Newb Q800 Build

Build Log
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I will post here my progress building the Q800 Hex. Being a complete novice in the multicopter scene it might highlight a few ‘issues’ that the more experienced out there would sail through without thinking.

I don’t have any pictures yet but will come back and edit the post as I get time and inclination, in the mean time I will steal the ones from the shop.

So options I have gone for for this build…

Q800 Carbon fibre frame
FY G3 Brushless gimbal - This is a great little gimble for gopro :wink:
880kv motor, 30A ESC, 12" Prop set - Couldn’t decide between 850 and 880 so it was one potato two potato :smiley:
Hex Wiring harness
Pixhawk APM
Ublox GPS with Compass
3DR Telemetry
Fatshark Attitude FPV
3 Channel Video switch - Might not use it but while throwing money away like water I bought it just in case.

The first thing I did was to assemble the FY G3 gimbal, it is really pretty straight forward and the only mistake I made was putting the lower board on back to front… Just look closely at the picture to get it right way round.

I stuck the gopro in it and plugged the gimbal into a 3s pack and it worked a treat, does not come much easier than that I have to say. How easy it turns out to be to get it tilting under radio control remains to be seen…

Next up I built up the frame and so the first warning… DO NOT START ASSEMBLY UNTIL YOU HAVE THE MOTORS! also do not assemble all 6 arms as per assembly guide, two of them need to be passed through the holes in the fuselage strut before you fix the Arm Mount on otherwise you cannot get the strut fitted. The round hole in this part :wink:

Before you assemble the arms there are some parts not detailed in the assembly guide which fit into the ends of the arms to prevent the tube distorting when you fit the arm mounts and motor mounts.

Of course I stormed ahead, assembled the entire frame and then realised I had two bags of bits left over, after a bit of head scratching realised they need to be put in the ends of the arms and so had to dismantle the thing again to put them in and then reassembled the entire frame feeling rather chuffed with myself at the progress I was making.

Of course at that point I did not have the motors but I figured I would just slide the wires through the tubes easy enough when the motors arrived… That plan would have worked absolutely fine had it not been for the paragraph above, with the inserts in the end of the tubes it is all but impossible to thread the cables through with the arm assembled ARRRGGGHHHHH

So dismantle frame yet again, and the arms, fit motor into motor mount, thread through first insert and attach motor mount to arm end, pull cables out of other end, slide insert over cables and into arm and attach the Arm mount…

While on the subject of motors, another thing to watch out for is the circular motor mounting plates - They need to be fitted the correct way up onto the motor. If you get them upside down the cable does not exit the motor in line with the arm (between two screw holes), it exits over the top of one of the motor mounting plate screws. If you look closely at this picture you will see that the motor mounting holes in the middle line up differently with the plate mounting holes on the top and bottom plate compared to the left and right - two are upside down two are not.

It never occurred to me that it would make a difference which way up they are until I realised that the first 3 motors I fitted the cable was not in line with the arm but the 4th motor it was. So, take first three motors off again and flip the mounting plate over to sort that out.

As I fitted the motors I checked they turned freely, and motor number four did not. It was not locked but you could tell it was not completely free running like the others. I thought maybe the screws were too long but eliminated that as a cause, it turned out the hole in the middle of the plate was just a gnats whisker too small and the circlip on the motor shaft was snagging. I just used the dremmel to open up the hole a tiny bit so the clip could freely rotate and everything was fine.

Also one of the motors the prop adapter would not fit, the little grub screw in the motor case was sticking out just a tiny bit but enough to prevent the adapter sliding on, so I took the grub out and using the dremmel with a grinding disk I shaved off a tiny bit of the end of the screw - the outside not the inside - it was only a tiny sliver so did not affect the hex key fitting in. That done the adapter slipped straight on no bother.

With this final re-assembly (well I hope it is the final one) I decided it would be best to thread lock the screws, with six motors spinning 12" props there is bound to be some vibration so I figured that would be a good idea. Also the 4 folding arms are simply pivoting on the little 3mm screws or whatever size they are, threadlock should help them not to work themselves lose too easy, that seems like quite a poor design to me but I guess time will tell.

I could not resist putting the props on to get an idea what it will look like, it looks much, MUCH bigger than I thought it was going to when I first opened the box! For amusement I sit here attempting to land the Hubsan X4 on top of the Q800 canopy :smiley:

So that is progress so far, next up is going to be fitting the electrics, still waiting on RX but that should be here tomorrow so day off today :smiley:

1 Like
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Couldn’t leave it alone I am afraid, so decided to fit the ESC’s…

What a game that is! Like a bloody mensa test that is! There is not a lot of room to squeeze six 30A ESC’s in the main frame, and when you have 18 bullet connectors, six sets of Deans connectors and all the associated plastic covered copper stuff its a fair old lump.

So I mounted four underneath the Hex and two inbetween the two plates that make up the body. This pic shows the four on the bottom surface, and arrows indicate where the other two are inside the body.

The ones inside are mounted back to back with the two on the bottom, this pic shows a view through the front of the body to show the one inside…

The two back to back ESC’s are tie wrapped using a single tie wrapped around both of them, I may have to re-think this idea at some point but it will suffice for now.

