Iam taking a Kadet LT40 and turningit into a tail dragger. Where should I center the gear? I'm thinking centered on the leading edge. Is that a good plcae, or should it go further forward?

That should work just fine. You want to make sure that half the wheels are in front of the leading edge. Good Luck, Dave

Works fine on my LT40. Be aware that the LT will now be tail heavy. Keep the TW mechanism as simple and light as possible.

Thanks. I picked up a plastic Dubro LG for it, and placed it right about where you guys said. Looks normal. THe tail gear will be the one from the P-51 kit that I didnt use. Its pretty light. Since I am putting in an )S .52 Surpass 4 stroke, hopefully the weight difference between that and a normal .40 2 stroke will help offset the tail wheel. I plan to mount the nose gear bracket, and maybe the pushrod tube so I can convert from one setup to the other with ease. Would make it a 4 wheeler that way

Just a "rule of thumb" note - 1 oz at the tail requires 4 oz. at the firewall to offset.

CG point should be the same though on the wing?

Absolutely correct

thanks for asking this question. im doing the same conversion

Well last night I placed the assembled fuse on the LG mount, and stuck the tail gear from the P-51 kit on it, and it looks just about right.  I centered the gear on the F2 Bulkhead, and placed 3"x1"x1/4" ply on either side on the floor for the bolt down.  If I place a ruler centered on the axle it lines up with the LE of the wing. <div>
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Dave,

Why?

Kurt

I checked several tail draggers that we have in the barn, including a real Cessna, and he is correct, every one of them has the axle centered on the LE. In fact the warbirds also have their axles on the LE.

Absolutely the commonly advised position for landing gear geometry when positioning taildragger configured landing gear is roughly with the center of the footprint even with the leading edge.

Sometimes however due to aspect ratio and wing planforms (taper configuration) This may not be an ideal location and there are varables. This is a minor point though and going the ball park location (leading edge is normally fine).

What I wanted to point out Acdii are the effects of this location and what happens when its to far forward or to the rear just for the information.

First I cringe when I see folks actually changeing the CG of the airplane just to suit the gear location and this which I think has already been covered in this thread is a hugh mistake, what happens is you not only get an airplane with poor ground handling but also one that flys poorly in the air.

So CG should never be changed to suit the landing gear instead if any conversions are made the gear position should be changed to suit the known good CG.

What happens if the landing gear is to far forward? The airplane will be difficult to take off because it will want to swap ends while on the ground no matter what, this because the CG is so far aft of the wheel footprint. In addition this long lever formed by the CG gear footprint will cause all but the most perfect landings to bounce or become uncontrollable crowhopping. The kind of landings I call 'Boingers' even the most skilled will have difficulty with this situation.

Not to what happens when the gear is to far aft and I will continue this in another post in a few moments to avoid being timed out, sorry.

John

Absolutely the commonly advised position for landing gear geometry when positioning taildragger configured landing gear is roughly with the center of the footprint even with the leading edge.

Sometimes however due to aspect ratio and wing planforms (taper configuration) This may not be an ideal location and there are varables. This is a minor point though and going the ball park location (leading edge is normally fine).

What I wanted to point out Acdii are the effects of this location and what happens when its to far forward or to the rear just for the information.

First I cringe when I see folks actually changeing the CG of the airplane just to suit the gear location and this which I think has already been covered in this thread is a hugh mistake, what happens is you not only get an airplane with poor ground handling but also one that flys poorly in the air.

So CG should never be changed to suit the landing gear instead if any conversions are made the gear position should be changed to suit the known good CG.

What happens if the landing gear is to far forward? The airplane will be difficult to take off because it will want to swap ends while on the ground no matter what, this because the CG is so far aft of the wheel footprint. In addition this long lever formed by the CG gear footprint will cause all but the most perfect landings to bounce or become uncontrollable crowhopping. The kind of landings I call 'Boingers' even the most skilled will have difficulty with this situation.

Not to what happens when the gear is to far aft and I will continue this in another post in a few moments to avoid being timed out, sorry.

John