Chinese motor test

[bertiedog]

The universal in best inboard of the first axle if you do Proto 2mm standards, but forward if curves are tighter than scale radius's. The universals are brass ball joints, all home made in the lathe. For P2 scale radius curves the uni can be dispensed with, the slack in a socket joint is enough to work.

Stephen.

[Richard Hall]

The 7mm coreless motors open up the possibility of a self-contained tender drive which intrigues me.  I remotored a couple of Farish J39 tender drives with Mashima motors, but the extra bulk of the motor meant I could never get enough weight in them for good traction.  The more hopeless of the two is now in bits while I try to rework it for the coreless motor, and persuade all the wheels to go round without sticking. I might have to replace the wobbly Farish gears between the axles with nice Polish ones.  If it works it might end up as my first 9.42 gauge loco - reprofiled tender wheels and an unpowered 2mm Assoc loco chassis.  I might even be able to get enough lead in the tender to bin the horrible traction tyres.  Rubber tyres belong on motor cars, not railway locomotives.

[Nig H]

It's not simply a question of fitting the motor in the tender, it needs to be far enough back so that the UJ is within the tender wheelbase, otherwise it can cause problems on curves.

 

Jerry

Also, most motors need to fit in the coal space between the front and rear bulkheads (and be hidden with a pile of dummy coal). The height of motors is usually too great for the motor to fit under the rear horizontal plate.

 

Nig H

[bertiedog]

There are simply no clearance problems with the loco to tender coupling, the shaft goes under the screws and coupling, completely out of any contact or tight spot. It is just as easy to mount as the "right way" round, but is far better. The low drive shaft is all but invisible to any inspection at normal viewing distance, better than above the footplate through the coal holes!

The loco if small wheeled will need gears, or belts, to get the drive up to the top of the worm drive, or on larger wheels the gear can be underslung mounted.

Stephen.

[queensquare]

Untitled.jpg

 

Outline for 2mm compact tender motor mounting. I have a 3F with this arrangement, pulls well, as loco is solid brass, with transfer weight as well.

If my hands and eyesight can take it I may do some more 2mm, the layout is still functioning at nearly 50 years old.

Stephen.

Can we see a picture of the 3F, particularly the tender arrangement.

[bertiedog]

On the mounting level for the Citizen coreless motor these are 8mm dia, and a Kirtley tender is an internal space of  about 15mm over the axles, allowing a motor to be within the overall space of the outline very easily, with no need to have a coal bulge to cover it. It would rattle around in a standard LMS tender internal space.

[bertiedog]

I do not have the locos to hand, stored away whilst ill long ago. I will find them later, or do a new one with these modern motors, as the older had hand made motors. A Kirtley outside framed 060 would make a good subject, restoring a 4mm at present, so no need for drawings etc.

Wheels are still a problem, but with outside frames plain disks would do with fake spokes,

Stephen.

[queensquare]

I do not have the locos to hand, stored away whilst ill long ago. I will find them later, or do a new one with these modern motors, as the older had hand made motors. A Kirtley outside framed 060 would make a good subject, restoring a 4mm at present, so no need for drawings etc.

Wheels are still a problem, but with outside frames plain disks would do with fake spokes,

Stephen.

 

I would be grateful if you could find them as I'm intrigued to see how this works, your diagram still doesn't convince me as it takes no account of axle muffs etc.

 

As for plain disc wheels with fake spokes, we left those behind well over fifty years ago.

 

Jerry 

[bertiedog]

On tight fits in 2mm, try off setting the shaft to one side to get clearances.

The wheel muffs? I don't use them, as they cause space issues, I use 1mm fibre glass rod for the tender axles, with pin points turned on the face of the brass or nickel wheel. I usually use insulated drivers, the pickup is tender only, allows 1.5mm stainless steel axles, for the loco drivers, with a 1mm stub end entering the wheel.

 

For split axles in a loco I use 1.5mm axles, with the centre turned to .5mm dia on one side, and a hole of . 7mm on the other, and glue with hard epoxy to join and insulate, no muff needed. The axle is joined up in the lathe whilst the epoxy sets hard. If a brass gear is mounted over the join, then a sleeve of perspex or other acrylic hard plastic is needed to prevent a short.

 

All of this is home mechanic level, a lathe is nice but a power drill can do some items or workarounds. The split axles can be made from tube on one side and assembled in a home made V block, no lathe needed at all.

 

Stephen.

Edited June 8, 2016 by bertiedog

[queensquare]

On tight fits in 2mm, try off setting the shaft to one side to get clearances.

