Improving the Lima class 31

[roythebus1]

I renectly read on here that the Lima class 31 is a fairly decent model so I ought a used version from an ebay source. The model runs well, but not on my hand-built track! despite pushing out the b-2b-b to 14.5,, I found there's so much slop in the axle slots on the trailing bogie that ny decent running may be near impossible.

 

I got a set of replacement wheels from Peter's spares, they arrived today so I fitted those. No improvement as there's still the problem of 2.5mm ales flopping around in 3.5mm slots with the middle axle tending to run sideways and derailing on single and double slips.

 

Short of digging out my ancient Unimat and making some axle bushes, does anyone have an easier answer to the problem? I've also thought of making a couple of frams out of scrap n/s etch as an axle runner between the centre axle and one of the outer axles. 

 

Sadly my super-details Hornby (China) 31 suffered badly from mazak pest so is unusable.

 

 

Edited September 4, 2023 by roythebus1

[37114]

36 minutes ago, roythebus1 said:

I renectly read on here that the Lima class 31 is a fairly decent model so I ought a used version from an ebay source. The model runs well, but not on my hand-built track! despite pushing out the b-2b-b to 14.5,, I found there's so much slop in the axle slots on the trailing bogie that ny decent running may be near impossible.

 

I got a set of replacement wheels from Peter's spares, they arrived today so I fitted those. No improvement as there's still the problem of 2.5mm ales flopping around in 3.5mm slots with the middle axle tending to run sideways and derailing on single and double slips.

 

Short of digging out my ancient Unimat and making some axle bushes, does anyone have an easier answer to the problem? I've also thought of making a couple of frams out of scrap n/s etch as an axle runner between the centre axle and one of the outer axles. 

 

Sadly my super-details Hornby (China) 31 suffered badly from mazak pest so is unusable.

 

 

The Lima 31 is definitely one of their better models but as you say is let down by a bad mechanism. The good news is it sounds like you have the answer to your problems in you have a mazac damaged Hornby 31. I will dig out the photos but basically you can take the motor and bogies from the mazac affected chassis and install them in the Lima 31 with some cutting of the lima chassis at the non motor end and some plasticard.

[37114]

Just remembered, there is a step by step explanation and plenty of pictures on page 4 of my Parsons Vale thread of the modifications (scroll down the page):

 

[roythebus1]

Thanks, that's most helpful. i'll have to try to find the pest-ridden 31 now! Shame as it had the early body without headcode boxes. At least the mechanism won't go to waste. As you say it's a pity the Lima mech isn't very well engineered on this one. Presumably the bogies pivot on the white plasticard bits seen in your photos? It seems a more sensible way than the very awkward Lima method. Is there a way to fit NEM coupler boxes or Kadees on your conversion?

Edited September 4, 2023 by roythebus1

[roythebus1]

Now sorted, a reasonably easy conversion. there's a bit fouling on the front valances under the cab, it would appear the Hornby version has shortened these a bit to clear the bogie swing.

 

The problem with them all is that the middle axle on the real thing was 3' diameter, not the 3/6 of the powered axles! But with all 12 wheels driven, it ought to go better than the Lima chassis with no traction tyres. Anybody want a set of Peters Spares wheels??

[37114]

9 hours ago, roythebus1 said:

Thanks, that's most helpful. i'll have to try to find the pest-ridden 31 now! Shame as it had the early body without headcode boxes. At least the mechanism won't go to waste. As you say it's a pity the Lima mech isn't very well engineered on this one. Presumably the bogies pivot on the white plasticard bits seen in your photos? It seems a more sensible way than the very awkward Lima method. Is there a way to fit NEM coupler boxes or Kadees on your conversion?

Hi, correct re bogie pivots, it worked well and was much more stable than the Lima and Hornby set up.

 

I am afraid I can't help on the NEM box conversion, from recollection it was tight behind the valances but probably not insurmountable.

