Hey every one!
so I have been deep in the bowels of my garage for the last couple months, working on a new flying wing design.
Here are some specs:
Wing span 38 inches
weight as flown 20 Oz
battery 2200 3s lipo
motor AX 3802 1100 kv outrunner
For the techpod 2.0, I want to have a high precision camera gimbal capable of continuous rotation in two axis. I have always likes the brushless gimbals that are so popular today. The control and drive systems are very nice but are not setup for continuous 360 degree rotation. furthermore the IMU algorithm is very CPU intensive and prone to needing the gyros calibrated frequently etc.
I decided to replace the IMU with a AS5048B rotary magnetic encoder for position feedback. The AS5048B outputs the 14 bit absolute position of a magnet rotated near the IC. After you include noise, it is good for about 0.06 degrees of accuracy. Here is a short video of it going from 90.5 degrees to -90.5 degrees every 10 seconds.
Here is a quick hack of the brushless gimbal software.
So I did a test flight yesterday, here is the result.
here are the Tlogs.
170 minute flight time, 76.5 miles over the ground.
this is the equipment list:
Techpod Kit
APC 12*8 prop
2x Zippycompact 6s 5000 mah lipo
APM 2.5
Hey everyone, Here is something cool that I have been working on that I think you may enjoy.
Variable pitch prop
So, I had been pondering how to make an inexpensive variable prop. I was thinking about using a heli head from a hk450 or perhaps a tail rotor. I eventually saw a post on DIYdrones.com where a guy was using a tail rotor from a HK500 (can’t find post). I got inspired and found a HK600 tail rotor has the same shaft diameter as the turnigy G10 I use on the techpod. this is what I have come up with.
variable pitch test rig
I measured 15 degree max forward pitch and 12 degree reverse pitch. at 15 degrees forward pitch it drew 40 amps from a 3 cell lipo and puts out just under 5 lbs thrust.
I got the blades here and the tail rotor assembly here. I removed one side of the tail rotor plates and replaced both the shaft in the tail rotor and the shaft in the motor with one long 5 mm shaft. I had to notch it a few times for the set screws.I then made a plate to help support the rotor plate so I could then brace it with some 4-40 all thread rod and nyloc nutsI also made a custom motor mount for the techpod.
After the motor was secured, I cut out a mount for the pitch servo. Then I cut a hole in the foam so I could attach the servo mount to the techpods rear fuselage brace. I grabbed a bell crank from the local hobby shop and mounted it to the rear brace as well.
I have the techpod mostly assembled and should have the batteries for it later today. I hope to be able to start test flying over the weekend. If everything works out well, I plane on offering this as an mod kit for the techpod.
Hey everyone!
I wanted to share some conceptual drawings of the next gen techpod. It will include a fully functional pan/tilt/zoom camera mounted on a stabilized gimbal with 360 degree continues rotation on two axis.
The Main steps to assembling the fuselage
- assemble spar box and rear bulkhead
- attach motor mount
- add fiberglass
- mount motor
- route motor wire
- Insert and align boom/tail assembly
- custom fit your gear at this point
- Fit and glue fuselage halves together
assemble spar boxand rear bulkhead
1. measure 1/2 inch inboard from the end of 6.top spar box piece and mark. then measure the center line and mark.drill a 1/8th inch whole in 6.top spar box piece
mark 1/2 inch inboard
mark center line and drill cross marks with 1/8 inch drill bit.
2. mark fuselage halves using a screw in the wholes you drilled
3. poke an access hole for the set screws on the mark you just made. I used one of the aileron push rods.
4. epoxy 6.top spar box piece to 5.rear spar box
5.epoxy 6.bottom spar box piece to 3.rear bulkhead
6. slide two parts and test fit the 39. Spar end tube
make sure it clamps on the nylon tube
7. sand slot until the camping action works well if needed
sand if needed for good clamping action
8. assemble and install t-nut with CA
drill hole with 3/16th inch drill an secure with CA
9. epoxy 1. Rear brace to 3. Rear bulkhead and make sure they are square
square rear brace and glue with epoxy
attach motor mount
Epoxy 2.Motor mount to 1.Rear brace. Make sure it is square. you may have to sand lightly to make it fit. The production units are a bit tight here.
add fiberglass
1. trim fiberglass to fit
you want the fiberglass to reinforce the corner of the two pieces. You want to make a fillet.
