QA250 Build, lessons learned. Now with added maiden flight!

[ChavasRegal]

Ok so whilst the dart is out of commission waiting for a part to arrive from HK I made the decision to start my second and (probably) final 250 build, the reason being the dart was a means for me to learn about quads and the hobby and to get some experience in the building side before moving on to something a little more refined, hopefully this is it.

Build spec:

• QA250 Carbon fibre frame, with 3D printed Spacers
• 36mm Switched PDB
• Flip 32 Flight controller
• Emax 12A ESC
• Emax MT2204 2300Kv Motors


• Mobius Action Cam
• Boscam 600MW VTX

So whilst I';m still waiting for bits to arrive I thought I';d dry assemble the frame and see how things fit.

Setting up the PDB:
I wanted the PDB to fit between the two bottom plates but not be too close to the plate on the live side, some long nylon bolts and a few nuts later...

[attach=1] [attach=2]  [attach=3]

Flight Controller:
The nylon bolts I used for the PDB were just long enough to mount the Flip32 and still get a nut on

[attach=4] [attach=5]

Frame dry-fit:
The Spacers fit great and although my bolts are a few mm too long for the legs things are looking good.

[attach=6] [attach=7]

This is as much as I can do today hopefully there will be an update soon, thanks for reading

[ChavasRegal]

Stripping the ESC';s heatshrink to find a few shorted pins, good or bad?

[attach=1]

[tupoar]

All good mate.

[ChavasRegal]

Quick update.

Today I had a few hours to kill before the wife got home from work so spent it working on the quad.
I had previously mounted my motors to the arms and thanks to Phil';s great service my ESC';s arrived today   

ESC';s
I started by trimming off the heat shrink from the ESC';s and de-soldered the motor and controller wires.
I trimmed down two of the motor wires to match the ESC pads in an ABC configuration and the last two in a CBA configuration to give me two CW rotating motors and two CCW.

Measured out my signal wires and soldered three of the ESC';s with just the signal wire and one with signal, ground and v+ to power the FC and Rx.

I';d forgotten to buy some heat shrink large enough to cover the ESC';s but I found some 18mm in my kit which was a tight squeeze but I managed to get over the ESC';s 

[attach=1]

Arms
I laid my arms out in the correct order and soldered the power wires to the PDB.

[attach=2] [attach=3]

Because I';m using the spacer kit the screws supplied with the frame were too short so I installed the arms using M3x16mm machine screws, which were just long enough to catch the nylon on the lock nuts.

I wired up the RX and ESC wires to the FC so that I could power everything up and calibrate the ESC';s, to my relief no magic smoke escaped when I plugged in the LiPo

[attach=4] [attach=5]

The intervention
At this point the wife came home called me a looser and dragged me out of the man cave. 

[ChavasRegal]

So, its time to assemble the quad and decide where bits should go, one dilemma I have is with the size of the Boscam VTx its a little too big to sit inside.

[attach=1]

So I could sit it on the top cage, or I could sit it under the bottom cage, but the VTx position determines the location of the battery.

[deano]

That vtx looks a bit too big. Might be worth ordering a mini vtx

[ChavasRegal]

FPV Setup
OK after a bit of tinkering and moving bits around I came up with a simple solution, turn the VTx on its side the result is this.

[attach=1] [attach=2]

I';ve left the camera signal wires long as there is still the dedicated FPV cam to go on (which is on order) hopefully it will be here next week.

I still have the MinimOSD sat on my desk in its wrapper, but that can wait until my Overcraft Batch 4 PDB turns up.

[attach=3] [attach=4]

All in all I';m pretty happy with the build so far I even managed a little hover in the garden.   

[Paul01]

Slightly of the UK 25mW max too  ::)

On a serious note, does anyone actually stick to the rules with FPV transmit limits. Only asking as I';m just looking to get into FPV.

[quadfather]

So, its time to assemble the quad and decide where bits should go, one dilemma I have is with the size of the Boscam VTx its a little too big to sit inside.

[attach=1]

So I could sit it on the top cage, or I could sit it under the bottom cage, but the VTx position determines the location of the battery.

Holy..! That thing needs a trailer.

[bazzerh]

i had exact same vtx in same frame, i removed the rear uprights and then it sits in there ok. replaced the vtx for something a bit smaller now but still have uprights removed. its faster like that

[ChavasRegal]

Slightly of the UK 25mW max too  ::)

On a serious note, does anyone actually stick to the rules with FPV transmit limits. Only asking as I';m just looking to get into FPV.

I think the general consensus is that we';re not hurting anything on the 5.8Ghz spectrum having OP Tx';s and that the authorities probably wont have the equipment to measure the output out in the field anyway.

I think the only people we would annoy would be other FPVers who were on the same channel.

