Wing mounted landing gear wheels spacing

[Matt Piatkowski]

Hello,
The wing's span of the stunt plane is 63".
The area with flaps = 703 in^2.
Expected RTF weight ~ 65 oz.

What will be the recommended spacing of wheels in the wing mounted landing gear? 2.5" diameter wheels will be used.

The possible range of this spacing, defined by the location of the 5" long wooden blocks that support each landing gear wire leg is 13.50 - 23.50".
The wire diameter will be 1/8" and the length of the "leg" is 4.5".

The model has tail landing gear.

Thank you,
M

[Brett Buck]

Hello,
The wing's span of the stunt plane is 63".
The area with flaps = 703 in^2.
Expected RTF weight ~ 65 oz.

What will be the recommended spacing of wheels in the wing mounted landing gear? 2.5" diameter wheels will be used.

The possible range of this spacing, defined by the location of the 5" long wooden blocks that support each landing gear wire leg is 13.50 - 23.50".
The wire diameter will be 1/8" and the length of the "leg" is 4.5".

The model has tail landing gear.

Thank you,
M

  That's an OK range, but I think 13 is narrower than I would like. 18-20" works very well. Err on the side of "too wide".

    Brett

[M Spencer]

The Phantom , with trike gear , had the main legs near half span .

One wheel on the deck , the plane would go flat on all .

Maybe gives a bit more ' give ' - wing flex - far out there . More ridgid inboard. to snap the wing . I had ' knock out ' ply plates , behind the spar .

Detachable / torsion bar , or some set up that doesnt wipe out the whole wing , if the pilot gets distracted, might be of benefit . For transport as well .

The funny plug in Yatsenko like ply boxes seem to work , too .Can angle boxes for straight leg .

[SteveMoon]

Matt: For a plane of that size, I'll place the landing gear blocks between
the 4th and 5th ribs. This yields a spacing of 22 or so inches.

Steve

[Carl Cisneros]

on my Sakitumi 60+   60 inch span and 742 square inch area
I am using 18"  between gear legs with 2 1/2" wheels

[Matt Piatkowski]

Thank you all for your comments.

Hi Carl,
Have you used 1/8" dia. wire for Sakitumi landing gear or perhaps 5/32" dia.?

Hi Steve,
In my wing, the landing gear support wooden blocks are 5" long and connect ribs 4,5 and 6.

Hi Air Ministry,
I know Yatsenko design and yes, the "funny plug" can save the wing if the landing is hard or on uneven or/and grassy field that was not properly prepared. The emphasis is on "properly".
 
All Yatsenko, Solomianikov and Leonidov RTF F2B planes, coming from the "Ukrainian Models Factories", have a relatively weak landing gear attachment area though.
There exists another solution to the problem and it is used by the top Polish F2B pilots.

Please see the attachment.

The main landing gear of this "Gee Bee" like plane is based on "U" shaped  3mm. dia. steel wire.
The "wing ends" of each wire sit in two matching tubes (carbon laminate with thin steel lining) epoxied to the spars and ribs.
The "U" wire wing ends are not parallel - their directions differ about 5-6 degrees. The resulting preload on tubes is sufficient to keep the landing gear in place having in mind the vibration spectrum and flight and ground loads.
When the "U" is slightly squeezed, the entire main landing gear is removable.
The pants are carbon fiber/epoxy laminate.

Happy Flying,
Regards,
M

[Tim Wescott]

  That's an OK range, but I think 13 is narrower than I would like. 18-20" works very well. Err on the side of "too wide".

    Brett

What if you're building a stunt-scale BF109?

[Carl Cisneros]

Matt

I am using 5/32" wire on mine
the plane is JUST A BIT PORKY  LOL

Carl

[Matt Piatkowski]

Hello Carl,
5/32" it is or...the Polish F2B gear.
I will ask my wife what to do: she does not know anything about strength of materials, bending and torsional stiffness and so on, so her advise will be as good as out financial advisor.
She always (advisor not wife ) wants more money but, when I ask some questions, I hear the same answer " it is up to you...".
Thanks,
M

[Avaiojet]

I decided on 21" for my GBR-3 which has a 55" wingspan. Doesn't look that wide at all actually.