Balloon Powered Single Cylinder Air Engine Toy Train

Balloon Powered Single Cylinder Air Engine Toy Train is a balloon powered toy train engine based on my earlier air engine design (https://www.instructables.com/id/Single-Cylinder-Air-Engine-Smaller-Edition) and single cylinder air engine rolling chassis design (https://www.instructables.com/id/Single-Cylinder-Air-Engine-Balloon-Powered-Rolling/). In order to move the increased weight of this design, I added a 4 to 1 (driven to drive) gear reduction. Even with the gear reduction, this vehicle when well tuned can run over 40 feet on a smooth surface, albeit at a much slower speed.

My wife laughed yet again so hard when this toy train engine chugged through the kitchen and into the family room that, well, now there's now quite a few more of them (this time she liked the colors I chose). And yes, it still sounds like a steam engine. I even clamped my iPhone to "Top.stl" and gave it a ride, I've included the video.

You will need to purchase 4 "AS568" #219 o-rings (1 5/16" I.D., 1 9/16" O.D, 1/8" section) for the tires and at least 1 "punch balloon" (I found mine at a local party supply store, but they also are available on line).

I probably forgot a file or two or something, so if you have any questions, please feel free to ask.

Designed using Autodesk Fusion 360, sliced using Cura 2.3.1, and printed in PLA on an Ultimaker 2+ Extended and an Ultimaker 3 Extended.

Step 1: Print, Purchase and Prepare the Parts.

As mentioned in the introduction, you will need to purchase 4 "AS568" #219 o-rings (1 5/16" I.D., 1 9/16" O.D, 1/8" section) for the tires and at least 1 "punch balloon" (I found mine at a local party supply store, but they also are available on line) for the "fuel tank".

I printed my parts on an Ultimaker 2+ Extended and an Ultimaker 3 Extended using .1mm vertical resolution and 100% infill for "Cylinder.stl", "Rod Balloon.stl", "Rod Balloon Coupler", "Rod Balloon Hook", "Journal Crankshaft 4mm 1.stl", "Journal Crankshaft 4mm 2.stl", "Journal Crankshaft 10mm 1.stl", "Journal Crankshaft 10mm 2.stl", "Gear Journal Crankshaft 4mm 2.stl" and "Bushing Journal Crankshaft 10mm 1.stl", 20% infill for the remaining parts, and no supports.

This is a precision print and build and as such requires a clean and level build plate (to eliminate warping) and trimming, filing and/or sanding (to remove edge oozing). Prior to assembly, test fit and trim, file, sand, etc. all parts as necessary for smooth movement of moving surfaces, and tight fit for non moving surfaces. Depending on the colors you chose and your printer settings, more or less trimming, filing and/or sanding may be required. Carefully file all edges that contacted the build plate to make absolutely sure that all build plate "ooze" is removed and that all edges are smooth. I used a flat jewelers file and plenty of patience to perform this step.

Study "Assembly.stl", the cad output of Autodesk Fusion 360 and the photographs carefully noting the locations and positions of the various components as assembly proceeds.

Step 2: Assemble and Test the Air Engine.

Slide "Rod Piston.stl" into "Head Cylinder.stl" noting the orientation of the hole in "Rod Piston.stl".

Press "Piston.stl" onto "Rod Piston.stl" positioning "Piston.stl" exactly 28mm from the end of "Rod Piston.stl". This is the cylinder head assembly.

Slide "Valve.stl" into "Cylinder Center Top Port.stl" noting the orientation of the valve holes. This is the cylinder assembly.

Press the cylinder head assembly onto the cylinder assembly. This is the air engine assembly.

At this point, you should be able to easily and smoothly move the valve and piston rod in and out of the cylinder. If not, disassemble the air engine assembly and lightly file until they do.

Step 3: Assemble and Test the Crankshaft.

Slide "Journal Crankshaft 10mm 2.stl" into the hole in "Arm Piston.stl" noting the orientation of "Arm Piston.stl".

Press "Journal Crankshaft 10mm 1.stl" onto the octagonal pin on "Journal Crankshaft 10mm 2.stl" noting the orientation of each.

Slide "Journal Crankshaft 4mm 2.stl" into the hole in "Arm Valve.stl" noting the orientation of "Arm Valve.stl".

