RELAPSE......
OK, i managed to stay away from the dream of the smell of combusted A1 for like a year....
Actually I’m waiting for a couple of Thundersky LoFePo4 cells to arrive so that I can finish up my electric motorcycle build.
And that may take to the beginning of next year.
So...in the mean time I thought I would build a FD3 in size XL, or double the size to be precise.
Of course I have an evil "take over the world" plan in the back of my head related to this project, but i can not tell you about that until this motor runs perfectly reliable.....which will probably not happen, but if....Mohahaha....peting my cat...
Compressor wheel, 70% finished
Combustion chamber 90% finished
Turbine wheel 20% finished
NGV-cone, 30% finished
Outer shell, disposable helium canister, just opened up.
FD3/64-2:1!
Moderator: Mike Everman
FD3/64-2:1!
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Fricke
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Re: FD3/64-2:1!
Wow Axel!!!
Very nice project.
//Fricke
Very nice project.
//Fricke
"woot"
A shrill, obnoxious noise/word used by immature people to express happiness or excitement.
Supposedly started in the gamer community, but is now used by any slack-jawed moron to express delight.
A shrill, obnoxious noise/word used by immature people to express happiness or excitement.
Supposedly started in the gamer community, but is now used by any slack-jawed moron to express delight.
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Johansson
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Re: FD3/64-2:1!
I agree, really interesting project!
How are you scaling the engine by the way?
How are you scaling the engine by the way?
Re: FD3/64-2:1!
Hej!
Im being totaly unsicientific in the scaling process.
I try to use my common sense, how ever it doesn’t always apply in the world of physics where knowledge is often superior to common sense …
I have added e few blades in the compressor-diffuser and the turbine and the exhaust guide vanes section as well. And by the way, I can not remember what NGV stands for; please can any one remind me?
I made the first row of primary holes and the largest holes in the secondary zone smaller than the double scale would suggest.
The shaft is not exactly twice the diameter either due to workshop limits, but i may have to rethink that decision.
Also, I decided to try using 10x vapour sticks instead of the suggested vaporizing coil.
And: thank you Johansson for all your inspirational topics and post!
It has been so very, very interesting to follow your projects development with their unavoidable ups and downs.
/Axel
Im being totaly unsicientific in the scaling process.
I try to use my common sense, how ever it doesn’t always apply in the world of physics where knowledge is often superior to common sense …
I have added e few blades in the compressor-diffuser and the turbine and the exhaust guide vanes section as well. And by the way, I can not remember what NGV stands for; please can any one remind me?
I made the first row of primary holes and the largest holes in the secondary zone smaller than the double scale would suggest.
The shaft is not exactly twice the diameter either due to workshop limits, but i may have to rethink that decision.
Also, I decided to try using 10x vapour sticks instead of the suggested vaporizing coil.
And: thank you Johansson for all your inspirational topics and post!
It has been so very, very interesting to follow your projects development with their unavoidable ups and downs.
/Axel
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Johansson
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Re: FD3/64-2:1!
Tjenare Axel!
I believe that you will learn more following the common sense route, if things don´t work so what. Rethink and rebuild.
NGV stands for Nozzle Guide Vanes.
You are doing the right thing when you fit vapour sticks instead of a vapour coil, that is an old design that was superseded at an early stage by the more effective sticks.
What material is the compressor made out of? The original compressor was made from plywood but from the pics it looks more like MDF.
Thanks a lot for the praise, there are many many guys out there that builds and writes about more interesting projects than I do but I find it fun in a tragicomical way to write just as much about my failures as my successes. It gives the threads a certain charm I guess...
I believe that you will learn more following the common sense route, if things don´t work so what. Rethink and rebuild.
NGV stands for Nozzle Guide Vanes.
You are doing the right thing when you fit vapour sticks instead of a vapour coil, that is an old design that was superseded at an early stage by the more effective sticks.
What material is the compressor made out of? The original compressor was made from plywood but from the pics it looks more like MDF.
Thanks a lot for the praise, there are many many guys out there that builds and writes about more interesting projects than I do but I find it fun in a tragicomical way to write just as much about my failures as my successes. It gives the threads a certain charm I guess...
