Skip to main content

I am hoping that someone knows the max operating voltage and max rpm for a KTM DC Motor model RH-4462S labeled as Katsumi Mokeiten Co. Japan. The motor is from a Westside O Scale Hudson. There are no specifications on the motor case. The web does not appear to have any info. If it is a 12V, it is just not fast enough and I will regear it. If it is 18V, I may be OK with the model "as-is".

Thanks for any assistance.

Original Post

Replies sorted oldest to newest

The stock KTM motors run pretty good in both the US Hobbies & the WSMs….they’re geared pretty good too, ….have you run the engine and you’re just not satisfied with it, or are you planning on DCC, or some control system?…the gear boxes on the KTM’s are about perfect as far as ratios go. These engines respond very well to a large Pittman swap, …..I believe 9433 is basically a drop in, as the ash pans on the KTM’s are removable,…..if you’re running it conventional, the stock KTM motor is plenty powerful, and pretty smooth,….I believe they are 12V stock,….

Pat

I have a few engines with this Katsumi motor. With no case markings, I was hoping that different voltages might have been used. This engine at 12 VDC runs at about 52 mph, based on my timing and after making some adjustments. The motor seems fine, but the engine is slow. I prefer to re motor and/or regear engines so they run at no more than 10V at prototypical Hudson speeds. Lower noise and vibration, and the lights last a LOT longer. I run conventional. The Pittmans I have used have been excellent but they are unavailable.

@Hudson5432 what I wouldn't give to trade places with you!  52 mph at 12 volts, that runs just about perfect!  In 3-rail with captive axles and long-legged gearboxes, we have to resort to all kinds of electronic voodoo that still leaves some low-speed performance on the table.

If your layout has wide curves, and straightaways long enough for higher sustained speeds, please adopt me! Or at least remember me in your will!  :-D

Last edited by Ted S
@Ted S posted:

In 3-rail with captive axles and long-legged gearboxes, we have to resort to all kinds of electronic voodoo that still leaves some low-speed performance on the table.

Ted, your constant denigration of modern electronics is really wearing thin, especially since it has no basis in reality.  I'll match the low speed performance of modern Lionel Legacy or MTH PS/3 against your benchmark anytime.  Perhaps you might consider just sticking to facts in the future and not taking every opportunity to trash other products or techniques at the drop of a hat.

Here's a simple test of a Legacy Consolidation that is to the point.  It'll do this same speed on level track or going up and down grades, with or without a load.  Try that with your "optimum" gear ratio and motor...

Attachments

Videos (1)
Legacy Low Speed Demo

Ted, your constant denigration of modern electronics is really wearing thin, especially since it has no basis in reality.  I'll match the low speed performance of modern Lionel Legacy or MTH PS/3 against your benchmark anytime.  Perhaps you might consider just sticking to facts in the future and not taking every opportunity to trash other products or techniques at the drop of a hat.

Thanks John for elaborating.

Most of us, in the hobby and especially on this forum, have much in common and enjoy writing about it, talking about it, and sharing it with others.  You're an excellent example.  Since this is a technical hobby most frequently it's technical facts that we're bantering about.  These are relatively easy to validate, for example as you're illustrating with your video.

There are some however who let emotions creep in to cloud the facts, and too often they show up in the form of an obvious bias against electronics, or any newer technology (software, communications, networking, etc.), usually because of a misguided perception that these things fail more often than traditional technologies, are too hard to understand, or most importantly were actually introduced intentionally to ruin the hobby.  This can easily be taken a step further, although this doesn't appear to have  happened here in the case of the previous poster with the aversion to electronics, to include a bias against the people supporting them.

The hobby was drying up until the infusion of modern electronics, which have been here for 50 years now, almost half of the lifetime of the hobby.  It didn't die after they came -- at least it hasn't yet -- not after the addition of realistic sounds, command control, or scale details, and it won't with the next infusion of technology, electronic or otherwise, whatever that happens be.

There has to be room and respect for all technologies and likewise for all points and views.

   Are trains with electronics, or any advanced technologies, still trains?

   Are we who love them more alike, or more different?

Mike

Last edited by Mellow Hudson Mike

I do not think I would be too concerned about the rated voltage. The difference between 12 volts  and 18 volts is not going to cause insulation failures due to the increased voltage. What raising the voltage is going to do is increase the current, resulting in a motor with more power. It will also increase the temperature the motor runs at. Hard to say how close to the edge the manufacture designs their product. If the locomotive runs fine at 18 volts and gives you the performance you want, you win. If running at 18 volts burns the motor out, well you needed a different motor anyway.

I do not think I would be too concerned about the rated voltage. The difference between 12 volts  and 18 volts is not going to cause insulation failures due to the increased voltage. What raising the voltage is going to do is increase the current, resulting in a motor with more power. It will also increase the temperature the motor runs at. Hard to say how close to the edge the manufacture designs their product. If the locomotive runs fine at 18 volts and gives you the performance you want, you win. If running at 18 volts burns the motor out, well you needed a different motor anyway.

