I have had an idea for some time to make another kind of scratchbuilt Climax, but was wondering what sort of chassis I could use. Then I spotted an old MDC shay chassis and removed the line shafts and crankshaft. I then ran the chassis around for a while. Whilst it ran reasonable, I renewed the power trucks with “Echo Mountain” contact wipers, which are better than the originals, and also stripped off the teeth from the wheels sets. Next step was to renew the gears using North West Short Line re-gear kit and Bull gear upgrade kit. The Bull gears set comprises a brass gear, and universal joints. Okay, after fitting all the new parts, I was very pleased with the performance of the chassis and was now ready to start scratchbuilding the climax body for it.
As will be seen in the drawing, it is full size for HO so all that is needed is to print it out and glue it to 1/16” card. 

Once cut out, use 1/8” or 1/16” stripwood and glue this on the card using white wood glue. When it is thoroughly dried (8 hours or so) you can trim the access wood off and assemble the main box together as per the drawing. I used cyanoacrylate (Zap A Gap) to make sure it would not move, once assembled. 1/16” angle (Brass or Plastic) can be used for the main 8 risers and 4 end caps on the body. The roof is made from 1/16” brass sheet, I curved it to shape over a Jam Jar with just some minor adjustments. 

Now onto the boiler. You can either fabricate your own from Brass tubing or in my case I used an old boiler from a Model Power loco and cut it down and fitted further side pieces to it. All that is required now is a little cosmetic detailing and you have a great looking climax, which runs well.

I also made this conversion from the MDC climax utilizing a scratchbuilt body

 This was made the same way as above.