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Richard Hall

Chinese motor test

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it is the low mass and efficiency in coreless motors that give troubles with feedback, to much back EMF from coreless, and pulses upset them, as each pulse makes them twitch in response, which makes them noisy, High frequency pulses work. but not low mains frequencies used on most older controller designs. They run better on pure DC or DCC set up for coreless running.

Stephen

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it is the low mass and efficiency in coreless motors that give troubles with feedback, to much back EMF from coreless, and pulses upset them, as each pulse makes them twitch in response, which makes them noisy, High frequency pulses work. but not low mains frequencies used on most older controller designs. They run better on pure DC or DCC set up for coreless running.

Stephen

Yes, that was my understanding.  The performance of this motor in the J39 was misleading.  Instead of going to bed at a sensible time I put one in the 2MT (it is indeed a direct replacement for the Farish one) and found the new motor behaved exactly the same way as the Farish one, i.e on the HH controller it skipped, stuttered and generally didn't want to know. I think the difference between the two is that the 2MT is very light and free-running  whereas the J39 tender has a lot more mass and a good deal of friction from all those little badly formed gears. So the motor is working much harder in the J39.

 

Controllers are vexing me.  The coreless motors and the very small (8 x 15) cans have totally different characteristics to the older and larger motors, and I haven't yet found a controller that will suit both.  DCC would get round the problem, but it's a big investment when I don't need any of the features that it offers.

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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.

That would be typical of the failure of a small coreless motor when subjected to a crude feedback controller, such as the HH. Proving the failure was down to the HH is nearly impossible.

 

- Nigel

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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

 

Handmaking six wheels in an evening is very impressive, are there any pictures of how you do these?

 

Jerry

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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.

 

I got mine for 14.00. I wonder how low he will go in accepting offers

 

Chris

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Handmaking six wheels in an evening is very impressive, are there any pictures of how you do these?

 

Jerry

 

Hell, making six wheels is impressive! :D

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Yes, that was my understanding.  The performance of this motor in the J39 was misleading.  Instead of going to bed at a sensible time I put one in the 2MT (it is indeed a direct replacement for the Farish one) and found the new motor behaved exactly the same way as the Farish one, i.e on the HH controller it skipped, stuttered and generally didn't want to know. I think the difference between the two is that the 2MT is very light and free-running  whereas the J39 tender has a lot more mass and a good deal of friction from all those little badly formed gears. So the motor is working much harder in the J39.

 

Controllers are vexing me.  The coreless motors and the very small (8 x 15) cans have totally different characteristics to the older and larger motors, and I haven't yet found a controller that will suit both.  DCC would get round the problem, but it's a big investment when I don't need any of the features that it offers.

 

A good place to start is with a reduced AC input voltage if you have a controller requiring that.  15vAC or more is way OTT for 2mm use.  I've used 9vAC plug-in transformers with great success with several controllers (AMR feedback, Varipulse, Gaugemaster, Pentroller).

 

The very cheap PWM controllers available on eBay for two or three pounds are pretty good. The only thing I've found where they come up wanting is with my Z gauge based NG models. They will run then smoothly enough but will not give a satisfactory slow start. For these, I like the System Joerger controllers specifically designed for Markiln mechs.

The PWM and System Joerger need smoothed DC input, so I use either rechargeable PP3 batteries or a switch-mode 9vDC power supply.

 

You shouldn't need more than 500ma for either AC or DC power supplies.

 

Another good option are the Medvend controllers. I only have a simple battery version so I'm not fully up on them.

 

The one controller that some people have found disappointing for 2mm & similar is the Pictroller. They seem OK for steady speed running but have been found lacking for slow-speed stop-start. It's thought that the motor sensing program on the PIC isn't coping well with very small motors.

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I dug out some Chinese PWM controllers that I bought a couple of years ago and briefly tested before sticking them in a box - disregarding the one that only throttles down to 10% I have two, one around 500hz the other 16khz or so.  Guinea pigs (all coarse scale, sorry):  Dapol Class 26 diesel (unmodified), Farish Pannier (Chinese 1015 can), Farish J39 (tender drive, Mashima M16K), Farish 2MT (Chinese 7mm coreless), Farish 4F (Chinese 1015 can, shaft drive from tender).  Results - the 500hz controller gave better starting and slow speed performance than the 16khz which is exactly what you would expect, but neither of them were really impressive on anything except the Class 26, which would run perfectly on a Triang train set controller. It really is a remarkable mechanism and tells you nothing at all about whether a controller is any good. Maybe I should give up on steam and build a model of Kyle of Lochalsh circa 1980 - I have photos...

