Coreless motor alternatives for locomotive remotoring

[Spalato68]

Hi everybody,

 

I decided to write this post after reading Wolf359's post „Need a new motor for a Mantua 4-6-0“. I do not know if my post will help him, but I hope it will help or inspire somebody here, as many members of this forum helped me in my considerations related to my issues of our hobby.

 

What follows is experience I gathered in a past year or so, when I started to “digitalize” my old (up to 38 years), but also some very recent European locomotives (mostly Roco, and some Fleischmann). As some of you know, Athearn Genesis uses in many of its models Roco motor. This is a very reliable, strong 5 pole iron core motor. It has not changed much outside (dimensions), but had several revisions related to its internal design. The most important was an introduction of a skew wound rotor, which has considerable weaker cogging effect than motor which is not skew wound. The other change is related to brushes, which sometimes can squeak and then you cannot get rid of that.

 

Anyway, when I installed several decoders (ESU & Zimo) in some Roco locomotives which were in mechanically absolutely impeccable condition (I completely remove old grease&oil and use Labelle instead), I could not get satisfactory results, especially in lower speed range (when starting or coming to a stop). No matter what I have done with motor control related CV’s (sometimes I experimented for hours), I could not get a simple thing: locomotive that starts from 0, accelerates continuously, and in the same manner, slows down and comes to a stop.  I would always observe some kind of irregular running: jerking, or how it is called in ESU and Zimo manuals – “Bock jumps”. In some cases, when locomotive was running with lower speed, cars coupled to a locomotive would slam to each other lightly (they rattled). This would occur in very narrow (slower) speed range, then it would disappear completely. After a while I realized that even Roco motors that look the same, are not the same in fact, at least not for the decoder installed on them. Running characteristics would change as I changed the motors, even they look the same, or almost the same.

 

I decided to try a coreless motor (because cogging effect is zero, and because I always read articles about these motors as a peak of locomotive tune up). So I decided to try. In the past period, I experimented and now use for all my locomotives four motors (all are used, price range between 6 USD – 12 USD, all motors have the same diameter - 16 mm, 7 or 9 poles). New motors are in price range 50-80 Euros. Probably this price is justified, but too high for me, considering the purpose.

 

Maxon 24 V (available on eBay (German seller), price around 5-6 Euros)

https://www.ebay.de/itm/5x-MAXON-Getriebemotor-Encoder-Spindel-und-Spindelmutter/123267642713?hash=item1cb352f559:g:3nYAAOSwfVpYsaYA:rk:2:pf:0

This motor has carbon brushes, which makes it very durable on a long run, especially when used with DCC. The main disadvantage is rated voltage (24 V), i.e. speed it relatively low, which will be a problem in many locomotives. But, for slower locomotives, or where gear ratio is low, this would be excellent motor. It is very strong (4,5 W). Link to datasheet is on eBay.

 

 

It has two 1,5 mm shafts – one 4,2 mm and other 2,54 mm long. The shorter one is where encoder was installed.

 

 

Maxon 12 V (source: eBay, microlocomotion)

https://www.ebay.de/itm/Swiss-Maxon-1629-7-pole-coreless-motor-internal-flywheel-and-22-mm-shaft/151383068316?hash=item233f224e9c:g:ALwAAOxySE9Q5-d3:rk:9:pf:0

This motor has precious metal brushes, due to rated voltage of 12 V it will satisfy every locomotive when motor speed is concerned. It is weaker than the above mentioned motor, but here “BEMF” can help.

 

 

It has two 1,5 mm shafts – one 20,6 mm and the other 2,54 mm.

Both Maxon motors look the same, only difference is in shaft length (and of course, the internal design).

 

 

Escap 12 V “G” motor

 

 

Available on eBay from different sellers from China. Price between 10 – 12 USD, for example:

 

https://www.ebay.de/itm/ESCAP-16-Coreless-DC-12V-540RPM-Gear-Motor-With-Encoder-16MM/181537865905?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

 

This is excellent motor. It is strong as Maxon 24 V (I cannot stop it by hand at higher speed), I assume (by sound when it is running) that is has metal precious brushes, and according to designation “G”, it has a new generation, high power magnet. I do not know the number of poles, but it is probably 9 pole motor. It is the quietest motor. You barely hear a motor when locomotive is running. I do not know how so silent running can be achieved.

 

Shafts are the biggest disadvantage (or problem) with this motor. One is 4,89 mm long, but for the most part, only 1 mm in diameter. The other is even worse: 1,5 mm but only 1,56 mm long.

 

 

Escap 12 V “E” motor

 

This motor is currently not available, it is a 9 pole motor (I can see the commentator segments – it has 9 of them), but weaker than “G” version (2,4 W). Metal precious brushes.

 

 

It has one shaft, 1,5 mm, it is 5,96 mm long. For small switchers, this is excellent motor. Quiet as “G” version. This is the only motor that does not come with encoder and planetary gears which have to be removed, which makes it almost a “drop in” solution, just 2,0 mm sleeve is needed.