Press "Journal Crankshaft 4mm 1.stl" onto the octagonal pin on "Journal Crankshaft 4mm 2.stl" noting the orientation of each.

Slide "Journal Crankshaft 4mm 1.stl" into the hole in "Chassis Center.stl".

Press "Journal Crankshaft 10mm 2.stl" onto the octagonal pin on "Journal Crankshaft 4mm1.stl" noting the orientation of the two journals. This is the crankshaft assembly.

Press the air engine assembly into "Chassis Right.stl".

Press the crankshaft assembly into "Chassis Right.stl", noting the orientation of each.

Press "Chassis Left.stl" onto the air engine and crankshaft assemblies.

Slide "Bushing Journal Crankshaft 10mm 1.stl" into the crankshaft hole in "Chassis Right.stl" then press into "Journal Crankshaft 10mm 1.stl".

Slide "Gear Journal Crankshaft 4mm 2.stl" into the crankshaft hole in "Chassis Left.stl" then press into "Journal Crankshaft 4mm 2.stl". This is the chassis assembly.

At this time, the crankshaft should rotate freely with no drag or catching. If it does drag or catch, carefully examine the entire crankshaft making sure it is "true" (meaning all journal surfaces are parallel to each other and the chassis surfaces, and no journal, bushing or gear rotates out of true).

Step 4: Connect the Air Engine to the Crankshaft, Then Add the Rear Wheels.

Using "Pin Arm Piston.stl", attach "Arm Piston.stl" to "Rod Piston.stl". Once attached, rotate the crankshaft to ensure no drag or catching occurs. If it does drag or catch, the air engine piston chain (includes the parts "Rod Piston.stl", "Head Cylinder.stl", "Piston.stl" and "Cylinder.stl") needs to be carefully filed until no drag or catch occurs.

Using "Pin Arm Valve.stl", attach "Arm Valve.stl" to "Valve.stl". Once attached, rotate the crankshaft to ensure no drag or catching occurs. If it does drag or catch, the air engine valve chain (includes the parts "Valve.stl", "Head Cylinder.stl" and "Cylinder.stl") needs to be carefully filed until no drag or catch occurs.

Place o-rings onto "Wheel Left Rear.stl" and "Wheel Right Rear.stl", then slide "Wheel Left Rear.stl" into the rear axle holes in the chassis assembly from the left (gear) side of the chassis assembly.

Press "Wheel Right Rear.stl" onto the octagonal pin on "Wheel Left Rear.stl". The wheels should rotate freely with no drag or catching. If they do drag or catch, check both "Gear Journal Crankshaft 4mm 2.stl" and the gear on "Wheel Left Rear.stl" for build plate ooze or extraneous filament.

With no drag or catch occurring, you should be able to blow into the top port of the air engine, give the rear wheels a nudge, and the air engine, crankshaft and rear wheels should all move with ease.

Step 5: Final Assembly.

Place o-rings onto "Wheel Left Front.stl" and "Wheel Right Front.stl", then slide "Wheel Left Front.stl" into the front axle holes in the chassis assembly from the left side of the chassis assembly.

Press "Wheel Right Front.stl" onto the octagonal pin on "Wheel Left Front.stl". The wheels should rotate freely with no drag or catching.

Place "Air Engine Cover.stl" in position on the chassis assembly.

Press "Nose.stl" onto the "Air Engine Cover.stl" and the chassis assembly.

Press "Top.stl" into position on the chassis assembly.

Press "Adapter Balloon.stl" into the air engine port.

Press one "Rod Balloon Coupler.stl" onto one end of a "Rod Balloon.stl". Press the second "Rod Balloon Coupler.stl" onto the remaining end of "Rod Balloon.stl". Press the two remaining "Rod Balloon.stl" into the remaining ends of the two "Rod Balloon Coupler.stl". Press "Rod Balloon Hook.stl" onto one of the remaining ends of the balloon rod assembly. Press the balloon rod assembly into the small square hole in "Top.stl".

Hook the punch balloon onto the balloon rod assembly hook. Place the balloon open end onto the balloon adapter.

To run the engine, I use "Adapter Balloon.stl" as a mouth piece to inflate the punch balloon, after inflating I press my thumb onto the balloon end of the adapter to seal the air, then press the adapter into the air engine upper port and off it goes!

Congratulations, you're done!

Hope you like it!