[SRman]

Body-wise, the Lima models are quite good, with the side detailing being excellent, including having somewhat delicate but very fine plastic driver's door handrails, but the cab fronts need the moulded handrails shaved off and replaced with wire to really add the cream topping.

 

You could add flush glazing and lighting if you are so inclined, but the Lima model does capture the right look even without those things (I haven't done them).

Mine has a later Hornby RailRoad chassis under it, which didn't have the buffer beam cowlings, so I had to add those from plastic sheet, and this photo shows up the rough edges rather cruelly.

[roythebus1]

The "used" 31 I got was missing a couple of cab handrails. the previous owner has made a bit of a mess with super glue trying to stick them back on which explained why I had a problem getting the body off the chassis.

 

I used to wrk on the 31s as a secondman at KX, loved doing the all-stations suburban trains from Welwyn to Moorgate and th Cambridge buffet expresses. 

[SRman]

15 minutes ago, roythebus1 said:

The "used" 31 I got was missing a couple of cab handrails. the previous owner has made a bit of a mess with super glue trying to stick them back on which explained why I had a problem getting the body off the chassis.

 

I used to wrk on the 31s as a secondman at KX, loved doing the all-stations suburban trains from Welwyn to Moorgate and th Cambridge buffet expresses. 

 

Nice work if you can get it! 😅

If you look at the photo I posted, you'll see one of my cab handrails had gone missing in action. I did fix that later.

[34theletterbetweenB&D]

11 hours ago, roythebus1 said:

The problem with them all is that the middle axle on the real thing was 3' diameter, not the 3/6 of the powered axles! But with all 12 wheels driven, it ought to go better than the Lima chassis with no traction tyres.

I am another using the mazak rotted Brush 2 mechanisms got cheap, but mine are stuffed into Airfix GMR bodies*.

 

You can modify the Hornby mechanism to make the idle wheelsets unpowered, by very slightly reaming out the central plastic axle and gear piece. Put a small dab of plastic compatible grease on the spigots of the wheel castings at reassembly and that's job done, the geared plastic axle turns, but the wheels don't. Mine have operated over 10 years in this state, no ill-effect to date

 

This is worthwhile in my opinion on three counts, the model runs that bit more smoothly because there is no tyre speed mismatch; and in having the bogies apart you can check that the brass pick up bars in the bogie sides are straight, they tend to deform, bowing outwards, which leads to shorting problems on live crossing points; and also that the wires are securely soldered on, one of mine was very marginal, 2 dry joints out of

4.

 

*Now on their third DIY drive arrangements, firstly paired Airfix mechanisms  on the metal wheels from the pick up bogies -NOISY! but really effective; then Athearn PA1mechanisms: both of which I wore out on an outdoor line. The Hornby mechanism is the sweetest so far, but of course there's an all-new one in prospect...

 

3 hours ago, roythebus1 said:

I used to work on the 31s as a secondman at KX, loved doing the all-stations suburban trains from Welwyn to Moorgate and the Cambridge buffet expresses. 

Then you have probably zipped me up and down to town from the later sixties until electrification kicking in. Always used the 'beer train' for preference for WGC-KX and return back in the day. Sadly a service that has evaporated, though no complaints about the efficiency of the current electrics.

[Halvarras]

12 hours ago, roythebus1 said:

 

The problem with them all is that the middle axle on the real thing was 3' diameter, not the 3/6 of the powered axles!

 

Not quite all - on the Hornby Railroad chassis the middle wheels are actually smaller than the outer wheels, although I haven't measured them to determine the scale diameters. 

I have one under a Lima body (easy) and another under an Airfix body (not so easy as it's slightly longer than the body - I cut the bufferbeams off and used them to improve the appearance of these (very plain) areas on the Airfix model. It helps to leave ledges on the rear of the bufferbeams for 'tongues' of 30thou plasticard glued to the cut ends of the chassis to rest on and keep it all level.