 

 

Below are the pictures of all of them, with some explanations. The biggest problem, or hurdle, to use them is the shaft diameter and length. In most cases, it is 1,5 mm in diameter, while in our locomotives, we almost everywhere need 2 mm shaft. I found some steel tubing that has 1,5 mm ID and 2,0 mm OD (in Europe, exactly 1,50 mm ID) and China on eBay, ID is little bigger than 1,5 mm. I am sure it can be found in the US too, but I could not find it.

 

 

It is not easy to glue tubing on these shafts as in some cases they are short, and you want them to be absolutely centric. Maxon 12 V (Motorman) is easy case, because at least one shaft is very long, and even the other is long enough to fit longer sleeve.

 

 

The most difficult is Escap 12 “G” motor, but I managed to glue longer sleeves on both sides (I used either ACC or better, 2-component glue with working time around 20 min).

 

 

With all the above motors, I achieved running as I have never seen in these locomotives with iron core motors. Not only that all of them are not quieter, but they roll on tracks smoothly and without any jumps in any speed range. Car “slamming” has either completely disappeared or is much less. Locomotive running does not depend only on motor of course, but on the rest of transmission: gears, worms, wheels, linkage (steam), universal couplings assembly. If any of these elements is not correct in any way, locomotive will not run smoothly.  No motor/decoder can rectify that.

 

Furthermore, I found that ZIMO decoder is better for these motors; therefore I use only these decoders in my European locomotives with these motors. All locomotives have the same CV setting when motor control is concerned. I do not need to experiment anymore, and to adjust decoder, I use the same two values for all locomotives for motor control (CV 9 = 71, CV 56 = 135). ESU is very good, but I like more the result with Zimo. For some locomotives where I had to leave 3-pole motors, I use only ESU, because here ESU is better than Zimo. In general I found out that ESU can “play along” more easily with larger number of motors when design is concerned compared to Zimo, but Zimo excels with these four coreless motors I used for most of my locomotives. That does not mean that ESU is not good with coreless motors – on some locomotives of my friend with coreless motors, ESU is excellent. Obviously, not all coreless motors are the same, which is normal.

 

Pictures

 

Maxon 24 V

 

As delivered from seller. Encoder (where wires are coming out) is removed relatively easy.

 

Planetary gear removed. A force has to be used; it is screwed/glued on the brass holder.

 

Planetary gear holder removed. Sometimes it falls off together with planetary gear, if glue is still holding. 

 

Now the gear has to be removed. It is extremely hard; therefore it is very brittle too. So, I put it in a big vise, and after several careful presses, it cracks. This must be done very carefully, because motor can be “ejected” like a rocket from vise and hurt somebody, if pressed too hard in a vise. But after several steps, where gear is turned around, it will start to crack. Gear remains are very sharp, like glass!

 

Gear removed, motor is finally ready. Steel cover with manufacturer’s data can be removed, it just slides off.

 

View from the side where encoder was installed. Shaft is here shorter. Carbon brush is visible.

 

Motor with sleeves already installed. One is already in the locomotive. As new motor is smaller than original, I usually fill the entire free place with lead sheets. I replace wheels with traction tires with those without, wherever possible.

 

Another installation, in tender of old Roco steam locomotive. Here I used brass tubing, but later I have found steel tubing, with ID closer to 1,5 mm, or exactly 1,5 mm. Old Roco motor is beneath. Later I installed here Escap 12 V G motor instead, because this is a passenger locomotive, so it should run faster. I kept this motor for the same tender of freight locomotive, where it can run slower. The remaining space can be used for decoder too, not only lead sheets.

 

Escap 12 V “G” motor

 

As delivered from China (I already cut the cables from encoder)

 

Planetary gear removed. It comes off easy, it is held by screws.

 

Planetary gear holder removed, also held with screws

 

Encoder comes off easily too, only the wires coming from motor must be unsoldered carefully.

 

Motor is free. Main gear removed in the same manner as with Maxon – cracking in a vise. This has to be done carefully, because shaft is only 1 mm in diameter on the most part.

 

Finished motor with new shafts. This shaft can fall of only if you try to use strong force perpendicular to shaft – a normal torque while use in a locomotive will not cause that shaft falls of. Modern glues do wonders.

 

Shaft on another side. Shaft is glued not only to motor shaft, but on this round shiny “plate” too, because it is part of motor shaft also, which further stabilizes the shaft. Here I used two tubes: one with 1 mm ID and 1,5 mm OD, and then 1,5 mm ID and 2,00 mm OD. To stabilize shaft even more.

