FeiJi's blog View Details
Archive for July, 2018
Posted by FeiJi | Jul 30, 2018 @ 07:23 PM | 8,345 Views
You gotta watch this thing take off and land. Incredible.

DRACO - The Most Badass Monster Bush Plane EVER! (20 min 37 sec)

Posted by FeiJi | Jul 30, 2018 @ 12:55 AM | 5,757 Views
Wow, awful maiden - too many problems.
Servos were reversed so nosed into the ground when I thought I should be pitched up. Prop mounted backwards. Servos loose. Bent motor mount on first take off. CG too far back. Windy.
So fixed all those except CG and it flies - but motor angle is down because of motor mount so will redesign motor mount and it should fly fine.

This micro camera is awful - audio out of sync and video got sped up. Ordered a head mount for my mobile phone as I like the video it takes.
Next flight should go much smoother. It does have a lot of lift and the tiny motor still can make it scoot. Put a proper propeller on it and it should really move.

Scratchbuilt Delta Maiden (0 min 58 sec)

Posted by FeiJi | Jul 21, 2018 @ 10:41 PM | 5,840 Views
Started building a plank using 5mm (and a little 9mm) EPP and carbon fiber fishing pole tube sections. Will skin in 5mm foam and then laminate. Won't be pretty but will be strong. Will build wing same way. Love foam and hotglue and just eye balling it.
Posted by FeiJi | Jul 19, 2018 @ 09:13 PM | 5,649 Views
Not quite finished, needs a couple of hatches made but it is functional and ready for maiden which I could do tomorrow but will probably wait to get a headmount for my phone camera to take videos. CG is back about 23 cm and had to use a little ballast to get it to balance. Could use a much heavier motor and/or battery with more thrust - this little motor gives about 1:1 but the lift should be awesome as the AUW is 340 grams. I added some tape covered skids on bottom to protect fragile leading edges and to keep motor mount from digging into ground.

If it flies nice I might try faster prop rather than this slowfly prop, and add a rudder with 5g servo. Also could go with a bigger motor.

Excited to fly it but am thinking about my next project already which will be a scratchbuilt hotliner using same 5mm epp foam and fishing pole tubes and just elevons with only a vertical tail.
Posted by FeiJi | Jul 03, 2018 @ 01:09 AM | 7,739 Views
Couple more photos of my delta wing. Learned a couple of lessons. Bottom is perfectly flat so next time might use symmetrical shape. See how this one flies. Might use some sort of software to design ribs but that is too work intensive for me. Probably use a single center fuse rather than two.

Strapping tape ironed on seems t adhere to epp ok, if not then will use hinges for elevons.
Made motor mount from couple layers of 3mm plywood. Want to be able to dismount motor mount easily. Plastic motor mount will be bolted to plywood.
Elevons are very rigid. Used a carbon rod and laminated them.
Not too much more work to do now.
Posted by FeiJi | Jul 01, 2018 @ 02:04 AM | 5,591 Views
Bought a few sheets of 5mm EPP foam and using one to build a delta wing with ribs and spars. I just like the idea of a wing having a frame of some kind. This is totally a design it as I go and it already has characteristics of that kind of build: adhoc structure, crooked cuts, dimples on the skin. But it should have a lot of lift and be very light.
I am using carbon fishing pole sections for the internal frame and 8mm epp foam for the ribs.
I plan on powering it with a 2206 - 1500kv motor tractor style.
It should light up nicely with leds inside.
It will have chord of about 53 cm and wingspan of 85cm.
Weight so far is 175 grams.
Should weigh about 12 to 14 ounces with 450in sq of wing area and WCL of 2.2 or so.

Working on elevons next. Will double the 5mm foam, add a carbon rod and laminate them. Heavy but since the motor is in the nose it doesn't matter.

Update: elevons done, tail cut - needs to be laminated. Then install servos, then figure out a motor mount, then install electrics, then final foam pieces, then fly. Unfortunately I have to go to Beijing for a couple of weeks so this project is on hold.