 

I suspect that for steam locomotives, with the inevitable varying degrees of friction caused by conrods and valve gear, slightly imperfect quartering, axles moving fractionally in their bearings etc, some kind of feedback control is needed unless you can build mechanisms to Swiss watch standards.  I found that the J39 in particular ran slightly better at slow speeds if I "pulsed" the controller by rapidly twitching the control knob back and forth a few degrees, but that quickly gets tedious.  Someone recommended an old AGW controller to me and it is on its way courtesy of Ebay, but I have my doubts as to whether it will work with the coreless motors.  These little trains are going to see me having an extended stay at Fulbourn Hospital if I don't find a controller soon that does what I want it to do.  Benchmark remains the J39 on a Gaugemaster HH (two minutes 15 seconds per driving wheel revolution) but I can't survive on J39s alone.

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I have found that most decent/better quality motors aren't always happy being fed the harsh feedback some controllers put out. Certainly most Mashimas I have used from 1833's down seem to prefer a simpler dc current or react just like coreless types, if perhaps to a lesser degree depending on the motor involved. Having seen one of the Medvend controllers in action recently I have to say they appear to give very good control of most N gauge stuff. Shop 3 sells the dual powered battery(9vPP3)/mains version and it seems worth a punt. I keep meaning to get one as the cheap Bachmann controller some say is quite good - I aquired one via the Farish 4F passenger set a while back, doesn't seem to have much in the way of decent low speed control compared to the simple and ancient homemade emitter/follower handheld controllers I made back in the 80's which I still use when dc is needed.

 

In my view it's a mistake to belive that going DCC is the easy answer. It can be, but only if you use the best chips, CT/Zimo, because you still find the need, well I have anyway, to configure the decoders to best suit each individual motor type/size in many cases, certainly the coreless, and only these makes seem to have the firmware and motor parameters to make this feasible. Otherwise, from and including Lenz downwards, dc control via my old controllers is better. And something I did not expect when I first went DCC.

 

Sometimes this modelling lark can be a right old game..........

 

Izzy

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I have found that most decent/better quality motors aren't always happy being fed the harsh feedback some controllers put out. Certainly most Mashimas I have used from 1833's down seem to prefer a simpler dc current or react just like coreless types, if perhaps to a lesser degree depending on the motor involved. Having seen one of the Medvend controllers in action recently I have to say they appear to give very good control of most N gauge stuff. Shop 3 sells the dual powered battery(9vPP3)/mains version and it seems worth a punt. I keep meaning to get one as the cheap Bachmann controller some say is quite good - I aquired one via the Farish 4F passenger set a while back, doesn't seem to have much in the way of decent low speed control compared to the simple and ancient homemade emitter/follower handheld controllers I made back in the 80's which I still use when dc is needed.

 

In my view it's a mistake to belive that going DCC is the easy answer. It can be, but only if you use the best chips, CT/Zimo, because you still find the need, well I have anyway, to configure the decoders to best suit each individual motor type/size in many cases, certainly the coreless, and only these makes seem to have the firmware and motor parameters to make this feasible. Otherwise, from and including Lenz downwards, dc control via my old controllers is better. And something I did not expect when I first went DCC.

 

Sometimes this modelling lark can be a right old game..........

 

Izzy

I have one of those Bachmann controllers and it is better than it has any right to be, especially since it looks and feels as though it fell out of a Christmas cracker, but as you say slow speed control is not 100%.  The Mashima M16K is the odd one out in their range, being open frame like the Tenshodo / Hanazono motors but with a better standard of finish.  Not very common, but undoubtedly the best motor I have yet come across with enough torque to pull the side off a 2mm house. It just loves feedback and "rough" DC, the harsher the better. In fact I don't know why I'm bothering with these Chinese motors, I should just fit M16Ks to everything.

