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  #1  
Old 08-26-2010, 03:18 AM
Jon Jon is offline
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Default Subaru powered Scorpion helicopter

Hello everyone. I am new to this forum. I have been working on a Scorpion helicopter for the past 5 years off and on when I have the funds. I am finally almost ready to put the blades on and start doing some serious testing of my new designs. I did extensive modifications to the original 133 frame for the new engine and drivetrain with 1 foot taller and 2 feet wider landing gear with 9 foot skids. I installed a 2000 EJ-25 engine with a drivetrain similar to the HRH. I used a differential case out of a Chevrolet truck for the 90 degree gear box and added a gear oil pump and cooler. I have a shaft driven tail rotor with superior gearbox and the tail boom has been extended an additional 2 feet so I could use longer main and tail blades than the original design. I machined everything out of 7075 t6 aluminum or 4130 steel including the entire rotor system and gearbox spool.

I hope to have the helicopter ready to fly next month. I am going to to start flight training in Houston in October for three weeks. I hope to have around 30 hours of training before coming back home and test hovering my helicopter.

Here is a video of me doing some testing after installing the rotor system. If anyone has any comments or questions feel free to let me know.

YouTube - Rotorway Scorpion Subaru helicopter
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  #2  
Old 08-26-2010, 03:48 AM
choppergabor choppergabor is offline
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Welcome aboard Jon. Nice job! Very impressive mods you have done. Looking and sounding good. What kind of blades are you going to stick on it?
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  #3  
Old 08-26-2010, 03:53 AM
StanFoster StanFoster is online now
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Jon- Way too cool. Keep up the good work. Keep sending more!



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  #4  
Old 08-26-2010, 06:12 AM
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animal animal is offline
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now that is looking good, what kind of gear box and blades are you using on the Tail rotor? please post some pics of the Details in this thread and for sure keep us updated on it. as you can see I have a Helicom Commuter H-1B I just restored.

check out my store thread in the link below, I have learned a Digital level is great for setting up the Blade pitch.

by all means give us more details on your set up.
that Subaru is sounding good.
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Old 08-26-2010, 07:30 AM
Jon Jon is offline
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Thanks for the kind words and warm welcome. I wish I would have found this forum sooner. There are other forums out there that don't really believe in experimenting anymore.

I have two sets of main rotor blades. One set is rotorway style blades (8" chord) that I bought from a guy on barnstormers and the other blades came from an A Star 350 (12" chord). I went with non-rotorway blades because my rotation is clockwise as viewed from below and rotorway is the opposite so the asymmetrical blades from rotorway would not work besides ther are a little shorter than I wanted. The AS 350 blades are for counter-clockwise rotation but they are symmetrical so I don't think there will be an issue there. I am going to use the 8" blades for preliminary flight testing and hover practice then switch to the larger blades later. The tail rotor gearbox is a series 100 from superior gearbox with a 1.4:1 ratio speed increaser. The tail blades are factory rotorway for preliminary testing then I plan to build some out of stainless or titanium and build a delta hinge tail rotor hub similar to the r-22 design.

I will post some pictures later. The pictures that I currently have are over the size limit.
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Old 08-26-2010, 07:42 AM
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gyromike gyromike is offline
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Do the A-Star blades have any built-in twist to them?
If so, turning them backwards may not work so well.
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  #7  
Old 08-26-2010, 08:31 AM
Jon Jon is offline
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There is a built in twist on the blade but it is only extends about 4' out from the root end. I thought that since I was going to shorten the blades anyway the twist will be mostly removed. I may not even use the AS350 blades on the scorpion they are really good looking blades and I would hate to ruin them. I may try to sell them next year or just design a 4 seater and use them on it.
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  #8  
Old 08-26-2010, 08:49 AM
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Default NIce work!

Hello Jon, welcome to the forum.

Your profile doesn’t have much information.

I feel it would help to answer your questions if we knew more about you.

How many hours do you have in a helicopter?

What helicopter did you get your training in?

Are you going to perform the test flights?

Your workmanship looks first rate.

What is your fabricating experience?

Thank you, Vance
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  #9  
Old 08-26-2010, 11:15 AM
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hillberg hillberg is online now
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That a nice mod for the scorpion. Nice work.
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  #10  
Old 08-26-2010, 11:32 AM
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Jon there is a guy on youtube that modded a Scorpion and has a set of MBB-105 blades on his. it looks like it fly's good. he posted on here a time or two, could be good to contact him.
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  #11  
Old 08-26-2010, 11:42 AM
Jon Jon is offline
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Quote:
Originally Posted by Vance View Post
Hello Jon, welcome to the forum.

Your profile doesn’t have much information.

I feel it would help to answer your questions if we knew more about you.

