Y6 build(s)

[Damian Axford]

Inspired by Rob's Y6, I've started converting the hex into one...  so far it's just some carbon tubes cut to length and motor mounts:

onto designing the body plates...

[Damian Axford]

After testing the body plates last night - there were just too many little things wrong to continue with them, so - stayed up late and finished tweaking the designs which are now printing.   Prior to that, I got the legs printed and the battery brackets.  The legs, based on 3mm solid carbon rod, actually work!  They are a bit ungainly at 300mm long, so will probably reduce to 250mm or even 200mm.

Also finished tweaking the shell design - will hopefully print that tonight.  Latest CAD:

[Robert Longbottom]

Nice.  I might have to look into making a lid for mine.  Though I do like the raw-see-the-electronics look :-)

I'll have to look into folding arms as well now I've seen how neatly yours folds!

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[Damian Axford]

Made a typical after-midnight decision and ordered one of these:

https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=63646

On backorder, but hopefully will arrive within a month or so.

:)

[Robert Longbottom]

And you're going to fly that massive y6 with those!!!!  Brave man, I'll be in the bomb proof bunker.  :-)

[Damian Axford]

:)

[Damian Axford]

mk3 top plate printing....

hope this one works - then I can get on and print the shell :)

[Damian Axford]

Good progress last night - got the body re-assembled, legs fitted, etc and the shell printed over-night - pics below:

rambling:

• Shell clearly needs cleaning up - the support material didn't break away as cleanly as I'd hoped, but I'm sure it'll sand/file down
• I've reduced the leg length to 200mm - they seem stable/strong enough now
• I've braided the motor wires to keep them as neat as possible, will try and wire up the ESCs and power distribution tonight
• Not happy with the electronics layout yet - too cramped.  Think I'll move the 3DR radio to the underside and perhaps raise the height of the shell by 10mm
• Folding arms have a more solid lock now - tweaked the body plates to grip them tighter

Overall though - looks awesome, feels fairly strong/light and the folding arms work really well :)

Hope to be test flying in a few days...

[Robert Longbottom]

Looks very nice.  I'm going to have to print me a top cover :-) Though first I'd have to move my fpv gear because it overhangs my main plate.  Hmm.  Body redesign time!

[Damian Axford]

Need to make it fold too :)

[Robert Longbottom]

Yes, I think Ill have to have a body redesign to make it fold and have a
nice shell. I want to fly it some more first though :-)

On 13 March 2015 09:52:49 Damian Axford <dam...@axford.me.uk> wrote:

> Need to make it fold too :)
>

[Damian Axford]

Lol - sounds reasonable :)

[Damian Axford]

Printed parts done, ESCs temporarily cabled in...  now to solder in a battery monitor and start configuring the APM :)

Weight, including 5000mah 4S battery, is just over 1.8KG - props will probably take that to 1.9KG. 

If everything works ok, then I plan to shorten the motor leads to clean up the arms and reduce weight - not a fun job, as it involves soldering 18 new bullet connectors :(

Then it's onto the "eye" firmware - I have a 5V Arduino Pro Mini set aside and have started some Arduino code based on the jD_IOBoard MAVLink source.  Might be a job for next Wed night.

[Jess Robinson]

Shiny!

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[Jamie Osborne]

Hmm.. Foldy!

Looks awesome! Look forward to seeing it in the air. :)

Jamie

https://telegram.me/jmeosbn

[Damian Axford]

so.... got the firmware done, calibrated, props on and checked.  Took it out for a very low hover test (in the dark of course) and crashed within seconds!  Turns out the radio guide had me invert the pitch control so ended up nose diving it and breaking the battery tray.

Fitted my previous battery tray design, corrected the pitch control and tried again - crashed within seconds.  Turns out the guide had me invert the aileron control as well!  FFS!  2nd battery tray also wrecked.

The good news is that the folding arms and cable tie joints protected almost everything else.  Except for one prop...   not sure I have a spare, so might be on pause for a week.

ho hum... the fun of making stuff :)

[Robert Longbottom]

Bah, that's bad news :-( You can always test on the ground by throttling up so its almost about to take off and gently rolling/pitching.  It should just lift the appropriate side or front/back.  You should really do this every time you fly just to be sure your settings haven't got messed up and to check you have the right model selected on your radio (if your radio supports different models).  Then check again once you are in the air in a hover before flying off :-)

I don't claim to be quite so safety conscious myself!  But I do it sometimes and its probably a good habit to get into, especially with the larger models that will do more damage in a crash and be more costly to repair!.  Also wise to check you've remembered to turn on self level if flying a KK board.  I've taken off a couple of times without self level and wondered what the heck was going on!

