mr magnolia Posted July 23, 2011 Share Posted July 23, 2011 I've decided (by dint of testing) that I don't have a problem with the cleanliness of the track, or with the cleanliness of the wheels, or of the provision of current through the pick ups from the wheels to the pointy bits that then carry the current to the copper strips in the loco that connect to the motor.. Current through the track seems OK also. I do however have problems with the motors stalling and stuttering and, in particular, refusing to start up after coming to a smooth stop in direction 1 and being asked to start again in direction 2. After wiggling the control knob wildly, a little nudge often (but not always) gets things going again, albeit at about 100mph because the control knob is set so high by that time... Sometimes I think it is actually a pick up issue as a sideways wiggle of the loco can also (but not always) kick things off again, but mostly it feels (in my head) as though its a problem with sticky motors or gears or wheels. I've a Farish 37/0 and a 24 and when they decide to run they run beautifully but when they decide not to, they is pigs! I've an 04 also, but I can get that to run nicely for a while by dismantling it and putting it all back together again. your experienced thoughts on the matter would be most welcome. Should I just bathe the lot in IPA and then drop some powerlube into them? Link to post Share on other sites More sharing options...
hollywoodfoundry Posted July 23, 2011 Share Posted July 23, 2011 From the evidence presented, I would probably concur that your problem is most likely to be stickiness in the mechanism. This is the reason why mechanisms need to be run-in to improve their performance. And your suggestion of using IPA to clean them is also good, but rather than a bath, I would encourage you to brush all areas with IPA using a cheap toothbrush. Some people say an old toothbrush, but usually old ones have bristles point in every direction, so a cheap new one works better. With regard to lubrication, small drops of oil on all the bearings plus a little Teflon bearing grease on the gears should do the trick. Any of the recommended plastic compatible oils will do the job, personally I use LaBelle 108. The Teflon grease I use is quite cheaply available from a cycle shop. I am afraid I am not familiar with the Farish locos you mention, so others may jump in here to assist, but if they are split frame designs, then perhaps you do have some power collection issues. The most irritating featue of split frame designs is that the power is collected from the wheels, to the stub axles, and via the axle bearings to the side power buss plates. This is a circuitous path and can be a problem because the power must be conducted from the axle to the axle bearings through a surface that needs to be liberally coated in lubrication, and therefore potentially insulated by the lubrication. However, because of the limited room in a N scale mechanism, there is little choice but to use this method. You may find cleaning is required more frequently and also the application of an electrically conductive oil, such as Electrolube, to the axle bearings. Link to post Share on other sites More sharing options...
bertiedog Posted July 23, 2011 Share Posted July 23, 2011 Actually in use grease becomes conductive on bearings as the minute metallic particles from the bearings conduct. In phone exhchanges we used this to good effect getting aluminium joints in DC power systems taking thousands of amps, the joint was cleaned with grease and a wire brush and the slush was left in place when done up tight. Electro-lube do both oil and grease that conducts, but only use tiny amounts, as Electro-lube can attack some paints etc. But with tiny N gauge mechanisms it may be out of true frames etc, that are the bigger issue, not allowing all the wheels to touch the track evenly. Check the chassis over, drop out the wheels if possible, and carefully check over the bearings depth, not easy at this scale, Add the wheels, if possible leaving out the gear connecting the motor, dependant on the design, and carefully check it all rolls freely down the flat track, no wobbles or Ducks progress! At the minimum leave together and run on even track under power and critically observe the action of the loco, check for any wobbles, grinds, or duck's(side to side), progress. If there is any, it needs attention. If it has pickups, then see that they bear on the wheels gently, and the wheels backs are smooth, remove any pips, marks or paint and if needed,polish gently with brasso etc.(remove all traces of brasso before final cleaning and lubricating). The backs should be mirror smooth if possible. The pickups should not be so tight as to drag, and when the whole thing is smooth,and re-assembled it will need about an hours running to settle it in. Finally clean and polish the track, do not use track rubbers etc, they leave rubber and grit behind. Wipe with IPA or meths, and then polish with a clean cotton cloth. If it is nickel silver track, do not clean with abrasive, unless you then clean and polish it with successive finer grades up to 1000 grit or finer. Nickel Silver has a work and age hardened surface, and vigorous cleaning with course emery ruins the surface. Restore with a finest grade grit, and then rub a polished steel drill shank along the rail top to work harden the rail top where the wheel touches.. Steel track can be cleaned with fine emery paper, at least 800 grit or better, 5000 grit is made!! 1500 grit is available from car paint suppliers. Sounds like a bit of work and it is, but N gauge needs clean track and wheels to give it best.Also check the type of controler, a PWM or feedback type is better with N Gauge in DC operation. Some simpler plain controllers are too crude in operation, all right for OO but not sophisticated enough for N gauge. Bear in mind though that a controller however good will not cure a bad loco. Stephen. Link to post Share on other sites More sharing options...
