marmalade1

I took my new BUHOR out for its maiden flight yesterday. It was built to spec and used a OS .46LA engine. The tailwheel was castoring (not recommended). I had an experienced flyer take it up. With a brisk headwind, on a smooth tarmac runway it barely flew. It made one turn, the pilot barely managed to bring it down. It had a rough landing but suffered no damage.

Clearly I need more power/less weight. I used 4mm corrugated plastic. I realize the OS .46 LA isn't very powerful, but it is much lighter than a TT .46 Pro and worked for my last 40 sized trainer of similar weight. People speak of flying a BUHOR with a good BB 25 engine. How come my nearly new OS LA is insufficient? I was using a 10x6 prop.

Any thoughts on how I can get this BUHOR flying?

Thanks

erik58

My Feedback: (4)

is the engine broken in? spads are heavy. just love 'em.I had the same problem with a dogfighter I ended up puttng a.40 bushing engine on it and it's ablast to fly. maybe a.60 would help.
balence is really inportant it sounds like it might be a little tail heavy. good luck erik58

mustangman177

Ditto on the more power. Is this your first SPAD ?


http://images.rcuniverse.com/gallery.../lg-232854.jpg

This has a OS 55 AX and flys great.

aspeed

If the motor is running good, and the nose weight doesn't help, you can always cut a few inches off the wingspan. I think the buhor is 60" which is pretty big really.

Villa

Hi marmalade1
Are you using added weight to get the CG correct? If yes, get rid of it and move something instead.

marmalade1

Thanks for the replies. I agree that less weight / more power would resolve the issue. To your comments....

Villa: I didn't add weight, but yes, that'd be the first to go.

Aspeed: Cutting a few inches off would make it lighter, but wouldn't it reduce the lift? On that note; one other concern is that as I folded the 4mm coroplast, it folded sharply at the spar, creating a triangular, rather than a smooth rounded aerofoil. I've seen very simple aerofoils work, but... maybe....

Mustangman177: This is my first SPAD. I've only flown 21 times total so far. I was just excited to make a simple plane with some spare parts (Read: from a wreckage I recovered from under a tree).

Eric58: The engine has had at least 3 tanks of fuel. It was wonderfully easy to start/adjust. It was a little rich (sub-optimal RPM at full; pinch of fuel line peaked RPM).

I read on a forum that prop size can make a big difference. I need a good prop for a take-off. Top-speed is not important at this stage.

I'm in the process of fixing the tail wheel to allow better runway directional control. Also, I do have a TT .46 Pro in a cheap Thunder Tiger t200 trainer that I can switch in, I just wondered why a more than adequate engine was incapable of flight. The OS .46LA will likely power the old Thunder Tiger T2000 trainer as it's original engine was also a bushed TT 40 GP.

If I end up remaking the wing to have a smooth rounded aerofoil does anyone know of a place to get 2mm coroplast in the Chicago area?

Further, I was considering converting the fuselage to a single C section (as per BUHOR 25) as this was described as a way of reducing the weight of the BUHOR for a .25 engine.

This was my first post on a forum. It's great to have such support. Thanks!

I'll keep you posted.

aspeed

I just flew a 39" x 11" wing with a .40 and it went fine. Maybe a bit fast, but not too much. It was out of 4 mm and creased to a diamond airfoil. (not flat bottomed) It has a shorter spar and the tips are squashed flat. There is no rudder on this one or steering which makes takeoffs a bit exciting and taxiing imposible. I have made diamond airfoils from balsa and they work fine. We used to make them for ease of building on a flat surface. A true airfoil may perform better, but in reality most people may not notice any difference at all unless it is a glider or a more high performance machine.

mustangman177

Mustangman177: This is my first SPAD. I've only flown 21 times total so far. I was just excited to make a simple plane with some spare parts (Read: from a wreckage I recovered from under .a tree).

Know the feeling...Taking spare parts from different planes and making 1 fly.....Is a great feeling, especially that first SPAD, Keep up the good work and building !!!

aspeed

The great thing about SPADS is that you can try different sized wings, fuselages, and just crazy designs that you would otherwise not try because of cost or especially time and you don't have to paint.

cncswiss1

sounds nose heavy-- and propped wrong

try an 11-4 prop, and recheck balance