Copter looks good though.  Looking forward to seeing it fly :-)

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[Damian Axford]

Sage advice - wish I'd thought of that :)

Going to swap out the lower 12 inch props for 10 inch, then need to design a stronger battery tray...

[Robert Longbottom]

Hindsight is a wonderful thing!

You might want to put the bigger props on the bottom; bigger and/or larger
pitch props on the bottom will further accelerate the already moving air
that has been pushed onto them by the upper props.

[Damian Axford]

I did, but I don't have any spare 12 inch props :( will continue testing with 10 inch and then order some more 12s after pay day!

[Damian Axford]

Finished the v3 battery tray - now on piano wire supports.  Beefed up the arm pivot brackets.  swapped out the 12 inch props on the bottom motors with 10 inch:

Took it out for a test-fly, checking the sticks behaved correctly before taking off and it worked much better.  However, I only it took up about a foot in a short "hop" to check everything was working ok, but two of the landing legs snapped on landing!  Clearly no surprise, given how spindly they were :)  So...  tomorrow will be focused on a mk2 landing gear!

[Robert Longbottom]

Nice.  Shame about the landing legs!  They do look very precarious though.  Maybe you could make them "consumables".  Just fit new legs after every landing :-)

If you're building this to fly in wind then landing is the most dodgy part, so you want something pretty solid.  Especially when you come in fighting the wind so it's tilted over a few degrees.  I like to be able to just drop it the last few inches to save hitting the props on the floor!

[Damian Axford]

I have a plan for legs mk2.... but have run out of filament :(  ...  delivery due Thurs, so still time to get legs re-done for the weekend!

Here's the rough idea:

• Move the motors in by approx 120mm
• Move the ESCs to the end of the arms, shorten motor cables to almost nothing, combine DC power and feed back down inside arm tube along with the signal wires
• Joint is a fixed piece, cable-tied or bolted to the end of the arm
• Toe is a 10mm tube (carbon or aluminium) that friction fits into the joint (to make transport easy) - probably with a ball or T section to contact the ground

Looks like this with all 3 legs - super-wide :)

[Robert Longbottom]

Very tripod / spider like :)

I like the idea of hiding the esc wiring in the leg. 

I've started my folding redesign, but either need to work out a neater way to mount fpv kit, or make the top plate bigger so it doesn't overhang. Think Ill get some flying in before I go making any enhancements though, so I'm not rushing at the minute. 

Weather for the rest of the week looks fairly settled so let's hope it holds until the weekend. 

[Damian Axford]

Refined leg joint - have added horns to the joint to protect the upper props in the event of flipping over.  Should also help protect the props in transport.

The nice thing about this arrangement is it also halves the amount of DC wiring needed within the body and gets rid of any external wires :)

I'm also tempted to put a shell around the battery to make it look "sleeker" - getting a War of the Worlds vibe from the layout, so perhaps something like one of the tripod eye/laser tentacles

[Jamie Osborne]

getting a War of the Worlds vibe from the layout

Definitely! 👾👾👾

Jamie

[Damian Axford]

So... after spending many hours last night trying/failing to get basic MAVLink info on my Arduino (Duemilanove), I've looked around for other projects to hack to bits as a starting point....

Next attempt is using the Ardustation 2 GCS codebase: https://code.google.com/p/ardustation-ii/

So far I've:

• Updated the included libraries to be compatible with latest version of Arduino IDE (basically search replace prog_char with char!)
• Ripped out all the non-essentials (LCD control, user interface, antenna control, etc)
• Added in the Neopixel library and SoftwareSerial for debug comms

Will squirt this onto the Arduino tonight and see if the bl**dy thing works!  Assuming it does, the Neopixel bit is easy enough - so should be quite a quick process to finalise the code and then wire up the Pro Mini that'll actually go on the Y6

Here's a pic of the NeoPixel ring from last night in all it's retina burning glory:

PS - All the source files for OpenSCAD and Arduino are currently in my dropbox - will publish them to github once they're stable-ish/working

[Robert Longbottom]

Good effort if it works!  Hopefully either that or the code I sent you will work. I've been having another play with what I did.  I always planned to use the tft touchscreen I have for Arduino to display some telemetry info, but never got round to sorting out how I could wire it because the shield covers all the Arduino pins and does break out the ones not in use.

