Powered Stewart Models 25 ton rail crane

[randgust]

I'm specifically interested in where you sourced the motor.   I get the trucks, the gear axle.   Not so sure about the worm - Kato?

One advantage to DCC is that keep-alive saves you, although Kato trucks are wonderful for pickup.   My Burro crane was too short and stiff on the wheelbase so I had to hot-truck the flatcar that it's paired with, used Kato caboose trucks, worked very well.

[Jim Starbuck]

The motor is a 12 volt 6 x 15 mm coreless with a single shaft .8 mm diameter.
The worm is from a Bachmann S4. I’m not sure what the gear mod is. I just held them up together and they matched so good to go.

Tramfabriek in the UK sells the motors. Very good to deal with and quick shipping from overseas. I’ve bought from him on EBay and also directly.
I had the worm on hand and made my own shaft adapter bushing on my lathe but the motor supplier also has worms, gears, flywheels  and shaft adapters. He’s an excellent resource for mech building.
This is the same supplier Ron used for his 3 truck Shay build.

https://tramfabriek.nl/

[mmagliaro]

I'd lay a bet that these are mod 0.3 gears, just because nearly everything in N Scale is these days, except for a few (like the Kato GG-1 and SD40-2 mid production, which are mod 0.2).  And visually, they just plain look like mod 0.3.  You could use a worm from almost any Atlas or Kato diesel (except the two I mentioned), and the only complication would be getting the correct sleeve to adapt it to the motor shaft size.
Old stuff, like 1970s Rivarossi, used mod 0.4, but that was a long time ago.

[Jim Starbuck]

The worm from the Bachmann S4 is 3.16 mm in diameter and fits a 1mm motor shaft. The small diameter worm is very helpful because of the small amount of room to work with. The shaft on the 6mm motor is .8mm so I drilled the worm out to about 1.5 mm on the lathe so the bushing would have a little thickness. I turned down the brass bushing so it was a slip fit into the worm then drilled it out so it was also a slip fit on the motor shaft. Just a touch of red Loctite secured both pieces to the motor shaft making sure no thread locker got into the motor bearing. There’s probably.005” between the worm and the motor bearing which is enough so that the end play of the motor shaft still clears the worm.
The worm and geared axle Kato uses on their 11-10x powered chassis may be a good candidate for this build as well. The parts in my build were in large part used simply because I had them on hand.
I did put the traction tire wheel from a donor Kato chassis on the geared axle.

[randgust]

This is an old shot of an even older model.  I think I made this back about 1975 and had it in my shop scene.  When I went to this layout I decided to come up with a short work train with this as the 'feature' car so I had to lay the boom down.  ATSF tended to use older stuff for boom cars, a drop-end gon worked fine.   But as much as I studied it, couldn't figure out how to power it, you get a special prize for pulling that off.



More along the line of what you've down was powering the Burro crane and tying it to a flatcar full of rail (no coincidence, I needed the weight for electrical pickup on the flatcar).  There's a build thread on this somewhere.   Actually runs very well, still the smallest powered thing I've ever made.



Video before Iphones were available..... wow, that was 10 years ago?

[Jim Starbuck]

Very cool Randy! Thanks for posting those.
I think that’s the only Stewart kit I’ve ever seen finished. I remember following the Burro build thread perhaps on the old Atlas forum?
I may make my flat car tender electrically live but just don’t know until I run this thing for a while. One drawback of having the rear truck rigid is the model doesn’t tolerate vertical discrepancies in the track very well. Again we’ll just have to see when it runs some more. It did fine on my Unitrack test loop.

Here’s a couple more photos of the build:

The front truck mounts to a piece cut from the donor powered chassis and epoxied to the new styrene. The rectangular part is .055” thick so I made a wafer the same thickness which the rear truck screws to.

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Most of the floor of the carbody was cut out and the opening filed flush with the inside walls. A long 00-90 brass screw threads into the hole at the counterweight which holds the back down and also doubles as the rear coupler screw. The hole in the middle is for the screw that goes up through the center pin and holds the front of the carbody down.

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I didn’t really like the block ‘o metal for the cab so I cut it down to the floor height and built the cab back with styrene and brass bits. I want to model it with the door open and an operator inside. Talented good friend Tom Breed painted an operating engineer figure for me.
I also cut the cab roof back so the windshield slopes backwards per a prototype photo I have.

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I’m exercising some modeler’s license here. Someone may point out that this isn’t correct for American model XYZ built in 19xx. Photos of these cranes are all over the board showing various details. I’m just going for a recognizable facsimile. This is what I’m shooting for with the cab.

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Photo credit : Keith Kohlmann

I drilled holes down through the edge of the roof then made some marker lights from drilled out styrene rod. These will be lighted with 0201 LEDs with red lenses of Gallery Glass.

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[BuddyBorders]

This is so awesome and inspiring! One more thing to attempt!

-Buddy

[Jim Starbuck]

I made some progress on the cab and interior.

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Operating engineer Mr.Thomas is overseeing the build for quality assurance.

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[Jim Starbuck]

There’s been a bit more progress. In addition to a few small cab details the boom is built and I was able to test run it some more. I think electrical pickup wise it will be fine on it’s own.
I scored a FVM caboose lettered for a Milwaukee crew car which makes a nice addition to the little work train.
The crane pushes the flatcar tender and crew car with no problems. A gondola or Difco dump car can be added into the train as well. It’s coming along nicely and runs well.

[randgust]

My original build had the boom up about 30 degrees as it was a shop scene.    When that was scrapped, and I made the crane a 'car', the boom was too high to clear overhead obstructions and it took some serious surgery to figure out how to lower it, as I'd ACC'd all the thread cables in place.

You can see on mine how low I set the boom, it now clears my highway overpasses, tunnels, and signal bridges.   I'm not sure what your overhead clearances are, but check that now instead of later.

I did note that in my actual ATSF employee timetables of the period, any wreck or work train with a crane in it was limited to 25mph.  The first American 25-ton crane I saw ever running under it's own power was a PRR one dispatched to a wreck/tank car explosion at Starbrick PA in the 60's, and it was just 'flying', with the boom oscillating back and forth and the hook swinging wildly, but it was an emergency situation.

I'm also a big advocate now of .010 wire as cables instead of the thread in that kit.   Compare the Stewart photo with the Burro photo, the Burro was done with .010 wire bent and ACC'd in as individual segments.

[Jim Starbuck]

The plan right now is to turn down new lightweight sheaves on the lathe for the 4 part bail then rig from there back to the cab with .007 fly fishing line. I’ll use wire from the two 2 parts glued at either side of the boom tip back to the bail as that would be heavier cable. Hopefully the wire will keep  most of the sag out of it.

[Jim Starbuck]

I made some progress over the weekend.

Got the carbody in primer and added Archer rivet decals over strips of .002 vinyl for some panel line detail.
There will be an Archer louver decal in the recess at the rear but I decided to add that after paint and before Dullcote so it shows up better.

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Some added details are grab irons, ladder, engine oil bath air intake and exhaust pipe.
The exhaust pipe is .026” wire drilled out on the end to show as pipe. Not sure if it will even be visible but it was fun to do.

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I also turned down styrene sheaves for the bail.

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Printed new decals for the counterweight with the Dieselectric logo.

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Jim

[randgust]

Wow, great job on getting those rough castings up to that condition.    I saw all your putty and sanding, it sure paid off.

[Jim Starbuck]

Thanks Randy,
The white putty is Tamiya. That’s a liberal coat of Tamiya surface primer airbrushed on then I sanded the orange peel out with 600 grit sandpaper.

[GaryHinshaw]

Beautiful job so far!