The space in the middle of the hex is pretty well packed as you can see in the next photo, with hindsight I think maybe a distribution board with the power lines soldered but that is more a permanent solution and being new to the game I am not quite ready to make it permanent yet :smiley:

I think it would maybe have been a neater solution to mount the ESC’s out at the motor mounts, they would not fit in the cages but could be tiewrapped underneath I think. Again this is something I am thinking about but at the moment I am working with as much ‘Plug and play’ as I can.

The power connector of the power harness is on top because (a) I have to remove the Deans and fit an XT60 connector to link into the power module, and (b) I will maybe be making a Y harness to go to the battery, or rather batteries as I may end up using 2 x 3s in parallel. The upshot of that will be the power module will tuck in the space in the middle out of the way.

Of course I have now realised I don’t have anything to mount the batteries with, I have the two accessory hangers so I think I will have to grab a couple of slotted Stack ups and another set of hangers to make two battery carriers which can be slung underneath behind the gimbal.

Anyway, that’s a bit more done, slowly slowly catch the birdy :smiley:

3

More progress made, nearly there now actually, just waiting on hangers & slotted stackups to make battery holders and we are nearly ready for ‘Thunderbirds Are Go’

Well another lesson has been learned the hard way, if you have never built one of these things take note… When you assemble the thing and put in the ESC’s mark up the arms with the rotor position numbers AND make sure to mark the corresponding ESC signal wires as well. Yes, I had to remove the central stack which I had mounted everything but the radio on in order to pull out all the power wiring to figure out which servo connector was which arm - Doh, Doh, Doh

Anyway, during that little distraction I decided to alter the central stack so all was not lost. I originally had the Pixhawk on the bottom level and reading a few posts kicking about it seems it is probably better to distance the Pixhawk from the black and white electro magnetic spaghetti which is my power wiring, so I put an empty layer in the bottom, then the pixhawk, then the GPS/ compass on the top of the stack.

As you can see in this picture of the rear view I put the RCRX on the top level with the GPS, I was going to put it in the bottom empty level (and still may do) but as the RX has not been bound to the TX yet I will need to be able to access the button.

The RX antenna are sticking out to the front from the stackup plate arms at 45 degrees to each other, I assume this will suffice but if anyone has a different opinion please enlighten me.

You can also see the 3DR Telemetry Radio mounted at the rear, I left the case on for the few grammes it would save but in time it may get stripped out to fine tune flight times :smile:

That is the front head on view where you can see the bottom level is empty, for now at least. The buzzer is mounted there as you can see but I may move that to the bottom of the frame so it is more audible when flying.

Just for completeness here is a left and right view showing my tatty untidy wiring…

It is quite embarrassing really given that I am, or was until I decided to start my own manufacturing business, a fully qualified electrical engineer creating things like this…

Wiring in washpactor panel

So, all bar the shouting that is the Hex built I think, like I said just the battery holders to make, oh and the Y power lead or at least a straight power lead extension XT60 to Deans converter.

If anyone sees any mistakes among my creation so far please do poke me in the eye and let me know :wink:

4

Looks like a great build so far with great photos!

I was going to say its quite abit neater than some I have seen :smile:

My only comment is that carbon fiber tents to block some RF signals, so if you plan on flying high and far away you might want to move your receiver antennas so they hang of the side more, but for general flying within 500m I am sure the current location will be fine.

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That looks like behind my computer desk!!!

I think when I have bound the rx and everything is ready I might move the rx and antenna as you suggest.

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I guess the ideal thing would be to stick the antenna out of the bottom, its rare that the hex would be flying lower than the TX :smiley:

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That’s fantastic Louise, very interesting. Thanks for posting.

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Here is my work in progress Tarot 650.

Just managed to get the TBS esc’s sandwiched between the frame plates.

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Nice :smile:

I was looking at a Tarot myself but decided on the Q800 in the end. I do like the landing gear on the Tarot though, to be honest I think the Q800 landing gear is the weakest link so to speak and that is without the battery, gimbal and gopro yet - then again I could be over thinking it so will just have to see how it goes in service.

I seem to think I have seen the Tarot landing gear sold separately somewhere, I wonder if its possible to fit that to the Q800? How is it fixed to the frame, any chance of a close up :smile:

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I spy a big jar of tie wraps… I have a bag of 10000 of them LOLOL I could build a hex out of nothing but tie wraps and still have some left over for cables :smiley:

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Well thunderbirds nearly went, nearly went out the window!!!

All the electrics/ electronics fitted, firmware loaded - that is quite a vital step that one, doesn’t matter how long you sit and look at the rapid flashing safety switch scratching your head and repeating over and over again “What the hell is wrong with you bloody hexapest” it just will not arm until you load a firmware :blush:

Once the firmware is in it makes it a lot easier to do the rest, trust me :wink: So calibrate rc, calibrate accelerometers, calibrate compass - telemetry saved my sanity trying to spin the thing through every conceivable axis and direction without wrapping the entirely too short to start with USB lead round everything including myself.