[quadfather]

Slightly of the UK 25mW max too  ::)

On a serious note, does anyone actually stick to the rules with FPV transmit limits. Only asking as I';m just looking to get into FPV.

If I understand the legislation correctly it';s 25mW radiated power.  Until someone actually goes and measures the radiated power of a VTX and it turns out to be 200mW+ I';m not too concerned.

[Paul01]

Thanks for replies, the main reason I';m being cautious is because I live next to GCHQ, otherwise I wouldn';t be too concerned.

[forest]

Nice m8.
I';m also planing my next 250 and built my pro250 as a training quad . I';m also choosing fpv equipment . It nice to follow your posts .its a massive amount to research ?

[ChavasRegal]

Nice m8.
I';m also planing my next 250 and built my pro250 as a training quad . I';m also choosing fpv equipment . It nice to follow your posts .its a massive amount to research ?

There is a lot of trial and error involved, I suppose it helps if there is someone  documenting their errors and ultimately their solutions, lf I';d known the Tx was this big I may have chosen differently. But for now it will do

Good luck with your FPV build.

[slurm]

If my first test flight goes to plan then I will be looking for a cheap fpv option. If I enjoy it as much as I think I will then I will upgrade

[ChavasRegal]

So its a little too windy (read blowing a gale) to maiden so far today so had a little tinker instead.
I';ve wired up some temporary LED';s until my strips arrive. I also did a DIY job on the camera plate to tilt the Mobius up a little, was a very complicated process that involved using two nylon nuts and bolts in the rear anti vibe balls to compress them a little to drop the back.

[attach=1] [attach=2]

All ready for the maiden.

[attach=3]

[slurm]

Well armed with 2 reasonably full batteries I went to a local empty playing field and fired my 250 up. After reversing the rudder she flew pretty good considering the wind and the lack of self levelling.

So when it';s calmer I will start to tune.

Was well happy to have her airborne for as long as I wanted, I won';t mention the broken prop on the first up.

Anyone got good settings for the kk mini please pitch in.

[ChavasRegal]

Glad it went well for ya, I';ve stopped counting props as damage now hehe

[Paul01]

Watched a bit of the Flight Test vid the other day with Charpu, and they all found it funny when they found out Charpu always carries a rucksack full of props only 

[forest]

cool what tx would you use if doing over again chav?   and what leds have you found for it ? im after knowing the brightest ones , the strips ive got  so far are not bright enough, that two lots now ive bought and not good enough do you know how to tell what ones are what?

looking good bro

[ChavasRegal]

cool what tx would you use if doing over again chav?   and what leds have you found for it ? im after knowing the brightest ones , the strips ive got  so far are not bright enough, that two lots now ive bought and not good enough do you know how to tell what ones are what?

looking good bro

I';ve been put on to this little Tx, requires a little soldering, you need an RP-SMA/SMA edge connector and a surface mount dip switch both are a few quid each.

The LED stops I';ve chosen are these, they can be cut down in to sets of 3 LED';s run off 12v and are self adhesive. 

Hope this helps.

[ChavasRegal]

Maiden flight

Finally got out and maidened the quad, the weather wasn';t ideal as it was blowing a gale, see the results below :)

http://youtu.be/M71gcb2jfHo

[Balders]

Managed to maiden mine today funny enough.  My CC3D had been badly drifting to the right, but after a quick google, someone reported vibrations causing that drift.  I hadn';t balanced the props up until that point and found two of them to be wildly out, must have been vibrating it';s proverbial teeth out.

Anyway, props balanced, test flight was a revelation...felt locked in straight away.  Here';s a minute of mobius action:

http://youtu.be/jyE0MhMjqAE

[ChavasRegal]

Nice one Balders,  was far too windy today for me to do any tuning, but think it flew well considering.

Here is footage the wife filmed during the maiden.

http://youtu.be/3ge0qqV4HZA

[slurm]

chavas, I read your chat msg about being excited, it is a funny thing, I know what you mean.

Anyway nice flight, is the camera that';s running your fpv better with light to dark transitions than the Mobius?

[ChavasRegal]

Yeah nerves, what';s that about? I';m currently using the Mobius for FPV as my cam hasn';t arrived yet, but from what I';ve heard its quick with the transitions, I';ll post an update when it arrives :)

[slurm]

its just that as you move against the horizon, its goes horribly dark for longer than I would like, I don';t have a clue about cameras but it was quite a surprise to me.

[ChavasRegal]

Yeah that';s the Mobius, hopefully the FPV cam wont do the same.

[Paul01]

I have just got this camera and its works very well with low light and changes.

http://www.aliexpress.com/item/Free-Shipping-New-Hot-HD-700TVL-Sony-CCD-PCB-Board-Camera-2-1mm-Wide-Angle-Lens/32271293903.html