Solar T-62 turbine

StanFoster

Active Member
Joined
Nov 16, 2003
Messages
17,139
Location
Paxton, Il
Aircraft
Helicycle N360SF
Total Flight Time
1250
I am finding this little turbine operating a lot of helicopters. Heres one in an Ultrasport.

I am finding it interesting the electronic fuel control that is necessary to tame this little beast.

Stan
 

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Yea, besides outrageous fuel burn, the little single stage self-propelled super-chargers eat themselves up in a short time running at a power setting they weren't designed to run at for so long. Then the cost to repair them is over $10,000, just for it to burn up again in the same amount of time.
 
T62

T62

Dennis-
I don't know the source of your wisdom regarding the T62- the engine Eagle is using with the large turbine nozzle is rated at 60KW for all conditions below 8000 feet and 125 degree ambient and as such has PLENTY of margin.
If you refer to the 30KW version with the small turbine nozzle, this one will run hot and will have less life and little margin dependent on ambient.
For the 60 KW engine number of starts is going to be more of a limitation than time at temperature/power.
avk
 
For the 60 KW engine number of starts is going to be more of a limitation than time at temperature/power.
avk

Cycles are what kills turbines, Not running.
That is why it is important to track the cycles, (starts) as well as the time.
 
I've always wanted to put a turbine on my sandrail. Let the tubine run ata speed, operating a hydrolic system. then strap the gas pedal to your foot, pushing donw for forward and pulling up for reverse. It's one of the projects that may or may not happen. But I love the idea. It would sure turn heads going down the road. But I've heard to many + and - things about turbine engines.
 
T62 control unit

T62 control unit

The electronic control unit BJ uses has been used by others before and is an industrial electronic control suitable for a variety of engines.
It is speed governing and has an overspeed shutdown mode- no temperature input. For a turbine control its rudimentary. Acceleration control is handled by a mechanical unit part of the original T62 fuel control.
avk

P.S.
Stan, you posted some great pictures.
You are off on the bearing however.
It's nowhere near that expensive and the picture you posted shows both, the roller bearing as well as the front ballbearing as well as the seals.
You are corect in that the bearings are high precision bearings which make them relative expensive.
They have a DN of close to 1.5 million which used to be state of the art 40 years ago.
Currently designers have access to better materials and coatings which permit DN's over 3 million.
avk
 
Turbine powered VW?

Turbine powered VW?

I've always wanted to put a turbine on my sandrail. Let the tubine run ata speed, operating a hydrolic system. then strap the gas pedal to your foot, pushing donw for forward and pulling up for reverse. It's one of the projects that may or may not happen. But I love the idea. It would sure turn heads going down the road. But I've heard to many + and - things about turbine engines.

I had a Solar turbine and always wanted to install it in my Baja Bug dune buggy. I mainly wanted it for cruise nights.

I couldn't come up with a way to "clutch" the beast. Your hydraulics sound doable.

I have a sand rail as well. It's another back burner project.
 
Dennis-
I don't know the source of your wisdom regarding the T62- the engine Eagle is using with the large turbine nozzle is rated at 60KW for all conditions below 8000 feet and 125 degree ambient and as such has PLENTY of margin.
If you refer to the 30KW version with the small turbine nozzle, this one will run hot and will have less life and little margin dependent on ambient.
For the 60 KW engine number of starts is going to be more of a limitation than time at temperature/power.
avk

I won't get drug into a debate again on using an APU as a primary power source for a helicopter, so I will leave a bit of hard learned wisdom and just let you guys chew on it. The problem with trying to discuss these engines is mostly based on dreams, hopes and faith. You can't argue or reason with people when you are up against those things.

Over many years now, people have archived flying helicopters with these little single-stage APU's. Actually, that is very easy to accomplish, but, the person does achieve hero status afterwords, because everyone loves the sound and smell.... You do read about all the successes of their first hours of flight, and left with the impression that it is a successful endeavor. The fact is with all the hundreds of installations that have been made, you don't see them around after awhile. But yet, you don't here about the end of the project, so you are only left with the memory of the initial successful beginnings of the project. There is a reason for that...

When a person succeeds in the installation and flights of an APU, they do achieve the status of greatness and successfulness, and are proud of their accomplishment, as well they should be. But later, after they start burning up the engine a few times, it is a little hard to announce that your project didn't work after all. That is understandable, and that is why you hear of so many of these first successes, and then silence later.

I'm not going to get into why these units will burn up, because it will start a never ending debate of which I am not willing to invest the time, because I can never win an argument against people that want these engines to be a reality.

I will say that every engine made is designed to have an operational duty cycle parameter. That means what percentage of the use of the engine is operated within it's working parameters. Some engines like APU's are designed to operate at 25% of their 100% power 98% of the operation, and doing this will last thousands of hours, let's just say 10,000 as a number. By operating at 50% does not mean the engine will be expected to last 5000 hours. It may only last 100 hours. Some of these APU's are being ran at 75, and even 95% power to fly these helicopters.

