I am trying to get an NOS Duraplane 40 with ailerons flying and have problems some because over the years lost the instructions and or plans to it but maybe someone can help?

it seems to very clumsily balance on a CG 1/3 back from the front edge of the wing it won't stay suspended in air but teeters to one end or the other not always one end like it heavy on one end.
From what I can find these are know to be really bad ground handlers and mine is no exception crashing on it's maiden take off never leaving the ground! Some have converted to a tail dagger others adding wing tip skids or both. My thinking from observation is: poor balance on the main gear :meaning the nose wheel comes off the ground with the slightest touch of the tail , so the nose grear /wheel is not biting in .
So why not move the main gear back until the nose gear / wheel gets a good bite ? That leads to how far back can I go ? this is an albatross for sure and will never be a good balanced flying machine so I'm trying for what will work and avoid crashes especially when pulling the throttle back to taxi and take off and it just flops over, very embarrassing !


Thanks for any help
Jayd

If your airframe is tail heavy, as you suggest, moving the main gear rearward will make it worse.

If you want the nose gear to "bite in", I suggest that you move your battery pack forward, or add weight to the nose.

Would like to add a thought. Make sure the plane is sitting not nose up or nose down by adjusting the nose wheel up or down.in its mount. I've used a level on the wing saddle area if the wing is flat bottom. A nose high position makes the plane takeoff too soon and is hard to land, while a nose down position keeps the plane stuck to the runway until you have enough speed for the elevator to take effect. Before I'd change gear or gear configurations, I would check CG, lateral balance and how the plane sits (level hopefully).

Thanks guys for the replies
T.C. I do wish the plane CG was a perfect balance where it just hung in mid air on my old sticks balancer but as it is tipping either direction I just can't say it is or is not tail heavy and I have put the battery as far forward as I can, now the other part of the CG is I am assuming the correct point is 1/3 back as I have no plans or instructions if it is 1/4 back than I could say it is tail heavy for sure.
Can you explain why moving the gear back would make a tail heavy plane worse ? for whatever reason I'm not seeing it ?

T.N. As for level It looks level but I could check with an actual know good spirit level to make sure, and I can recheck total lateral balance: I did balance the wings.

As far as lateral balance, just don't balance the wing, balance the whole plane.

Here's a manual for the Duraplane Aerobat 40, is it the same plane? http://manuals.hobbico.com/dur/dura1130-manual.pdf Page 12 recommends the CG at 3 1/2" back from the leading edge.

DuraPlane Trainer 40, CG at 3 5/8" http://www.flyhobbies.com/duraplanetrainer40arf.htm

Tom
Thank you for the manual
It is mostly the same with out doing measurements I can see the areo bat has less diheral in wings, a build up cover to the leading edge where mine is a simple straight fuse.

This is the one I have. I'm thinking to cut lightening holes in the solid 3/16 balsa horizontal and vert stabs to help the tail heavy situation done properly they should not weaken them much, now to figure the correct size and placement? I hate to add weight to an already brick heavy plane.
On a brighter note I have my old Lou Andrew A Ray about ready to fly again. wish I had the original wing with ailerons .

Jayd

Isn't the wing just placed further back to balance per the described CG? That's what I did on a Spad Debonair. The wing placement was determined by how the plane balanced out. That way, you don't have to add weight to the nose or try to lighten/weaken the tail.

I'll look into that: mine came with rubber band dowel holes pre drilled, however I may be able to move the wing if the cut out for servo access allows.
Jayd