SparrowHawk Redo

[brs]

OK, I wasn't going to put this build on the forum as I suspect there will be some things here that others may not agree with. But the truth is "there is wisdom in many counselors" (Prov 15:22). No doubt the comunity will able to teach me a lot, and who knows, I might come up some useful stuff here.

So I have this Sparrowhawk-1 which I just purchased. It was built in 2004/2005, never quite finished and never inspected. But its all here (some of it in boxes), mostly done, and priced to where I can afford to back-up and "redo" some of the work and designs. Then finish what the previous builder didn't. Thus the name SparrowHawk Redo, or SHredo.

Now that I have it, I have several mods in store:

So here is what I plan on doing with this machine.

• Change the tall-tail to a low-tail with three vertical stabilizers.
• Increase the angle of rotation before the rear wheel hits the ground. (More tail wheel ground clearance.)
• Change the steerable nose wheel to a castering nose wheel.
• Change the hand brakes to toe brakes.
• Improve the cooling system.
• Shed a few pounds and hopefully be light enough to put it in LSA category.
• More ....

So here is my first question I'm hoping someone knows the answer to. In my mod to make the nose wheel caster, I first plan on welding up the four holes on the top of each fork, where you see the attach bolts in the photo, and redrilling to cause the wheel to trail more. However, this will lower the nose a bit and I'm afraid of making it hard to "unstick" the nose upon takeoff. So perhaps I should lengthen the forks at the same time. Has anyone done this already?

[lanichol]

Originally Posted by brs

I first plan on welding up the four holes on the top of each fork, where you see the attach bolts in the photo, and redrilling to cause the wheel to trail more. However, this will lower the nose a bit and I'm afraid of making it hard to "unstick" the nose upon takeoff.

I have considered the exact same changes. You could just build new side plates.

Consider a SportcopterII suspension, attachment points and nose wheel.

Gabor built a nice nose wheel.

Go to hydraulic brakes rather the stock cable.

[brs]

Yes I will likely change the suspension too. Probably just make a new top tube (a-la SportCopter) with a rod-end on each side and that nice McPherson style shock. Will likely keep the bottom two tubes, brakes, spindle etc. Anyway this is secondary to the other mods, as this can be easily accomplished after I get it flying.

So are there no comments on the nose height vs ease of rotation?

[Vance]

Originally Posted by brs

Y

So are there no comments on the nose height vs ease of rotation?

Hello Brock,

I would try the lighter tail and nose wheel further back as it comes out to see if you like it.

I feel that mounting the new lighter empennage further back would be a good thing aerodynamically and alter the CG less.

When I have a heavy passenger and full fuel in the two place tandem gyroplane I fly it increases the weight on the nose. I have found that she rotates later and takes off flatter and faster.

I kind of like it.

When I flew a SparrowHawk with a heavier instructor the take off was flatter and I didn’t have to drop the nose as much after liftoff to pick up airspeed.

I kind of liked it, it felt more stable to me and I felt the nose lifted more gradually.

I liked the tall tail on the SparrowHawk because it seemed to manage torque roll well. It did seem heavy and prone to wagging if things weren’t adjusted correctly.

Thank you, Vance

[brs]

Yesterday I installed ceramic wool in the supertrapps. The stuff I got was 1' thick which was too thick. But it easily pulled into two 1/2" layers, so I used that. Took about 10"X10"X1/2" per muffler.

I also drilled all the bolt heads, reinstalled with anti-sieze and safetied. The only unknown was how tight do I get those plates. I tried not to snug them down very much.

Also, at the PRA73 meeting yesterday I met Dennis Dubois who has a very clever little gyro. I liked his approach to suspension and am considering doing this to the SH-redo (shredo). Still studying the idea.

[CLS447]

I think you are supposed to remove the wool, so that it doesn't break down and clog the discs. I have seen this happen and it blew out the entire baffle system. It almost caused a forced landing.

Why are you reinstalling it?

[Steve McGowan]

Just thought Id drop my two cents in the pot.

Get RIDDA the Super traps... (conventionally they're for 2 cycle engines) They will clog up. cause you to use more fuel and come apart in flight, tearing your prop up.

It's much quieter and an automotine engine w/muffler system.

[Steve McGowan]

Originally Posted by lanichol

I have considered the exact same changes. You could just build new side plates.

Consider a SportcopterII suspension, attachment points and nose wheel.

Gabor built a nice nose wheel.