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I have one of those Bachmann controllers and it is better than it has any right to be, especially since it looks and feels as though it fell out of a Christmas cracker, but as you say slow speed control is not 100%.  The Mashima M16K is the odd one out in their range, being open frame like the Tenshodo / Hanazono motors but with a better standard of finish.  Not very common, but undoubtedly the best motor I have yet come across with enough torque to pull the side off a 2mm house. It just loves feedback and "rough" DC, the harsher the better. In fact I don't know why I'm bothering with these Chinese motors, I should just fit M16Ks to everything.

But it has been confirmed so far Mashima have indeed stopped production.......unless proved otherwise!

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...... I should just fit M16Ks to everything.

OK, so how do I shoehorn one of these into a 0-6-0ST with an open cab and a 4ft diameter boiler?    :scratchhead:

 

Jim

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OK, so how do I shoehorn one of these into a 0-6-0ST with an open cab and a 4ft diameter boiler?    :scratchhead:

 

Jim

At least it's not a well tank.  Then you'd really be struggling.

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At least it's not a well tank.  Then you'd really be struggling.

Been there, done that (Faulhaber 0816)!

 

post-25077-0-00411200-1465593441_thumb.jpg

 

Jim

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Been there, done that (Faulhaber 0816)!

 

attachicon.gif1A and saloon.jpg

 

Jim

That is exquisite.  There is no other word to describe it. It's a shame so few people model early railways now.  Even pre-Nationalisation modelling seems to be in decline. Something to think about if I ever get round to actually building something in 2mm.

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Thanks, Richard. The motor sits in the firebox cab and bunker, with the DCC chip under the cab roof. As far as I'm concerned a model of a loco with a cab half full of motor is better than no model of the loco at all! It has 3 point suspension arranged to try and put as much as possible of what little weight there is onto the drivers.

 

Jim

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Been there, done that (Faulhaber 0816)!

 

attachicon.gif1A and saloon.jpg

 

Jim

Pull the other one Jim. We all know the carriage is really pushing the engine around!

 

Interesting topic on (cheap) motors. Bearing in mind the gestation period for most of my projects, the motor cost is a small proportional investment on a time basis and I prefer to use my old tried and tested favourites.

 

Tim

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I will treat that remark with the contempt it deserves!

Jim

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Interesting discovery this evening.  Titting about with small motors as usual, I put a variable pot in series with the coreless motor in a Farish 2MT.  This one has always struck me as a bit too lively for its own good.  By experimentation I found that at around 400 ohms resistance I get - starting voltage 2.5V, top speed in keeping with prototype, current draw around 18ma flat out, and perfectly smooth running throughout the speed range on a feedback controller. It doesn't seem short on poke, will happily spin its wheels even on a fairly low power setting if I stick my finger in its way. Surely it can't be that simple? I'm guessing that the same trick, with a lower resistance, will tame the small (8 x 15) can motors as well, in which case all my controller problems are over - three way switch and a couple of 10 watt resistors will give me a controller that will work with anything.

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Yes, extra resistance may load the controller output better, as long as the current is low, and the resistor does not get hot, which it will not at 18ma. A small value electrolytic capacitor, 50uf for example, my help as well, must be wired in before the reversing switch. It will absorb voltage spikes which make the coreless motors noisy, might need a bit of experiment to get a good value.

 

A picture of the very small can motors from Ebay, 37 pence each!, first tests show good quality motors. About the same size or smaller than the minitrix motor. The 1mm shaft would need sleeving to fit worms of 1.5mm or 2mm etc. They are 15.5 mm long, and 12.3 dia with flats at 9mm width. Contacts at shaft end. 3 Pole Armature.

 

post-6750-0-30908600-1465926891_thumb.jpg

 

Certainly able to power any 2mm loco they would fit. Also tiny 4mm shunters etc, with a big gearbox.

Stephen.

Edited by bertiedog

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Yes, extra resistance may load the controller output better, as long as the current is low, and the resistor does not get hot, which it will not at 18ma. A small value electrolytic capacitor, 50uf for example, my help as well, must be wired in before the reversing switch. It will absorb voltage spikes which make the coreless motors noisy, might need a bit of experiment to get a good value.

