Jet Bike

[mr_byte31]

Hi All,

I saw a youtube video for a Russian guy who use a small jet engine to drive his bicycle. It sound really crazy but it was very cool idea.
I saw before people adding a small motor to the bicycle but this need a lot of modification to the bicycle( not a simple thing).


I searched internet but it seems a small jet engine with good thrust costs a lot :/ . I was thinking to make the engine but I couldn't find much information ( step by step) on how to make a reliable one. do any one have some resources here?

I was also thinking about the control circuit for the engine. I think i need :
1- temperature sensor to avoid overheating
2- control for the fuel to control the speed
Ref : https://www.youtube.com/watch?v=_O4mw0OMukE


did anyone try something like this before?

[Sideshow Bob]

I think I saw a bike with ram jet on some TV show perhaps Top Gear. This was some years ago and I may very wrong here. I leave the googling to you

[LabVIEWguru]

These engines are extremely popular with people that build and fly large scale radio-controlled aircraft. There were several PDF books floating around a couple years ago on building your own engines. Obviously they are not inexpensive to build. There are a lot of videos out there of "F" and "SKU" series scale model fighters built with these and they are very impressive to see.

Just to show you what a great guy I am, I looked this one up...

[dennis78]

Control circuit is easier to build. Main problem is engine, if you chose turbo-fan variant(as this I think). It need specific material, precise mechanic - speed is about 100000rpm + hight temp... Before long time I had idea about simplest engine than this - without turbine, only compressor driven by small RC gas engine + air cooling(with same RC aux engine) , combustion chamber  and precise injection system. But problem about extreme heating nozzle maybe still exist... I never had time to try something like that.

Engine as this was produced (I don't know now, that was called Samba - cost about 3-5k$) by small company with engineers that had work experience in hi tech company - I don't remember, but I read that someone worked on company who worked on cruise missile engines.

Short running time maybe not very big problem, but long time and stable work is big challenge.

[solutions]

Go pulse jet... https://www.youtube.com/watch?v=bKHz7wOjb9w

Instructions how to build it here: https://www.youtube.com/watch?v=D1EHZPjLNHk
   ...and here: https://www.youtube.com/watch?v=u5ceYtR22Ww

[mr_byte31]

@solutions, never ever a pulse jet.
It looks scary !

[pickit2]

maybe you should convert your skate board or build one of these.

[mr_byte31]

maybe you should convert your skate board or build one of these.

and the bike shall provide me with hot water and transportation.
you are genius pickit2 !

[adamantium]

A friend actually made one:


Note the fire extinguisher xD

He just used an RC Jet engine and the controls, modified the exhaust as he was going to try to implement an afterburner but I'm not sure if he ever finished it. The fuel container is in the bag on the side.

While it sounds and smells amazing, it doesn't provide much thrust. On a level road at full thrust it barely keeps him going and it is incredibly loud, for about 10 minutes before he's out of fuel. If there's even a slight hill he has to pedal anyway.

If you actually want a bike you'll use you're much better off with electric motors.

If you want to learn about Jet engines, then go for it! Although, if you are thinking to make one from nothing, just note that Jet engines usually spin at upwards of 60,000 RPM! Any slight imbalance will cause it to rip itself apart. There's a reason they're not cheap.

I suppose you could just get an engine and make the controller yourself? The electronics for that would still be an interesting project alone.

[solutions]

Go hybrid and use a model helicopter turbine (model jet engine with a reduction geartrain) to drive the alternator.

Cool sound PLUS fuel economy (it'll run for 12 minutes...)

In passing, given the diameter, 60kRPM is not that horrific. A lot of machining, precision high speed bearings,  and not fabricating many makes it expensive.

It's a pain in the butt to set up the lubrication system, but you could convert a vehicle turbocharger into a centrifugal jet engine. The same YouTube channel I posted builds one and he goes through the math on designing the burner can for it.

[mr_byte31]

many thanks all for the reply.

I had a look on the basic design of diesel and petrol engines.

I see the process as : inject air , compress air, inject fuel , ignition, release exhaust.

I think it is the same process of the jet engine. I don't see much difference !

I would imagine the difference maybe because jet engines has high compression ratio but if this is true, why don't they use the same concept in cars !

any explanation why turboshaft are not used for cars or bikes? I would imagine that Noise would be the reason !
but those motors have high efficiency !

[dennis78]

Turboshaft engines have extreme short running life (look at any spec some of them) because many parts are under extreme conditions and require expensive materials and replacement some components after only several working hours. I'm sure that micro turbo machines like this need everyday cleaning,etc (it not easy because parts are small and need precise hard work on it)... It very hard to keep it in working conditions.

Only several "vehicles" use tuboshaft engine... aircrafts (not all), helicopters,  abrams tank(in abrams it d'ont give any significant better performanse in compare with standard diesel engines, but extreme good spends military budget   ),...

[Sideshow Bob]

It is an urban legend about a car with JATO bottles(the storry has never been confirmed). That took off and crassed in a hillside. You could perhaps try a JATO bottle strapped to a bike. They will give you 1,000-lb thrust unit of 15 seconds duration. So it is kind having sex for the first time it is over before it relay started. Be sure to have someone take a lot of pictures and use the hashtag DarwinAwards