Go to hydraulic brakes rather the stock cable.

The LONGER side plate swivel type, were originally tried and tested on SH,s They broke off in ruff terrain.. It also has to have some type of restraint or it will shimmy violently..

As well as the tail wheel MUST have clearance to tilt bak as the rotor system loads up... again,,
Again........... me runnin my mouth..

Steve

[brs]

CLS447:
It was my understanding that it was the fiberglass that was breaking down and clogging the traps. I've installed Ceramic Wool which can take all the heat one can give out.

Steve:
Thanks for your two cents, here is a penny change. I might get rid of the SuperTrapps eventually but for now I'm going to leave them. I know of a really good custom muffler shop that I'll eventually go visit. My first hesitation though is weight. I have way too many things on my to-do list to accomplish all at once.

Shimmy on the nose wheel is a simple matter. Figured that out long before purchasing the machine. Also I will have more tilt than stock. Basic idea is to move the stock tail wheel forward about 12" and mount it slightly higher. The tail will be further back, by about 4", than stock but the bottom of it will be higher. I'll put on a skid just in case but don't think it will hit. Pictures to come- eventually.

[CLS447]

OK, I hope it works out for you. Why do you need it in there, anyway ?

The other changes seem interesting. Please keep us posted & use pictures. Thanks !

[bmoore2156]

I tried ceramic wool in my muffler (not a trapp) and it blew out.. They use it at work for making insulation blankets for steam lines so I got a piece and tried it... I dont think the heat causes it to break down as much as the compression pounding on it fractures it. The trapp is prone to plugging because of it's small passages.
Brad

[Steve McGowan]

Originally Posted by brs

CLS447:
It was my understanding that it was the fiberglass that was breaking down and clogging the traps. I've installed Ceramic Wool which can take all the heat one can give out.

Steve:
Thanks for your two cents, here is a penny change. I might get rid of the SuperTrapps eventually but for now I'm going to leave them. I know of a really good custom muffler shop that I'll eventually go visit. My first hesitation though is weight. I have way too many things on my to-do list to accomplish all at once.

Shimmy on the nose wheel is a simple matter. Figured that out long before purchasing the machine. Also I will have more tilt than stock. Basic idea is to move the stock tail wheel forward about 12" and mount it slightly higher. The tail will be further back, by about 4", than stock but the bottom of it will be higher. I'll put on a skid just in case but don't think it will hit. Pictures to come- eventually.

Less your 260 or better ,, the weight,,, Your not flyin the cabin,, your flyin Sport Copter Blades.

But I don't know much bout these things,, only built about 9 of them so far and thats not nuthin at all to talk about. U may have sumthin tho!!

Again,, Your Gyro,,

Ole Fools didn't get there easy!!! Just glad to be alive....

[brs]

Originally Posted by Steve McGowan

Less your 260 or better ,, the weight,,, Your not flyin the cabin,, your flyin Sport Copter Blades.

Again,, Your Gyro,,

Sorry Steve but Google-translate was not able figure out the meaning of this. I think you are saying "Hey stupid stop worrying about the ounces, that EJ22 will fly the thing just fine unless you weigh 260lbs or more." Did I get the gist of it?

Fortunately, I'm only about 10# from the official FAA passenger weight. Yes I can be a bit obsessive about weight but I've come to equate better weight/pwr ratio to better performance. No doubt I'll make some choices that will add to the weight so a little savings here and there are good.

Originally this was on an unpublished blog but I put this on the forum because I know you guys have a lot of good and specific experience and tips. So far I've learned a lot - thanks everyone for your help.

[Steve McGowan]

Didn't mean anything bout being stupid...so please excuse me if I gave that impression.

Thats Y it's called "Xperimental"

I didn't realise that your pushin a 2.2 insted of a 2.5, ,,, your right,, every ounce will make a difference in a lil while.

Id love to see pics of your changes,, may be sumthin I can do too..

[MichaelBurton]

Shorter nose wheel height will do little to change the lift off unless you do not have the required pitch range on the rotor head.

We put a smaller wheel on the rear to increase rock back. It worked well. I think you will need more trailing angle on the nose wheel and some tension or it will shimmy and break. Look at other aircraft nose wheals to get a good idea. I hate super trap mufflers. They break and go into the prop. They are Very expensive when that happens. I refuse to fly with them on my gyro.

Remember my opinion is just that and nothing more. You are the test pilot.