So, a few wires soldered onto the back of the Arduino to connect to my telemetry receiver and some quick chop and paste coding and I have it working in principle.

Just need to work out what I want to put on the screen exactly now!

So far, just the flight mode is displayed : stab(ilize)

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[Damian Axford]

Ooooh.... Pretty :). Like the touchscreen, would be great for PiD tuning if it was interactive - Arduststion does that I believe, but with crappy text LCD

Battery monitor, distance from home, altitude and mode would be my top picks.
Extra cool if it was in a case and somehow attached to the top of the Tx

[Damian Axford]

Fixed it!!  Turns out, for no logical reason, having the Arduino connected over USB prevents FastSerial from working correctly...   so, to make developing easier with so many ports, I just switched onto an Arduino Mega.  Simples.

So - I've now got a basic Cyclops thing working.  GPS fix and/or low battery determines the colour.  Whereas the pattern is a pie-ish graph of battery voltage (between sensible min/max values).  Arm/disarm status is reflected by the brightness (dim is disarmed, blindingly bright is armed)

The battery graph is v. cool - and it's clear I've consumed approx 25% of the battery whilst sat here this evening!

Just need to add bright red flashing if the batt voltage drops below safe level and this will do for a mk1.

[Damian Axford]

added the red flashing - sooooo bright :)

here's some pics - camera can't really cope, but a paper diffuser helps a little - you can just about make out the battery graph (white is the level)

Next job is to burn the code onto the Pro Mini and wire it up...  perhaps tomorrow night

[Gyrobot]

Kitt's, aerial cousin from Knight Rider.

Long live the Hoff!

[Damian Axford]

+1

[Damian Axford]

haha - HobbyKing order of racing quad bits has arrived:

4x 2300kv motors, props, ESCs

1x Naze32

and carbon spars from hyperflight...

cool - lots to design, build and fly... if only I wasn't off to romania :(

[Damian Axford]

Arduino pro mini wired in... Looks sweet and the battery monitor is v useful

Printjng the last of the new legs now, so should be ready to test fly again later tonight :)

[Robert Longbottom]

Cool. Looking forward to seeing it fly.

We'll have to arrange another flying meetmeet sometime soon.

[Damian Axford]

it flies!!!  not only that, but it actually flies rather well - haven't tuned anything yet, but clearly stock PID values are ok.

the Cyclops eye is super bright - looks v. cool in the dark - probably blinded a few of my neighbours :)  Also makes determining the direction of the copter very easy - which was the point.

Here's a pic of it on the ground, note the new legs - they work well, but make it even bigger...  packs down smaller though

Battery indicator on the eye also works fairly well, although as you'd expect, the battery voltage fluctuates under load, so it works like a motor power indicator in the air...  also means it flashes the low battery warning under very high load (e.g. takeoff)

Battery is proper flat now - time for a charge and some more flying tomorrow, will try and get a video clip to share

[Jamie Osborne]

the battery voltage fluctuates under load

I've wondered about that before and how hubsan's etc. reliably indicate the battery is low. I'm thinking you could account for it by comparing voltage with either the current draw from battery, or the estimated load expected?

For example, multiplying voltage measured against current drawn gives the power being delivered; if the voltage is low, but the power is acceptable, then you know the battery is ok.

Jamie

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[Jamie Osborne]

Oh, P.S. Would be interested in a BOM if/when available. :)

Jamie

On 20 Mar 2015, at 20:59, Damian Axford <dam...@axford.me.uk> wrote:

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[Robert Longbottom]

The Hubsan will probably be just monitoring voltage.  With lipos you aren't supposed to discharge them below a particular voltage (3v I think) so it probably cuts off well before that.

You can see some evidence of this if you fly for a bit to flatten the battery and then punch the throttle.  It will immediately activate the flashing LEDs to indicate low voltage because of the sudden demand, but then continue to fly for a while anyway before giving up totally.

Current measuring is better, but requires more components and knowing the battery capacity.  I have the power module on the y6 that does this.  Its scary watching how fast those milliamps get used up!

