I started this project 8 or 9 months ago and never finished it so this week I decided to continue where I left off.

The original plans came from RCgroups (http://www.rcgroups.com/forums/showthre ... twin+cargo) but after giving some thought to having to deal with twin engines, I decided to make some modifications and use a single engine instead.

I increased the wing loading by adding another 3 inches to the chord of the existing wing on the twin.

I added a cargo box inside and made a nose gear from 1/16" phonelic.

The AUW came out at 36 oz so I used a BP 2217-9 with a 10x3.8 slow fly prop and a 2350 mah LIPO.

I cut a hatch opening in the fuse after completion of the build when I could determine where the CG should be and finding it needed more weight up front. There is a tray already there which allowed me to add some velcro to hold the battery in place and I made a 6" battery extension with deans plugs on each end which was hot glued into the fuse so I connect the ESC from the wing and fasten the rubber bands and then still be able to remove the battery without taking the wing off in between flights.

I attempted to maiden the plane yesterday but the wing folded up on takeoff so back to the shop for a carbon fiber and aluminum wing tube to strengthen the wing.

I thought I could get away without the carbon by using the 90 degree folded supports under the wing but I neglected to run the supports the full length of the wing.

Tomorrow I will try the maiden again.

Here are some photos and the SU files I used in case you want to build one for yourself. Attached files HalfInchMotorMount.skp (51.5 KB)Â SingleEngineCargoPlaneFFF.skp (2.8 MB)Â nosewheel_phonelic.skp (73.6 KB)Â

 

Hey Flash that looks pretty cool! Looking forward to hearing how the carbon and aluminum helps out.

 

Here is the flight report for day two...

Todays flight went much better, got in a full flight with video, but not without one minor problem.

The nose gear was glued together with CA glue and did not hold up during the takeoff attempt, so we had to hand launch the plane and land carefully to avoid further damage. I wasn't going to let a little thing like no landing gear stop me from flying.

I also noted that the plane wanted to tip over when taking off as the wind got under one wing more than the other. I am not sure what to do about that. I am thinking maybe of putting a couple of stiff bent back wire supports down from the wing about 6 to 8 inches from the fuse to keep the plane from being able to tip over. Anyone have a better idea?

At 50 seconds into the video, I opened the cargo bay door and nosed up and dropped two nerf bombs out of the plane since I didn't have any parachutes to drop. They are on order...

The plane flew perfectly once I got it airborne! I forgot that I have it setup for flaps and did not try them out. It flies very slow as it is.

I had a camera mounted underneath the nose but the lens got wet during the first takeoff attempt when it went into the damp grass, so that video did not come out well. I hope to get more video later because there is a lake behind us and the video from overhead should be excellent.

All in all, I am quite happy with the plane.

 

If it were not for having to extend the wiring in one way or another I would have gone with the twin setup. I had purchased the motors and ESC's intending to do just that, but then got lazy and decided to go with a single motor based on the SeaBB design.

I put dihedral in this wing unlike the original twin. It flies almost identical to the SeaBB except it is land based. I may make another wing without the dihedral just to see if it makes much difference in performance.

Between the two of em, the SeaBB and the Cargo plane, they both make an excellent video platforms and the cargo plane will be able to carry a good bit of luggage onboard!

 

Yes, the cargo door is controlled by a small HXT 900 servo setup on the gear switch of the transmitter. It is a simple two position control when used in this manner.

 

I stopped by the park on the way home from indoor flying yesterday to make another flight with the cargo plane.

I had extended the rear landing wheels out from the fuse and wanted to see if it helped any with the tendency to flip over by the wind when on the ground.

There was a pretty good wind present so it was a good time to test it. I think the combination of the larger wing, the dihedral, and the battery weight making it top heavy all contributed to the problem.

Anyway, by moving the wheels out 3 inches from the edge of the fuse did put a stop to it, even in the heavier wind. Looks a little strange but now I can try reducing the amount of overhang to find an optimum setting.

In the air was another story! With the huge wing surface and the plane being so light, it was like taking up a kite! While I had plenty of control surface to counteract the wind, you certainly noticed the effects of the wind on all that surface area.

For landing, I engaged the flaps this time and was pleased with the way the plane slowed to a walking pace for landing. Just a very small amount of throttle increase provided such a lift I overshot my intended runway touchdown point by about 15 feet.

This plane is going to be really great for those still summer days in which there is little breeze blowing. I think I will probably want to add some lead weight for winter months when we have stronger winds. It is just so light and the wing area so great that it could be handful in those winds.

I can always make a second wing with less wing loading for the winter months. That's the beauty of having a Phlatprinter on hand.

 

The parachutes came in. Another couple of flights for more video opportunities.

I edited the new video to include the 2 nerf bomb drops from the previous day and added some background music.

The parachute just cleared the tree line in the video and landed on the pavement on the other side. What luck!

I bought 4 parachutes expecting to loose 1 or more eventually. I now know to go out further before the drop or not to go as high.

 

Is that a Kline Fogleman wing?

 

Look at the end of the wing in the very first photo.
http://en.wikipedia.org/wiki/Kline_Fogleman_airfoil :geek:

 

yes