Comments

[maljg]

Cant open STL files in Fusion360 so it looks like I am going to have to wait for the 'Wind up' version.

[maljg]

Nice model and I was keen to print it. I use a Qidi Tech 1 printer and I had some issues. It needs .3xg format files, not standard Gcode, so I had to use the Makerware slicer set to use Makerbot Replicator Dual format and I don't know if that was causing the issues. It didn't like printing out at .1 vertical resolution but I did get clean prints at .2 but that may have upset the 'tolerances'. Anyhow, every 'joint', circular or rectangular were way to tight and needed extensive filing. This meant that there was more room for error in the fit or slightly miss aligned fit. The model did go together well but due to the slight inaccuracy of tolerances, which when multiplied by the number of inter-dependant moving parts, meant that there was no way a balloon was going the drive this thing. Even blowing as hard as I could I couldn't get the wheels to turn. I commend you on an excellent model and at owning an obviously superior printer. My model doesn't run by air power but my grandson still loves pushing it along and watching the crankshafts rotate. Good job.

[gzumwalt]

Thank you, and thank you for printing this model.

I'm truly sorry you experienced difficulty in printing this model. In my "things to do" file is making a windup version of this model for those with printers that have difficulty with this model.

Thank you again, and again, I'm sorry for the difficulties.

[maljg]

There is nothing to be sorry about, it is my problem not yours. I have found from m experience that if I build a model using Fusion 360 the finished dimensions when I print it out do not match those on the drawing so there is obviously an issue there too but I no know to allow for that when I create something in Fusion which has to match a particular size when printed. Yours is such I nice model I might try opening the files in Fusion and adjust the 'holes' in the model pieces so I don't have to file or trim so much off. I would love a 'wind up' version of this train but I fear I might experience similar issues. Again, great model. I will post a picture of the finished model as it does look very nice.

[zposner]

Awesome

[gzumwalt]

Thank you very much!

[bourno]

Very cool. Are you going to be publishing these onto thingiverse? Just much easier to download all the files at once, instead of individually.

Thanks again for a cool item. When I get caught up on printing some current projects, I plan to print at least one of the designs out for fun.

[gzumwalt]

Thank you very much, I'm truly glad you like it!

I've kind of drifted away from Thingiverse and as such I no longer publish there. Is there a better way for me to format the files for easier download? I'm new here and I'll take all the help I can get!

Thanks again, and I hope to see your train engine soon!

[bourno]

Taking a look around, it does appears one could load a .zip file into the Instructable. Could still have the individual files as well, in case someone doesn't trust Zip files.

Thanks again for the work into your creations.

[gzumwalt]

I've added "Stl.zip" to the files. Let me know how it works.

Thanks again!

[bourno]

Not seeing a Zip file which would contain all the individual part files in it. Or did you try to change the extension of the previous files?

I can just download them individually. Thanks

[gzumwalt]

I think it's there now.

Editor came back online.

[bourno]

Looks to be. Thanks for making it simpler to download your files. And not have to download individually.

[gzumwalt]

I'm still trying.

The last one didn't go up, and this morning I can't edit this Instructable. I'll keep checking back.

Sorry.

[sbelectrics]

A very nice toy, if somewhat expensive, time-wise.

(BTW, shouldn't that be 'formerly' in your bio., not formally?

[gzumwalt]

https://www.instructables.com/id/Balloon-Powered-Single-Cylinder-Air-Engine-Open-Ch/

[gzumwalt]

Thank you!

Yes it does require more time and plastic to print and assemble. I do have a simple open chassis version that I could post if you are interested in it, just let me know.

And I would like to "formally" thank you for my "formerly" mistake. I'd like to blame it on the spell checker, but I think I possibly did that at some late hour. And to make matters worse, I copied and pasted that bio on all the web sites I post on.

Thanks again, and let me know if you are interested in the open chassis version, I have three on my desk right now!

[The Awesome Inventor]

Great job! I have always enjoyed the sounds and looks of a single cylinder steam engine, so this is very cool! Thanks for posting, and I'd love to see your open chassis version!

[gzumwalt]

Thanks again for you interest!

Here's a preview:

https://www.youtube.com/watch?v=Aa2imDpycXo

[gzumwalt]

Thank you so very much, I am indeed happy you liked it!

Give me a few hours for pictures and instructions, and it will be published!

Thanks again!