The wheel muffs? I don't use them, as they cause space issues, I use 1mm fibre glass rod for the tender axles, with pin points turned on the face of the brass or nickel wheel. I usually use insulated drivers, the pickup is tender only, allows 1.5mm stainless steel axles, for the loco drivers, with a 1mm stub end entering the wheel.

 

For split axles in a loco I use 1.5mm axles, with the centre turned to .5mm dia on one side, and a hole of . 7mm on the other, and glue with hard epoxy to join and insulate, no muff needed. The axle is joined up in the lathe whilst the epoxy sets hard. If a brass gear is mounted over the join, then a sleeve of perspex or other acrylic hard plastic is needed to prevent a short.

 

All of this is home mechanic level, a lathe is nice but a power drill can do some items or workarounds. The split axles can be made from tube on one side and assembled in a home made V block, no lathe needed at all.

 

Stephen.

 

......and this is easier than using tried and tested methods with components readily available from the 2mm Association!  As I said, I remain to be convinced, would still love to see photos please.

 

Jerry

[bertiedog]

A friend who built 2mm fine scale, made his split axles without any lathe, using hypodermic needles, with a steel wire though the holes, all held in alinement in a hard wood jig whilst the glue set hard. Made over length and then filed to length, perfect accuracy in stainless steel. He off set the split to allow brass gears direct to mount on the axle.

Stephen.

[bertiedog]

Please do not take it wrong, but relying on parts from a single source or method limits the choices, there are a legion of other tried and tested ways, just scale down 4mm methods, they work these days as motors are smaller. The days of cumbersome hand made motors and cramped fitting in 2mm should be long gone, and the muff should go too, unless you want to use it, it is up to you completely.

 

Stephen.

[bertiedog]

A little ingenuity goes a long way in 2mm, my first fine scale 2mm was built in the early 60's with perspex drivers, with nickel tyres, and pickups, the spokes were engraved in a home made indexer made from a clock gear!, "engraved" with a scalpel into the perspex, and then loaded with black epoxy paint, then polished flat on the front, instant illusion of perfect scale spokes!, (apart from reflections!). Good enough to run at MRC Central Hall shows without people realising there were no spokes..........

All the stuff is stored away, and as I am crippled with arthritis now, difficult for me to find at the moment.till recovered from joint replacement surgery.

Stephen.

[nigelb]

 I am still getting my head round tender mounted motors  so please excuse the daft question

 

  would it not be possible to  have the   nice round motor mounted in the nice round boiler  feeding a gear box in the tender ? surely the tender would / could be driven on all 3 axles   with space for  extra weight ?

[bertiedog]

It has been done, but people do not generally like a pure tender drive. Also it is only recently that commercial motors small enough to fit the boiler diameters were made.

Most older designs were too large, tank locos could end up with the pole pieces in the tanks to get the motor in, and small 060 tender locos were a nightmare till coreless motors turned up.

I'll strip one of the micro motor boxes to show what is inside for reuse in transmissions.

Stephen.

[2mmMark]

The motors on the eBay gearboxes recommended by Stephen Bertiedog are definitely useful. They have longer shafts than the cylindrical coreless motors so they're a bit easier to mount worms on, as they are designed for that in the first place.  The gearboxes are also very neat, some nice gears in there.

 

Question about the up-market coreless motors - do they have a 5.5mm mounting thread on the motor face?

 

Mark

[2mmMark]

 I am still getting my head round tender mounted motors  so please excuse the daft question

 

  would it not be possible to  have the   nice round motor mounted in the nice round boiler  feeding a gear box in the tender ? surely the tender would / could be driven on all 3 axles   with space for  extra weight ?

 

I mostly model tank locos.  Avoids getting a tender behind.

 

Mark

[bertiedog]

Yes the nose is threaded about 5.5 which seems a sort of standard.

I do not still use fake spokes, the wheels are solid nickel silver, then recessed at the front, spokes added from rounded edge strip,the boss added and the lot silver soldered, then the back is machined away to reveal the fully spoked wheel blank. Six in an evening are possible, cost minimal

.

4mm wheels are done in the same way.

 

Stephen

[Yorkshire Square]

I mostly model tank locos. Avoids getting a tender behind.

 

Mark

I had heard that you tend to carry most of your ballast up front...

[Quarryscapes]

Yes the nose is threaded about 5.5 which seems a sort of standard.

