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One little problem with the Maxon Coreless motor they detail in their literature.  Virtually all the command stuff uses PWM for the motor drive.  I imagine that back-EMF would be minimal, so forget about ERR Cruise.

Your right choke and 20K + PWM.   The ERR board will do, probably no cruise.   Do you know the frequency of the PWM on the DCS boards ?   If high enough you might be able to cruise with a Tach.   I keep looking at H bridges on eBay and they have some that operate at 80K supposedly designed to play nice with coreless motors.   The HO crowd have DCC boards that do so.  I know one thing the DCDR and other non legacy Lionel boards don't get along at all with coreless.           j

I found this motor on a popular auction site.  It seems like it might be a good choice if the original one is really bad.  BTW the drivers should be about 1.625"   I'm not a fast runner, I've been advocating lower gear ratios (slower) for years.  But if you want RPMs you need more voltage!  Even Lionel's 700-series Hudsons were rated for 20 volts.  I'm pretty sure Right Of Way developed its 16-amp, 24-volt transformer with these Williams locos in mind.  Circa 1990, that's the way the hobby was going.  Those transformers still command a good price when you can find them.

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@Ted S posted:

I found this motor on a popular auction site.  It seems like it might be a good choice if the original one is really bad.  BTW the drivers should be about 1.625"   I'm not a fast runner, I've been advocating lower gear ratios (slower) for years.  But if you want RPMs you need more voltage!  Even Lionel's 700-series Hudsons were rated for 20 volts.  I'm pretty sure Right Of Way developed its 16-amp, 24-volt transformer with these Williams locos in mind.  Circa 1990, that's the way the hobby was going.  Those transformers still command a good price when you can find them.

That motor is good for like a cordless drill ....no??.....looks to be an amp hog....

 

Pat

Ted one question are you planning to run this motor with TMCC, DCS, DCC ? If so forget it. Does the seller give the static resistance I would be willing to bet it is not much higher than the original which is .8 ohms  There are several problems with using high current motors.  All those amps they pull eat up pick-up rollers and track.  All those amps create arcs and affect DCS and TMCC signals. You may get away with that current draw using an original mechanical e-unit or the Williams electronic e-units which use relays, not the ones with triac outputs. However no motor driver board is going to stand up to the load it will create. Well perhaps a TAS board with the 15A triacs, long out of production.  That Johnson motor with vent holes is going to squeal like a pig on a pitch fork at 14k.  I keep looking for alternative solutions to the 42:1 problem. An intermediate gearbox may be a solution we have not considered.  I have boxes of small gears and the idea of making an intermediate gearbox with somewhere between a 1.5 and 2 step up keeps gnawing on me. A 1:2 step up would bring that 42:1 ratio down to 21:1 since even in an oil bath box there will be losses due to friction so perhaps 25:1 should be the target which would be a 1.68 : 1 intermediate box.  A 12 tooth turned by a 20 tooth gear will be 1:1.66  close enough. Though I have all the parts you can buy brass gears shim brass and bronze or ball bearings on eBay cheap enough that such a intermediate gearbox should cost less than $20.   By the way, my measurements for wheel diameter and gear ratios are based on my N&W J not the Williams Hudson with approximately  .1" larger diameter wheels.  The proto J only has 70" drivers while the Williams drivers are a scale 73".  The motors and gear ratios which work well with the J would also work well with the Williams NYC Hudson. The Hudson will just be about 7% faster.          j

Even though the Mabuchi 550 and 555 have high stall currents, you can still run them with command control. I upgraded a couple Williams Niagaras (550 equiped) for two local clubs using ERR Cruise Commanders and they are still running today even after logging hundreds of hours. While running currents are higher than a comparable Pittman they are still a fraction of their stall currents. 

My personal engines get Pittmans but its not necessary to replace a Mabuchi for every upgrade.

Pete

John I don't agree 100% with your line of thinking.  There's nothing inherently wrong with a high-ratio gearbox.

In NMRA modelling contests, to get full points a loco has to run smoothly at 4 scale mph (which is also the maximum coupling speed of the prototype.)  If the drive "leaps" from zero to 4 mph, that greatly detracts from the observed realism.  But the 4 mph number is a good starting point.

My experience testing many different locos in O gauge over the years, is that common can motors, including Pittman motors, just don't run consistently below about 800 RPM when the loco is running "light."  Depending on how quickly current consumption increases near stall, and the characteristics of the drivetrain, it might run slower for short distances.  But a drive designer shouldn't bank on that.

With 73" drivers, to achieve 4 scale mph at 800 RPM, you need -- surprise! -- 44:1.  Samhongsa knew this, because they built many brass locos in other scales before they took over and improved the Williams Crown Edition line in the late '80s.  That's why those Williams gearboxes say SAMtech.