Ain’t that the truth!!….run it till she pops, then gather up the carnage for a forensic examination, ……I’ve done that one or twice, or 200 times….destruction & mayhem,….part of R&D,…..😁

Pat

My Westside J-1E has a Pittman 9432. Rated rpm is 6730. My crib sheet describes the 9432 as having radial pins and a length of 1.82 inches. This motor length will fit a NYC H-10 or an L-2 Mohawk in a USH chassis. I do have a 2.38 inch long 9534 in a scale USH Hudson but it was a tight fit, and somewhat dependent on whether axial pins or radial pins are used.  The rated rpm of the 9534 is 5980. I have used rare earth magnets and ball bearings and much prefer them. I have never had a Pittman fail.

I have failed individual windings of the USH open frame motor running at 14V. These motors are random wound and centrifugal force sometimes lifts the winding between the pole and the commutator at any elevated voltage/speed. I have found that using a can motor over its rated voltage causes a significant increase in brush wear, and eventual failure. Insulation failure is not an issue at the low voltages common on O gauge/O scale.

The answer to my question would be less critical if replacement motors were commonly available.

Ted, your constant denigration of modern electronics is really wearing thin, especially since it has no basis in reality.  I'll match the low speed performance of modern Lionel Legacy or MTH PS/3 against your benchmark anytime.  Perhaps you might consider just sticking to facts in the future and not taking every opportunity to trash other products or techniques at the drop of a hat.



John this is a harsh personal diatribe, and frankly undeserved.  I really don't want to hijack this thread to debate you. You're an electronics expert, and you generously share your knowledge on the Forum, but that doesn't give you the right to bully me, so I feel compelled to respond.  I didn't intend to denigrate or "trash" anything.  Arthur C. Clarke said that any sufficiently advanced technology is indistinguishable from magic.  I generically and playfully referred to the top-shelf modern technologies as "voodoo."

Getting back to topic, the FACT is that our motors have a finite operating range, including some minimum RPM below which they are prone to erratic operation, because the torque being produced at that RPM isn't sufficient to overcome transient frictional events.  This minimum RPM translates directly to minimum loco speed via the gear ratio.

A closed-loop feedback system (aka "speed control") as illustrated in your video can force the motor to turn slower than it would if supplied with unadjusted track voltage.  My point is, the end result is always better if the loco is geared properly in the first place.  Excessive top speed (which immutably plagues many 3-rail locos) ALWAYS entails a trade-off with slow-speed performance.  On most home-sized layouts, slow speeds are more important, there just isn't enough room for high-speed running.  That's why I made a tongue-in-cheek reference to the size of OP's layout.

Then there's the subjective "feel."  Motion capture with a stroboscope or high-speed camera would reveal a subtle surging as the speed control hunts around a target value.  Generally it's well-damped.  However, some of my locos with speed control seem to have TOO much damping, which gives them an over-controlled feel that just isn't train-like.  Somehow the sense of mass is lost or muted.  Conventional drivetrains with torquey motors, low gear ratios, and large flywheels (a rare combo, but I have a few) are smooth, predictable, and gratifying to run.  God bless Sir Isaac Newton!

Speed control requires excess input voltage, a "reserve" to increase power when needed.  Absent the need for such reserve, a motor with a higher-voltage winding could have been specified to attain the same top speed.  Thus, as with the gear ratio, some performance (typically the starting behavior I described in another recent post) is compromised.  Many closed-loop systems rely on a tach sensor, which introduces new failure modes and sometimes mandates a smaller flywheel for packaging reasons.  Because modern locos are crammed with electronic components, it complicates basic maintenance.  The electronics also add to the price, perhaps $200-$300 retail per loco.  So yes, electronic speed control has been widely adopted in 3-rail O, and a lot of folks love it.  But it's not strictly necessary  for good performance and it has its own set of drawbacks.

Companies like Westside and its predecessor US Hobbies used to publish the gear ratios and motor designations in their catalogs because serious hobbyists knew those numbers were important for operation, and they provided evidence of thoughtful, deliberate engineering.  At least the prospective purchaser could make an informed decision!  Even if you didn't like the OE specs, the split chassis and "divorced" driveline inherent to these locos from the golden age of 2-rail make it easy to change the motor and gearbox to achieve the desired performance.  This is exactly what the OP is proposing to do.  I'm not a villain for pointing out the advantages, or for wishing that we had locos of this design in traditional O gauge.  Peace.

Last edited by Ted S

A 32 is a small motor, probably underwhelming, especially if you have that massive weight bolted in that KTM is famous for, …..I know for sure a 9433 will fit in the fire box of a WS J1, all of those Pittmans, 32, 33, & 34’s are going to give up around 6K RPM, or in that neighborhood, …..did you ever figure out what the actual gear ratio of your model is? ……if you’re anywhere between 18-25:1 you’d be fine with a 9433, …..and I’d think you’d be happier, ….Lionel still shows 15.1V 9433’s in stock,…..that 32 is more than likely begging for mercy with that big angry weight in the boiler, and if you’re trying to pull a train…..

Pat

Add Reply

Post

OGR Publishing, Inc., 1310 Eastside Centre Ct, Suite 6, Mountain Home, AR 72653
800-980-OGRR (6477)
www.ogaugerr.com

×
×
×
×
Link copied to your clipboard.
×
×