Banggood C1 Chaser Wing
|Small Package - Big Fun!|
Another wing! I was looking for something smaller than the FX-61 and easy to throw in the car or on my FPV backpack. A fellow RCGroups poster brought this up in a post so I checked it out and was pleasantly surprised by what I saw. It is basically the "missing link" between the 1550mm FX-61 and the 800mm WingWing Z-84!
So I ordered the kit and was again very pleased with the plane itself when it arrived. It has some great features like bottom mounted servos with through-wing accommodations for top-side linkage. This keeps the weight low in the airframe and also keeps the linkage from snagging on grass or weeds when landing. It has two different nose pieces, one for a camera and one that is just solid EPO. The Hatch has a front key to hold the nose down and two snap in hold downs that seem to work very well. It also comes with a nice low profile tow hook and skid piece. All in all, some nice improvements over the FX airframe.
Distributor - BangGood USA
Aircraft - C1 Chaser Wing
Build Date - January, 2017
|Airframe Type -||Wing - FPV Specialist||Flying Type -||Powered FPV Glider Wing|
|Wingspan -||47.25 inches (1200mm)||Length -||19 inches (483mm)|
|Wing Area -||2.80 ft^2 (26dm^2)||All-Up Weight -||29.2oz (829g)|
|Motor -||Cobra 2213/22-1100kv||Wing Load -||10.4 oz/ft^2 (32g/dm^2)|
|Propeller -||8 x 6 Graupner Folder||Max Motor Power -||276 watts|
|Static Thrust -||32oz (917g) @ 2550ft ASL||Static Thrust/Weight -||1.11:1|
|Battery Type -||4S1P LiIon||Capacity -||3500mah/3C|
|In flight efficiency -||~100mAh/mile||Flight Time -||Up to 56 minutes|
Wings & Fuse
Pretty much a straightforward build. No decision whether to make the wings remove-able or not. The elevons are dense enough to use the stock control horns and when it is all glued together it seems quite stiff.
For glue I use E6000 which is similar to UHU POR and Zap Goo. It has a 24 hour cure time which really should be followed and it is very strong with EPO foam. The following list are key points to my build:
- The stock motor mount is garbage (like the FX-61) so I designed up a 3D print version
- Laminated the leading edge with 50mm wide strips
- Laminated the wing joins with 80mm wide strips
- Put three blenderm tape strips on each elevon
Like the FX-61 aluminum mount I designed, this 3D printed motor mount moves the motor back a little (5mm) to accommodate a folding propeller and to quiet the prop noise a bit. I also added "nut wells" to hold four nyloc hex nuts to make installing and removing the motor that much easier.
|Prop clearance difference|
Canopy & Camera Mounts
For the initial camera mounts I copied, in part, the mount I designed for the FX but smaller because I planned on using a very light Mobius Mini for HD and a Fatshark 700TVL FPV camera. Once I get the plane all sorted out and dialed in I will move the FatShark FPV camera into the nose to get it out of the airstream.
Controls and Linkage
For this build I decided to use some small digital servos, the Turnigy D561MG Coreless servo which weighs 7.5g and makes a respectful 1.2kg/cm with 5.2v. These may be a bit undersized for this wing so some flight testing will be in order.
On the linkage parts I am using the stock control horns with 2mm link wires, Dubro 2mm ball joints and 2mm Qwik-Clips. I use the ball joints anytime the linkage is not perpendicular to the control surfaces. This is the best way to deal with high linkage miss-alignment.
Battery, Motor & Prop
For a pack I decided to use Li-Ion which I already had. To begin with, I chose a 3500mAh/4S1P pack of NCR18650GA cells. These are very good cells with decent charge cycle life and a max continuous current rating of 10A. The burst rating is 18A for 12s.
I am also starting with the Cobra 2213/22-1100kv motor because I am a Cobra fan and it seems to fit (on paper) very well for this weight and size airframe. I also have a Cobra 2213/18-1350kv that I will set-up for longer flight times on 3S at some point. A 3S2P, 7,000mAh Li-Ion pack only adds an additional 106g. Both motors are exceptionally smooth and light.
For a propellor I chose an Aeronaut Cam Carbon folding prop. With the motor and pack selection I will use an 8x7 blade set on a 38mm center piece (yoke). Below is a simple set of static tests of both motors with four different props. If you do your own testing your results will be different! I live at 2550ft ASL (777m) so these tests reflect this altitude and a rather warm climate.
It should be noted the current values shown in yellow highlight are over the motors design limits for continuous operation. The yellow highlight with red denote a severe over-load (over-prop) and should not be used. In the case of these two Cobra motors, the 30 second max current value is determined by an ROA (rise over ambient) heat test.
Gear Layout & Flight Controller
Because it is a small plane, care must be taken to get everything in the right place so that the plane can be balanced without adding weights. To do this I designed a 3D print gear deck and corresponding deck mounts. I also printed up a small bracket to attach the BEC and ESC bits.
|Gear Deck, Bracket & Motor Mount|
My initial pick for a flight controller was a Pixracer Pixhawk derivative. The folks over at AUAV.com are the principle purveyors of this unit but were out of stock so I opted for the Banggood copy. This was a mistake. After spending hours working to get this unit set-up on APM 3.7 I finally got a chance to fly the maiden flight and it did fly very well. The problems then began again with it not being able to initialize unless there was power to the USB port, continuous AHRS and Baro problems and a general distrust of its reliability.
I have now replaced the Pixracer with an APM Mini 3.1 which I have used before. Like all the APM 2.6 clones these are essentially bulletproof with the only caveat being the crappy (IMHO) wire connectors.
|APM Mini mounted on gear deck|
|Gear deck bottom view|
|5v BEC, 12v BEC and LC filter|
- Changed from a Pixracer to an APM Mini 3.1 (see above)
- Changed from the APM Mini to an Omnibus F3 flight controller with iNav because it is lighter and simpler with an on-board OSD.
- Changed (again) to an Omnibus F3Pro flight controller to get rid of the need for a separate BEC and to have an on-board current sensor.
|Omnibus F3Pro flight controller|
- Added a Matek 4S/12v/300ma regulator to run the 200mw 1.3G VTx. This regulator weighs 1g.
- Added a Diatome 4.2v regulator to power the Mobius Mini. MM is damaged and needs its own regulator.This regulator weighs 1.2g.
- Changed the prop to an 8x6 Graupner Cam Carbon folder which launches better and is slightly more efficient.
Below is the C1 Chaser maiden. It was a beautiful 65F degree morning at Eldorado drylake and wind was near zero. Had a couple minor issues with the OSD (now resolved) but all in all, a very successful maiden.
She flew beautifully and can't wait for the weather to get more flyable so I can do some real shakedowns.
Maiden Day - 24 September, 2016
Project 3D Print Files
Print files can be found on Thingiverse here - C1 Files
Some Vendors used for this Project