8MadDog8's Gas Turbine

[wolfdragon]

was it sitting on concrete?

[8maddog8]

The battery or the turbine? haha (both were on concrete actually)

Anyway, after a full days charge the battery is nackered... off to get a new one tonight.

Was able to test the oil system briefly until i found a small leak..... Just a pinhole in one of my quality welds LOL
So after re-welding hopefully i can try again tomorrow after the paint is dry.

[8maddog8]

So I got it all back together last night and tested the oil system. Seems to be working fine and no leaks
Wasn’t able to start it because my little blower wasn’t able to spin it fast enough when the turbo had oil pressure. Gonna borrow a big one from a mate tonight and hopefully try and get it started ;D

Pulled out the camera and took some decent photos of the finished product:

[rythmnbls]

That's a really tidy looking GT you have there, very nice job. Good luck on your maiden run.

Regards.

Steve.

[racket]

The turbo oil drain tubing diameter looks a bit restrictive , generally the diameter of the drain hole in the centre housing is the ID of the required drain line .

If you find that there is lube bypassing your seals, a change to a larger ID drain may be required

Cheers
John

[nersut]

Your Gas Turbine looks very simple & clean!

Mine is very messy! ;D
But I can easily disconnect the turbo/combustor from the base/frame so I can have my Gas Turbine in my car's trunk.

Looking forward to see your G.T. running & the test results.


Cheers
Erik

[Johansson]

I second Johns opinion, a larger drain wouldn´t hurt. Especially since it is has a rather long way back to the tank.

Other than that I think it looks great, much room left for a freepower turbine once the gas producer is sorted out!

[8maddog8]

The oil inlet hole in the turbo is 1/8" or a bit smaller, and the outlet piping is 1/2". So there is a fair bit of difference in the flowrate that each should be able to handle. And after testing, the oil was flowing fairly freely into the tank.

But on Friday avo i had SUCCESS ;D

After a couple of tries i was able to get it started just had to get my starting process refined (when to spark/fuel and when to remove blower).

Just a quick question, what kind of temperatures should i be limiting the TOT to?

Also, has anyone used a tacho like this one:
www.jaycar.com.au/productView.asp?ID=QM1448

Just wondering where to point the laser. Not really keen on sticking the reflective tape to one of the compressor blades, and not sure if the laser would work at an angle.
One idea i had would be to machine up a little boss that can be screwed onto the shaft in front of the nut, then the reflective tape can be put on this and then the laser will be able to be mounted perpendicular.

Cheers
Adan

[pitciblackscotland]

G,day Adan,
I have used one of those laser tachometer on my first turbo jet seams to work OK. I panted the comp nut half black and the other half white.

Cheers,
Mark..

[nersut]

Hi Adan

Your max TOT temperature should be 650 degree Celsius.

I bought a similar laser tachometer on eBay for just $13 with free international shipping. Just visit eBay & search for "Digital Laser Tachometer"

Cheers
Erik

[8maddog8]

Thanks for the feedback guys.

When using the laser on the painted nut, does it work at an angle?



If i can i will use option 1, and just use the laser at an angle against the nut. But if this does not work, i can extend the shaft a little so the laser is at a right angle to the face (option 2).

OK, i will keep the temps under 650
Im pretty sure i saw them fluctuate a little above this when it was running the other day.

Is running rich the cause of high TOT temps? And therefore the flametube needs a few more holes to let some more oxygen in?

Cheers

[racket]

Hi temperatures are caused by too much restriction down stream of the turbine wheel , this reduces the pressure drop across the turbine wheel and the only way the turbine wheels power can be restored is by burning more fuel and having higher temperatures , the "remaining" pressure drop is required to get the gases through the restriction by having the pressure turned into velocity .

BUT , you don't appear to have a "restriction" downstream of the turbine wheel :-( .......maybe its caused by your running conditions , does temperature change with large rpm/P2 changes??

Cheers
John

[8maddog8]

I think the temperatures increased with increase fuel/rpm, but i am not certain.

I will get a video so you might be able to see what is going on a bit better.

[jayakod2]

hi
i need cirkit diagram for rpm detector
plz somebody help me.

[alan]

Hi Jayakod,

Here is a design for a tach: tech.groups.yahoo.com/group/DIYGasTurbines/files/4_Designs%20and%20Ideas/Sal%27s%20Stuff/Tachometer/