Home made jet engine

Inpired by comments on the 'See through Jet Engine' thread, here's my engine:

It's based on the plans in Thomas Kamps' book and eveything except the compressor wheel (a turbocharger part) was made in my shed on my Chinese 7x14 lathe.

The turbine wheel was hacked out of an Hastelloy X disc with an angle grinder and a Dremel, but came out well, I think:

There's a fairly detailed write-up of the build on my website

https://misterg.org.uk/turbine-html/

(Link)

First start-up

For the real massochists, an video of me mumbling as I assemble the parts:

I'm currently waiting for parts for a Hall-effect RPM sensor before I run it again.

Edited By Andy_G on 01/07/2022 09:31:25

Beautiful to behold.

Superb

Thank you!

Brilliant ! I am really impressed with hacking out the Turbine with a Dremel and Angle grinder.

Keith

Have you made the jet pipe yet?

When I was an apprentice and at college in the late 1960s anyone suggesting that a model jet engine would work, let alone be made in a small workshop with simple tools, would have been laughed out of the room.

JA

Pulse jets seemed to be popular with model types back in the 60s. But a whole lot simpler than the above!

Magnificent!

Very impressive. Superb workmanship, and model engineering of the highest quality.

For those really interested in these machines search

**LINK**

I've made the tail cone, but it only appears in the first video - I want to confirm that the exit temperature is under control before running the engine up with it in place. I think that people who fly these things sometimes use an internal exhaust duct that they call the jet pipe - I don't have any plans to put this in a plane, so I haven't made one of them.

Thanks to all for the kind comments.

That is quite stunning ! How long did it take you to make the turbine wheel ?

Thank you!

The turbine wheel didn't take as long as I thought it would - it was split over several sessions, so it didn't seem too bad:

• Cutting the blank and turning the profile;
• Slitting the disc into blades;
• Putting the initial twist into the blades;
• Cleaning out between the blades and the initial shaping (with an angle grinder);
• The first go at smoothing and shaping the blades;
• Second go at shaping, and carving the concave faces with a dremel.

Each of those took an afternoon, pretty much (some afternoons were longer than others!)

More details of the process I followed here:

Turbine wheel blank

Forming the blades

Some useful download plans can be seen here from Gerald Rutten (zip files)
http://www.gerald-rutten.nl/turbines.htm

They use the same gas container as the early Shreckling engines ,the most thrust obtained from the engine that i made was about 6 lb ,i think the GR 180 in the plans above produces about 36 lb.

---------------------

https://www.turbomaster.info/eng/applications/compressor.php

shows the sizes of nearly all made compressor wheels and is a
useful reference.

-----------------------------------
The 2 compressor wheels here (1st photo) were from Aliexpress ,the one on the left
is a K27 wheel 47.3 dia inlet and 73.9 dia od 14 blade
the one on the right is a TO4B 45.8 inlet and 70 mm dia od 16 blade.

------------------------------------
The 2 compressor wheels shown here (2nd photo) , on the left milled from
2014 t6 aluminium 68 mm od for KJ 66 engine , the one on the right
is a KKK 5326 123 2038 cast wheel also for a KJ 66 engine.

---------------------------------------
The turbine wheel seen here (3rd photo) is for Shreckling FD 3 /64 turbine engine
milled from 718 inconel 20 years ago, perched on top of the remaining 17 inch
of 2 3/4 inch dia inconel 718 bar .

It is perhaps not worth making a turbine wheel from solid these days
unless you already have the material and the means to mill them ,back then
ready made wheels were only just appearing from the GTBA when they had a
batch made for members of the organisation.

www.jetmax.ch sell ready made wheels from about 66 to 82 mm dia from
about 165 Euros which suit the KJ 66 engines and also the Gerald Rutten
turbines.

John

That's really good and I love the details like the engine mount, that really makes it stand out from the others.

Did you make your own spot welder too. If so which plans did you use or was it the Gas Turbine Builders Association spot welder made from a microwave.

Thanks

Thank you!

Yes, I did end up making a spot welder, after trying and failing to TIG everything - I didn’t follow any specific plans, just used a larger than usual microwave transformer (from a very old commercial microwave) and replaced the secondary with the heaviest cable I could fit in there. It’s controlled by a 555 timer IC and a solid state relay. It packs quite a punch and welds 0.5mm stainless in less than 0.1 seconds.

A little more info

Edited By Andy_G on 02/07/2022 22:59:59

Great stuff. Thanks for taking the time to post and take pictures etc.

If there are any aspirations towards high performance, then a commercially cast inconel turbine is a necessity. Unfortunately, they are probably less available now that they were ~15-20 years ago, as the co-operative DIY efforts have morphed into commercial entities, and the supply of parts to hobby builders has dried up. (There is nothing available via the GTBA - I am a member.)

About the only non-Chinese source is Jetmax, as you say, but taxes and shipping pretty much double the advertised 230 euro cost of a 66mm turbine wheel (and you'd probably want the matching inconel NGV which would cost the same again.).

There are cast turbine wheels advertised on Alibaba and other Chinese sites which are about half the cost of the Jetmax ones.

In any case, I thought that was too much money to sink into a project for me (I didn't want a jet engine, particularly: I wanted to *try to build* a jet engine) - the Kamps design is one of the few still available that will tolerate a home made turbine (even a stainless one), albeit ar reduced performance, which is why I chose that design - I was very tempted to try one of the original FD3 variants (since this is what had sparked my interest, back in the 1990s) but the Kamps is a much better design.

If you just want a jet engine, the answer is to buy one! :D

There is a GTBA project engine coming to fruition that uses a radial inflow turbine (rather than an axial turbine as used in most of the model jet engines) that would allow turbocharger turbines to be used.