Newbie Build - FT Style H-Quad

[Heppie]

My plan is to build a FliteTest inspired H-Quad and document the build from my multi-rotor novice perspective.

After deciding on this project my first purchase was 4x 18A Turnigy Plush ESC';s from eBay as they are the ones mentioned by FliteTest on multiple occasions. I was not planning on buying these at the time as I had not researched enough into what motors were easily available in the UK, but they were on an auction and they were going really cheap. So I put a cheeky bid of £25 and to my amazement won the set of 4 for £21 delivered! So only recently have I realised that the 18A plush';s may be a tad feeble, but hey ho lesson learnt I';ll just have to order in some blue wonders or Hextronik 24g';s.

Just ordered myself a Turnigy Accucel-6 charger and a Turnigy Nano-Tech 2200mAh 3S (and a charge bag of course) needed for my next post.

Next post will be opening up the ESC';s and flashing them with either SimonK or BLHeli depending on the chips I find

[Heppie]

ESC Flashing

For multi-rotor flight it is very important that ESC';s respond to throttle adjustments provided by the flight controller very quickly without any smoothing applied by the ESC firmware. Excluding newer multi-rotor oriented ESC';s, this means that the firmware needs to be changed on the ESC to a custom version suitable for a multi-rotor.

Silabs or Atmel? That is the question.

For those that don';t know Turnigy Plush ESC';s can either be powered by either an Atmel or Silabs micro-controller. Atmel versions can be flashed with SimonK firmware but Silabs have to be flashed with BLHeli firmware.

Which do I have?

As far as I';m aware most stock of Plush ESC';s are now Silabs, so buying new generally means Silabs. The only way to be sure though is to cut off the heat shrink and check the writing on the chip.

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As you may be able to see the chip has SIL written on the top meaning its a Silabs chip. To the left you can see the pads needed to flash the new firmware.

How do I flash the firmware?

I';m not going to go into too much detail on here as there are lots of threads on flashing ESC';s with multiple different methods. I am going to be using a Arduino Uno R3 as my programmer.

[teslahed]

You need to download the software and configure your arduino correctly in order to flash using that.

This guide may help;

http://flitetest.com/articles/how-to-flashing-blheli-firmware-using-arduino

Worst case scenario if you are based in the UK i can probably flash them for you for a few quid but it sounds like you';ve got all the necessary bits so good luck

[Heppie]

Yep had a look through them already and pretty happy with how to do it. The only issue I';ve encountered so far is getting the wires soldered on the pads, think I need a smaller tip for my iron. I';m tempted to make a clip from a peg rather than solder onto all 4 boards, good idea or not?

[teslahed]

Yeah any kind of adapter, possibly with sprung tips, would make the process easier.

[Heppie]

Small update:

Had another go at soldering the pads with different wire this time and had some success. The joints are not pretty but they are solid, most of the mess on the board is from the previous attempt and just needs some acetone. My only concern is that there may be a bridge between the pads so need to get the multimeter out.

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The videos I have seen show the 3rd wire can be soldered to the black lead of the servo wire instead of the hard to reach pad on the far left. I have chosen to use the same idea but use the servo connector instead.

[Heppie]

Small Update #2

Battery and charger finally in stock and dispatched from HobbyKing today so should be able to get on soon.

Big thanks to Philtrum for reserving me a Naze32 which I received yesterday.

When I opened the packet I was shocked at the size of the board, I knew it was small but didn';t think it was this small lol

[Hands0n]

ha ha - they are awesomely tiny FCs for sure.

[Heppie]

Received my battery, charger and bag so will be getting on with flashing the ESC';s soon. In the meantime I have populated the Naze32 board with its pin headers 

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[Heppie]

Since the last update I have now received all the parts I need to build my quad and have flashed my ESC';s. Didn';t take any photo';s of the process as it is already well documented. I have also soldered all the bullet connectors onto the motors and ESC';s again no photo';s. Next update will the the main build of the frame with lots of photos :)

[Heppie]

Right, today I finally had time to build my frame. I printed out the Flite Test plans for the centre plates and knuckles and stuck them to the plywood sheet with spray mount. I used a coping saw to cut out the parts as it is the only fine tooth saw I own, would have been better to buy something more suitable as the cuts did not end up as straight as I would have liked.

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After quite a long time and a lot of breaks due to numb hands all the parts were cut out ready for drilling.

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I was planning on drilling the holes with a friends drill press but I got impatient and did them all with a cordless drill.

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Now the end result is not neat and I was going to file/sand it all down but I decided that it was not worth it as it will be my first quad and will most likely get wrecked during its maiden. If it survives while I learn I will tear it down, sand and paint it.

The Flite Test guys use 4 x 10" lengths of square dowel, but they use their motor mounts which move the motor ~1" out either side. As I am bolting the motors onto the dowels I decided to make my motor arms 30cm (~12") and keep the connecting dowels roughly the same as FT at 25cm.

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After marking out all the holes required and drilling them it was time to see how straight I had managed to drill. Most of the plates went on fine, but a couple were out and required a bit of fettling. After tightening it all up I was amazed that the frame was completely level and square! It really does show how well this design works without the need for precision.

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[Heppie]

Cont....


To attach the motor mounts I had to drill out the holes to accommodate the 3mm bolts I have been using. I then added an ESC to test the placement.

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Right, question time.

The holes in the props I bought are too small to fit on the prop adapter, to make the one fit as in the picture I had to drill it out. Is this OK? or should I get some different props?

[dockman]

Looking good so far!

I am a fan of the h-quad design, should be a good starting point for you.