Replacing Mashima motors

[Ruston]

N20 gearbox/motor unit into a Judith Edge Kitson long boiler pannier tank. £3.60 for the motor/gearbox and pennies for the gears. The chassis is fully compensated even though the motor/gearbox is firmly fixed to the frames and doesn't move. It isn't finished yet and has no pickups but running tethered to a controller it is virtually silent. When the body is on all that is visible of the power unit is part of the vertical shaft.

 

[Michael Edge]

That looks very neat, good idea.

[burgundy]

N20 gearbox/motor unit into a Judith Edge Kitson long boiler pannier tank. £3.60 for the motor/gearbox and pennies for the gears. The chassis is fully compensated even though the motor/gearbox is firmly fixed to the frames and doesn't move. It isn't finished yet and has no pickups but running tethered to a controller it is virtually silent. When the body is on all that is visible of the power unit is part of the vertical shaft.

 

Longboiler-002.jpg

 

Dave 

Very neat - but could you please describe in a little more detail what gears are involved? Some seem to be part of the N20, but presumably the final drive bevel gear has been added?  

Best wishes

Eric 

[Ruston]

Dave 

Very neat - but could you please describe in a little more detail what gears are involved? Some seem to be part of the N20, but presumably the final drive bevel gear has been added?  

Best wishes

Eric 

Everything except for the plastic spur gear and crown wheel is part of the unit as bought. I have seen these units on sale, listed as 200rpm and 300 rpm. The voltage at which those speeds are produced isn't mentioned and some are sold as 3-6v and some at 6-12v. This particular one was advertised as being 200rpm and intended for credit card type door locks. Others mention being for car door locks.

 

The plastic spur gear has a D-shaped hole to fit the output shaft and the crown wheel, which originally had just a 2mm hole, has been opened out and mounted on a turned brass carrier that is fitted with a grub screw to allow for the wheels to be turned for fettling the rods etc. The plastic gears were given to me, so I don't know the source but if anyone can find more I'd like to know. Searches on ebay do show these gears and wheels but they are always packaged with lots of other sizes of gears, which is a bit of a waste but I suppose the packages are still very cheap and the other parts can be used for motorising things such as level crossing gates, turntables etc..

[JohnGi]

Everything except for the plastic spur gear and crown wheel is part of the unit as bought. I have seen these units on sale, listed as 200rpm and 300 rpm. The voltage at which those speeds are produced isn't mentioned and some are sold as 3-6v and some at 6-12v. This particular one was advertised as being 200rpm and intended for credit card type door locks. Others mention being for car door locks.

 

The plastic spur gear has a D-shaped hole to fit the output shaft and the crown wheel, which originally had just a 2mm hole, has been opened out and mounted on a turned brass carrier that is fitted with a grub screw to allow for the wheels to be turned for fettling the rods etc. The plastic gears were given to me, so I don't know the source but if anyone can find more I'd like to know. Searches on ebay do show these gears and wheels but they are always packaged with lots of other sizes of gears, which is a bit of a waste but I suppose the packages are still very cheap and the other parts can be used for motorising things such as level crossing gates, turntables etc..

 

I was also going to ask where you got the final gears from! I found one of the sets you mention on ebay.

 

https://www.ebay.co.uk/itm/Plastic-Gears-Pulley-Belt-Worm-Rack-Kits-Crown-Gear-Set-0-5-Modulus-60-kinds/162509200917?hash=item25d64d9e15:g:~38AAOSwlY1ZETZj

 

Containing 75 gears in total, with 11 crown gears identified thusly.

 

 

Crown Gear: 11 kinds

C152A C203A C282A C282.5A C303A C322A C20082A C28082B C28102.5B C30102B C40102B

 

Searching for "c152a plastic crown gear" which I guessed were the smallest ones I found these, 10 for £1-90

 

https://www.ebay.co.uk/itm/10pcs-C152A-0-5-mold-15-teeth-Crown-gear-Plastic-gears-Aperture-1-95MM/152726691491?hash=item238f385ea3:g:xuQAAOSwYXVY0eGC

 

Product Description

product description:

 

material: plastic

Modulus: 0.5

Number of teeth: 15

D: 1.95mm

D1: 8.5mm

D2: 4.9mm

D3: 4.9mm

H1: 3.0mm

H2: 1.0 mm

H3: 1.0mm

L: 1.0 mm

H: 1.7mm

 

Package Including:

gear  x   10 pcs

 

 

 

 

You can also search ebay for the other types, e.g C203A seems to be 20 teeth, fitting a 3mm axle. Hope this is helpful to people.

