New RAF 2000 build

[Mike Leimetter]

Agreed. This forum is very dear for builders like us. Glad we have it. Consider supporting it with a donation if you haven't already. Will be anxiously following your progress. Cheers.

Brian

Good idea for all! Already have!

 

[Mike Leimetter]

Well, we managed to get the project home. Now to inventory parts. Looking for the main gear assembly as the previous owner apparently drilled the holes wrong, ordered a new one and misplaced it. Any help in finding one would be greatly appreciated!!

Mike

 

[Waldo]

Mike,
How fast do you need it and what parts specifically. I'm building an RAF but I am designing and building my own landing gear so I don't need the ones I got with my kit.

Matt

 

[Mike Leimetter]

Mike,
How fast do you need it and what parts specifically. I'm building an RAF but I am designing and building my own landing gear so I don't need the ones I got with my kit.

Matt

Hi Matt! Well, obviously as soon as possible so I can get it up on gear. The previous owner did some initial work to it and the cabin is mounted along with the vertical stab so it’s lying on its side. What were you thinking? I will have to remove the cabin to repaint it because it’s pretty marred up from lying on its side.

 

[Mike Leimetter]

Mike,
How fast do you need it and what parts specifically. I'm building an RAF but I am designing and building my own landing gear so I don't need the ones I got with my kit.

Matt

Sorry Matt I didn’t read your post correctly. Im hoping I just need the main axle shaft assembly. I haven’t had time to do a complete inventory of parts just yet, that will come this weekend. Im hoping the mounting brackets are there but may need them too.

 

[Waldo]

That might work out fine. I'm not planning on using the axle or mounting brackets in my build. I don't know if it will be cost effective for me to send them to you from Virginia or for you to just have them fabricated locally. I could give you all the dimensions if you wanted to do that too.

 

[Mike Leimetter]

So I want to add a horizontal stabilizer. Who has the best ones, and where can I get them? Also, is a drop keel and lowering the engine necessary if I have a horizontal stab and stabilator? Also seriously considering calling Jim at Sportcopter for a blade set up

Mike

 

[Mike Leimetter]

Hi gang! After a long summer (great to meet many of you in Mentone), building is coming along. Work
hours are short as it gets to be 120 in the garage here in Vegas. As it cools down we will ramp up the process. On a sour note, my SportCopter blades arrived and were damaged during shipping. Heartbroken. Jim was great as always and has started on a new set for me pronto. Thanks Jim!

 

[Mike Leimetter]

Got the Boyer stabs mounted. Lot of work by myself but it turned out nicely.

 

[Vance]

She has a nice tail Mike.
Than you for sharing the fun.

 

[Mike Leimetter]

Going thru my old posts I realized I have not updated much lately. Here are some photos of work done so far. New carpet in, Brakes and rudder pedals installed, radiator mounted, tail section mounted. Tried to mount the cheek plates with rotor hub but the ceiling in my garage is too low. Engine is at the mechanic getting an overhaul to make sure no corrosion.

 

[Mike Leimetter]

She has a nice tail Mike.
Than you for sharing the fun.

Thanks Vance. Doing my best with what I have to work with.

 

[Vance]

You will likely need to move the main landing gear back to compensate for the added weight so far back.

 

[Mike Leimetter]

You will likely need to move the main landing gear back to compensate for the added weight so far back.

Well we will see when it comes time for the hang test!

 

[Vance]

The hang test is about the location of the center of gravity in relation to the rotor head.

In my opinion the landing gear should also be adjusted for changes in the center of gravity.

My own experience is that the mains will need to move rearward for the extra weight out back or it will be difficult to balance on the mains.

It is important to me that she is easy to fly.

 

[Doug Riley]

Hi, Mike:

You asked months ago if a drop-keel mod is still needed on an RAF with H-stab.

