I came upon this video by sheer accident.
Its a Stihl saw customised with a turbine engine and has 19500 rpm.
https://youtu.be/zzK-Fz9LybQ (https://youtu.be/zzK-Fz9LybQ)
Quote from: joe_indi on February 15, 2017, 11:45:12 PMIts a Stihl saw customised with a turbine engine and has 19500 rpm.
Sorry, I missed a zero in the rpm ;D
Pretty cool. Put a little deflector on that exhaust and have a hand warmer for the winter ;) Wow, 195k rpm.
:D I guess you have to be familiar with small gas turbines to consider 55,000 rpm as an "idle" ;)
I would not want to anywhere around that saw when it broke a chain...
Quote from: Kbeitz on February 16, 2017, 07:59:30 AM
I would not want to anywhere around that saw when it broke a chain...
Naw, the chain ain't moving that fast. The end talked about some gearing. But, still, 195k on the input side! :o
It is just like an aircraft turboshaft engine, high rpm low torque in, low rpm high torque out, through the gearbox. It has normal chainspeed on the power output, or it would be too dangerous. It sounds really cool, the exhaust temps will cook flesh in a heartbeat as they are probably around 450-600 deg C at the outlet. I calculated the HP output based on the KW rating in the end credits, 6.8 hp for a saw that looks to be the size of a 362, that is pretty impressive, though i bet it sucks fuel like crazy, would bet that run time on a tank would not be more than 15 min. 8)
The legal-beagles will pounce on this if it ever escapes captivity. Imagine an instance of kickback at full power/rpm where the chain not only slices the operator, but a half-dozen folks standing behind. Oops!
Not a good application of gas-turbine, IOW.
Quote from: CTYank on February 16, 2017, 05:02:09 PM
The legal-beagles will pounce on this if it ever escapes captivity. Imagine an instance of kickback at full power/rpm where the chain not only slices the operator, but a half-dozen folks standing behind. Oops!
Not a good application of gas-turbine, IOW.
Naw, the chain is NOT going any faster than a normal chainsaw. The big benefit of this saw, though, is if you do get kick back and a cut, the exhaust will immediately cauterize the wound! :D
I dont own one of those engines my self but a friend at the RC flying club does. They are pretty cool and very reliable but they lack torque with out the RPM. I'd dare say a well tuned regular saw will out preform that saw and is very likely not as noisey. Those little turbines scream for the size of em.
True, but just like in the R/C world, the coolness factor trumps the effectiveness factor :D
Turbine engines have been used in many applications .Some with good results some not so much .
The good side in say the Abrams tank,which btw is made in Lima Ohio is the fact they will run on about anything that burns .From gasoline to marine diesel.It's a lot of power in a small package .
They were tried during the 60's in big over the road trucks which proved to be not so good .Some Navy surface crafts used turbines which were iffy at best as opposed to diesels .Helicopters it was a good idea .I think in automotive it was about like the Wankle,worked but had a lot of problems .Really had an appetite for gasoline for one
I wouldn't be too rushed to short change the application in small hand helds like a chainsaw but I think some more R and D would be done before one is on the market .
I've had a Wankle setting on my shelf for years. I never did have
time to do anything with it.
(https://forestryforum.com/gallery/albums/userpics/39553/Rotary_wankle.jpg?easyrotate_cache=1487330784)
Here's some pics of a plane a local customer of mine built. He built about 15 of these planes over the years, he's a retired engineer from our local mining company.
This one he's replacing the cowling which offered me good pics of the turbine from underneath.
He claims just the carburetor is worth over a $100K.
(https://forestryforum.com/gallery/albums/userpics/21589/20160923_115244.jpg?easyrotate_cache=1487346669)
(https://forestryforum.com/gallery/albums/userpics/21589/20160923_115547.jpg?easyrotate_cache=1487346770)
(https://forestryforum.com/gallery/albums/userpics/21589/20160923_115301.jpg?easyrotate_cache=1487346843)
I don't want to be anywhere near that saw if the turbine comes apart. :D It is an interesting idea but I expect cost would be prohibitive and as I see it there would be little if any gain. The added weight and bulk of the gear reduction would negate any engine advantage.
I saw some turbo shaft conversions in the aircraft industry and while impressive they were too costly to be practical. The DeHavilland Beaver is a real hot rod, it will lift off in little more than it's own length. It was tried with the Canadair CL-415 water bomber and while it worked very well the conversion cost almost as much as a new plane.
