My expierience with big locos

[Schraddel]

Hello!

The following is part of a locomotive upgrading project. There were traditional styled brass castings of Commonwealth tender trucks. Each sideframe consists of an outer brass casting which represents the typical Commonwealth truck frame and an inner brass casting double acting as axle bearing and mounting plate for brake shoes. This double layer construction rises the measurement of the overall width of the trucks and made them very broad.


This photos also shows the double layer sideframes.
First step is to make drill starting points for the axle bearings in the outer castings. The inner side of them is flush and this procedure avoids the trouble to find out the exact location for it when the parts are divided. So it is simple to get the right locations.
The drilling is not very deep, just for starting points. I used a 1.5mm drill bit.




Next is you take your cutting-off wheel and clamp it in your Dremel or else. Wear eye protection!
First cut off the outer brake shoes. Carefully pay attention that they do not fly off anywhere into the universe ...
Then made four cuts in the inner casting where the axle bearings are to divide and separate them. The wanted parts are the brake shoes and the mounting angles. The unwanted parts are the six bearings which are the main reason why the trucks are so broad. So the inner brake shoes and the mounting angles will be stay fixed. In the photo one of them has got loose and will have be resoldered.
One of the sideframes looks a little bit strange.




Then drill the bores which will became the new axle bearings. Again a 1.5mm drill bit is used and as depth stop i used an lenght of a brass tube with 1.5mm inner diameter. Only the tip of the drill bit is now active and the brass tube limits the depth of the bore.
Later the bores were enlarged to 1.7mm as this 6 wheel truck is rigid and the axles must have some more bearing clearance ratio.




Then "release the brakes". By milling and filing the outer edges of the brake shoes so, that they under no circumstances do not touch the wheels anywhere.
Otherwise not only are the "brakes applied", there will be a solid short circuit. A very solid one




Here the strange sideframe was repaired by soldering small sections of suitable brass tube into the oversized holes.
Also the broken off mounting angle was resoldered.




Next is to narrow the center pieces of the trucks, Drill 2.0mm bores just beside the existing bores, but further to the middle.
File slots to connect the remaining inner halfs of the old bore with the new bore. Now this will have the form of a fork. Cut off excessive material on the tips of the forks to get the correct width, the cutting line will go just through the middle of the old bores.
Screw trucks together and make sure the outer frames are paralell.
Refit the outer brake shoes by soldering. Here also pay carefully attention the "brake is released".
Make a test run of the trucks on a powered strech of rails. Are there any sparks and electrical shorts?
When yes you have to remove further surplus material on the brake shoes.




Old vs reworked.



The brake shoes are now exact were they belong to. Not before, but just in the level of the wheel rims.



And this is how it looks now when mounted under the tender.



Good bye broadgauge.

So long, i hope you like this spleeny ideas of a emphasized maniac.

Lutz

Edit: grammatics, misspelling, supplementations