pics of my turbine

[ger21]

Paul, did you take down the video? The link just takes me to a link back to this thread?

[Ken_Shea]

Paul is making us work for this one , just click the link and scroll down to where it says "Visit Link".

My computer will not play it, I think I do not have enough memory

[CNCgr]

Hi Greg, I'm new to the forum, I was thinking of trying my hand on a KJ66 myself. So I have a couple of questions. Did you "guesstimate" the turbines airfoil, reverse engineer an existing one or had plans for it?
I've made 3d models for most parts but I have nothing on the turbine and the compressor. Do you have 3d drawings you can share?
Also could you give me some info on the spot welder?
Thanks, Nikolas.

[CNCadmin]

Paul is making us work for this one , just click the link and scroll down to where it says "Visit Link".

My computer will not play it, I think I do not have enough memory

Yeah I know, the next software update should have the old upload/download set-up as the old site.

[gv71]

At the very beginning of the video before the rpm increases I am spinning the turbine with compressed air and running it on propane to heat the combustion chamber to about 400 deg. F, so the kerosene can be turned into vapor so it will light. When the rpms increase is when the liquid fuel (kerosene) is being introduced, then I stop with the compressed air and it was running on its own but I noticed I was a little low on rpms for sustained idle so I gave it another shot of air to get the rpms higher and stopped giving it air right at the end when you see it move forward.

JFettig,

At the end of the video when you see it move I would have to say it was around 35,000 rpms, idle speed, you can measure rpms with case pressure thats the brass tube you see coming out of the top of the turbine, .1 bar is idle and since I'm running steel bearings maximum rpms should be around 80,000 rpms which is .8 bar, ceramic bearing can take it up to 120,000 rpms. I have a chain hooked up to the trolley and it was just taking up slack, I made sure it wasn't going anywhere. If you let it idle at to low an rpm there won't be enough air going through the engine to keep it cool and if you let it go for a while you will have a melt down.


CNCgr,

I would suggest getting the cast turbine wheel and NGV, but if you don't I got the basic design from the plans and kind of drew it free hand with some nurbs curves in the cad program I use, the blade profile is not to critical for it to run. The compressor wheel is also a bought part its a car turbo charger spare. So far all the comercial built turbines for RC use turbo charger compressor wheels. There is alot of info and I suggest joining the GTBA: http://www.gtba.co.uk/. What would you like to know about the spot welder, its really very easy to make once you understand what to do. I think I spent about 5 bucks making mine. This yahoo group you should join too:http://groups.yahoo.com/group/homebuildturbines/


Greg

[CNCgr]

Thanks for the response, Greg.

I asked a couple of shops for the KKK turbo and the didn't have it, it's an old model. I'll keep searching though and might try other models with similar dimensions. I was planning on making the turbine model myself and CNC machine it but I hoped you might have info on the specific airfoil.

I have already registered in the Homebuildturbines groups and I'm waiting for the activation.

From what I've seen in the 5bears site you can live without the timer and just do the transformer mod, is that right? We have 220VAC over here, would the 4VAC on the secondary still be ok or should I change it to keep the current the same?

[gv71]

Nikolas,

You should be able to find a supplier on the GTBA website for the compressor. I still have the drawing file that I used for turbine blade profile if you want it, the profile is not that critical if I profiled one with a hand grinder. Yes you can live without the timer, I just use a light switch and 4v will still work just fine.


Greg

[CNCgr]

The shipping cost would be more than the compressor's price. I asked a friend who is more into cars than me though and he told me that I'll probably find it here.

Good point about the hand grinded turbine, so I'll go ahead and improvise. I'll do the same with the spot welder. BTW, if I add a timer and solid state relay what timing settings are we talking about?

Thanks, Nikolas

[CNCadmin]

Do you know where l can get plans to machine my own?

[CNCgr]

You mean the compressor and turbine? I'll make a 3d solid for the turbine when I have time and post it here (I'll improvise the airfoil as gv71 suggested. The compressor on the other hand would be more difficult to model and machine. I've modeled about 2/3 of the KJ66 parts, when I'm done I'll post them here.

[CNCadmin]

That would be great, I may start to make one this winter, I saw a turbine fly yesterday and got turned on to the idea.

[ger21]

That would be great, I may start to make one this winter, I saw a turbine fly yesterday and got turned on to the idea.

Then you'll have to build one of these.

http://www.su27projekt.de/Inhaltsverzeichnis.htm

see #78