Reptile500 – my new FPV quadcopter project

FPV flying is more and more fun for me. The X550 quadcopter does very well on this part with the MultiwiiPro board running MegapirateNG. But my problem is space for all the FPV equipment and the props, which blocking partly the view of the camera.

In my last post I was thinking about the Hobbyking H style frame and the SK450 conversion kit. The latter would convert the SK450 (a Flamewheel 450 clone) in a TBS discovery style quad. But it also gets a bit expensive, you also pay for a lot of parts you will throw away – as the are not needed after the conversion.

reptile500Too late I discovered that the Reptile500 could also be found in the Hobbyking online store. It has a similar, but not 100% same layout, like the TBS discovery and comes with DJI style flamewheel arms. The whole kit is about $22 and perfectly meets my requirements.

The weight is just 316g, thats a little 4g heavier than the X550 due to its fiberglass top and bottom plates. On the picture you might see the letters “FC” cut out of the top plate, in mirrored letters. Thats because the frame is assembled with flipped top/bottom plates. The chinese manufacturer made a mistake. When you assemble it according to the manual, the space for the FPV camera is left and the GoPro would sit right. That way, the GoPro lens (due to the fact that GoPro has its lens on its side of the casing) wouldn’t be in the middle – like you have it with the original TBS Discovery. So its wise, to flip the plates and to NOT do it according to the manual. It brings your GoPro into the same positions, like on the TBS Discovery.

Unfortunately, this frame doesnt have a built in power distribution, but most owners seem to be quite happy with it.

As my family will move into a different country in a few month, there is no real budget for my hobby. I decided to use most of the components of my X550. Exception are motors and propellers. I still have five Keda 20-28M with 1050kv . According to one rcgroups forum member, they produce 1KG thrust on a 10×4.5 propeller. On my DJI F450 flamewheel I am using the same motors with 8×4 propellers and they perform extremely well, giving me flight times of almost 10 minutes with 2200mAh battery.

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The disadvantage of these motors was, that I have to mount them upside down. So the shaft is pointing downwards. On the spinning bottom of the motore, a big alloy prop adapter needs to be mounted. Which is included in the accessories it comes with.  There is also a spare shaft included, but whoch is basically useless when you mount the motors that way. In a crash, the alloy prop adapter is very likely to be bent. That makes using this motor a kind of fragile business. But it is possible to “flip” the shaft and make it stick out on the top. So in the upper part of the picture, you see how the motor comes from the factory and in the lower part how it looks after flipping the shaft. I will use them without the mounting bracket and the weight with propeller is just 62.3g.

Mounting it that way makes sense and the 3.175mm shaft is really robust. I also have 8 spare shafts.

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I already got four 3.175 mm prop adaters and bought 9×50 GemFAN carbon fiber propellers. The shape is the one from the Graupner e-Prop, which is known to perform very well on multi copter. The price for all four was $23 USD in a local hobby store. There was a thread comparing them with the originals from Graupner. They GemFan carbon fiber props did very well, and even the flight time of the quad increased from 8 minutes to 8:30. I cant await to see my quad flying with them. I am hoping for at least 850g thrust.

Only thing I am waiting for at the moment, is the frame to arrive. This time I ordered from www.himodel.com. That was the first time I ordered from there and I was immediately impressed. Two hours after ordering, my frame was shipped and I received an email with my tracking number. About five hours after the purchase, I saw that the shipper (TNT) already picked up the item and it was on its way. With Hobbyking it can get frustrating. It usually takes 3 days after purchase, before its shipped. Often (strangely) another two days before some tracking information is available. If you order a larger item, it needs to be send from the main warehouse which takes according to Hobbyking 3-5 working days. My experience is, that it takes just for that additional 5-7 working days. Thanks to Himodel, I will have the frame within a week, instead of 3 weeks…

Just have to be patience for another 48 hours ;-)

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