Sticky running

[idris]

Newly laid (mostly) new Setrack.

 

Old rolling stock, all with XO4 or XO3 motors which have been stripped and thoroughly cleaned, and have life left in the bushes. I was hoping to strip and clean the axles, but the wheels look as though they're press fit, so I'm reluctant to start applying force to such old models.

 

Vintage H&M Clipper controllers.

 

I know older kit has a reputation for being harder to reliably run slower, but with limited testing I'm finding it nigh on impossible to get the engines to move without cranking up the controllers to about 75%.

 

My guess is that the controllers may be the issue, but I've yet to pop them open and clean them. Any thoughts on how to service what I've got to solve the problem?

[kevinlms]

I wouldn't attempt to remove the wheels from axles, more trouble than its worth. You may be able to see bits of fluff & hairs perhaps, remove with tweezers.

 

What is the top speed of the loco like? It should run fairly quickly, unless perhaps you have a smoke unit fitted, which could slow down the loco considerably.

 

Can you borrow another controller from someone, or take to anther layout? You need some investigative work, before you go dismantling old controllers.

[johnb]

It may not be the controller, someolder locos will shoot off at a low setting with the old H&M conrtrollers. It could be that the magnets in the old motors  have weakened seriously How far did you go with the stripping down? Taking the magnets away from the motor frames can weaken them, it's ll to do with the magnetic circuitry. Maybe some new magnets are needed.

 

Re opening the controller, I would very strongly advise that you don't open it. There's mains voltage wiring in there, so unless you are trained  in electrical works it NOT a good idea.

 

John

[idris]

I don't think I can easily borrow another controller of get the locos on another layout.

The problem doesn't seem to be unique to one loco, hence my attention on the controllers.

 

That said …

The magnets were removed (anything that could be disassembled and cleaned was). IIRC they felt strong, but I confess my fingers haven't been calibrated for Wb/in² recently.

From what I've read about neodymium magnets they have the effect of increased torque, but I'm not convinced that's a problem. The locos are pulling nothing and really ought to get started more easily and run quickly (too quickly for a small twisty layout) once they get moving. My feeling is that that would be treating the symptoms, not the cause.

 

I'm not concerned about servicing the controllers as I have sufficient technical knowledge and equipment to be safe. What I lack is H&M controller specific knowledge, though that is compensated for by their beautiful Victorian style engineering and simplicity.

[stewartingram]

Older Triang style chassis are easy to strip down. Remove the rods, and you will find the wheels are different on each side. The insulated wheels (pickup side) have a plastic insulator in the centre, btetween the wheel and axle. This is prone to damage if the wheel is incorrectly removed.

Having been a service engineer (big title, small job !) for many years, I developed a safe way to remove these wheels. The secret is to go to the opposite wheel, ie the non-insulated one. Then use a fine pair of electronics/modelling pliers, inserted behind the wheel. This enables the wheel + axle to be levered out of the insulated bush at the other end, the pliers giving equal support to the wheel either side of the axle.

Re-assembly is little more that pushing the insulated wheel back onto the axle by hand, with a gentle tap with a small hammer on the non-insulated wheel if required, whilst supporting the insulated wheel on a flat surface. A visual check to see if the wheels are parallel, and a measure of the back-to-back is required. I prefer calipers, though it is possible with care to use a steel rule!

Having repaired many many locos, often removing axles, I find this way works.

To clean axle holes, I use a very thin strip of rag, with a tiny knot tied in it. Just poke/pull through the hole. Lubricate the (cleaned) axle with a smidgeon of Electrolube rather than oil, before re-assembly.

 

Stewart

[DCB]

It is inevitable that a crude resistance controller like the clipper will have trouble starting a crude direct worm drive chassis like an X04 powered Triang Hornby one.

The half wave feature is useful but "Sticktion" will always be a problem.  It is caused by among other things the coarse worm pushing the worm wheel sideways as it starts to revolve and with Triang / Hornby chassis it can move quite a way.  

 

There are a couple of things that can be done, firstly the locos, Shimming the worm wheel  is a big help, shim between the worm and the chassis sides with brass and or steel washers on the driven axle to give just a few thousanths of an inch clearance, 10 thou perhaps.  If you have a plastic worm wheel slip a brass washer into the recess between boss and re bulge for teeth, better still change it for a brass X04 one.  

Shimming really helps starting and slow running and reduces the tendency for the 4-6-0 s etc to crab down the track.  Be careful removing wheels, apart from shimming the worm wheels, I try to leave them alone or fit Romfords on Markits Triang axles, (Actually several of mine have Hornby Dublo wheels) but if you push the non insulated wheel off it may be loose on the axle when refitted, if you push off the insulated one you may need a new bush, which ever way you choose re setting the quartering is challenging.  However you have to remove at least one to shim the worm wheel but don't take them off unnecessarily.  Incidentally the really old 1950's Mazak wheels flanges can with care be turned down to run on code 75,  the steel tyred ones are nothing like as easy (Impossible).

 

The X04 is a bit fussy about the brushes being exactly the right length, I bend mine to get them exactly on the centre line of the commutator when seen from in front.  If you can find them the brass single start (TT) worm helps starting and slow running but gets very noisy at line speeds.

 

The other necessity is to get a better controller,  Other people like pulse power and feedback, but the X04 tends to overheat when fed spikes of 16 volts so I like variable voltage like OnTrack or Morley, or a Hammant and Morgan Safety Minor which is a variable Transformer, crack them just off zero and you can light an LED from the output of around 2 volt, try it with a clipper and it will go Pop a the voltage will be circa 16 volts.  The old Playcraft controller was also variable voltage but they all must have been scrapped years ago.

 

The later "Layshaft" chassis are much better theoretical engineering wise but I have several worn out Bachmann chassis and have even replaced a Bachmann pannier chassis with a Triang one under a Lima 94XX body.

 

A nicely shimmed Triang Chassis will never equal the slow running crawl of a 2015 Bachmann but wont start like a drag racer either, come to think of it  full size steam locos cannot crawl along particularly slowly either...