3 Simple Ways to
Share What You Make

With Instructables you can share what you make with the world — and tap into an ever-growing community of creative experts.

PhotosPhotos

Share one or more photos of a project, recipe, or whatever you've made, quickly and easily.

Step by StepStep-By-Step

Share your step-by-step photos with text instructions of what you made so others can do it too!

VideoVideo

Share your how-to video. You'll need your embed code from a video site such as YouTube.

Turbojet Engine (how NOT to)

Turbojet Engine (how NOT to)
This is not finnished because it won't work. You could make it work though according to rajat1sharma by making a bigger multistage compressor, or mabey with a big centrifugal compressor. Sorry to anyone who started building this, you will have to do your own problem solving if you want it to run.

The concept of a jet engine is basically a rocket that uses air as the oxidizer instead of something that's already stored on board. There are many types of jet engines, but I will focus on turbojets. The purpose of a turbojet is to push a lot of air out the back of itself at high speed to provide forward thrust. It does this by combining the air with a fuel like propane or kerosene in a combustion chamber and igniting it to cause it to expand and rush out the rear of the engine. The heated, high pressure gasses flowing out spin a turbine at the back of the engine which provides the power for the compressor. The compressor is a fan at the front of the engine that forces air into the combustion chamber to be mixed with fuel.

This instructable will show you how to build a small turbojet from scratch. This design could be scaled up to be used on anything once you have practiced with a small one.
 
Remove these adsRemove these ads by Signing Up
 

Step 1Gather Materials

Gather Materials
«
  • DSCN0702.JPG
  • DSCN0894.JPG
  • DSCN0690.JPG
  • DSCN0707.JPG
  • DSCN0691.JPG
  • DSCN0714.JPG
Materials:
-Stainless steel water bottle, the mouth should be narrower than the main part.
-Steel tube that fits snugly in mouth of water bottle (1 3/4" diameter on mine). Make sure it has no weld line or a flat weld line on the inside. 
- ~ 1/32" thick stainless steel pan or tray.
-1/2" diameter steel rod.
-1/16" steel wire and 1/32" steel wire.
-Bearings that fit over the rod and can handle high RPMs and heat.
-1/2" diameter bolt (x 3) with fitting nut (x 3).
-Spark plug with short threads ( x 3) with fitting nut (x 3) and washers (x 3). 9/16" with 18 threads per inch works for the nut.
-Propane cylinder and valve.
-Piezoelectric igniter.
-Small diameter copper or steel tube for fuel line.
-JB Weld.
-Electric motor for starter (optional).
     -Battery and switch for the motor.

-Note: If possible, use stainless steel in place of regular carbon steel on every steel part. I used mild steel on some parts because it is easier to get and cheaper. Do not use any aluminum, plastic, or glue, only use steel.


Tools:
-Angle grinder or other metal cutting saw.
-Grinding wheel (or a hand file).
-Drill.
-Welder.
-Lathe, helpful but not absolutely necessary.
-Tin snips.
-Vice.
-Dremmel tool or other small cutter/grinder. Optional but very helpful.
« Previous StepDownload PDFView All StepsNext Step »
18 comments
Oct 20, 2011. 7:09 PMbrendonl says:
You have done an excellent job, it looks like you you put a quite decent amount of work into this bit of engineering. You have got some inventors potential :)
Jun 3, 2011. 7:09 PMmarksteamnz says:
. Your design unfortunately has zero chance of working. Even if the compressor stage was perfectly designed and the combustor correctly dimensioned you can not get enough pressure rise in the compressor to over come the drag of the bearings etc. Axial Gas turbines need multiple compressor blades stacked with stators and the blades need to be aerodynamically perfect and unfortunately this gets worse the smaller the turbine is.

Thumbs up for trying but by your lack of responses recently I guess you have found it won't spin up.
Don't give up, just take a step back. You need to go to a gas turbine forum and talk to experienced builders and perhaps start with a bigger engine with a centrifugal compressor and an axial exhaust turbine. Get your eye in. and slowly sneak up on a pure axial, it's a monster of a mission
Jun 27, 2011. 5:55 AMrajat1sharma says:
Hi Jaycub
I am agree with marksteamnz as i tried the project and found it not working. to get it working i increase the size of compressor so that more intake air can flow into combustion chamber. and this worked. also i opened the ball bearing covers and washed the excess grease which make them run smoother.
Jun 30, 2011. 12:12 AMrajat1sharma says:
Yes it worked and runs fine.. but now trying to add a turbo prop to make cooler.
Jul 5, 2011. 9:40 PMmarksteamnz says:
You need to clarify. You can not have got this design to run with a bigger axial fan compressor. With out many compressor stages of vastly improved sophistication the design will not run. As far as I can determine no amateur builder had ever got a home made axial turbine to run certainly not in the small sizes this instructable refers to. If you have used a centrifugal fan that is quite possible but that is not what is under discussion. Pictures or a youtube video would help clear up the confusion
May 25, 2011. 5:20 PM_Scratch_ says:
Argh! Don't cut the tubing with tin snips! Use a pipe cutting tool, the one that clamps down and spins around.
Apr 4, 2011. 12:27 AMrajat1sharma says:
Hello Jaycub.. Great work ... your way of design is very simple and will definately runs.. I am waiting for your last steps.. I have already build till the step discribed..

Please get well soon and help us to finish this project.
Apr 1, 2011. 10:30 AMfixitmankeith says:
I got most of the parts to build the engine. It sure would be nice to get the plans on how to finish it.
Mar 21, 2011. 5:01 AMrimar2000 says:
Video? This work deserves it.
Mar 21, 2011. 4:25 PMrimar2000 says:
OK, thanks. Please, then send me a PM.
Mar 21, 2011. 12:15 PMfixitmankeith says:
Hi nice job, is there more? As how it is the tube attached to the pipe ? Could the blades be silver soldered in place? All of that wire does not look like it will be balanced to well.

Pro

Get More Out of Instructables

Already have an Account?

close

All Steps Viewing
View all steps of an Instructable on the same page when you're a Pro Member.

Upgrade to Pro today!
19
Followers
5
Author:Jaycub