2. fill motor mount screw holes with vaseline to prevent filling with epoxy. make sure not to get any on the front side of the motor mount as it will cause the epoxy to not bond.
3. lay down fiberglass and work in epoxy(15 minute)
4. allow to cure and add more epoxy if needed to make a fillet.
trim edges after curing.It should look like this when done.
mount motor
attach motor with appropriate screws add spacers if needed for prop clearance.
route motor wire
cut tunnels into the insides of the fuse to allow the motor wires to pass
use a razor blade to make clearance for the motor wires. Run 2 on one side 1 on the other,
pro tip: install bullet connectors on the motor side so you can replace the motor if you need to.
Insert and align boom/tail assembly
1. insert tail and boom assembly
2. mix and apply an ample amount of JB weld to glue the carbon fiber to the wood
3. Align the F.Vertical stabilizer with the 1. Rear brace
4. brace and allow glue to cure
custom fit your gear at this point
now it the time to fit that mammoth lipo or the vertical camera, custom table or whatever you desire
Fit and glue fuselage halves together
1. Rear brace 20. Quick nuts
2. Motor mount 21. Wood screws #6
3. Rear bulkhead 22. Brass tubes
4. Forward bulkhead 23. Nylon bolts
5. Rear spar box 24. Nylon washers
6. top/bottom spar box 25. Rudder push rod
7. hood tabs 26. Padding
8. nylon screw capture 27. Bay window
9. Tilt mounts 28. Velcro straps
10. Tilt servo side left 29. Silicon tubes
11. Tilt servo side right 30. metal washer
12. camera mount 31. T-nut
13. pan mount 32. Wing screw
14. pan/tilt plate 33. screw (not needed)
15. Vertical camera plate 34. Elevator push rod
16. Plate tabs 35. Aileron/flap push rods
17. Bay sides 36. Push rod keeper
18. Bay hing 37. control horns
19. Fiberglass 38. clevises
39. Spar end tube
40. Dome
41. Covering
42. Spars
43. Tail boom
44. Spar joiner
45. short tail rod
46. Tail rods
.
.
.
A. Right wing
B. Left wing
C. Left spar cap
D. Right spar cap
E. rear fuse trim pieces
F. Vertical stabilizer
G. Left fuse
H. Right fuse
I. Horizontal Stabilizer
J. Hood
K. Servo cover
The main steps to building the wings (pictures coming soon)
- drill servo arms to fit push rods
- Fit and mount servos
- adjust servo arms for neutral point
- Fit spar cap
- Glue in spar cap
- attach spar capture tube
- install control linkages
drill servo arms to fit push rods
use a #50 or 5/64″ drill so the push rod will fit through
Fit and mount servos
fit servos
add extensions
run the wires and tack them down.
Fit spar cap
- notch spar cap to fit wires
Glue in spar cap
- coat spar with goo
- coat spar cap area with goo
- make sure to align end of spare with end of wing
- tape weight down spare cap, allow to cure
- finish edges with CA and kicker
attach spar capture tube
- Cut tube in half
- rough surfaces with sand paper
- mix JB weld and apply to spar
- slide on capture tube
- clean up excess
- allow to cure
install control linkages
attach control horns with CA and kicker
- assemble push rod and clevis
- adjust clevis so control surface is centered with servo at neutral point
- install push rods
This is the Construction manual for the techpod.
I will take you through all the steps for making your techpod kit into a high performance flying machine. The Techpod can be broken into a few major parts.
Nick Weber has been kind enough to make a few build videos
this is some video of me flying the techpod over 60 acres park. Sorry it is so burry the camera was not in focus and I didn’t have time to adjust it. I was running out of daylight.
It used about 0.75 amp hours of battery for about an 18 minute flight. The all up weight was 7 lbs. With 10,000 mah 6 cell lipo.
