Gas Turbine build, pictorial build log.

[rythmnbls]

I thought the membership here might be interested in a pictorial build log of my current gas turbine project. The turbine is a 180N/40lbs thrust design by Gerald Rutten. Plans can be downloaded here http://members.tele2.nl/geraldensuzanne/turbines.htm .

The engine presented here has some changes from the original design, the turbine wheel is larger, 75mm instead of 70mm, and the compressor wheel is a Garrett TO4E-54 instead of the Schwitzer 316954.

Here is the link to the album on photobucket http://s87.photobucket.com/albums/k142/madluther/Turbine 2/

Slideshow of the above http://s87.photobucket.com/albums/k142/madluther/Turbine 2/?albumview=slideshow

Thanks for reading.

Steve.

 

[blighty]

40lb'er what are you putting that in? or are you just going to bug the neighbours with it ;D

interesting build, i wouldn't mind having a go at one my self, just need to find some inconel.

what ecu are you running with it and how is the NGV holding up? as in, are you getting any warping with the fins?

 

[Swede]

Lovely build, Gerald! I'm kind of surprised that gas turbines don't receive more attention than they do from "traditional" model engineers. They are absolutely fascinating to build and operate, and the power to weight is frightening... in fact, I've always found operating them a bit intimidating. You've certainly got to respect them.

They are a bit unique vs. any reciprocating engine in that if you give the latter more fuel and air, they accelerate, up to a point, but in the end, friction and forces win out and it becomes difficult to get more power out of them. Gas turbines, OTOH, give them more fuel, they suck their own air, keep accelerating, and the limiting factor usually becomes heat.

Some of these smaller turbines turn at 160,000 RPM or more, and they'd happily turn 250,000 if they didn't get so hot they lose integrity under the immense forces at play. For all this, the fuel controller becomes a crucial component of any successful build.

Again, nice work!

 

[rythmnbls]

Thanks for the comments.

40lb'er what are you putting that in?

With the addition of a free power turbine stage it looks like (on paper) it will produce in excess of 40hp, so a lightweight motorcycle frame is the the most likely destination. Something like an RGV250 frame.

what ecu are you running with it and how is the NGV holding up? as in, are you getting any warping with the fins?

This engine is yet to run although a similar NGV I have in another turbine doesn't warp at all, these NGV's are heated to red heat after welding and prior to final machining for stress relief.

I've always found operating them a bit intimidating.

I agree, especially the first time I ran one on kerosene, the most stressed component of that event was me ;D

Steve.

 

[petertha]

Look forward to your build & lots of pictures. I think miniature turbines are an incredible feat of engineering effort. Ive been involved in RC a long time & I'm just blown away at how far commercial turbines have advanced - jets, heli's, turbo-props, boats & everything in between. But to make it yourself, and strap it to a bike, well thats just too cool!

I just finished reading 2 books, more history orientated: "Genesis of the Jet Engine" (Frank Whittle & the Invention of the Jet Engine) by John Golley. And "Not Much of an Enginee" (Sir Stanley Hooker Autobiography). Fascinating stuff.

 

[blighty]

the most stressed component of that event was me Grin

with you there ;D

the first time i started my home build up i was jumping around like a little girl. think it was a case of OMG it works..... OMG!!! how big are those flames!!!

there is a guy doing what your doing on the GTBA, but as i haven't rejoined i don't know hows he getting on. any how worth a look if you a member.


Petertha.

just to let you know, Wren turbines are now given the plans for there MW54 away for free. i would post a link, but for some reason i cant get on the site. if you build it or not, it's still worth a look see.

 

[gmac]

http://www.wrenturbines.co.uk/mw54-turbo-jet-and-turbo-prop-second-stage-plans

thanks blighty, I've been looking for a set of turbine plans! And thanks for posting Steve, I'll be following your progress with interest.

Cheers Garry

 

[rythmnbls]

there is a guy doing what your doing on the GTBA

That's me ;D same engine.

There isn't much activity on the GTBA these days so I thought I would post the links here. Hopefully the photos will show that the more difficult parts, ie the turbine wheel and NGV, are quite manageable in a home shop. The material costs for those parts were less than $50, much less than the commercially available parts. Hopefully that will inspire a few more HSM'ers to give it a try

Steve.

 

[blighty]

that's you is it on the GBTA? as i said i was following you then my member ship run out (don't think i will rejoin). i remember thinking when you announced what you was going to do with it..... i thought you bloody nutter!! (that's in good way )

yes, turbine parts are very expensive. i looked in to making another MW54 and just to buy the parts you cant make would of cost £800. i mean £112 for a fuel pump. really, what is it? a 280 motor and 2 little gears.

i don't think it will encourage more home builders until the stigma of turbines dies down and people begin to realise there not all that.


flame suit on for my last comment.

 

[Tony B]

I love the sound of a turbine,

Nice work on yours,amazing what you can do in your shed

 

[Swede]

The big money items for a home-built GT are the bearings, the compressor, and the turbine wheel. The latter two for a beginner are best purchased at least as a casting for the turbine, as materials and geometry make or break a design in many cases. Anyone who creates their own turbine wheel, compressor, or guide vanes, certainly has my respect.

I agree that the fuel pump costs are a bit silly. The pump head can be machined by anyone with decent tools and hands, and the motor itself only costs a few $$.

