Making a MICRO gas turbine, how to overcome some issues

[Jake gazzard]

Hello everybody, i am wanting to build a micro working 100mm long and 60mm wide. Now, my grandad owns a big engineering firm with industrial lathes, cnc's ect so making the casing, main shaft, things that need welding, cones, combustion chamber ect are fine to make there BUT the compressor wheel and turbine wheel cannot be made there as i dont have a clue on how to make them! Has anybody got any idea on how to make these 2 components? They are the MAJOR parts of the turbine, well they are the turbine but the hardest things to make. Any help and comments would be very appreciated! Thank you.

[Reno Racer]

Try a do a search for Kj66 turbine (some build details here) many have built their own turbine using this method/plan and component parts are sometimes available on EBay.   

If you can make all other metal component parts (obviously less ECU etc), you could search for a spare parts for a MW44 turbine (turbine wheel and compressor wheel), then scale your own build around that. 

That way there is also a good chance that MW44 or KJ66 parts, ECU particularly will work with your home brew turbine.

Edited By Ackers on 04/08/2010 14:42:33

[Doug Ireland]

I would think the hardest part would be keeping the compressor/turbine in one piece. Bearing (no pun intended) in mind that the turbines we already have for RC use spin at over 100,000 RPM. If yours is going to be smaller in diameter then I imagine it would need to spin a lot faster than that to get any useful thrust out of it.

 

How about getting hold of a small turbo from a car and see what size the spinning bits are?

[Jake gazzard]

Posted by Doug Ireland on 04/08/2010 16:01:33:

I would think the hardest part would be keeping the compressor/turbine in one piece. Bearing (no pun intended) in mind that the turbines we already have for RC use spin at over 100,000 RPM. If yours is going to be smaller in diameter then I imagine it would need to spin a lot faster than that to get any useful thrust out of it.

 

How about getting hold of a small turbo from a car and see what size the spinning bits are?

 i completely agree, i now think i have a soloution to the compressor and turbine wheels, ill draw it up and post it here

[Frank Skilbeck]

Try 243,000 rpm see here

 

Maybe you could but the compressor and turbine wheels here.

[Simon Chaddock]

Jake

Even if you have the turbine and compressor wheels don't forget the problem of the bearings. 200,000+ revs and 680 degrees gas temperature makes for a challenging environment.

Also note that 680 degrees is pretty close to maximum temperature acceptable to even high temperature alloys but is nowhere near the maximum possible by burning kerosene.

Care is thus needed to inject just the right amount of fuel to keep it running but not so much that it melts the turbine blades, hence the sophisticated electronic control system.

 

Keep posting on how you get on.

[Allan Bowker]

'Wren' are a small British company that make small turbines. It may be worth while looking them up too!