How many hours do you have in a helicopter?

What helicopter did you get your training in?

Are you going to perform the test flights?

Your workmanship looks first rate.

What is your fabricating experience?

Thank you, Vance
I must have skipped the profile page when I signed up. I currently have one hour in an R-22. I am going to Houston for three weeks in October for business and I intend to get at least 30 hours of flight training in an R-22 with Heliserv at Hooks airport.
I am planning to do extensive tethered operation with my machine after my initial flight training in October. I will be the test pilot after the tethered operation.
When I decided to build a helicopter I bought a lathe and milling machine and started making parts. Most of my first parts were un-usable but over the last 10 years I think I have gotten better at it. I had a few contracts doing small production runs of small parts as a subcontractor for larger machine shops.
I have machined everything on this helicopter from the main rotor system to the engine pulley and flywheel except for the large drive pulley and the tail-rotor bellcrank and that was only because they would work for me as-is.

Thanks for the interest.
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  #12  
Old 08-26-2010, 12:21 PM
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magilla magilla is offline
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Jon,

Welcome to the forum!!

Excellent work! Your craftsmanship, from what I can see, is first rate.

Looks to be a very interesting project, and I wish you all the best!

There are a lot of helicopter guys on the forum, and you will get no end of advice and tips and thoughts, especially with the more details you provide. There is an astounding amount of technical knowledge possessed by members of the forum, and you will find out in short order, especially if you dig through the threads, those that are well respected and have a LOT to offer. PM me and I'll give you a list of the guys who have been (from an engineering and physics standpoint) godsends to this community.

I am glad to see that you have scheduled training. I cannot stress that enough in the experimental arena.

While it sounds like a no-brainer for you in the way you have described your training approach, there are many in the experimental category who would eschew training in favor of self-learning. Being that close to the project, and erecting a helicopter from scratch, the desire is there (from first hand experience) to go ahead and try it out...

Anyway - not trying to hijack the thread - just merely saying that by scheduling training, you have done the right thing and set the example...

As far as helicopter aerodynamics and some of the phenomena you will experience while flying a helicopter, there are some excellent reference materials that give excellent layman's knowledge of understanding how the helicopter operates.

Topics such as blowback, translating tendency, transverse flow effect, settling with power (vortex ring state), and effective translational lift, as well as environmental factors such as brownout are good things to know, and I can hook you up with the Army's "aerdynamics" manual and guides for conducting different maneuvers (airspeed over altitude take-offs, high gwt approaches, pinnacle approaches, autorotations, etc.)

I would definitely research further your blade situation - the aerodynamics of rotor systems is a tricky business, especially in autorotation with driving, driven, and stall regions. Cutting the ends of blades with a negative twist at the root can have disastrous effects to your lift/drag coefficient and could hinder autorotational capability... I don't know enough about your particular situation and set up to tell you anything else.

Anyway - congratulations on completion to this stage so far in your project! Looking GOOD so far!

(FYI - I am a helicopter Instructor Pilot and former Maintenance Test Pilot in the UH-60 Blackhawk, so I know a little bit bit about the above topics, but not as much as a lot of guys here. My experience is in military helicopters, and not so much in home built, but I can definitely provide some pointers on conducting different maneuvers, and would be more than happy to pontificate over a beer about the right and wrong ways to fly a helicopter...)

I am at once envious and at the same time happy for you, and wish you the best of luck!

(cue in soundtrack of Apocalypse Now "Ride of the Valkyries"...)
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Last edited by magilla; 08-26-2010 at 12:31 PM.
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  #13  
Old 08-26-2010, 12:40 PM
StanFoster StanFoster is online now
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Jon- I was having slow internet connections and I had only seen a small part of your video. I have now seen it all...and wow....very impressed.

However.....Magillas opiinion is a lot higher value than mine.....and you have a heavy hitter when he is on your side.

Excellent wiork....and you will have an amazing helicopter...one of a kind....



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  #14  
Old 08-26-2010, 07:05 PM
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I'd like to see more video of the engine itself and all the belts and gearboxes that connect it to the rest of the machine.
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  #15  
Old 08-26-2010, 07:47 PM
Jon Jon is offline
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Thanks to everyone for the great feedback on my project I really appreciate it. Magilla if I ever get to Little Rock I will definately contact you and if you ever find yourself around East Texas or Northwest Louisiana let me know.

I will make another video showing more of the helicopter drivetrain for those that are interested.

I finished the blade straps and pitch change assembly today I need to get them mounted so that I can get the correct length for the pitch change rods coming up from the rotating swashplate to the pitch horns. I hope to have that done within the next couple of days.

Last edited by Jon; 08-26-2010 at 07:59 PM.
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