 

A picture of the very small can motors from Ebay, 37 pence each!, first tests show good quality motors. About the same size or smaller than the minitrix motor. The 1mm shaft would need sleeving to fit worms of 1.5mm or 2mm etc. They are 15.5 mm long, and 12.3 dia with flats at 9mm width. Contacts at shaft end. 3 Pole Armature.

 

attachicon.gifMicro motor.jpg

 

Certainly able to power any 2mm loco they would fit. Also tiny 4mm shunters etc, with a big gearbox.

Stephen.

My latest thinking is to put the resistor in the loco rather than have it on the controller output, so that I get the benefit of the higher track voltage.  As you say 18ma should not get too hot, I'll put a 100ma polyfuse in there to stop the loco catching fire if the motor develops a short. I still need to establish the best resistance for the small 8 x 15 can motors which are half way between conventional and coreless motors in their characteristics. So I might end up with a switchable resistor on the controller output for the small cans, and a loco mounted one for the coreless motors. I haven't found the coreless motor at all noisy with the controller I am using (Gaugemaster HH) but other feedback controllers may differ in this respect.

 

I'm also a bit dubious about whether resistors will work on large passenger engines with coreless motors.  The top speed of my 2MT is fine for my needs, but I suspect a Duchess on a 15 coach train might struggle with a 330 ohm resistor stuck in the motor circuit.  Not my problem, I only model small branch lines.

 

Those Chinese cans are the ones I have been testing. We live in a Golden Age for small motors at silly prices. My only fear is that at the end of all this the Japanese manufacturers (Mashima, Hanazono etc) will have given up, the Chinese will have moved on to other things and we'll be stuffed.  From what I understand the latest consumer electronics tend to use linear motors which aren't much use unless you are modelling the Listowel and Ballybunion railway.  (Is there a 2mm FS standard for monorails?)

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Those Chinese cans are the ones I have been testing. We live in a Golden Age for small motors at silly prices. My only fear is that at the end of all this the Japanese manufacturers (Mashima, Hanazono etc) will have given up, the Chinese will have moved on to other things and we'll be stuffed....

 

Not me. I now have more motors than I can ever think of using!

 

Chris

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Not me. I now have more motors than I can ever think of using!

 

Chris

Yes, I have 20 of the 37 pence cans and 16 of the 63 pence coreless.  But pity the poor souls who come after us.

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Yes, extra resistance may load the controller output better, as long as the current is low, and the resistor does not get hot, which it will not at 18ma. A small value electrolytic capacitor, 50uf for example, my help as well, must be wired in before the reversing switch. It will absorb voltage spikes which make the coreless motors noisy, might need a bit of experiment to get a good value.

 

A picture of the very small can motors from Ebay, 37 pence each!, first tests show good quality motors. About the same size or smaller than the minitrix motor. The 1mm shaft would need sleeving to fit worms of 1.5mm or 2mm etc. They are 15.5 mm long, and 12.3 dia with flats at 9mm width. Contacts at shaft end. 3 Pole Armature.

 

attachicon.gifMicro motor.jpg

 

Certainly able to power any 2mm loco they would fit. Also tiny 4mm shunters etc, with a big gearbox.

Stephen.

 

Call that a small motor? THIS is a small motor!

post-12815-0-20931400-1465935662.png

 

OK, it's quite useless for traction but I have been testing these "Linear motors" here:-

 

http://www.rmweb.co.uk/community/index.php?/topic/52987-dcc-controlled-stepper-motor/page-2

 

It does have applications but, perhaps, no more taxing than moving a gate, moving a signal mans arm and flag out of a signal box window or lifting a signal semaphore arm!

 

As here, investigations are on going...

 

 

I have been following this thread with interest.

Because lots of these motors are from Japan, should a title change be in order or do we want to emphasize the cheap/quality aspect as the emphasis of these tests?

(No negative intentions intended, just trying to be accurate/informative?)

 

 

Kev.

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Yes, I have 20 of the 37 pence cans and 16 of the 63 pence coreless.  But pity the poor souls who come after us.

 

They can buy mine when I kick the bucket and my wife sells off my gloat box. Which is where they almost certainly will still be.

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