Start cycles are a major factor in the life of these engines, and most of the time after being started, are left to run for hundreds of hours.

Shielding is also a major concern, because there is none. Real turbines are designed to contain a catastrophic failure, but not APU's, they rely on the aircrafts or groundpower units containment housing to do that.

I know, what I say is meaningless, I've been here before so I know the outcome of the debate and as I said, you can't argue against faith, hope and wishful thinking, and you will also argue that it is not just faith, hope and wishful thinking, I know, I know. The only way for me to win the debate is to let time take it's course, and even then I find that people have short memories.

Good luck, try to be safe going down this old traveled road, at least it's keeping out of the pool-halls.
 
T62

T62

Dennis-

You may have great experience and technical know- how but turbomachinery does not appear among it based on the generalities you post, some applicable, others out of context and not applicable to this engine.
I happen to have spent 40 years in the field, designing and developing turbomachinery - gas turbines, not turbochargers.
In my book the Solar T62-32 is an OK engine for the task -even though a single spool -as long as the TOGW is not much more than 900 lb and the engine has sound components to make containment a non issue.
The mayor problem I see is the limited engine supply till someone builds them new.
So let's leave it at this- time will tell.
respectfully,
avk
 
Dennis-

You may have great experience and technical know- how but turbomachinery does not appear among it based on the generalities you post, some applicable, others out of context and not applicable to this engine.
I happen to have spent 40 years in the field, designing and developing turbomachinery - gas turbines, not turbochargers.
In my book the Solar T62-32 is an OK engine for the task -even though a single spool -as long as the TOGW is not much more than 900 lb and the engine has sound components to make containment a non issue.
The mayor problem I see is the limited engine supply till someone builds them new.
So let's leave it at this- time will tell.
respectfully,
avk

OK, we'll forget about all my experience with turbines and APU engines over the years, and ignore every attempt in the past years that tried and disappeared. You know what you want to know, don't need me, so there is no debate here.

Best of luck.
 
T62

T62

Stan,

You are correct- I fly a Helicycle with a Hirth engine which I evaluate as alternate powerplant. Its my believe that the design warrants an alternate lower cost power plant for people flying in high air density environments.
The engine was built for BJ by Hirth, I did the installation with BJ too busy doing the turbine. Have 50 hours on it and put the engine on Eagle's dyno last summer to check the output which turned out lower than advertised as I expected based on the way the ship performed.
Made some subsequent changes which hopefully correct the situation and will continue evaluation later this spring when returning to US.
I do own a Eagle modified T62 which will be installed at a later time once I'm done with the Hirth. I did run the engine stationary to see how it starts and check out my wiring.
As for the comments Dennis made predicting bad things, overtemps and other failures there have been no engine design related shutdowns so far and the high time ship has more than 400 hours.
There were some damaged ships but all are/were rebuildable and no personal injuries happened except for BJ's accident which is not certain why it happened.
In my opinion a pretty good record.
avk
 
Stan, a $2500 bearing is nothing, just a drop in the bucket, I throw away bearings like that everyday. Aviation is expensive, especially turbine aircraft.
The bearings are most likey of a proprietary design, built by only one manufacturer.
A CFM 56 costs about 1.5 million to overhaul.
 
T62

T62

Scott,
You are correct- but this bearing has a 0.773 ID , 1.25 OD is 0.354 in wide and has no inner race- its almost an instrument bearing - and Class7 instrument bearings go for a few hundred bucks or less.
Some of your CFM56 bearings you can stick your head through. The material alone will cost a bundle.
Its in the NSN inventory and two Co's made it. Its still in use on the Sundstrand engines.
avk
 
.........You are corect in that the bearings are high precision bearings which make them relative expensive.
They have a DN of close to 1.5 million which used to be state of the art 40 years ago.
Currently designers have access to better materials and coatings which permit DN's over 3 million.
avk
This is another great thread Stan. It is like being in school taking your favorite subject ....:) ... thanks for the 'ride' .

Angelo (akoschier) .... when you say DN 1.5 million or DN 3 million ...... is this millionths of an inch measurements ? Many thanks for sharing your knowlege with us.

Arnie - Bell 47-G2

ps:
Bearing trivia I barely remember from school 'way back then' .... the manufacturers would drop a precise amount of molten metal from height inside an enclosed tower. I think it had a hot air updraft,. The idea was to let the metal cool in nearly zero gravity . Hopefully in a perfect circle to make ball bearings . Next , they would be rolled down a special ramp and the best ones would bounce 'just right' into a small cup. These ones ( 1 in a thousand I think) would be the ones used for turbine bearings.
 
I had to get some Barden bearings the other day, about that same size, but with an inner race, for A/C Hyd motorpump $1800.00 each. And you guys think Rotax prices are high!!! :)
 
need the attachment..

need the attachment..

more internal pics. The last one is the turbine wheel having chewed on something harder than kerosene!

Stan you need to get the hoover or dirt devil HEPA vac baggie attachment to keep the m & m's / kids toys and / small animals out of the compressor !

otherwise that is what happens.


J
 
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