Concept for gear drive vertical boiler Shay

[jugtown modeler]

With an auction lot win that included Atlas Shay parts, I started playing with the idea of a working vertical boiler model in N scale. Ultimately, narrowing the gauge as well.

After playing around, searching for previous attempts and/or successes, I came up with the concept of putting a motor in the vertical boiler and try to figure a way to transfer power to the Shay gear cases. This is my amateur attempt to solve.
[ Guests cannot view attachments ]

This is a concept, a crude MS Paint patched "drawing", not a final plan or attempt at an engineering drawing (clearly).
I know there are some brighter minds than mine, some with more experience and likely a few engineers that will immediately see my folly or, hopefully, point out some potential.(?)

Original "vision" had hoped the drive shaft might be able to be hidden in or below the Shay deck. Perhaps with a lower gear case/assembly, like a Kato 11-105(?)

Any constructive feedback, immediate observations, previous attempts or successes that you might have is welcome.
Thanks for any help offered.

[metalworkertom]

First thing I see is finding a motor that will fit in the boiler and not be too tall. What does the boiler measure out to ?

[SkipGear]

First thought is that you don't need a gearhead motor. The Atlas Shay gearing stock is very low. Adding reduction at your crown/pinion combo as well as in the motor might be a bit overkill. This will save some height issues with the motor.

[randgust]

The bugaboo on working with the Atlas Shay mechanism parts is controlling the tolerance between the worm and the trucks.   On the Atlas shay, the only thing controlling that is the motor position in the bracket.   You're on your own setting up a block / bearing above the truck.   

While a gearhead wouldn't hurt, my 'go to' drive of a Kato 10mm 11-105 motor with a gizmoszone gearhead with a 5.14:1 reduction is no longer available since Gizmoszone went out of business.   BUT, lately I've been searching for 10mm gearheads and found a ton, but instead of reduction they simply advertise a 3.5V motor and ending RPM.. rather than reduction.   Still tinkering.

My 'go to' drive for my Class A Climax kits is a Solarbotics GM15A 6mm motor with a 25:1 reduction, paired up with a 100 ohm resistor.  Cheap, reliable, available.   Length is more of a problem than diameter with a gearhead.    On my vertical boiler Climax models, the gearhead motor is partially recessed into the frame with a horizontal driveshaft powering one truck only.   That's not going to help you with a Shay.

Gizmoszone appeared to buy from a Marsten company in China, also gone.  It's kind of sad, too, because Gizmoszone had some wonderfully tiny crown gears and matched spurs to do tiny differential drives.   I got a set to do hirail trucks.   

I'm sure that our resident machinist, Mark Graulty (narrowminded), could figure out about any gear you want.   I've seen his tiny gears for Nn3.

An eye-opener for me is the tiny motors in the Rokuhan SA001 critters for Z scale - very small, high RPM, 9V, and with a set of motor magnets in them that can suck parts off the workbench.   Worth looking at, and they have a worm on the end that could be paired with something on that driveshaft, and that double-worm reduction might actually work.   I have SEVERAL of those motors left over, if somebody wants one, contact me.

Before Atlas ever announced their Shay, I scratchbuilt a 28-ton Class B shay using Kato 11-105 power truck and chassis.  I made an attempt to spin the gearshafts back from the wheels using watch gears, nice try, completely failed although I did successfully make my own crank.   I had an 8mm Faulhaber without a gearhead in it, and while it was nice and quiet, it was way too fast and had poor torque.   I replace the Faulhaber with a Gizmoszone gearhead and it's now much better.

The drive in this was really the predecessor to my Climax A kits, this was the test bed for a bunch of ideas.   The Kato truck is 27" wheels on 5'6" wheelbase where the Atlas Shay is based on a 65-ton Class B with riveted trucks (the big ones) but at least the drive train actually works.



The Climax A vertical boiler on a more 'stock' Kato chassis succeeded in getting darn near the entire drive train out of sight (horizontal motor in the round tank, shaft barely visible above the floor) with a cast metal boiler and woodpile for weight.  But again, this doesn't even begin to solve the problem of working cylinders.   If you're content with static drivetrain, this would work just fine.



I've taken my Climax A kits and figured out how to put the Rokuhan Z trucks under them for Nn3 versions, and there's no reason why this won't work to this vertical boiler idea.   The Rokuhan trucks and pickups are Kato quality, but you REALLY need the gearhead in this one.   I have some video of the Nn3 out on YouTube.   I don't know of anyone that's successfully narrowed Atlas shay trucks to Nn3, if anybody has, I'd like to see it.