The answer is yes. The prop thrustline is quite high above the CG on the stock RAF (in the 12-plus-inch range). This produces a nose-down torque at high throttle that's more than than an H-stab can counteract. The H-stab helps the situation, but isn't a complete fix by itself.

A substantial H-stab located in the propwash can overcome the nose-down torque of a prop that's a couple inches above the CG -- but not one that's a foot or more above the CG.

This conclusion arises both from the math and from a few PPO crashes of H-stab-equipped RAF's that had stock thrustline locations.

 

[Rowdyflyer1903!]

The hang test is about the location of the center of gravity in relation to the rotor head.

In my opinion the landing gear should also be adjusted for changes in the center of gravity.

My own experience is that the mains will need to move rearward for the extra weight out back or it will be difficult to balance on the mains.

It is important to me that she is easy to fly.

I was searching the threads for any reference to the placement of the main gear in relation to the influence of the CG and the lift of the rotor during the take-off. I would think that a design which is too light or heavy one the nose in relation to the center of effort of the rotor would produce additional pilot load and challenges during departures. The transition between something which rolls to something which is flown should be as forgiving as design compromises allow. Where can one find data to advise the scratch builder vs the kit assembler on such matters?

 

[Vance]

I was searching the threads for any reference to the placement of the main gear in relation to the influence of the CG and the lift of the rotor during the take-off. I would think that a design which is too light or heavy one the nose in relation to the center of effort of the rotor would produce additional pilot load and challenges during departures. The transition between something which rolls to something which is flown should be as forgiving as design compromises allow. Where can one find data to advise the scratch builder vs the kit assembler on such matters?

I have not flown a gyroplane that I felt had the mains too far back in relation to the center of gravity so I don’t know what that feels like.

If the mains are what I feel is too far forward the nose comes up early and it is difficult to balance.

I flew one modified RAF where once the nose came off the ground I could not get it back down with the cyclic all the way forward. I had to stop and wait for the rotor to spool down to get it off the tail wheel.

Because of the low speeds when the nose tire leaves the ground it is difficult to control the direction of travel with the rudder and with a linked nose gear once the nose is off the ground directional control may be challenging.

I found making that transition from nose wheel control to rudder control difficult when the mains are too far forward.

I have a very light friend and client who very nearly ran off the runway several times before moving the main gear back.

He has a lot of diverse flying experience and is an airline transport pilot.

If you are going to design your own gyroplane I recommend you go to as many gyroplane events as practical and take pictures of every gyroplane you can find directly from the side and ask the owners how she flies.

I have found it impossible to tell where the center of gravity is without a double hang test.

In my opinion a gyroplane is not as simple as it looks and small changes in the center of gravity, the location of the rotor head and the location of the mains can make large differences in how she flies.

My recommendation is you purchase a known design, carefully refurbish it and get several hundred hours flying her and modifying her before designing and building your own.

An experienced gyroplane pilot can manage most design errors but they may be a trap for a low time, inexperienced gyroplane pilot.

The Predator is pretty easy to balance and steer with the rudder and typically lifts off around 45kts if the nose tire is kept near the ground.

Her center of gravity is typically about an inch above the thrust line and about half way between the fuel filler and the fuel sender (black thing on top of the tank ahead of the fuel filler) depending on fuel and passenger weight.

She flies pretty much at the angle she sits on the ground.

 

[lindandavid]

Vance, don't know if you ever actually got to fly my old RAF that Vic had, but we moved the gear back 5 inches as I remember, and the takeoffs were much easier. About the time the nose wheel started coming up the rotor speed was such that it was ready to fly. I just gradually powered up and away we went.

 

[Vance]

Vance, don't know if you ever actually got to fly my old RAF that Vic had, but we moved the gear back 5 inches as I remember, and the takeoffs were much easier. About the time the nose wheel started coming up the rotor speed was such that it was ready to fly. I just gradually powered up and away we went.

We never got her airworthy so I did not fly her.
She had some mystery intermittent electrical challenge and we were not able to address it inside of his time and budget constraints.