 

To glue motor shafts, I do it one by one. I put a motor in a small vise, slide new shaft thru old Roco flywheel (shaft can rotate freely; I enlarged a hole in flywheel with a reamer). I attach a motor to a decoder, and let it rotate very slowly. Then I put a shaft&flywheel assembly on a motor (glue already applied on both motor shaft and the new shaft, but not too much, because flywheel should not be glued too). After a while by observing, exactly centric position is established. I leave it to run like that for a few hours, until glue has set. Then I repeat the procedure for the other side. This can be done with ACC glue too, but it must be done very quickly.

 

Escap 12 V “E”

 

Easy case – shaft is already free, no encoder. Unfortunately, it is not currently available. Price was around 8 USD. I achieved excellent results with this motor in small switcher – it glides almost without any sound on tracks, this difference was even noticed by my friend, who is btw deaf on one ear. He asked, “is it rolling on tracks, or hovering over them?”-:)

 

Few videos:

 

Maxon 24 V

 

 

 

Escap 12 V “G”

 

Installed in a Roco locomotive from 1981 (picture of motor in tender was shown above). Even at very high speed, you hear very silent motor noise, that is all.

 

That is all-:)

Hrvoje

[7j43k]

Thank you, Hrvoje.

It is very interesting and I will use the information you provided.

 

Ed

[tankertoad70]

Superb review and thanks!!

[PED]

Be nice to have a similar writeup for N scale motors :)

 

[Wolf359]

Thank you for posting this information. It's definitely something to consider.

[Spalato68]

Paul,

check this out:

https://www.ebay.de/itm/New-Two-shaft-Coreless-micro-motor-12V-8mm-x-16mm-Worldwide-exclusive-product/283264202464?_trkparms=aid%3D444000%26algo%3DSOI.DEFAULT%26ao%3D1%26asc%3D20170221122447%26meid%3De9875b56cf9446ffb92c84861bdcc6e1%26pid%3D100752%26rk%3D2%26rkt%3D3%26sd%3D282915067966%26itm%3D283264202464&_trksid=p2047675.c100752.m1982

and this:

https://www.ebay.de/itm/Coreless-micro-motor-12V-8mm-x-16mm-like-Faulhaber-Maxon/282915067966?hash=item41df0d583e:g:lwIAAOSwi8xaDqOA:rk:7:pf:0

I just came across this. I never tested these, but it is really for the first time I see two shaft coreless motor of such small dimensions. With diameter of only 8 mm, it should fit in many locos. Seller even advertises 3-year warranty?

They do not cost a fortune, so maybe you can try one 

Hrvoje

[7j43k]

I have just ordered one of these small motors.  I would like to try it in an HOn3 2-8-0.  Northwest Shortline sells adapters for the 1 mm motor shaft.

 

Ed

[PED]

Here is english version for the single shaft motor from same seller. Did not see english version for the double shaft

https://www.ebay.com/itm/Coreless-micro-motor-12V-8mm-x-16mm-for-use-in-small-model-trains/283163646458?hash=item41edde59fa:g:h0EAAOSw93ZaoCMz:rk:3:pf:0

 

[Spalato68]

Here is english version for double shaft motor:

https://www.ebay.com/itm/New-Two-shaft-Coreless-micro-motor-12V-8mm-x-16mm-Worldwide-exclusive-product/283264202464?hash=item41f3dcb6e0:g:Zl4AAOSwBfhb74Cv:rk:1:pf:0

He offers 7 or 8 mm motor, it seems that 8 mm is stronger. 

I will very probably order two, for testing and possible install in one small Roco switcher that originally has Roco N motor. This 5-pole iron core motor is good, but it requires very frequent oiling, otherwise it squeaks a lot. The other I would like to install in one of my Roco N locomotives - just to see, how these motors work. I have around 10 N locomotives, and much more cars (European and US prototype). 

Hrvoje

[7j43k]

I just received my motor.  It's the 8mm one.  Diameter is .318 (about 5/16").  Length is .661" over the body (about 21/32").

I expect to someday be using it to repower my NCNG 2-8-0.  The existing motor pretty much fills up the cab, and sticks out its back.  This one would not stick out, though it would be into the cab.  It is small enough that it would be below the bottom of the cab windows.  A possibility is to mount the motor forward of the gearbox.  Then it won't be in the cab at all.

 

This project is likely far far into the future.  But it would fix the most glaring irritant of the model.

 

Oh, yeah.  I put some power on the motor, and it runs nicely.

 

Ed

[SeeYou190]

Great write-up and information.

.

Thank you very much for sharing.

.

-Kevin

.

[7j43k]

These motors are so promising that I just ordered two spares to go with my first one.  I just KNOW when I need another, they'll be gone.  Sort of like most of the Sergent couplers.

 

Ed

[Spalato68]

Thank you for this information, Ed. I have two other projects before I will need this motor, but it is good to know it is a good motor. I hope they will not be gone, because the market opportunity for such motor is relatively large, due to the fact that there is almost no competition for this seller. This motor should fit in almost all N locomotives, and of course, in some very small locomotives of larger scales.

I will use it for this HO locomotive: 

Source: Roco web