Subaru powered Scorpion helicopter

[Jon]

I used solid 1.5" 4130 steel rod. It weighs 6.008 per foot. When I build another one I am going to use at least 2" od material stainless or 4340 so I can use larger bearings. I looked at titanium rod but it is too expensive for me because I make mistakes from time to time. I messed up two rotor shafts before I was satisfied with the finished product. I am a perfectionist when it comes to machine work. I am going to switch my tail rotor shaft to stainless because I started to get some corrosion on the un-painted 4130 tubing. I coated the shaft with acf 50 and it is not rusting any more but I still like the idea of stainless.

[titanhank]

jon, do you have any idea what rotorway uses for their factory mainshaft? i know the secondary is ams 6265. i was wondering if the mainshaft is the same. i came considering titanium, but at $1400 for a bare 2" rod, i think i will let a pro machine it for me.

thanks for the info. i hope to get out and visit soon.

hank

[Steve McGowan]

Red Smith and his Air Command Boys had an Exect with a 13B Mazda Rotary mounted in it for remote control usage.. I believe Anthony Spangoletti purchased it a few years later.. Suburu is ok,, But it AIN'T a HOSS like a Mazda..

[Jon]

Hi Hank. I had to look back through some articles that I had to find the Rotorway shaft material. It is 4130 HT 125 with 101.4 ksi yield strength, standard 4130 has the same yield strength. Rotorway apparently heat treats their shafts to get a little more fatigue strength out of it. Be sure to get your prototype shaft perfect before you shell out the money for titanium and also be sure that your machine shop is familar with handling and machining titanium.

Let me know when you are headed to Dallas and I will make sure the helicopter is in flying condition. I am still making changes and adjustments. Just yesterday the remote oil filter mount started leaking so it was down for a few hours while I welded up the crack. I am going to just build a new mount out of 7075 t6 and chunk the store bought cast one.

I did fly for about 30 minutes yesterday it was 65 degrees outside and I was able to fly the whole time using only one set of radiator fans. I was able to hover in ground effect and still had 8 inches of power available. I then went up vertically to 30 feet and still had 4 inches of power available. The main gearbox temp never got above 160. I also made an adjustment to the governor and it is working even better than before, I was able to rely completely on it and didn't have to back it up at all.

[subyflug]

Hi Jon!
Today i found your Artikel - you instold a Subaru Engine - how is it flying?
Herman from Austria is asking!

[Jon]

Hi Herman. It is flying very well. I just flew for 30 minutes yesterday. I have 41 hours on it now with no major problems that have forced me to land. I have done several upgrades to make it lighter. I need to sit down and write a post detailing everything that I have done since last year.

[StanFoster]

Jon- Congratulations to you for your positive results with your Subaru powered Scorpion! That could not have been easy. Many of us would like to learn from any experiences and pictures you could post about it. Stan

[Cmte.Mampian]

Jon!
Good day. Here are 11 hours of the morning.
Among these profiles, which you find most efficient for the helicopter?
I'm in doubt because of the different factors of sustainability and efficiency in autorrotação. I would like to help me, for I trust in you.

Thank `s.
Sorry about the bad writing. It was translated by google.
Cmte.Mampian

[Jon]

Everything engine related seems to be working fine and staying relatively cool given the 95-100 degree days that we have been having. I did put two 5" supertrapp mufflers on the engine to try to quiet it down some but they took 3" of manifold pressure away and raised the engine temp 20 degrees. I am going to add twelve more discs to each muffler to see if I can get the lost power back without adding a lot more noise.

I am having some blade issues I think. I can fine tune the rotor system down below .2 ips horizontal and vertical in hover but when I add 5 gallons of fuel the vertical ips will go above 1.0 every time. I have tried everything that I can think of so the next thing to do will be to change to my set of aluminum blades. I am currently running the round tip Waitman blades. Any suggestions would be appreciated. The Waitman blades are symmetrical and made for a clockwise rotation (mine is counter-clockwise) so that could be my problem but it just doesn't seem like it would make any difference.

I haven't taken the helicopter out for a real flight because I am concerned about the tracking problem and do not want to get 100' off the ground and suddenly run into a severe tracking problem. I have gotten up to 30mph and it seemed that everything smoothed out.

Here is a new video that I made on Saturday 8-25-12. The ips in this video are .3/.5 horizontal/vertical.

http://youtu.be/ymd3UFCYibI

[Scary Gary]

Nice video.
Is that a REMOVE BEFORE FLIGHT flag flapping in the wind ?
And over by the power pole, is that the entrance to your underground bunker?

[Jon]

Originally Posted by Scary Gary

Nice video.
Is that a REMOVE BEFORE FLIGHT flag flapping in the wind ?
And over by the power pole, is that the entrance to your underground bunker?

Hey Gary. The red strap is just the loose end of a ratchet strap tied to the pitot tube. The strap holds up the center of my ground handling wheel front axle. It is just there temporarily.

No underground bunker (yet), it is just a buried 40' shipping container that is being used as a culvert. I used the shipping container because I couldn't find a large enough culvert or tank car for less than $12,000. We actually came within 1 foot of flooding our neighbors house in 2009 because our driveway acted like a dam and the three small culverts wouldn't flow enough so the water just kept backing up.

[James]

Nice vid! How many RPM's is that Soob turning when in a hover?

James Lee - TN

[Jon]

Hey James. Ideal engine rpm is 4700 but it varies because the throttle is all manual with no correlation, rotor rpm stays between 500 and 510. I do have an electronic governor that works I just prefer to use it as a backup and keep it set at 500 just in case I get distracted.

[Cmte.Mampian]

Originally Posted by Jon

Everything engine related seems to be working fine and staying relatively cool given the 95-100 degree days that we have been having. I did put two 5" supertrapp mufflers on the engine to try to quiet it down some but they took 3" of manifold pressure away and raised the engine temp 20 degrees. I am going to add twelve more discs to each muffler to see if I can get the lost power back without adding a lot more noise.

I am having some blade issues I think. I can fine tune the rotor system down below .2 ips horizontal and vertical in hover but when I add 5 gallons of fuel the vertical ips will go above 1.0 every time. I have tried everything that I can think of so the next thing to do will be to change to my set of aluminum blades. I am currently running the round tip Waitman blades. Any suggestions would be appreciated. The Waitman blades are symmetrical and made for a clockwise rotation (mine is counter-clockwise) so that could be my problem but it just doesn't seem like it would make any difference.

I haven't taken the helicopter out for a real flight because I am concerned about the tracking problem and do not want to get 100' off the ground and suddenly run into a severe tracking problem. I have gotten up to 30mph and it seemed that everything smoothed out.

Here is a new video that I made on Saturday 8-25-12. The ips in this video are .3/.5 horizontal/vertical.

http://youtu.be/ymd3UFCYibI

Jon!
Very nice job! Congratulations!
You are flying very well.

[Jincamty]

Hi Jon,

Any more updates with the Heli?
How is your Chevy diff working out?
What would you suggest as a Japanese alternative? Toyota landcruiser maybe?
I am looking at building another helicopter based on the 2.5 SOHC Subaru engine.

Cheers Cam.