2 replies to this topic

[Mr.RC-Cam]

There are a number of inexpensive DJI style Quadcopter frame kits on the market. I decided to purchase a few of the 450 size frames, check out the quality, then build the one that I liked best. So I ordered these:
HobbyKing Q450 Glass Fiber Quadcopter Frame 450mm, $11USD + shipping
HobbyKing Hobbyking SK450 Glass Fiber Quadcopter Frame, $17USD + shipping
DealExtreme HJ450 Multi Flame Wheel Flame Strong Smooth MWC Quadcopter Kit, $28USD (with free shipping)

First, let me say that the prices are so low that keeping spare parts on hand is as easy as buying an extra kit. And the low prices are competitive with DiY Quadcopters frames made from aluminum towel bars and hobby plywood. So unless you need a special size model, these low price kits are a convenient solution.

As soon as the kits arrived (about one month postal shipping time from China) I did an inspection of the parts in each box. The HJ450 had an arm with one missing brass nutsert, which is a minor nuisance. I discovered that the Q450 and HJ450 were made by different Chinese companies but had identical parts. So they both appear to be copies of the same DJI model. I'm not a DJI expert but I read these are clones of DJI's first generation 450 frames.

They all looked nice, but I decided that the SK450 was the best choice for my new build. It is similar to the other two kits but its parts are not the same; So this kit must have been copied from a different model (this Hobbyking kit seems to be exactly the same as the one sold by Tarot). The SK450 got my attention because I like the removable landing feet (which mount to the motor arm with two screws) and the fiberglass motor mount plates. The plastic parts were well made and the bag of hardware looked complete.

I finished the build this week and here's what she looks like.

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Edited by Mr.RC-Cam, 21 June 2012 - 07:54 AM.
Added info about Tarot.

[Mr.RC-Cam]

Total AUW (with battery and FPV system) is 37 ounces.

Here's the main parts list to the new model:

• Frame Hobbyking SK450 Glass Fiber Quadcopter Frame, $17US
• Brushless motors: 2208x2208-17 Outrunner / 1100KV, 84hobby.com ($10 x 4)
• ESC's: HobbyKing 20A BlueSeries Brushless Speed Controllers ($9.50 x 4)
• Props: 10 x 4.7 (APC LP10047SFP and LP10047 ($3 x 4)
• LED's: Red and White LED strips, hobbypartz.com ($4 x 2)
• MultiWiiCopter Controller: GoodLuckBuy MWC Controller Board, $33
• Sensor Board: Custom designed 10DOF IMU-X board (described in this post).
• Flight Battery: 3S 2600mAH Hyperion VX G3, 35C

I pulled off the heatshrink on each ESC, soldered five wires to their tiny solder pads, and reflashed them with SimonK's ESC firmware.
https://docs.google....dBQkZZRlE#gid=0

The ESC reflashing task used the popular FlashTool, which is a nice way to do it:
http://www.rcgroups....d.php?t=1577773

LED strips are installed on all four motor arms. White up front, red in the rear. They are controlled by some custom software I wrote for the MWC. Details on the hack are explained here:
http://www.multiwii....php?f=15&t=1198

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[Mr.RC-Cam]

The FPV video Tx is a DiY 5.8GHz 10mW module. It works great in the small fields I fly at. With a Bluebeam (Skew Planar Wheel) antenna on the video Tx, and a circular polarized patch on the Rx, the video quality is awesome (MUCH better than with dipole rubber ducky antennas). This antenna combination eliminates the multi-pathing interference I normally experience and it is highly recommended on 5.8GHz FPV video systems.

But getting to the main point, the model had its maiden flight today! It is very stable (I'm running MWC V1.9 release 3) and has ample power. I get 10 minute flight times on my 3S 2600mAH Hyperion VXG3 packs. I can easily see this one becoming my favorite FPV Quad.