings are than filled with solder, drilled through with an 0.80 drill then tapped with a 12BA tap.
Place the retaining washer over the crank pin and between the wheel face and the coupling rod as a spacer and fit the adapted bearing with the flange to the outside and tighten with a pair of serrated tweezers.
The tweezers will slip before the thread strips. Just ensure that the reduced face of the bearing is square and not at an angle which could cause the crank pin to tilt on tightening producing a slight eccentricity.
Should you strip the soldered thread, simply repeat the process and don't overtighten.
Our foreman is just visible behind the rear wheelset.
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