Repowering old brass

Model Railroader Electronics and DCC
1

Hi guys,

Looking to repower a beautiful old Westside Brass SP Daylight. I really like the price and performance of the Kato motors but can’t find any specs on the HM-5 motors.

Can anyone recommend anything else? I’ve looked at Mashima but at $85 a motor, I think I can do better for power with a stock set up out of another mass produced loco like the Kato.

Thanks,

Mike

2

Look into the Mabuchi SF266SA motors. They are very powerful with a 2mm diameter shaft. They do not have a skewed armature but they have 6 poles. The price it right too, under $3 on eBay.

I have installed 12 so far and got ten more last week. They are small enough to fit back to back in an Athearn SD40 frame.

They work great in Rivarossi articulated. Below is a Cab Forward and a kitbashed Cab Forward into an AC-9. Both run great.

They have tremendous power at very low current.

Here is a pair in an Athearn SD40-2 frame.

3

Thanks Mel,

Good call on those motors. I remember we used those for things in r/c stuff so I don’t know why I didn’t think of that for repowering.

I’d like to stick with something with dual shafts for flywheel options but I’ll check those out! Thanks!!!

4

Running them back to back I can’t tell the difference in the Athearn frames. As my Cab Forwards didn’t have flywheels the dual motor easily makes up for a flywheel.

I haven’t installed a SF-266 in a regular steam locomotive but they don’t need flywheels in any of my installs so far.

Mel

My Model Railroad
http://melvineperry.blogspot.com/

Bakersfield, California

I’m beginning to realize that aging is not for wimps.

5

Thanks for that suggestion, Mel. I found them at a really good price, but there’s a click-on which asks if I want the motors with pins or no pins. To what are they referring?

EDIT: Never mind, the info was there once I took a closer look. [D)]

Wayne

6

Wayne

The pins are needed if you keep the plastic endbell. The plastic endbell can be removed to shorten the overall length of the motor housing. I haven’t removed the plastic endbell in any of my installs.

The pins are shown in the first picture in my first post on this topic. The pins press into slots on the side of the plastic endbell.

The motors I’ve ordered haven’t listed the pins as an option. The link below has good pictures of the motor, scroll through the pictures.

https://www.ebay.com/itm/Mabuchi-SF-266SA-Mini-18mm-Square-6-Pole-Rotor-DC-12V-24V-14500RPM-High-Speed/173694924153?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

EDIT:

I would like to add that the Mabuchi SF-266SA motor is “my best find” in

7

Thanks, Mel. I’ve been following your comments on those motors, and was very surprised by the prices that were on the first Ebay seller’s site that popped up when I googled the model number of the motor.
The seller had included several photos of the motor, but it took me a while before I was aware that there were more photos than the one which was shown - I’m a very infrequent browser on Ebay.

Wayne

8

Mel,

Would the Mabuchi be a reasonable replacement for an old Pitman in a '70s issue MDC 2-6-2? Also, can you imagine the compatibility with a good back-EMF decoder should this little beast ever be rigged for DCC?

John

Merry Christmas, all!

9

John

I would think so as far as the motor dimensions go, the Pitman is 16.15mm wide and the Mabuchi is 18.3mm. The problem will be the shaft size. The Pitman has a 2.25mm shaft and the SF-266 has a 2mm shaft so the original worm won’t just press off and fit the shaft of the Mabuchi, that would be kinda tough to sleeve.

The MDC worm gear is fine tooth 7.88mm diameter with a 1.2mm pitch. Trying to match shaft size in gearing isn’t my thing.

I’m quite sure the Mabuchi motor will fit in the boiler (my MDC 2-8-0 has a 20mm opening) and could be glued to the frame using a silicone glue, I use Amazing Goop to glue my motors in place.

As for BEMF the Mabuchi SF-266 has capacitors internally that may have to be removed. My layout is not operable so I can’t check the BEMF for sure but it seems to work OK with the caps on my short test track. The picture below shows the SMD internal caps on the circuit board.

10

Thanks, Mel.

Sooner or later I’ll find reason to end up re-gearing the old Prairie so the shaft size may be a moot point. And, who knows? For the short term, someone may jump in here with news of an available bushing to accommodate the .25mm differential.

As for the internal caps and their compatibility with BEMF decoders, that kind of stuff still causes my head to swim.

You da man, Mel.