Sawguy21 have you heard of the Talo Custom Aircraft Co I posted above?
Sven Talo claims he built a number of them in Ontario about 30-40 years ago.
This is a little tangential, but maybe some you remember the 1967 Indianapolis 500 and Parnelli Jones driving the car with the turbine engine. Jones dominated the race, I think he won about every lap till about the 197th when he had to drop out with a bad transmission bearing. He had a whole lap lead when he dropped out.
The next year, there were several turbine cars entered, but they put such an air restriction on the cars that the turbines didn't do very well. They were all over heating.
:D :D I remember that. The organizers got their shorts in a wad because nobody else was competitive.
The plane conversions are relatively common. It's a standard aircraft engine after all.
This is a locally built FU-24 ag plane with the ~350hp piston engine replaced with a 550hp turbine.
https://www.youtube.com/watch?v=9C_MbG6Rybo
The newer version's are called the PAC 750, with a 750hp turbine.
Problem with turbine race cars is the lack of engine braking and the turbine spool up time. With those old turbine race cars the driver basically had to drive into corners under power, using the bakes to hold the engine back, Otherwise when they came out of the corner the turbine was spooled down, and took seconds to come back up to power.
Now a turbine with a hybrid drive system would be the bee's knees. When you buttoned off for the corner you shunt the turbine power into the battery, and use regenerative braking. Then coming out of the corner the turbine is still making power, and you have the energy in the battery to use.
There are prototype truck system with electric drive and gas turbine generators. You can build a system with ~800 hp of electric drive, run off a 200hp gas turbine generator. You only have 5 or 10 minutes at 800 hp, but that gets you up most hills, then the 200 hp keeps you rolling all day. Braking and downhill energy gets recaptured for the next hill.
Nothing to do with chainsaw, but it's just cool how that sort of technology is being developed.
Quote from: Kbeitz on February 17, 2017, 06:27:14 AM
I've had a Wankle setting on my shelf for years. I never did have
time to do anything with it.
(https://forestryforum.com/gallery/albums/userpics/39553/Rotary_wankle.jpg?easyrotate_cache=1487330784)
out of a 1969 arctic cat snowmobile??
There is a guy with a Piper Malibu at the local airport that he did the turbine conversion on. I know it is a Pratt & Whitney and was done in Spokane. If I remember correctly it is around a 550 - 600 HP engine and he really likes it.
I make my living flying a 1000hp garrett turbine in a thrush agplane. I burn 65 gallons an hour and carry 550 gallons of pesticide. They are very reliable, but very expensive to repair, and if they come apart it's bang...
And yes most are able to burn about any fuel, some are better than others. But mine wood burn firewood if I could shove it thru the fuel nozzles. :D
Ianab,
Is that video from down under? I don't understand what he was spreading (though quite a load!). Out here, the crop dusters doing rice planting/pesticide spray are about on the deck when they disperse. That guy was so high and dropping so randomly.
Quote from: ljohnsaw on February 21, 2017, 11:03:57 PM
Ianab,
Is that video from down under? I don't understand what he was spreading (though quite a load!). Out here, the crop dusters doing rice planting/pesticide spray are about on the deck when they disperse. That guy was so high and dropping so randomly.
Superphosphate fertiliser spreading over the hill country that's common in a lot of NZ. Too steep for ground spreading, but the fertility drops off fast if it doesn't get fertiliser.
The drops aren't at random, he'll just be avoiding roads / rivers / neighbours paddocks etc while making straight passes over the farm. Height is to get some spread on the drop. The modern planes are GPS guided and the flying pattern is laid out in strips, with the hopper open and close controlled by the computer.
This one is a later model Cresco plane. Turbine engine and a 2 ton payload. When you have logging truck drivers looking DOWN on your plane, that's plenty low enough in my book :D I've ridden shotgun with those guys, and still remember looking UP at our own cows peering over a fence, looking down at us flying past.
http://www.youtube.com/watch?v=-2AmhKKSItg
There's not any large scale cropping around here, and what aerial spraying that's needed is usually done from a helicopter, easier to get low and slow in the hills and trees. They use choppers for fertiliser too, but it's more expensive per ton to spread that way.
My youngest brother had a 70 Panther with a Wankle rated at 20 hp,it had a definite pop pop pop exhaust noise and kinda loud. It was easy on gas