Then the fly in the ointment, ESC calibration… What a bleeding nightmare that was, not helped by the fact that it did nothing like it says it should in the ESC calibration page in the wiki, well that’s not entirely true because it does similar things but in a completely different order!

I tried a umpteen times, nearly threw the thing out of the window, one motor was not turning at all, eventually it seemed to work and the non turning motor started working, when I armed the thing the motors spun and after about 3 seconds slowed down and stopped, read the esc programming pdf for the multicopter ESC, cross reference it with the wiki instructions, try again and a different motor stopped working… AAAARRRGGGHHHHHH bloody AAARRGGGHHHHH how could it do this to me at this stage for crying out loud, if I had a shotgun licence it would be history!

So I gave up and decided to try the manual calibration method which is apparently untested with the pixhawk, might have known really, so yank all the esc signal leads out of the pix and one at a time calibrate using the rc rx channel 3. Plug everything back into the pixhawk, arm it and motors don’t spin but do start up with throttle input. So spend 3 months looking through parameters trying to find something that could cause that besides the obvious one which was set to 70 anyway and nothing. In desperation I jump back into radio calibration page again and run through that again and everything works

Happy dance, happy dance, whoot whoot…

So, being an idiot an all I decide to see what will happen with a bit more throttle, maybe a tiny little hop in the living room, I am now fully qualified in the indoor flying thing because I have had the Hubsan x4 for 3 days :smile:

Well not so much a little hop as nearly bounced its way out of the window! the arms where rattling about like my old automatic washing machine with a dozen bath towels in it, scared me half to death! Of course I never balanced the props but still, this was seriously nasty vibration, really serious.

So take a prop off, find the prop balancer buried in gawd knows what rubbish in a corner and check the thing. Now no disrespect Unmannedtech, but I have had some rough props in my time but I have never in my life come across anything so badly balanced in my life! OK the epp props are cheap and if you pay peanuts you get monkeys n all that but man these are seriously rubbish! I had to cut a lump off the end of a blade with scissors and then sand off so much material I seriously wonder if there is enough left to make them structurally sound - I am not joking, they were THAT bad. Unless the ones I got in the motor kit were just a crap bunch I think really you would be better selling none at all that those!

Well, that’s my rant over, almost, OK £3-95 for a set of two props expecting them to be great props is a bit much but still, come on… Right, rant over now, tried again after balancing as best I could and as you can imagine a HUGE, MAHOOSIVE improvement, unfortunately the stuff to make battery holder is not here yet so 4ah 3s lipo was dangling on its power lead from one side and clearly not helping the centre of gravity a whole bunch but it did just get off the ground a tiny bit so I am well chuffed :smile:

Now while I wait for the postie with the stuff for the battery hangers I will pick up all the letters, invoices and assorted litter which has blown all over the room due to some muppet firing up a hexacoper in the house.

Just one thing… when armed the hex disarms its self after about 10 seconds with no input, the IRIS it is about 20 - what parameter controls that delay because it is just a touch on the short side I think?

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Bloody hell Louise, what did the cats think of that whirly gig taking off in the house,lol.

Here are a couple of pics of the, well, foldable landing gear rather than retracts.

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Looks like it could be possible, I was thinking folding rather than retracts anyway.

The cats were not entirely impressed, I think Toshi thought it was Hubsan X4 big brother come to get revenge on Toshi for knocking him out of the sky several times LOL

On the plus side, he has not as yet chewed the ends off the props like he did with the IRIS LOL

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Well its built, battery hanger done but I really need to stick some none slip rubber on it and make a bigger velcro strap when I find my sewing box but that is it ready to start trimming and such like.

Really busy work wise now so not sure when I will get chance to do that, and of course free time has to coincide with wind free day too, but when it does all systems are go.

Without the gopro, but with gimbal and 4ah 3s battery the all up weight is 2.02kg, that is excluding FPV but that’s only going to add about 60g I think. Quite an impressive looking bit of kit now, I might have to hang it from the ceiling as a feature :smiley:

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I don’t believe it, Just got up to find two props eaten. The bloody cat is insane, completely and utterly insane, once more and its vet dentist to have his teeth out!!!

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:smile: I guess one thing with cats is that they usually can climb on things so your props are not safe anywhere!

Which props where they? I can send you another set if you want?

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they were only the cheap things that come with the motors so its not a problem, I was intending to get something better anyway…

I might order the cf ones when I get chance - at moment I am trying to find out why I have an arm failure on radio failsafe grrrrrr

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I see on the shop site you only have 12x6 props in CF… Are they suitable for the 880kv motors? being a greater pitch and all…

Oh darn, just noticed only 1 set available :frowning:

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Yes you can use those props with the 880Kv motors, should have some more in stock of the props in a couple weeks (factory is is closed for Lunar new year holidays)

But for now if you want, I have a couple of 11x50 CF props that we received as part of a sample if you would like them for your hexa? Hopefuly your :cat2: will not like the taste of carbon fibre :stuck_out_tongue:

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he hasn’t eaten the 10 x 4.5’s carbon fibre ones I have sat on the floor so fingers crossed he doesn’t.

There is no rush, I will wait till they are in stock then I might get some work done instead of playing with multicopters LOL