Re: FD3/64-2:1!
Hi,
"NGV stands for Nozzle Guide Vanes."
Thanks!
There will be no MDF in this motor i can assure you!
Maybe it is the paper template i have glued on that is fooling your eyes.
Now i have turned the compressor wheel down to 132mm and reinforced it with carbon fibre.
The glue has not dryed yet on the photo, Im eager to post progress....
A have a little more work to do with it beforeits time for final finish and balancing.
I also need to make a new aluminium hub on the intake side, there is a
plastic dummy there right now since I’m out of aluminium round bar at the moment...
The shaft was also completed today, I’m not really happy about the proportions though.
I think it looks a little weak.
"NGV stands for Nozzle Guide Vanes."
Thanks!
There will be no MDF in this motor i can assure you!
Maybe it is the paper template i have glued on that is fooling your eyes.
Now i have turned the compressor wheel down to 132mm and reinforced it with carbon fibre.
The glue has not dryed yet on the photo, Im eager to post progress....
A have a little more work to do with it beforeits time for final finish and balancing.
I also need to make a new aluminium hub on the intake side, there is a
plastic dummy there right now since I’m out of aluminium round bar at the moment...
The shaft was also completed today, I’m not really happy about the proportions though.
I think it looks a little weak.
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Johansson
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Re: FD3/64-2:1!
The compressor wheel looks great, it is incredible that reinforced plywood can be used at those speeds.
I wonder how scaling affects the efficiency of the wheel? A larger wheel will rotate slower so it will have the same tip speed as a smaller one, but could the wheel be scaled say 10 times or 100 times and still function as a gas turbine compressor? Assuming that the scaling is done correctly of course.
If so a +500lbs gas turbine could be built from scratch by anyone with some tools and enough knowhow. *dreaming*
I wonder how scaling affects the efficiency of the wheel? A larger wheel will rotate slower so it will have the same tip speed as a smaller one, but could the wheel be scaled say 10 times or 100 times and still function as a gas turbine compressor? Assuming that the scaling is done correctly of course.
If so a +500lbs gas turbine could be built from scratch by anyone with some tools and enough knowhow. *dreaming*
Re: FD3/64-2:1!
Brilliant! I'm currently reading Kurt Schreckling's book based around the FD3/64. I have opted to restrain from commencing construction until I get my head around all of his design formulaes. He talks about the single stage compressor being efficient at the original scale, it will be interesting at this slightly larger scale. Very nice work ;D
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racketmotorman
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Re: FD3/64-2:1!
Hi Anders
500 lbs of thrust isn't out of the question
) ............pretty crappy fuel burn rate though with such a low pressure ratio 
( .............better to hunt around for a really big turbo rotor from an industrial sized diesel that can be spun up to produce some serious pressures . .
Have started work on the "brass bushed" version of my 9/94 engine , it'll be a 10/94 , 10 inch diameter casing running a TV94 rotor , 98mm comp inducer 141 comp exducer , 129mm turb inducer 107mm exducer , the bearing overhaul kit has all the necessary bits and pieces , I just have to make up a centre housing for them to be installed in , the rotor clearances are very generous so no fine tolerances required , the brass bushes can be run with anything between 0.003 - 0.007" radial clearance , just about got the housing finished after a good days work .
Cheers
John
500 lbs of thrust isn't out of the question
) ............pretty crappy fuel burn rate though with such a low pressure ratio ( .............better to hunt around for a really big turbo rotor from an industrial sized diesel that can be spun up to produce some serious pressures . .Have started work on the "brass bushed" version of my 9/94 engine , it'll be a 10/94 , 10 inch diameter casing running a TV94 rotor , 98mm comp inducer 141 comp exducer , 129mm turb inducer 107mm exducer , the bearing overhaul kit has all the necessary bits and pieces , I just have to make up a centre housing for them to be installed in , the rotor clearances are very generous so no fine tolerances required , the brass bushes can be run with anything between 0.003 - 0.007" radial clearance , just about got the housing finished after a good days work .
Cheers
John
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Johansson
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Re: FD3/64-2:1!