A gas turbine project deviates from steam or IC in that it generally has a LOT more sheet metal work, welding, and soldering, vs the latter. Sheet metal work can be intimidating... it did me, until I found it really wan't all that tough. When my first MW-54 ran, it was exhilarating, and also a bit scary, as mentioned.

TORCHING is never fun. Torching is the burning off of excess fuel during a start, a very fuel rich mixture. This really doesn't hurt so long as a lot of air is kept moving through the engine, but 2 meter roaring flames don't look really good. One problem I have had is torching from my turboprop. Because the engine is "backwards" relative to the intake (the intake is at the rear of the engine), it torches towards the operator during a wet start. Trying to remain calm while pinned in place by two roaring jets of flame is tricky! ;D

 

[blighty]

it torches towards the operator during a wet start. Trying to remain calm while pinned in place by two roaring jets of flame is tricky

i can see how that could put a downer on your day.

not doing the one up bit, but i had flames coming out both ends of my turbine once. that was definitely a "WTF" moment. i think that's what melted the inlet cone :

 

[Swede]

i can see how that could put a downer on your day.

not doing the one up bit, but i had flames coming out both ends of my turbine once. that was definitely a "WTF" moment. i think that's what melted the inlet cone :

Oooooh, that's bad. Obviously you had some sort of compressor stall. Did the compressor wheel survive?

 

[blighty]

i'll try and make this short ;D

the starting instruction in the building notes for the '54 are a bit vague. it basically says, turn the glow on then the gas, spin the turbine up to about 9000 rpm. when the turbine slows down you should here a popping noise. at this point give it some with the starter. (well that's how i interpreted it anyway)

this i did, but when ever i gave it some it blow the flame out, so the temp would never get to the point where the ecu would kick in (@102deg) and start the fuel pump. so when the flame blow out i would take the start motor away and the turbine would slow down. when it got to the 800rpm mark it would then relight, i would then think "we're off" so i would put the motor back on and it would all happen again...... every time i did this the temp was slowly increasing, until the point where i had the flame out at about 98deg. i then took the starter motor away, like i had before, but this time when it lite the temp went above 102deg and the fuel pump kicked in. i now have a turbine at 800rpm,ecu chucking more fuel in and the turbine slowing down. flames then shot out the back of it and when the turbine got to 0rpm flames started to come out the front as well. i shut the turbine off with the Tx and turned off the fuel valve, flames then stopped coming out the front so i could spin it up and blow the flames out........ i should of used the fire extinguisher, but Oh Well never mind.

only damage was the rear of the inlet cone, that was made out of nylon. when i spoke to wren about it they said why did you make it out of nylon? 'cos it says so on the plans. no no says wren, you should make it out of ali, 'cos the nylon one melts and goes out of shape........... well i know that now : any thing else i should know that you haven't put in the plans????


well it all works now and the eurofighter its going in will be here any day soon ;D ;D ;D

 

[Swede]

I can see it all in my mind...

I built an early MW-54 from plans, and my cone was turned from delrin - I haven't had any problems like yours, but such things are ECU related as much as anything else.

Back then, there were few electric starters. Guys would start turbines with air, lots of it. I took an old leaf blower and turned it into a "GSU", a ground start unit, by adding a flexible duct, and a piece of 3" PVC with a 90 degree el, and the face that mates with the engine, I shaped so as to fit well and deliver a lot of air. I noticed I could very reliably start the engine and the temps were low, nice and low.

Then I fitted an electric motor start, and went through a period of time trying to make it work. It did, but the temps were always 300+ degrees higher than the air start. I took the electric start off and revived the GSU, and have never gone back. Being able to control and deliver, as needed, huge volumes of cold air, has saved my butt more than once.

I'd say more than 50% of the jet engines out there, full scale, use air for start, not electric motors. Usually it's an internal APU blowing air, sometimes it's an external cart. I'll admit a hand's-off electric start is cool, but I do prefer air. Even if you do electric starts, it might be a good idea to have air on hand for problems like torching, or hot starts.

 

[doubleboost]

Hi
Steve.
That is some fantastic work you are doing there.
I have built a few gas turbines (using turbochargers)as the core
Not quite modells but small scale
This is how we start them
[ame]http://www.youtube.com/watch?v=IND3eAI3YZk[/ame]
[ame]http://www.youtube.com/watch?v=am8P-OleztQ[/ame]

 

[blighty]

bloody ruddy hell and holy crap to boot. that was brill!!!

any tips on how to that with my eurofighter ;D ;D ;D

 

[rythmnbls]

Minor update.

There are a few more photos that have been uploaded to the Photobucket site.

Here is a sample.

Rolling flanges on one of the CC rings.

I have built a few gas turbines (using turbochargers)as the core

I love that AB, it looks like it lights fairly reliably, thats an achievement in itself.


Steve.

 

[doubleboost]

Thanks steve
After burners are fun
I am just modding turbos
What you are doing is simply amazing :bow: :bow: :bow:
John

 

[rythmnbls]

Work on the combustion chamber is progressing, I still need to finish welding the front CC ring to the outer wrapper, and make up the spacers that fasten the CC to the diffuser.

A shot of the parts prior to welding.

A shot of a test assembly, here I am checking the clearance between the diffuser and the combustion chamber in order to get the sizing for the spacers that mount between these components.

There are more photos showing details of building the CC uploaded to the Photobucket site.

Thanks for reading.

Steve.