A new quad: SCX200 Buildlog – The parts

Buildlog, Multirotor, RC

It’s time to build a new quad!

Even though the HMB-235 has served me well and it’s still flying pretty well, I decided to build a 2nd quad. One of the reasons is to have a spare quad if 1 breaks in the field. Nothing is more frustrating then driving to a spot for an hour to go fly with some friends, only to break something in a crash on your first lipo and can’t fly anymore.

Apart from that I am starting to notice the downsides from the HMB-235’s frame; The arms flex in a hard crash so they don’t break, but since they usually flex inwards, the props tend to hit the ESC’s a lot. I have already lost 2 ESC’s to propstrikes, even tho they are protected by some tick heatshrink, some tape and some tiewraps.
The quad is also quite large and heavy, which wasn’t a problem at all when I just started  to fly, but I can certainly feel the weight and lack of power now.
When I was flying with others, their quads just have sooo much more power and can do much smoother acro manoeuvres.

The HMB-235 will still be my ‘indestructible’ backup quad for races or parking garage flights, but it’s time to build something better, faster, stronger [Daft Punk Pun totally intended].

So it was time to hunt for parts again!

IMG_20160819_162723

Frame: SCX-200
Motors: EMAX RaceSpec RS2205  2300kv
ESC’s: Racerstar RS30A V2 30A Blheli_S
Flight Controller: Motolab Cyclone F3
VTX: Foxeer 5.8G TM25 Switcher 25/200/600mW (40CH)
VRX: Skyzone RD945
FPV Camera: Foxeer XAT600 600TVL
OSD: Micro MinimOSD with KV Team mod
RX: Corona R4FA-SB

Other misc parts:
L-C Power Filter
FOXEER 5.8G Circular Polarized RHCP Antenna

While looking for frames, I wanted something small and light, but sturdy enough that I don’t have to replace arms all the time. It had to be able to swing 5 inch props, but I wanted to keep the size as smal as posible. Eventually I chose the SCX-200. It has 4mm arms, a nice formfactor and it looks really cool 😉
The 1 thing I am not that stoked about is that the integrated PDB is a structural part of the frame, but armattan has a good track record for making awesome frames and I hope it will be fine. It does make for a very tidy build and since there is very little room in the frame, it will be a great space saver.

I decided to go for the same motors as on the HMB-235, since I already had some spares lying around (including spare C-clips and bearings) that I could use. They aren’t the absolute best motors on the market anymore, but they are still very decent motors.

For ESC’s, I initially wanted to buy Littlebee Pro’s, but then I ran across the Racerstar RS30A ESC’s. They seem to be identical to the Sunrise Cicada ESC’s, which are known to be very solid ESC’s, and at under €12 each, they are very affordable. They also run BLHeli_S, which was a must for me. I could have gone with the 20A versions as well, but the difference in price, size and weight with the 30A was so small, that I got the 30A versions. This will also give me the option to upgrade my motors to more powerful ones later if I feel the need to so do.

The choice for the Flight Controller was quite easy, the Motolab Cyclone F3 is a very popular FC with all the right specs to make it almost perfect for me. The only thing it’s missing is some onboard flash or an SD-card reader for blackbox logs, but for now I will have to live without that.

I decided to go with an OSD for this build for cost reasons. The cheapest Futaba RX with telemetry is over €90, since no 3rd party manufacturer is making them. The official RX’s are also very bulky and heavy. I could have de-cased and de-pinned one, but that still leaves the preposterous cost of the RX. Besides that, I would only have battery voltage telemetry, since Futaba telemetry is not (yet) supported by any flight control firmware. So I went with a cheap and small Corona RX and a micro minimOSD to show me my telemetry on screen.

The FPV cam has not changed. The Sony HS1177 based camera’s are the industry standard and for €35 you can’t really get anything better. An alternative could have been a runcam owl or eagle cam, but they are more expensive and the daylight performance is identical to the 1177’s. It also allows me to use the same modded OSD cable to set up the camera as on the HMB-235.

As for other parts, I did decide to add an LC filter to the setup to go in between the PDB and FPV system to minimize any noise on the FPV feed. My old VRX exploded a couple of months ago, so I had already changed that to a new one with diversity. At around the same time I got some new antenna’s for both my quad and the goggles since the old ones had all been damaged in crashes. I got some of the cheap, but excellent Aomway cloverleaf antenna’s and a pair of FOXEER 5.8G Circular Polarized RHCP Antenna’s. The difference in reception was huge, I could easily fly 3 times as far away as with the old shitty ones without any breakups.

Leave a Reply

Your email address will not be published. Required fields are marked *