[jugtown modeler]

First thing I see is finding a motor that will fit in the boiler and not be too tall. What does the boiler measure out to ?

      - The one pictured is a gearhead that is too big. I have a smaller motor that does fit but no gear reduction.

First thought is that you don't need a gearhead motor. The Atlas Shay gearing stock is very low. Adding reduction at your crown/pinion combo as well as in the motor might be a bit overkill. This will save some height issues with the motor.

     - Thanks. This is an area that I would need to experiment. My gear math says there should be enough reduction but can you really ever have "enough"?

Randall, Thanks, was hoping/counting on you to respond here. Your work has always been inspiring.

The bugaboo on working with the Atlas Shay mechanism parts is controlling the tolerance between the worm and the trucks.   On the Atlas shay, the only thing controlling that is the motor position in the bracket.   You're on your own setting up a block / bearing above the truck.   

     - This has been a challenge. Looking at the Kato set up for inspiration or actual use.

My 'go to' drive for my Class A Climax kits is a Solarbotics GM15A 6mm motor with a 25:1 reduction, paired up with a 100 ohm resistor.  Cheap, reliable, available.   Length is more of a problem than diameter with a gearhead.   

     - Thanks

Gizmoszone appeared to buy from a Marsten company in China, also gone.  It's kind of sad, too, because Gizmoszone had some wonderfully tiny crown gears and matched spurs to do tiny differential drives.   I got a set to do hirail trucks.   

     - Have been scouring the web for this.

I'm sure that our resident machinist, Mark Graulty (narrowminded), could figure out about any gear you want.   I've seen his tiny gears for Nn3.

     - I am looking at slot car parts but would love to find something smaller and finer.

An eye-opener for me is the tiny motors in the Rokuhan SA001 critters for Z scale - very small, high RPM, 9V, and with a set of motor magnets in them that can suck parts off the workbench.   Worth looking at, and they have a worm on the end that could be paired with something on that driveshaft, and that double-worm reduction might actually work.   I have SEVERAL of those motors left over, if somebody wants one, contact me.

     - I have a half dozen shortys to play with including 2 that have been re-motored for Nn3 use. But could def use use the worms if they are still on your motor?

The Climax A vertical boiler on a more 'stock' Kato chassis succeeded in getting darn near the entire drive train out of sight (horizontal motor in the round tank, shaft barely visible above the floor) with a cast metal boiler and woodpile for weight.  But again, this doesn't even begin to solve the problem of working cylinders.   If you're content with static drivetrain, this would work just fine.

I've taken my Climax A kits and figured out how to put the Rokuhan Z trucks under them for Nn3 versions, and there's no reason why this won't work to this vertical boiler idea.   The Rokuhan trucks and pickups are Kato quality, but you REALLY need the gearhead in this one.   I have some video of the Nn3 out on YouTube.   I don't know of anyone that's successfully narrowed Atlas shay trucks to Nn3, if anybody has, I'd like to see it.

    - I have your Climax A kit tucked in a project box. I had visions of building it into a narrow gauged loco but it was on a back burner. Then you actually did it and I hope to copy.

As for this project, I was testing the waters here to see if anyone would point out an absolute fail point.
 
I am at sticking point as I actually have narrowed the Atlas Shay gear case, truck frame and axles in a proof of concept. (until I mistakenly sanded a hair off the bottom and gear cover does not fit back over axles...)  The wheel/gear/drive shaft still turns. I am laying out a "jig" to hold the gear cases snug for consistent machining - in my case, saw and filing.
I have cut the 3 cylinder Atlas part down to 2 and still need to shorten the crankshaft... somehow.
But, the Atlas Shay gear case is too tall to hide the driveshaft in or below the deck. The Kato truck/gear drive / worm assembly is lower but I don't see me successfully turning the geared shafts and crank shaft with that set up.

That is why I am turning to more experienced modelers. So far, nothing screams "impossible"....

Thanks for replies.
-Steve

[CRL]

Does anyone remember the “pancake” style motors used in the Aurora HO slot cars of the 1960’s. I wonder if anyone makes motors of that configuration & if they would have enough torque for this type of application.

[nickelplate759]

I do remember those pancake motors (in "Thunderjet" cars) - and Lima used pancake motors in some of their early N scale.
The Aurora motors were more about RPM than torque (because these are race cars), but it was possible to rebuild them for higher torque (stronger magnets and finer wire).  That said, the magnets took up a lot of space.     The motor shaft was vertical, with spur gears to carry motion to the rear of the car and a crown gear driving the rear axle.   How would you fit such a motor into a Shay in order to drive the axles?