I do not still use fake spokes, the wheels are solid nickel silver, then recessed at the front, spokes added from rounded edge strip,the boss added and the lot silver soldered, then the back is machined away to reveal the fully spoked wheel blank. Six in an evening are possible, cost minimal

.

4mm wheels are done in the same way.

 

Stephen

 

That's given me some great inspiration on how to make cast wheel centres strong enough to turn the rims when assembled, having had more than enough failure with cast centres and separate tyres and axles, I'm now looking at a 1 piece cast nickel silver wheel with stubs as per the association wheels, but bored to fit an internal insulating spindle rather than an external muff. 

[Caley Jim]

..... You would then have to have more gears/pulleys to get the drive back up again in the loco.

Why?  The worm doesn't need to be on top of the wormwheel.  My three tender locos (they're actually quite hardy   ) all have the drive going below the footplate and the worm mounted under the wormwheel.  Like Stephen, I have an aversion to driveshafts going through the cab, especially on the older types of loco with a very open cab.  (and 'elf an' softly wouldn't like it!)

 

This is the arrangement on my 98 class 2-4-0, also showing the compensation beams.

 

Because of the large wheels the driveshaft is angled down slightly from the tender to pass under the rear coupled axle.  The rear beams pivot about the layshaft.

 

Jim

[decauville1126]

http://www.ebay.co.uk/itm/Citizen-Micro-Coreless-Electric-Motor-with-Pinion-Gear-Job-Lots-5-Pieces-/191883192173?hash=item2cad21276d:g:BIsAAOxyf1dTJaN4

 

Try UK supplier on Ebay, 5 for £10, 10mm dia 9 volt coreless, made in Japan, by Citizen. Some coming, will report. Previous Citizen motors were top quality.

Stephen

Well I've taken the plunge and using the 'make an offer' option have got 10 for £16.00, post free. So again a big thankyou for sourcing these.

[queensquare]

Why? The worm doesn't need to be on top of the wormwheel. My three tender locos (they're actually quite hardy ) all have the drive going below the footplate and the worm mounted under the wormwheel. Like Stephen, I have an aversion to driveshafts going through the cab, especially on the older types of loco with a very open cab. (and 'elf an' softly wouldn't like it!)

 

This is the arrangement on my 98 class 2-4-0, also showing the compensation beams.

DSCN0414.JPG

 

Because of the large wheels the driveshaft is angled down slightly from the tender to pass under the rear coupled axle. The rear beams pivot about the layshaft.

 

Jim

Thanks Jim that's a lovely bit of work, a picture is worth a thousand words on something like this. Personally I prefer the much simpler approach, I don't find the drive obtrusive through the coal holes- 9 or 10 thou spring steel with a very slight arc so that when it's spinning, like a very shallow skipping rope, it's invisible.

On a loco with drivers that big I find a straight 38:1 reduction perfectly adequate which reduces the number gears. When I have used multiple gears for reduction I have found the noise irritating, how quiet are you mechs.

 

Jerry

Edited June 8, 2016 by queensquare

[Caley Jim]

......... When I have used multiple gears for reduction I have found the noise irritating, how quiet are you mechs.

Depends n what you mean by 'quiet'.  Some are noisier than others, but I don't find that intrusive at home and under exhibition conditions you can hardly hear them.

 

Jim

[Richard Hall]

An evening of coreless fun and frolics, and not really sure what I have learned.  I managed to bodge one of the Chinese coreless motors into the Farish J39 tender drive and tried it with a basic DC controller.  It ran but not especially well.  So (and disregarding all the warnings that have been published over the years) I hooked up my HH feedback controller.  My only previous experience of coreless motors has been the ones that Farish use in their recent models, and those won't run on feedback at all.  So I was surprised when the J39 ran beautifully, with good slow speed control and no juddering.  It did this for about thirty seconds, then stopped dead and could not be persuaded back into life.  The multimeter showed an open circuit across the motor wires.

 

I pulled the dead motor to bits but couldn't see anything obvious.  So I fitted another motor to see if I could kill that one the same way.  It has now run on the HH at varying speeds for about an hour with a moderate load (four coaches) and still works. However I'm not yet convinced that it has any advantages over the cheap 1015 cans apart from its size.  Low speed torque seems pretty feeble. Having said which the Farish tender drive is possibly the worst piece of model railway engineering seen since Lima went bust: this one occasionally locks up randomly for no apparent reason, which may have been what caused the demise of the first motor. I'm tempted to try one in a Farish 2MT (the motor dimensions are identical) and give it a bit more of a fair trial.