Hi John,
Yes, it would be a thirsty bastard for sure. But besides that, is there any reason not to build a full scale engine after the FD3 calculations in Schrecklings book? Drawings on more efficient turbine wheels are available in newer micro-turbine books but Schreckling is the only one that talks about building his own compressor wheel.
Efficiencies aside, it would be soooo interesting to build a gas turbine completely from scratch without having to rely on turbocharger parts that might be expensive and difficult to obtain if the engine gets damaged somehow.
It must be the true american way of building engines: Crappy efficiency and not enough power? Well sonny, just build it twice the size!
OT: So you´ve given up the ball bearings and PBD? That was a downer for sure, I had hoped that you would could see it through and fix the problems with ball bearings and radial turbines.
But after all the trouble you´ve been through with this it must be a wise decision to go for brass bearings and get on with the engine. How are you going to solve the oil pressure, 2-stroke pump?
Sorry Axel if we are spamming you thread, perhaps we should continue this in PM.
Yes, it would be a thirsty bastard for sure. But besides that, is there any reason not to build a full scale engine after the FD3 calculations in Schrecklings book? Drawings on more efficient turbine wheels are available in newer micro-turbine books but Schreckling is the only one that talks about building his own compressor wheel.
Efficiencies aside, it would be soooo interesting to build a gas turbine completely from scratch without having to rely on turbocharger parts that might be expensive and difficult to obtain if the engine gets damaged somehow.
It must be the true american way of building engines: Crappy efficiency and not enough power? Well sonny, just build it twice the size!
OT: So you´ve given up the ball bearings and PBD? That was a downer for sure, I had hoped that you would could see it through and fix the problems with ball bearings and radial turbines.
But after all the trouble you´ve been through with this it must be a wise decision to go for brass bearings and get on with the engine. How are you going to solve the oil pressure, 2-stroke pump?
Sorry Axel if we are spamming you thread, perhaps we should continue this in PM.
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racketmotorman
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Re: FD3/64-2:1!
Hi Anders
LOL........just a case of flowing sufficient air and accelerating it , but there are some engine weight "problems" once the size increases ...............probably better to have a gas producer feeding a freepower with its own larger fan to move the greater mass rather than relying on the engine being a pure jet .
OT ..............the main reason I've gone to "brass bushes" is convenience and cost , its much easier to achieve the desired machining accuracies with "brass" than "balls" when one only has very old equipment in their shed , and the cost of "brass" is minimal , we have been able to source complete TL92 bearing overhaul kits for a bit over $US 50 , these suit all the very large framed Garrett turbos in the TV/TL 91 - 94 range , so go well with our TV94 comps at a bit over $US100 and turbs at ~$US400 , a full 2.33 lbs/sec rotating assembly with all bearings including thrust bearings and piston ring seals ( both ends) for less than $US 600 , even adding on the cost of our own design comp housing castings, super alloys and stainless steel for NGV and flametube along with assorted odds and ends , its possible to potentially make a 125 lb thrust ( dry) , 175lb( wet) engine for a bit over $US1,000 ..................add on a freepower and theres 150 shp to be had
I feel with more time spent on development, the ball bearings could be made to work , but all the extra complexity adds to cost and time making/modifying parts , eg , the turb shaft needs grinding , bearings need to be accurately fitted with correct preloading , labyrinth seals made for the rear of the comp wheel and fitted to fine tolerances , turbine oil , with all its health issues needs to be used instead of readily available and safe automotive lubes., heat extraction from the hot turb wheel soakback needs consideration , not easy when ball bearing don't like too much lube ..................etc etc etc( .......hopefully my 9/94 engine with the balls and comp labyrinth will work OK , if it does , then its possible to say its possible to do so , but why make life harder than it needs to be .
The lube system for the 10/94 , which one of my fellow collaberators is constructing , uses a 500W 24Volt motor from a battery powered lawnmower , driving a modified automotive power steering pump, he's getting ~10 litres/min at 80psi on just 12 Volts at acceptable Amps
Cheers
John
LOL........just a case of flowing sufficient air and accelerating it , but there are some engine weight "problems" once the size increases ...............probably better to have a gas producer feeding a freepower with its own larger fan to move the greater mass rather than relying on the engine being a pure jet .