[metalworkertom]

What diameter motor do you have that will work ?
I've been toying with the idea of shortening the Faulhaber gearheads. I think I have it worked out mentally anyway.

[peteski]

Fleischmann uses pancake-style motor in some of their smaller N scale steam locos.  The are coreless motors, as the flat rotor consists of just windings (no iron core). They also come with a thin flywheel which is the same diameter as the motor, and also high price tag (around $60 US).  However I'm pretty sure their diameter is too large for this application.

There was also a similar motor (but smaller) geared motor sold by IHC to motorize their carnival ride kits.  That motor might fit the bill.  I think I have few of those (without the "gearhead") I bought at a surplus dealer.  I think they are rated for 6V.  The problem is that they have the flat commutator made out of PC board material, so its longevity is limited.  I'll have to look for them.

[jugtown modeler]

What diameter motor do you have that will work ?

     -There are quite a few small motor options available. The Nn3 community has been using various small motors. This won't need too much power. A few narrow gauge cars. The
      Kato 11-106 critter motor will fit. This photo shows a Nigel Lawton motor 6mmx12mm and a 3D printed boiler (which may be a bit big, but is hollow): [ Guests cannot view attachments ]

The Aurora motors were more about RPM than torque (because these are race cars), but it was possible to rebuild them for higher torque (stronger magnets and finer wire).  That said, the magnets took up a lot of space.     The motor shaft was vertical, with spur gears to carry motion to the rear of the car and a crown gear driving the rear axle.   How would you fit such a motor into a Shay in order to drive the axles?

     -I played with the idea of the motor turning spur gears, obtaining some reduction and keeping a low/flat profile in the deck, but transferring the motion from a flat plain
      perpendicular to the gears in the truck has stymied me.
      Slot car gear arrangement has been floating in my head for years. Wondering if anyone had ever considered using that configuration to minimize space in a model locomotive.
      Probably because there has not been a real need and I am still guessing that there are many engineering reasons why scale locomotives are are designed as they are.

[jugtown modeler]

First thing I see is finding a motor that will fit in the boiler and not be too tall. What does the boiler measure out to ?

Good point.

I have been looking at the Climax as well, which can have a taller boiler.
The Shay does tend to have a shorter boiler.

[metalworkertom]

     -There are quite a few small motor options available. The Nn3 community has been using various small motors. This won't need too much power. A few narrow gauge cars. The
      Kato 11-106 critter motor will fit. This photo shows a Nigel Lawton motor 6mmx12mm and a 3D printed boiler (which may be a bit big, but is hollow): (Attachment Link)

     -I played with the idea of the motor turning spur gears, obtaining some reduction and keeping a low/flat profile in the deck, but transferring the motion from a flat plain
      perpendicular to the gears in the truck has stymied me.
      Slot car gear arrangement has been floating in my head for years. Wondering if anyone had ever considered using that configuration to minimize space in a model locomotive.
      Probably because there has not been a real need and I am still guessing that there are many engineering reasons why scale locomotives are are designed as they are.

I have a couple of the Nigel 6 mm motors. Not sure of the not sure what one would pull . I think gear reduction could be added , it could be a little larger diameter Hidden in the cab. So maybe a shortened 8 mm Faulhaber gearhead will work.

[mmagliaro]

While driving the truck tower gears with a worm directly like that will "probably" work on curves, because there is enough slop in
our gears to tolerate the truck swivel, I would suggest building carriers for the worms on top of the trucks, so they can
stand alone, and joining them to the main horizontal shaft through U-joints.

[jugtown modeler]

While driving the truck tower gears with a worm directly like that will "probably" work on curves, because there is enough slop in
our gears to tolerate the truck swivel, I would suggest building carriers for the worms on top of the trucks, so they can
stand alone, and joining them to the main horizontal shaft through U-joints.

Thx. The Kato drives utilize that set up for it's single truck drive. Have been using that for inspiration but may end up actually using it but sacrificing rotating side truck shafts...

[narrowminded]

For a basic review of concept viability a few basic dimensions would help.  What is the boiler OD and height and what is the offset in the frame?   The boiler dimensions will dictate the maximum motor size and the offset will suggest, at least in part, the room for gears.  A double worm would afford the necessary gear reduction for a small motor without using a planetary reduction and because of the vertical motor position, would provide the two shaft direction changes that this requires.  The motor could be as large as just under the boiler diameter and if there's extra room, the motor could be further offset within the boiler for even a little more gear room.  With those numbers I could quickly figure if there was even a prayer and then more final details could be pursued.  If the basics aren't there...   And finally, assume that the necessary parts, if not standards, could be produced if the basics lay out OK.