Lima Class 50 HO bogies Upgraded to Class 37 OO bogies

[jwpalfrey]

Thought I’d post up a small project I’ve been working on ever since I learned that my beloved childhood collection of my favourite loco was fatally flawed. 
 

By this I meant I recently learnt that the Lima class 50 has got undersized HO scale bogies from the 1980s when they dabbled in both HO and OO and switched to OO mid development of the class 50.

 

Anyway after searching around it seems there’s some other “minor” flaws in the model around the cab area which Hornby have addressed as well as the bogies and general upgrade to the model. However Hornby examples are £200 new and easily £100 second hand. My collection of Lima 50s are on the whole in very good condition and have sentimental value. I also happen to like the sound of the ringfield motor (I think at certain speeds it’s quite diesel like) and it can be controllable too (perhaps there’s also some childhood nostalgia there too).

 

Anyway I had read that Lima Class 37 bogies are actually far closer to the prototype and can be modified to fit. I have a Lima 37 so took apart both to assess. It looked feasible, so I started the hunt for parts. Having aquired a few sets and having now done 3 or so I thought I’d do a small write up upon the task.

 

The class 37 being a later model there are a couple of benefits to this conversion, firstly the trailing bogie comes with two additional pickups, and the motor bogie having larger wheels gears the speed down some vs the class 50 (at least it seems that way). Currently the only downside is availability of parts and the 37 steps are in the wrong position.

 

The conversion is quite simple now that I’ve done a few, I’ll start with the trailing bogie which is a very simple mod, simply cut a hole for the addition pickup wire to feed (I usually oversize the hole to allow wire movement freely) then on the underside of the 50 chassis grind down the two tabs that prevent the bogie rotating too much, either completely or to about 1mm in height. These foul the larger middle wheels of the bogie if not ground down. Then simply fit the bogie and wire up. Done!

 

The motor end is a little more involved, so I’ll break it down;

 

1. First the motor Bogie will need the flanges removed from the ends of the moulded part as the motor sits lower in the 50 chassis.

 

2. Using a template open up the 50 chassis to take the larger motor. A good 5mm or so has to come off the front end then 2mm off the rear end. You can use a template from a 37 chassis (if you have one) or just work a little at a time. Not much can come off the rear to be honest and I try to remove a good 2 mm or so from both ends of the bogie to shorten the length of the bogie in the aperture.
 

3. Once the aperture is the correct size and the bogie now fitting and turning we can get the height sorted. This is where my 15mm counters come in! Purchased online cut the counters with a side cutter taking off the sides to create a 6-7mm oblong shape with two curved ends. Do this to two counters, you should now have four offcuts which are just the right size to glue in place to lift the chassis, these will need a trim once in place to follow the form of the original part of the chassis. You can now test fit the motor which should now sit at the same height as the trailing bogie. 
 

4. Now to get the motor fitting as it used to. The oblong bits of counter, cut them in to two with one section of 1/3rd length the other 2/3rd, put them on top of each other and then drill a small hole in them and screw to the bogie to replace the flange that was cut off. One piece acts as a washer to lift the flange. The other is the flange to retain the bogie when lifted, minor trimming may be needed once fitted to ensure it all turns as it should.

 

Now simply wire up and re-build

[jwpalfrey]

A few more images added to hopefully help. 
 

The photo of 50015 and NSE one show modified (50015) vs original (NSE) for comparison.

[Rich Papper]

This looks like a good idea. A set of these might improve running still further: https://www.petersspares.com/peters-spares-ps77-replacement-lima-large-wheel-gear-on-axle-pk2.ir Obviously you'd need some of the plain ones too. I've some of the smaller ones put aside for a Lima DMU but haven't got to it yet. I have used Peter's Spares replacement wheels for Lima coaches though, and that has made them much smoother and more stable through pointwork. No connection, etc.

Good luck with it.
Rich

[Wolf27]

I had a fleet of around 12 Lima 50’s I. The early 90’s that all were fitted with class 37 bogies, I still have 5 of them in a sort of preserved state, ie not touched for years and of sentimental value. The Laira railtour pair are among them.