Personally I think the top speed, or even the typical speed of the prototype is irrelevant.  On a small layout with typical 3-rail curves, 60 mph or even 45-50 mph is plenty fast.  So if 800 RPM = 4 mph, you'll need at least a 9,000 RPM motor to reach track speed.  This has been the reality in all other scales, for years.  If you need a bigger power supply, or special attenuation of NVH for high-RPM operation, that amounts to built-in quality of design.

This is the direction 3-rail O scale was headed too, until MTH entered the market circa 1992.  Coming from a tinplate background, their designs were a throwback to 1950s toy trains.  Tall gear ratios.  No separate gearbox or "bottom plate" with removable wheels & axles.  Only small-drivered models (like the Y6b) were capable of smooth operation at switching speeds.  This was definitely a step backward!

Speed control came along in 2001, introducing a new set of possibilities (and headaches!)  Like a giant band-aid, it greatly masks what I perceive as a tragic design error.  To me, 30:1, even 36:1 with a 10,000-12,000 RPM motor would be ideal.  With a balanced drivetrain in a die-cast metal body, that shouldn't pose insurmountable problems with NVH.  This combo would maintain a wide range of realistic speeds without cruise control, and run phenomenally with it.

The command setup is icing on the cake, and it should NEVER be the constraining factor.  If there isn't a control system and decoder combo on the market that can handle a 12000 rpm motor with enough torque for O scale, then someone needs to invent one, pronto.  Because ^^this is the right way to build a train!

Last edited by Ted S
@Ted S posted:
Speed control came along in 2001, introducing a new set of possibilities (and headaches!)  Like a giant band-aid, it greatly masks what I perceive as a tragic design error.  To me, 30:1, even 36:1 with a 10,000-12,000 RPM motor would be ideal.  With a balanced drivetrain in a die-cast metal body, that shouldn't pose insurmountable problems with NVH.  This combo would maintain a wide range of realistic speeds without cruise control, and run phenomenally with it.

I don't get the animus toward speed control.  Truthfully, even when I have had the Williams with the 44:1 gearbox, it still needed speed control for consistent speeds on grades and curves.  I also am not enamored with the idea of 12,000 RPM motors, it has to be a pretty high quality motor to keep the screaming noise down at those speeds.  I have absolutely no issue at all running any number of my Legacy locomotives at 3-4 scale MPH all day, so your idea that can't be achieved with current models flies in the face of reality.

Instead of going wayyyyyyyy off the deep end.....which these threads always seem to do with all the Maxwell & Farady equations, why not wait and see if the OP actually says what his plans are for the model....THEN make the best suggestions based on what he’d like the locomotive to do....all the nomenclature and mathematical equations are worthless until we know what the OP would like to see the locomotive do.....I’m not sure at this point if we’re running a Hudson or firing up the Enterprise to go where no man has gone before......geezzzzzzz....

Pat

I don't "hate" speed control; I think of it as a way to make something that's already good even better.  If the speed control is too "tight" or reactive it can take away the feeling of momentum and mass.  And a lag can make it feel like you're operating a robot, instead of running a train.  It's better to achieve smooth operation the natural way, embracing the laws of physics instead of fighting them.  It's a bit like the discussion of a tube amp vs. solid state, vinyl vs. mp3, or drive-by-wire vs. a cable throttle.

Two years ago we almost lost ERR.  Now as MTH closes its doors, the future of Protosounds and DCS is unknown.  Historically Lionel hasn't offered it's Legacy electronics in a retrofit kit.  With a conservative gear ratio, quality motor and drive train, ANY of the non-proprietary R/C systems such as Airwire (which has been around for YEARS) would give you individual control with Legacy-like performance.  The only sacrifice is a muted top speed.

The Williams by Bachmann 4-6-0 is a good example.  I've seen this loco in action, and everyone on this Forum says it's a great runner even without speed control.  Williams uses the common RS-385, but at track speed, I'm pretty sure the RPMs get way up there.  It coasts nicely too.  It's well-enough engineered that I've heard few complaints about NVH.  I would like to see more locos use this gearing as a starting point.

At some level, even MTH has admitted the error of its ways.  They didn't make a big deal about it (probably so as not to devalue existing inventory.)  But beginning around 2008, many of the RailKing locos got lower gear ratios.  The Mohawk, Pacifics, and Hudsons gradually changed to 26:1, which is lower than most 3-rail trains marketed as scale models!  And the "new" 726-style LionChief Plus Berks were geared at 25:1, which is the slowest I know of in any postwar-styled train.  Hopefully more will follow this pattern.

I'm not saying that they should stop selling trains with speed control, or that people shouldn't consider a thoughtful upgrade if a train has a lot of sentimental value.  My point to JohnA is that Williams (Samhongsa) wasn't wrong.  A 42:1 gearbox isn't a disease to be excised.  For use on a typical small layout, 800 RPM = 4 mph is an excellent starting point.  Whatever issues of NVH and current draw might arise from that can be addressed through careful motor selection and quality design.  Then, speed control becomes the cherry on top of the sundae.

 

Last edited by Ted S

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