Edited May 15, 2018 by JohnGi

[cctransuk]

I have recently taken delivery of a pair of :-

 

https://www.ebay.co.uk/itm/2PCS-DC-12V-6500RPM-Large-Torque-6-Pole-Rotor-Minebea-15MM-Square-Motor-for-Toy/252631354230?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

 

These seem to be very well engineered - no slop in the bearings, incredible torque, virtually silent and a general 'precision' feel. Running at full throttle from an old Tri-ang transformer / H&M controller there was no significant heating whatsoever.

 

Also ordered at the same time, and received today, is a :-

 

https://www.ebay.co.uk/itm/Minebea-3-Pole-Rotor-Carbon-Brush-Motor-DC24V-12000RPM-Screw-Hole-for-RC-Car-Toy-/282369397467

 

This, again, seems excellent, with only the slightest whine at full revs; pretty much silent under normal operating conditions. Size-wise, it would be ideal for larger locos at 4mm. scale.

 

Both types of motor have threaded fixing screw holes; at the price, they are well worth trying.

 

Regards,

John Isherwood.

Edited May 16, 2018 by cctransuk

[johnarcher]

I've had a couple of the smaller square motor -

 

https://www.ebay.co.uk/itm/Minebea-Square-Motor-DC-6V-9V-7-2V-14700RPM-10-10mm-6-pole-Rotor-Large-Torque-/282607882699 

 

Being careful with voltage and resistor in series they seem to run quite happily at reasonable revs (just hand-held, not put in anything yet). Once running they'll slow down to pretty low revs, but don't start very smoothly (I hoped better of six poles), seeming a bit stiff to start, then jump off at some speed - feedback helps tame this though (old ECM Compspeed).

They do seem pretty well-made too though.

[Izzy]

I believe motors need an odd number of poles to enable slow controlled starting, 3,5, or 7 being most common. When I saw these I did wonder, if the spec was correct and not an error, just what kind of slow speed control they would have.

 

Izzy

[johnarcher]

I believe motors need an odd number of poles to enable slow controlled starting, 3,5, or 7 being most common. When I saw these I did wonder, if the spec was correct and not an error, just what kind of slow speed control they would have.

 

Izzy

That makes sense I suppose, it hadn't occurred to me.

The 15mm square motor is also 6-pole apparently, how gently do they start John?

[cctransuk]

That makes sense I suppose, it hadn't occurred to me.

The 15mm square motor is also 6-pole apparently, how gently do they start John?

 

I didn't notice anything adverse - but, at those prices, why not see what you think?

 

Regards,

John Isherwood.

[bertiedog]

Motors of the plain pole tyes must have an odd number of poles to self-start, but six pole are made that self-start due to offset magnets and a biased armature, with a centre gap to allow the windings to be staggered.

It is expensive to wind a 6 pole and frankly, at the low price, these cannot be 6 poles.

These appear to be a high-quality 5 pole, but I have not taken one apart to confirm it.

 

https://www.ebay.co....353.m2749.l2649

 

Stephen

[cctransuk]

Motors of the plain pole tyes must have an odd number of poles to self-start, but six pole are made that self-start due to offset magnets and a biased armature, with a centre gap to allow the windings to be staggered.

It is expensive to wind a 6 pole and frankly, at the low price, these cannot be 6 poles.

These appear to be a high-quality 5 pole, but I have not taken one apart to confirm it.

 

https://www.ebay.co....353.m2749.l2649

 

Stephen

 

..... and I'm not taking one to bits to find out either.

 

However, the photo of a dismantled motor in your link clearly shows six sets of windings - surely not just a mock-up to perpetuate mis-selling?

 

Regards,

John Isherwood.

[bertiedog]

This form of six pole motor is arranged with two pairs of magnets, giving in effect two three pole motors on one shaft. Each magnet pair is out of phase and overlaps giving self-starting. This makes the motor very smooth as the magnet field being split up makes for less cogging. Six pole are noted as powerful for the overall size, it is after all two motors in one.

 

The other form of 6 pole has two six pole armatures on the same shaft, with a gap left between them in the centre, and the windings are staggered around the poles on each end as pairs. This in effect is the same as having dual magnets. This type was used in the Castle Arts Gaiety loco in the 1950's

 

6 pole were once common with field coil motors, where the field coils were divided to make four field magnets. The four magnet solution used in the Ebay motor only became possible as magnets improved.