hollywoodfoundry Posted July 24, 2011 Share Posted July 24, 2011 Just one additional point, the split frame design can often cause wear in the axle bearings. This is due to minute sparking from the power collection process across the gap between axle and bearing. Good point, it was first noticed by Gordon Varney in 1938, when he changed from the axles running in plain diecast bearings and he changed to brass. His friend Bob Lindsay had noticed the zinc was electroplating the axles and then wearing away to a slush. Most US tender locos used no pickups, they return to tender, and plain diecast frames wear badly, Mantua introduced brass sleeves for this reason as well, in about 1939. Frank Hornby did not worry in the UK, the wear was there, and the slush, in Dublo mechanisms. ,Early Roundhouse (US) had steel axles in mazak bearings and they wore due to the electrical reactions. The makers who disregraded this were Bachmann etc in China and Hong Kong, with mazak stub axles, plated with copper and chrome, running against mazak, it was a mechanical and electrical mess!!.They learnt the mistake, and now use steel axles in brass or plastic etc. Oddly through all of this, one maker, Tri-ang got it to run right, steel on steel!! it wore, but not due to electrical effects!! Stephen. Link to post Share on other sites More sharing options...
RMweb Premium Steven B Posted July 25, 2011 RMweb Premium Share Posted July 25, 2011 It sounds like you've got problems with the electrical pick-up. The models you mention are all newer ones, and the axles run in plastic frames so the comments about split frame or metal chassis don't apply. Each of these three locos does have a set of brass contacts that take the power from the wheels to the main chassis. Nudging the loco sideways as you do is enough to cause the wheels to shift on the track and improve the contact of the pick-up wipers. I've got one class 37 that suffered from similar problems (and is the only one I've completly stripped down), and the 04 is notorious for having poorly working pick-ups from the factory. All it took to get both running perfectly was to adjust the pick-us. Proding and poking the loco whilst you measure the continunity can be enough to get the loco moving. Just because they appear to work whilst you're testing doesn't mean that it'll work when it's in normal use. It's also worthwhile checking that the contact between the rear of the wheels and the electrical contact strips are clean. Happy modelling, Steven B. Link to post Share on other sites More sharing options...
hollywoodfoundry Posted July 26, 2011 Share Posted July 26, 2011 Thanks Steven, I was not sure if this model used split frames, but if not, then I suspect you are right in your diagnosis. Link to post Share on other sites More sharing options...
mr magnolia Posted July 26, 2011 Author Share Posted July 26, 2011 many thanks guys - i shall investigate and report back in due course Link to post Share on other sites More sharing options...
mr magnolia Posted July 27, 2011 Author Share Posted July 27, 2011 sorry for the rather brief reply above - I was constrained by some non-train family matters! I really appreciate the time you guys have taken to answer my query - many thanks indeed. You have armed me with a number of approaches that I shall be exploring in the next 'little while'. Meantime, I have just wired up my first loco release set of turnouts in the terminus, and i believe that gives me a complete track circuit to allow full scale testing manoeuvres while I complete the rest of the sidings trackwork. I have my toothbrush and IPA at the ready! Perhaps the one thing that I had wondered about that hasn't been mentioned here is the 'back to back' dimensions of the loco wheels? Would a fault in that effect pick up of power, or is more a running/derailing type of problem? Link to post Share on other sites More sharing options...
hollywoodfoundry Posted July 27, 2011 Share Posted July 27, 2011 As you guessed, the B2B has more effect on the locomotive when running through points and crossings. An incorrect B2B, unless it is vastly out of spec., will not cause what you described. Link to post Share on other sites More sharing options...
mr magnolia Posted August 14, 2011 Author Share Posted August 14, 2011 I keep trying and then failing to get a reply up here via an iPod, so will be brief pending access to proper key pad: Have stripped class 37 completely and cleaned all. Looks as though the issue here was/is the sprung copper strips that I presume take the power down from the pcb to the motor contacts. Have fettled with dodgy soldering to fix the one that came apart in my hands, guv with wire replacement. Performance much better but still sticky and noisy- should I try new motor? What type and where from? Link to post Share on other sites More sharing options...
mr magnolia Posted August 21, 2011 Author Share Posted August 21, 2011 And just to add a late night footnote: The major problem in my case seems to be the droppers from the pcb not securely picking up the motor terminals. I've given them some dodgy replacements made from short lengths of wire that seem to the trick and I've dismantled and cleaned and filed the backs of the wheels and reset the pickups, all of which becomes much easier once you've worked out how to pop the axles out! So the unit now goes in two directions and hopefully I can do some running in tomorrow and bed it all back down... Link to post Share on other sites More sharing options...
Dr Al Posted August 23, 2011 Share Posted August 23, 2011 filed the backs of the wheels 'Filed' and 'wheels' are two words that shouldn't be heard in the same sentence!! Best Regards, Alan Link to post Share on other sites More sharing options...
mr magnolia Posted August 24, 2011 Author Share Posted August 24, 2011 It was getting late and my thinking was failing. No doubt it will end ip as a hard learned lesson but at the minute I have shiny wheel backs... Link to post Share on other sites More sharing options...
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