APT Fan Posted January 23, 2021 Share Posted January 23, 2021 Good afternoon, I've just converted a couple of Lima locos to DCC, which will obviously run on DC too. They run fine but lack a decent top speed, I'm assuming that these are quite a few years old now and I'm wondering whether it is worth replacing the motor or if it is even feasible? Thanks Link to post Share on other sites More sharing options...
decauville1126 Posted January 23, 2021 Share Posted January 23, 2021 Might be worth a look and a bit of research: https://diesel-trains.co.uk/lima-replacement-motor-kits.html https://www.ebay.co.uk/sch/strathpefferjunction/m.html?item=362596121842&gclid=CjwKCAiAr6-ABhAfEiwADO4sfRWFBB6w7W3zGW1QSfMZAqfPL9hUnL6KeFWJOvtlDACv2z2K2Y-3bhoCgX4QAvD_BwE&rlsatarget=pla-1139674279347&abcId=9300480&mkgroupid=118098821498&itemid=362596121842&mkrid=710-134428-41853-0&norover=1&targetid=1139674279347&merchantid=6995734&poi=&mkevt=1&googleloc=9045822&mktype=pla&device=c&mkcid=28&chn=ps&campaignid=12125451035&rt=nc&_trksid=p2047675.l2562 I'm sure there must be users on here who can give some feedback. 1 Link to post Share on other sites More sharing options...
Nigelcliffe Posted January 23, 2021 Share Posted January 23, 2021 My limited experience, of one Lima model, and some years ago, was the replacement motors derived from CD drives ran worse than the Lima motor. 1 Link to post Share on other sites More sharing options...
stewartingram Posted January 23, 2021 Share Posted January 23, 2021 With a bit of TLC the :Lima motor is good. In my opinion, a cheaper version of the Hornby one, which itself is a chea[er version of the first Hornby ones, which were copied from the Fleischmann design, fitted to the early 92220 & Brush 4. I have examples of all of them. Link to post Share on other sites More sharing options...
wasdavetheroad Posted January 24, 2021 Share Posted January 24, 2021 Search for 'servicing a lima motor' video. There are several available. I like the one that is 26.16 minutes long 1 Link to post Share on other sites More sharing options...
DCB Posted January 25, 2021 Share Posted January 25, 2021 I like the computer motors, like Modeltorque, but mine come from computers and are helf by a simple strap across the Lima backplate fixing screws. A scalextric white pinion from a crown wheel and pinion fits the shaft. They work well on low voltage and woud need resistors for 12 -20 volts of usual "12 volt" ralway power supplies. The Lima motor has a bit of PCB as a commutator which burns away, and a soft motor pinion which wears like fury which the CD motor cures which leaves the plastic idler gear pivots to wear out and plastic spur gears to strip. The brush spring tension needs to be set accurately and the commutator kept scrupulously clean if they are to run at their best, but they were kids toys designed in the 1970s... Link to post Share on other sites More sharing options...
APT Fan Posted January 25, 2021 Author Share Posted January 25, 2021 On 24/01/2021 at 07:01, wasdavetheroad said: Search for 'servicing a lima motor' video. There are several available. I like the one that is 26.16 minutes long This one? https://www.youtube.com/watch?v=U_66Yq4NkgE Umm, I've already pretty much carried all of that work apart from cleaning the armature in a bath! I might have another go. Link to post Share on other sites More sharing options...
Crosland Posted January 25, 2021 Share Posted January 25, 2021 On 23/01/2021 at 13:13, APT Fan said: They run fine but lack a decent top speed, What's the track voltage? Have you checked the decoder settings are not limiting the top speed? Link to post Share on other sites More sharing options...
Frank Sharp Posted January 25, 2021 Share Posted January 25, 2021 I've fitted one of the 'computer' motors into a Lima diesel chassis. It is actually under a Sierra Leone/Welshpool 2-6-2. Formerly it had two speeds, stopped and rocket. The new motor has made virtually no difference except that now it has some degree of controllability provided you use feed back. Mercian do/did a Fowler Dock tank, an 0-6-0 but the coupled wheelbase is within a fraction of a millimetre so that will be the basis of two others I have to make......sometime. Incidentally that means it will do Russell. Link to post Share on other sites More sharing options...
DCB Posted January 25, 2021 Share Posted January 25, 2021 The computer motor does tend to go from stopped to full speed instantly on the old resistance controllers and on the old variable transformers. These motors draw too little current to work nicely with the usual resistance mats. The variable transformers, autotransformers tend to have a dead spot between -5 volts and + 5 volts. and as many, but by no means all computer motors are basically intended to work on the 5 volt supply from the PSU . Putting a resistor in series does wonders for controllability as does using a Morley controller. If a OO Lima motor isn't fast enough on 12 volts then it's not running right. Should be good for a scale 100, which is plenty fast enough for most diesels apart from Warships and Deltics. Sadly the Deltics and class 50 have HO Bogies and slily little wheels so may be a bit slow. Then again the 08 /09 does an easy 150 when its going right.... Link to post Share on other sites More sharing options...