 

Stephen.

Edited May 16, 2018 by bertiedog

[bertiedog]

Thinking back, Pop Keyser of K's made an early 6 pole motor that looked like the MK1 or Mk 11, and used the same outline, putting two sets of armature stampings on the same shaft, but staggered..

K's design bears a close resemblance to Castle Arts effort. It only lasted a few months in production, too expensive to make.

 

Lindsay in the States offered 6 and12 pole motors made by Pittman in the early 1950's, killed off by cost.

 

Stephen

[bertiedog]

I have found a couple of the six pole motors stored away, to try and test, and they are really very smooth runners. The only point against them is the overall power is a little lower than others of the same size, with the current proportionally lower as well.

I was mainly using the small Mitsumi, but this motor is better made, and suits all but large 00 pacific locos etc.

The Ebay listing I got them from did not show the internals, nor claim 6 poles.

Quite a useful motor. and about £1.25 or so each........incredible value.

 

Stephen

[micklner]

I have found a couple of the six pole motors stored away, to try and test, and they are really very smooth runners. The only point against them is the overall power is a little lower than others of the same size, with the current proportionally lower as well.

I was mainly using the small Mitsumi, but this motor is better made, and suits all but large 00 pacific locos etc.

The Ebay listing I got them from did not show the internals, nor claim 6 poles.

Quite a useful motor. and about £1.25 or so each........incredible value.

 

Stephen

 

Which motor is this one ?

[Pebbles]

Old Hornby 13:1 gears; using a signal start worm 26:1, I've still got a few. Romford also did/do a 20:1. If the bore in either the worm or the gear is too large, the lathe does the rest.  Using the Markits 27:1 with motor at 8500 rpm - the figure quoted when I purchased mine  - gives a wheel rotational speed equal to 62mph with 5' 6'' wheels and 73mph for 6'6'' wheels. By the way Jol many thanks for the info on resistors.

In the case of the 15mm sq motors. Found some 20 tooth plastic gears that could be compatible with the brass worms found on some of the Mitsumi motors. This could be the solution to the gearing issue as it produces a maximum of 7 revolutions at the driving wheels.

[bertiedog]

Which motor is this one ?

https://www.ebay.co.uk/itm/2PCS-DC-12V-6500RPM-Large-Torque-6-Pole-Rotor-Minebea-15MM-Square-Motor-for-Toy/252631354230?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

[alfsboy]

I just ran a Mitsumi motor for about 2 hours round our Roco Geoline carpet roundy  at the weekend .its installed in a 0n30 Bachmann gas mechanical  hack  using the gear that came with the motor and stuck on with some quick cure epoxy putty .It worked well and kept to a moderate speed that is well usable.it was pulling  two 00 Farish coaches ,a few Hornby  open wagons and my Bachmann adaptor  box van that has a Kadee one end and a standard hook and loop the other end .it survived a two year old grandaughter as well .The body and couplers were attached.

 

Edited May 18, 2018 by alfsboy

[sir douglas]

got motors from ebay

 

1x Mabuchi SF-266SA https://www.ebay.co.uk/itm/282390341666, which is now in my o gauge Hunslet and runs nicely but i also got 2x ESCAP 16N28 https://www.ebay.co.uk/itm/282822079237 when i tested one of the escaps it ran nicely but was still running when the controller knob was turned off and only stopped with the direction switch at neutral, my controller is a Hornby R965

Edited May 20, 2018 by sir douglas

[sir douglas]

does anybody know how the motor is running when it shouldnt be?

[chris p bacon]

It's either extremely free running or it must be getting power from the controller.

 

Is there a chance the controller has a feature to slowly stop as in the prototype,  rather than a dead stop. ?

 

Try another power source.

Edited May 21, 2018 by chris p bacon

[Izzy]

As it's rated as 12v-24v why not just test it with a 9v PP3 battery? This would show whether the controller is the problem.

 

Izzy

[Ruston]

does anybody know how the motor is running when it shouldnt be?

Put a voltmeter on the wires from the controller when it is turned down to zero to see if it isn't completely turning the power off, even though the dial shows that it should be.

[cpman46]

Put a voltmeter on the wires from the controller when it is turned down to zero to see if it isn't completely turning the power off, even though the dial shows that it should be.

Portescap motor will start to run on tens of millivolts i.e. tenths of a volt so I suspect that your controller does not give zero volts out when the dial is fully anticlockwise which is confirmed by your statement that the motor only stops when you set the direction switch to its off middle position.

Mike