Lima Class 201 improved running

[Dhu Varren]

Much has been said on this forum, rightly or wrongly, about the poor running qualities of Lima locomotives. It must be remembered that when the Lima 201 was produced, it was as good as you could get in British/Irish outline locomotives, and well before the ‘super’ all wheel drive, all wheel pickup and twin flywheel motored locomotives that we all take for granted these days.

Twenty five years ago I ran a fleet of Lima BR locomotives, and at exhibitions, I was frequently asked how I got them to run so well. The answer was simple, modification. This post describes how to modify the Lima 201 to get the best out of it.

 

You will need a back to back gauge to check the wheels after the modification. If you don’t have one, make one up using a piece of plasticard or brass, and adjust it till it fits between the existing wheels.

You will also need two spare Lima wheel and axle sets.

 

1. Remove the body from the chassis.

2. Remove the two screws from the bottom of the power bogie. This will release the sideframes and allow the motor unit to be lifted out of the chassis.

3. Push the bulb at the motor end of the chassis out of its holder, this will give extra slack in the wiring.

4. Remove the drive wheels. They are a simple clip in fit, and will unclip easily by pulling downwards.

5. Remove both wheels from each axle using a suitable support and a drift. A blunted nail about 2mm diameter will do the job. A good hard knock will be required for the non-tyred wheel.

6. Using a sharp craft knife or blade, push it in behind the plastic gear and slice it off. The bit being sliced is only about 3mm diameter at the centre of the gear, so not much effort is required. Remove any excess plastic there may be left where the cut was made, ensuring the gear is flat on both sides.

 

 

7. Discard the wheel, having removed the tyre for reuse. (I retained the wheels, and when I had twelve, I turned them down to get rid of the tyre groove, reprofiled the flange, and used them to rewheel a complete loco, but that is another story).

8. Remove the raised boss on the back of the other wheel, using a file. I use a drill to remove most of the metal and finish off with a file. It is imperative that the back of the wheel is perfectly flat.

 

 

9. Gently knock the axle back into the wheel, till about 0.5mm short of flush at the front.

10. Push the gear onto the axle till flush with back of the wheel, it will be a good tight fit. It must sit flush.

 

 

11. Using a suitable support, drill a small hole through the wheel and gear, and fit a pin to lock the wheel and gear together. The size of the hole is dependant on the diameter of the pin you are going to use. The pin must be a good tight fit. Ensure the pin is flush at the front, and trim off flush at the back of the gear.

 

 

12. Remove the insulated wheel from the spare axle set, and fit onto the axle with the modified wheel. Ensure the wheel goes on straight. Roll the wheel set on a flat surface to ensure there is no wobble. Check that the back to back measurement is correct using the gauge. Lay the wheel sets to one side.

13. The centre axle does not need any modification.

14. The Lima motor unit, as it comes, collects current via the wheels on the opposite side from the gears. Because we have modified the axle so that the drive gear is now fitted to the pickup wheel, which is now on the opposite side, it means that the motor bogie is now picking up the opposite way round to the trailing bogie. The simple way to correct this is to disconnect the wire which connects the motor bogie pickup strip to the left hand brush holder, and reconnect it to the right hand brush holder. The wire will not be long enough to do this, so it needs to be replaced. No other wiring needs to be touched.

15. An extra pickup strip is now fashioned by making up a Z shaped piece of phosphor bronze strip to fit vertically as shown. At the top of the strip, a 90 degree bend is made, and trimmed to be 1mm long. The Z piece should be tinned at the bottom, for the pickup strip, and near the top for the wire, before fitting to the motor housing. The Z piece is then positioned and the 1mm tab is melted into the plastic with a soldering iron, making sure the Z piece does not foul the centre wheel. It will not cause any electrical problems if it fouls the wheel, but rather a physical problem on tight curves. A piece of phosphor bronze strip is then soldered to the bottom of the Z piece, cut to length, and bent as shown. If difficulty is experienced in fitting the pickup, it may be necessary to remove the centre wheelset, and refit later. A short length of wire is soldered to the Z piece near the top, and connected to the left hand brush holder from where the original wire was removed.

