MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.

Download Now


Compressed-air engine straight twin V. 2.0

by Max_Kevin Jan 22, 2019
Download All Files

Thing Apps Enabled

Please Login to Comment

Also another question. Is it possible if you made a video Constructing/Using the engine. I am sure i could figure out how to put it together and im pretty sure i did but i would love to make sure and know im not messing up my 16 hours worth of printing in any way. also how did you connect the valve cover to the body?

I glued only the valve cover on. The rest is just press-fit.

Make shure the valve-lifters move freely up and down.
Make shure the valves are inserted in the slots in the underside of the valve cover.
Assemble the crankshaft (with pistons and everything) but leave the outside axels out.
Insert the crank and pistons in the underside of the body.
Put in the valve lifters in their designated slots.
Put in the axels you have left in the holes in bothe sides of the body and line them up with the crank.
Put in the valvecover with the valves.

Your done!

Just thinker with it. you wil find it out.

PS. I’m starting to think you’re a troll.
Plz send a picture of your print when your done or you will be blocked.

ok its fine
I will send a pic lol im not a troll but ok haha lmao. picture will be given in about an hour and a half being the cams are printing currently\
it isnt quite done yet but i did not have time to finish it

Cool, I like that your printing my stuf. Sorry for thinking you were a troll.

Its a really nice print and I hope everything fits together.

Did you print the entire thing in one print or parts in multiple prints because i sliced it in cura and going to print in one big print? my slicer says about 16 hours was that as long as you print?

No, it should NOT be one big print. the frame/cylinders/body (Same thing) is one print, but all the included ''. St'' files should be printed separately.

Some files like the one for the piston should be printed twice, but you will find that out when printing.

I printed all the parts separately, but the biggest part (the body) took about 5 or 6 hours to print on 0.06 mm layer height.

it's not realy a big print.

Ok thank you for the quick response. I have a second question do you think it would be fine to print all of the for example all the cams together and all the pistons like the small things are one big print and the larger items are another print. when i say large print i mean all of the things scattered out on the build plate. being i also have a mono price select mini you can understand the issues with build plate size. Also are there any required parts other than the 3d printer components if so what are they. as well as what sandpaper grit should be used and how should it be used to sand down the cylinder and piston if needed. also i am planning on using .1 mm layer height on all of the parts is this ok?

I printed all parts separately. Usually prints turn out better when printed separately, but if your printer can do it, I'm not going to stop you.

With a well tuned printer you can definitely do it.

I recommend you print the Axel's standing up for better quality.

ps. i get a push notificaton when you comment. that's why I'm quick to respond.

sorry for bothering you again but did u print with or without supports i am printing with?

No problem man. Wasn't toing mutch annyway.

And without support.

i have about 15 minutes left on the print for the frame/cylinder/body and i printed it at 100% infill. hopefully 100% infill will allow me to extend my pressure operation range to extend higher. what was the amount of infill you used and also how many psi did you run it at? thank you for answering all my questions.

No problem man. I like that people want/are making the stuff I designed.I don't know how match 100% infill will extend your pressure range (I printed at 20% infill) but it will definitely be able to run at pressures above 2 Bar/30Psi. I do recommend you glue on the valve cover when you want to run it at higher pressures. Your not going to keep that in place just with your fingers at like 2Bar/30Psi.

I was able to run the engine from just with my breath to like 2.5 or so Bar's (35 Psi.)

This looks similar to a wobbler engine but this one doesn't have swinging pistons. It looks like the upper block is both the valve control, and the piston. I see a vent on the top in the front but no air inlet for an air hose to connect to a compressor. Could you post a video of it working? How fast could it go? Is it noisy since there are no bearings?

Well, the engine is not inspired form a wobble engine nor a CO2 engine. I was inspired by one of Tom Santon’s videos where he tried to make I compressed-air airplane. The piston and cilinder styles are the same as a regular internal-combustion engine and the valves are operated just like in tom’s video. (With a cam and pushrod).

I admit it is a bit hard to connect a compressed-air supply to the engine, since the intake on the top is not circular. I will try to upload a extra stl. file with a circular air-intake.

The engine is designed to be fully 3D printed. I made some prototypes and tested if it was possible to run the engine without any bearings. And yes, it is. It does have a really quite a little amount of friction and doesn’t make much noise at all.

I will try to make a video of the engine running in compressed air.