APT Fan Posted January 26, 2021 Author Share Posted January 26, 2021 19 hours ago, Crosland said: What's the track voltage? Have you checked the decoder settings are not limiting the top speed? I have a gang of Mainline 56s and they all run quite a bit faster, they are all fitted with Plux22 Zimos. The Lima's have Plux22 Lais, yesterday, I swapped out one of the Zimo's into the Lima 47 and it pretty much runs exactly the same so I'm discounting the decoder setup. All decoders have default setting with the exception of lighting controls but for reference CV2,5,6 are all set to 0 after your message prompted me to check. Maximum speed from the command station is set to 127. I haven't tried it back on DC directly yet as there's a bit of wiring hassle with me going the Plux22 route rather than 8 pin. Don't get me wrong, they do run well at lower speeds but just seem to run out of puff at the top end. Perhaps I'm asking too much given the age of the models. Link to post Share on other sites More sharing options...
APT Fan Posted January 27, 2021 Author Share Posted January 27, 2021 (edited) I had some spare time today, so I completely stripped down a class 50 and cleaned it electrically with IPA, including the armature and a thorough cleaning of all the wheels and pickups. The commutator was a little sooty but cleaned up well and I took the courtesy of checking the magnet and the magnetism looked good to me. Running on DC the motor achieves good speed and when I put everything back together and ran on DCC it does appear to run slightly better / smoother and perhaps a little faster, oh the traction tyres have been replaced too. A couple of questions though, given that its had a complete strip down, what is a reasonable run-in time? Also, I notice that in the video only the centre bearings of the gears were oiled. Is it inadvisable to oil the actual teeth of the gears? Thanks Edited January 30, 2021 by APT Fan 1 Link to post Share on other sites More sharing options...
d00m Posted January 27, 2021 Share Posted January 27, 2021 In the Lima manual it says that the gears are 'self lubricating' so yes, just the bearings. Oiling the teeth causes them to pick up dirt and fluff. 1 Link to post Share on other sites More sharing options...
APT Fan Posted January 30, 2021 Author Share Posted January 30, 2021 So the 47 came into the depot on Thursday night for a full service on the motor and gearbox and everything cleaned up nicely, plus the magnet seems okay, brushes showing some slightly uneven wear. When running directly on DC, two things were noticeable, firstly it seems to run slighly faster in one direction (reverse) and adding extra pressure to the back of the brushes seems to increase the speed slightly. I'm wondering if there is a mechanical issue here in terms of a slightly uneven commutator surface or perhaps the sleeves for the brushes not being completely square. DC voltage applied was 16 volts and the motor was drawing 150mA. I carried out some DCC tests on a 3 metre test track, comparing three locos. Class 56 (Mainline) - 0.7 m/sec (actual) = 120 mph (scale speed) Class 50 (Lima) - 0.5 m/sec (actual) = 85 mph (scale speed) Class 47 (Lima) - 0.4 m/sec (actual) = 68 mph (scale Speed) So the 50 is borderline acceptable and the 47 would only look authentic hauling heavy freight, the system reports it is drawing 140mA and the measured rms track voltage was 16.3 volts. The Lima figures are for the forward direction which are slightly worse for the 47 (73 mph in resverse). The next stage was to have a look at the Limas on a DC track which required making up a Plux 22 blanking plate, not easy given how small the connections are and my failing eyesight! The Lima 47 yielded the following results. Class 47 (Lima) - 0.55 m/sec (actual) = 92 mph (scale speed) for Forward direction. Class 47 (Lima) - 0.65 m/sec (actual) = 102 mph (scale speed) for Reverse direction. Really I cannot say there is a motor issue given that it runs well enough on DC. I need to be thinking about whether the DCC setup can be tweaked. Link to post Share on other sites More sharing options...
stewartingram Posted January 31, 2021 Share Posted January 31, 2021 I could be wrong here, but way back when I was in the local club, and did a swap of mechanisms with one of my mates. If my memory is right , I put the mech from a 50 (slower geared) into my AEC GW railcar, the faster geared mech from that went into his class 50. See if you can compare the gears on different mechanisms. Stewart Link to post Share on other sites More sharing options...
Crosland Posted January 31, 2021 Share Posted January 31, 2021 You never answered my first question, what's the DCC track voltage? The max. voltage at the motor will be a volt or two less due to losses in the decoder. In comparison, what DC voltage are you using? Link to post Share on other sites More sharing options...
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