 

 

16. The trailing bogie already has four wheel pickup fitted, but on one side it is the centre wheel that picks up. There is no weight on that wheel, which I am not keen on, so I have fitted a pickup to the third wheel on that side, by soldering a piece of phosphor bronze strip to the back of the existing pickup and adjusted it to bear on the back of the third wheel. This gives the trailing bogie a five wheel pickup.

17. Refit the centre wheelset, if it was removed. Clip in the modified drive wheelsets taking care not to damage the new pickup strip, and that it is in position against the back of the wheels. Refit the motor bogie into the chassis, refit the bogie sideframe, refit the bulb, clean all the wheels and the chassis is ready to test. A job well done.

18. Due to the lack of traction tyres, the modified chassis will need extra weight. Many DIY stores like B&Q sell flat steel strip about 1 inch wide, which is very useful for weighting locos. My preferred option has to be Cerrobend, which is heavy like lead, non-toxic, and, best of all, it melts at less that the temperature of boiling water, so you can make a mould out of thick plasticard, or any other material, and cast your own weights to whatever shape you like. All my modified Lima BR locos were weighted with Cerrobend.

 

I hope this will be helpful to someone. It is quite a straightforward job and does not take long. It has taken me far longer to compose these instructions, than it would have done to do the job.

 

If you feel you are not up to being able to do this modification but you would like it done, I can do it on an exchange basis. You send me your chassis and payment, including return postage, and I will send you a modified chassis by return. PM me for details.

 

If you are planning to visit Modelrail Scotland next week, and you let me know by midday Wednesday, I can have a chassis ready to exchange there, thus saving two lots of postage. I will be at the exhibition all three days. PM me if you are interested.

[burnthebox]

Well done Dhu Varren, an excellent discription of what to do with your Lima 201's to boot them up, do you have any video.'s of yours running,

[Dhu Varren]

Well done Dhu Varren, an excellent discription of what to do with your Lima 201's to boot them up, do you have any video.'s of yours running,

 

No BTB, I don't have any video of Lima 201s running. However, if you go to Youtube and search for Drumslochtock Summit, there are a number of clips taken at Modelrail Scotland and Aberdeen exhibitions with my modified BR locos. Any loco without lights has been modified. One clip shows a Class 47 with 33 tank wagons going over the summit unaided, and not a traction tyre in sight in any of the clips.

[Kirley]

I always loved my Lima/Murphy 201’s but lived in irritation of their poor running qualities. When the new Murphy 201’s came out I was loathed to ditch the earlier models and I replaced the Lima chassis with Bachmann Class 66 ones. The last Lima 201 I had left I tried to modify the Lima chassis by having two motor bogies using the same principal as on my A Class models. It was not a great success and it lay unused until David’s very interesting modification as posted above.

 

I got talking to him at the Glasgow Show and offered him the challenge of doing his modification on my double motor bogie 201. He rose to the task and I included a set of Ultrascale wheels which I had bought some years ago to replace those on the Lima 201, which worked fine on the level but without the ‘traction’ tyres they slipped on inclines so I had abandoned that idea.

 

 

 

David not only replaced the wheels, made new pickups, a new weight made from Cerrobend, but also did a superb job on my lights including a circuit board out of a non-powered HST power car, suitably modified.

 

 

 

Well how did it turnout as a running model, what would it pull and how would perform on inclines? Have a look at it in motion in my Kirley Junction Layout Thread and judge for yourself.

[DiveController]

This is a very timely resurrection of this recent thread. I have a Lima 201 Flesk on the way to USA purchased based on David's thread that these could be made to run. NO experience doing any of these modifications but will give it a go. Any more photos of how to update her would always be appreciated.

Edited May 5, 2015 by DiveController