John

11

NWSL has u-joints to fit various shaft sizes and also gears and gearboxes for the MDC locos, so if you’re going to upgrade the motor, it’s probably worthwhile to do the drive train, too. I’ve done so on Bowser and Mantua steam locomotives, and will be doing a John English Pacific, too.

I’ve also used NWSL bushings for mating various shaft sizes, but they’ve been discontinued in favour of the U-joint sets. The only bushings I have left are the ones with a 1.5mm bore and an O.D. of 3/32", unfortunately not suitable for John’s locomotive.

Wayne

12

John

As Wayne suggests NWSL will have the proper worm for MDC locomotives with a 2mm bore. Their web site isn’t fully up as of yet so maybe a call would get the correct worm to fit the Mabuchi 2mm shaft.

https://nwsl.com/collections/worms?_=pf&pf_t_bore=Bore%3A%202.0mm&pf_t_outside_diameter=Outside%20Diameter%3A%208mm

NWSL is in business, I ordered five 2mm universal kits two weeks ago and received them in five days.

Mel

My Model Railroad

13

Thanks, guys. The sighs of relief continue in NWSL’s being re-born. Thousands giving thanks that they seem to have retained their corporate vision and mission. IMO, not common these days.

John

14

Mel question for you the Mabuchi motor lists 7200 rpm at 12 volts you say about 6000 rpm the athearn motors I think ran in the 10 to 12000 rpm

so does the new install run slower now will it match up with an original athearn

thanks

15

All of the Athearn motors I’ve checked are well under 7000 no load. I haven’t checked any of their newer models but I didn’t think they changed their gear ratios.

I just checked a new out of the sack Mabuchi at 6600 RPM at 12.0 volts no load.

EDIT:

I just checked an Athearn SD40-2 Blue Box motor and you are correct, I turns at just over 9000 RPM. I have remotored a total of 8 Athearn Blue Box SDs and when running them on my layout I haven’t experienced a problem at the slower RPM, I never run them over a scale 60 MPH.

I just finished a pair of SD40-2 frames with Cary cast metal bodies and weighing in at 35oz each they easily do over 60MPH scale. I would expect it would be a problem in a consist with the two different motors but I don’t run any Athearn with the original motor. The Canon EN22 is also in the 6000RPM range and they do well with the Mabuchi motors.

Thanks for

16

Thanks for that info Mel I think I will get some of those and give it a try

I wonder if I can squeeze two of those into a gp frame looks to be real close

other wise the Kato HM-5 will work just more $$$

but I do have about a doz of the sd type

17

I have several GPs but haven’t done one yet. I think they will fit.

Mel

My Model Railroad
http://melvineperry.blogspot.com/

Bakersfield, California

I’m beginning to realize that aging is not for wimps.

18

My layout is still under a major wiring overhaul but I was able to get power to my mainline to check the speed of the Athearn SD9 that I’m in the process of finishing the remotor using a pair of Mabuchi SF266 motors. I have an electronic stop watch over a measured HO scale mile. The SD9 clocked in at 58.86 seconds or 61MPH at 12.0 volts DC.

Measuring the locomotive speed is much easier when my layout is up and running but due to my Arthritis it’s still unfinished. Our doctor has me on a new med and it seems to be better so maybe I can get back to it.

My layout is a HO scale twice-around with 121’ of track or two scale miles. I have two sets of sensors, one at 60.5’ and the second at 121’.

A stock Athearn SD40-2 frame does the mile in 41 seconds or 87.6MPH

For anyone wondering the 2 mile loop was an accident, not planned. It wasn’t until I started playing around with Arduinos that I measured the length of my mainline track.

Mel

19

Mel on the sd40-2 frame what exactly did you use to connect the Mabuchi motor to the athean truck Is it a nwsl part and if so which one

20

Mike

Yes I used NWSL universals.

I ordered two of the MABUCHI FK-280SA-14200 motors to see if they will work better than the 266, their listing says they are 12300RPM. They have dual 2mm shafts.

In experimenting I found that I can sleeve the Athearn flywheels using K&S 3mm brass tubing to fit the 2mm shaft. It’s kinda touchy but by inserting a short 2mm rod into the pulley end then using super gel to glue the 3mm tube it is centered close enough that it doesn’t vibrate.

The FK-280 motors arrived at US Customs 1/22.

Mel