HOn30 Baby Shay

Here is another HOn30 geared steam locomotive, this time though it’s a Shay! This model was designed to be printed on an FDM printer with a standard 0.4 mm nozzle and uses the inexpensive and readily available Kato 11-105, 11-106, or 11-107 chassis for power.

Tips for printing:
Print each of the files making sure to orient them correctly. I find it best to print the frame, stack, rods, roof hatch, and domes upside down; the cab upright with support, and the truss rods and pilot steps on their backs. I find it's best to print the roof on it's side and the boiler sticking straight up. Support is needed for the boiler and cab. I also recommend brims for the domes, stacks, and roof to help them print. (I’ve attached a picture of how I orient my parts for the “best” surface finish.)

Print 1 of each file and print 2 domes and 4 pilot steps.

An alternate stack with a spark arrestor has been included. (Since this uses the same design standards as my Class B Climax the stacks and roof from it can be swapped out for even more customization. The stacks from the Porter will also fit!)

Assembly:
What you’ll need: Printed components, Kato chassis, paint, super glue, small file or sand paper (just in case of fitment issues), and any additional detail parts you want to add,

Start by dry fitting the frame, boiler, and cab to the chassis. They should slide down over the top of the chassis without forcing them (they are a snug fit and can be a bit fiddly, sand or file the openings to your desired fitment. Also check the fitment of the roof on the cab and adjust if necessary. Once satisfied with the fitment you can paint the parts first or just glue them together. For me it was easiest to glue everything together except for the roof, paint the model, then glue the roof on.
To assemble the model, I like to use the chassis for alignment, use glue sparingly on the bottom of the cab and boiler slide them into place. The rods glue onto the right side of the frame and glue to the bottom of the pistons on the cab. The truss rods glue to the left side of the frame with the notch towards the rear so it fits around the deck support. The stack and domes have pins to help with alignment (the holes on the boiler may need to be drilled out slightly depending on your printer and settings). The roof has a guide built in for alignment and should fit snuggly on top of the cab and the hatch glues to the top of the roof. Finally glue on the pilot steps to the front and rear of the frame, there are notches to help position these. The chassis can be secured with some Blu-tack or a small drop of hot glue but I just leave mine loose for easier maintenance. Add your fuel of choice to the rear (coal, wood, or leave it empty for oil) and you’re ready to go!

Final notes:
I wish there was a way to make moving side rods for this but alas any kind of mechanism would be way too complex or defeat the purpose of making this a budget model. Like the Class B Climax I took the time to make sure the static rods are quartered.

For couplers, you can use the standard Rapido style couplers, but I switched mine to Kato 923500 knuckles with minimal fuss using Kato 923524 cover plates. Roundhouse and Fox Valley Models also make nice more straight forward conversion knuckle couplers (but I only recommend the coupler swap for more experienced modelers doing it at their own risk).

The model pictured is my personal model that has been painted.

If you have any comments, questions, suggestions, or funny remarks feel free to reach out to me. My goal is to offer a decent selection of FDM friendly HOn30 locos (and maybe even some rolling stock) for beginners or those that don’t want to mess with resin printers (and some models for those that do!). As always, stay tuned for more models.

Best Regards,
Dr. Fixet