OT ..............the main reason I've gone to "brass bushes" is convenience and cost , its much easier to achieve the desired machining accuracies with "brass" than "balls" when one only has very old equipment in their shed , and the cost of "brass" is minimal , we have been able to source complete TL92 bearing overhaul kits for a bit over $US 50 , these suit all the very large framed Garrett turbos in the TV/TL 91 - 94 range , so go well with our TV94 comps at a bit over $US100 and turbs at ~$US400 , a full 2.33 lbs/sec rotating assembly with all bearings including thrust bearings and piston ring seals ( both ends) for less than $US 600 , even adding on the cost of our own design comp housing castings, super alloys and stainless steel for NGV and flametube along with assorted odds and ends , its possible to potentially make a 125 lb thrust ( dry) , 175lb( wet) engine for a bit over $US1,000 ..................add on a freepower and theres 150 shp to be had
I feel with more time spent on development, the ball bearings could be made to work , but all the extra complexity adds to cost and time making/modifying parts , eg , the turb shaft needs grinding , bearings need to be accurately fitted with correct preloading , labyrinth seals made for the rear of the comp wheel and fitted to fine tolerances , turbine oil , with all its health issues needs to be used instead of readily available and safe automotive lubes., heat extraction from the hot turb wheel soakback needs consideration , not easy when ball bearing don't like too much lube ..................etc etc etc
( .......hopefully my 9/94 engine with the balls and comp labyrinth will work OK , if it does , then its possible to say its possible to do so , but why make life harder than it needs to be .The lube system for the 10/94 , which one of my fellow collaberators is constructing , uses a 500W 24Volt motor from a battery powered lawnmower , driving a modified automotive power steering pump, he's getting ~10 litres/min at 80psi on just 12 Volts at acceptable Amps
Cheers
John
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Johansson
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Re: FD3/64-2:1!
Is it harder to design a well working combustor for a low pressure ratio (larger volume needed etc) than for the "normal" turbocharger comp engine?
With a higher fuel burn rate for a low compression engine will the engine also run hotter?
OT: Brass bearings really sounds like the way to go considering the alternative, but it might be a bit draggier with the higher oil pressure that is needed to make the axial bearing survive the massive thrust. I´ll do my best to figure out my Yahoo password so I can follow the progress on your engine.
With a higher fuel burn rate for a low compression engine will the engine also run hotter?
OT: Brass bearings really sounds like the way to go considering the alternative, but it might be a bit draggier with the higher oil pressure that is needed to make the axial bearing survive the massive thrust. I´ll do my best to figure out my Yahoo password so I can follow the progress on your engine.
Re: FD3/64-2:1!
The EGT is 630C at full throttle, quite reasonable. This allows the builder to use ordinary stainless steel in the turbine section (wheel and NGV).
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- Compressor, balansed with CA glue and small pieces of paper.
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- Turbine disc, 1mm thick, will it work? Lets find out!
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- Spot welding - a love affair!
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- Front cover.
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Johansson
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Re: FD3/64-2:1!
The 1mm turbine disc looks a bit weak to me, the blades might bend from the centrifugal force and heat. Anyway, only one way to find out.
I found a video with some info on how to build an improved turbine wheel for the FD3 from a 3mm plate, might be worth a look.
http://www.youtube.com/watch?v=HTrJnMHOH1s
Can you estimate how much difference in weight there would be between a compressor wheel made from plywood and one made of aluminum? An FD3 compressor wheel made from aluminum sheet wouldn´t be so difficult to make, but if it becomes noticably heavier any gains in material strenght might still be less than the loss from the increased centrifugal stess.
I found a video with some info on how to build an improved turbine wheel for the FD3 from a 3mm plate, might be worth a look.
http://www.youtube.com/watch?v=HTrJnMHOH1s
Can you estimate how much difference in weight there would be between a compressor wheel made from plywood and one made of aluminum? An FD3 compressor wheel made from aluminum sheet wouldn´t be so difficult to make, but if it becomes noticably heavier any gains in material strenght might still be less than the loss from the increased centrifugal stess.