HOn30 H.K. Porter 0-4-0

Here is my take on the ubiquitous H.K. Porter 0-4-0. This model was designed to be printed on an FDM printer with a standard 0.4 mm nozzle and all parts are designed to be printed with no support. Also, this model is designed for use on the readily available Bachmann N scale Percy 0-4-0 chassis.

Tips for printing:
Print 1 of each file and two sets of steps, steam chests, and coupler spacers (optional). I included three different styles of funnels/stacks for customization and you only need to print one of your choice. I recommend printing the cab, stacks, dome, filler cap, steam chests, and steps upside down. Print the smokebox and tank so the part with the “tab” faces the build plate. Print the cylinders and pilots with their fronts toward the build plate and the thinnest parts sticking upward and finally print the roof on its side sticking upwards. I’ve found brims to be useful for the stacks, domes, and the roof. (I’ve attached a picture of how I orient my parts for the “best” surface finish.)

Assembly:
What you’ll need: Printed components, Bachmann N scale Percy, 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 disassembling your Percy model (be advised this will most likely void any warranties so make sure you start with a good running model). Using a small, fine, Phillips; on the underside of the model remove the 2 screws near the cylinders, the 2 screws on each side of the chassis near the center of the model and the 2 screws under the cab. The boiler should lift off and the body should pull free from the chassis. With the body removed flip the boiler upside down and remove the screw near the smokebox and gently pry the weight backwards out of the boiler. This weight is what the Porter body is built around.

To assemble the Porter body, I like start with the steps, these press into the slots on the side of the tank and should be secured with a drop of super glue, the beveled sides should face downwards. These are a snug fit and I find it best to start them then “pinch” them into place with one finger inside the groove on the bottom of the tank and the other over the end of the step. The tank slides over the Percy weight with the “tab” facing the front, it should key into the slot in the weight to assist with alignment. The smoke box pushes onto the front of the weight and should be glued to the front of the tank with a small drop of super glue. You can glue the 3D printed components to the weight but I leave mine as just a push fit. Add the dome to the rear of the tank, the filler cap to the front, and the stack to the smokebox, secure each with a drop of super glue. There are holes in the tank and smokebox to assist with alignment. Next glue the roof onto the top of the cab using the tab on the bottom for alignment. Glue the steam chests to the top of the cylinders using the holes to position these. At this stage I like to paint my parts before final assembly. I painted the boiler assembly, roof, and cylinders black and the cab and pilot a wood shade. To finish assembling the model, the weight and boiler assembly slide down over the gear tower on the chassis, make sure this is seated and pushed as far back as it will go. The cab slides down over the chassis and glues to the back of the tank, there is a “nose” like tab on the cab and a pocket on the tank to assist with alignment. Finally slide the cylinder cover over the cylinders and make sure it is seated as far back as it will go. (I found that this didn’t need glue and held itself in place just fine.) Add the pilot and with a small drop of glue attach it to the front of the cylinder cover. There is a tab and slot on these to help with alignment.

Final notes:
Finally a chassis that doesn’t use Kato couplers! I used Bachmann Long Shank N Scale E-Z Mate couplers on my model. If you use these couplers you’ll need to add the optional coupler spacers. These slide under the couplers and glue to the keeper plate to keep the coupler from drooping down. (You might also need to adjust the trip pins on these!) You can also use the factory Rapido style couplers or since the factory couplers use NEM pockets you can use Dapol knuckles or the hook and loop couplers from Bachmann’s HOn30 line.

I’ve very pleased with how this model turned out and I hope you like it as well. I’ll probably end up remaking mine with carved balsa pilot and some handrails, although I do have a resin version that I’ll release at some point in the future. The models pictured are my personal model and an early prototype before I redesigned the cylinders and cab.

If you have any comments, questions, suggestions, or funny remarks feel free to reach out to me. As always, I hope to be sharing more of my models in the future and if you have any suggestions for models you’d like to see in HOn30 let me know.

Best Regards,
Dr. Fixet