[Jamie Osborne]

I have noticed this, normally when taking off with partial battery.

I'd think you only need to know capacity to tell how many mAh are actually left/used. If you just care if the battery is losing power, then I think that should be observable without knowing capacity. i.e, if battery voltage is low without sufficiently large power draw, then it is time to change batteries. If battery voltage dips suddenly, but power delivered is adequate, then either ignore the dip - or wait to see if voltage level returns when draw is lowered.

I've not studied the characteristics of lipos, or their use in quadcopters, but I'd imagine it should be reasonable to rule out low voltages when sufficient power is being delivered; worth trying?

Jamie

[Damian Axford]

good points - the battery monitor circuit I'm using does current as well, but I've not configured it yet - and will also need to dig into mavlink messags to find the relevant one - should be easy enough.  On the other hand, it's not really necessary, just return to a hover to check battery status....     if it's flashing red, then it's time to land.

I've set the voltage threshold fairly high (3.4v per cell) - will have to time a few flights and see how long it lasts.  Can always lower the alarm level.

For now I'm just pleased it flies - looking forward to getting some practise in the air and yes, def should do another flying meet.  Might have to be a couple of weeks time for me - weekends are looking pretty solid.  Unless anyone fancies a night flying meetup?  assuming it's a park with streetlamps nearby... :)

[Jamie Osborne]

> Unless anyone fancies a night flying meetup? assuming it's a park with streetlamps nearby... :)

There happens to be such a park by my place - opposite from Lidl, along a bit from the car park you drop me off in.

Jamie

[Damian Axford]

We're down on the south coast this weekend and manged to get out flying on the beach at low tide yesterday - perfect conditions, almost zero wind.  The Y6 flew really well - and I had a chance to practise some proper flying - great fun!  

All was going well, and after 8min or so, I was getting more confident and therefore a crash seemed imminent... sure enough, doing a fast pass and tight turn went a little awry and the Y6 ended up heading towards me a little fast than I'd like.  Then mgd to get a little confused with which direction I wash moving the sticks and ended up ditching it nearly on my feet.  The folding arms did their job, as did the legs and only one prop damaged.  Plus a little bend in one of the motor mounts.  

New props on order from HK (orange ones this time :) ) and should have it back flying by next weekend.

Might also have time to get the FPV tx/camera wired up!

[Robert Longbottom]

Not wanting to be out done in the multirotor game ;-) and because it's a good upgrade, I spent yesterday rebuilding my Y6 to fold and managed to get my lid printed.  

Annoyingly some of the support material came unstuck from the bed halfway through the print (which was about 6h30min in the end).  I managed to bodge it so it completed the print, thought I'm not sure how much difference my bodge made and I'm wondering if I could have managed without the majority of the support material anyway.  Still the end result came out okay and seems to be reasonably robust.  I'll be interested to see how long it lasts...

Folding my Y6 isn't quite a slick as Damians I dont think because I have a couple of bolts to remove, but I like having the reassurance that it wont fold mid flight.  And I'm worried about pinching wires when I fold it.  So I probably wont fold it that much, but it's nice to know I can.  I might look into replacing the bolts with little metal locking rods.

Just need some decent flying weather now to test it out and see if the lid makes any difference to altitude hold, which I'm hoping it will.

[Robert Longbottom]

Sounds like fun, never good flying fast towards yourself nose in though!  Thats how I usually manage to crash the Hovership :-)  I've always wondered about beach flying, fine if the tide is well out, but having a large body of water to crash into is kind of like having a button that says "do no press" :-)  And I'm never sure the GPS isn't just going to fly off on it's own, though, touch wood, they seem to have improved that quite a bit in the firmware these days.

[Damian Axford]

looking good :)  the shells certainly make them look a lot less cluttered - will be interesting to see if it improves the alt hold.  

I haven't added any locking pins (or equiv), but still tempted - although having seen the arms fold neatly during crashes, I'm concerned that pinning them open would increase the risk of damage to the arms/body.

Flying on the beach (with tide waaaay out) was great - although I was similarly nervous of landing in a rock pool, etc   Where I crashed was just damp sand, not too bad - although I was very quick to get it up out the wet and dry off the battery/ESCs - the shell did a great job of keeping the rest of the electronics sheltered.  

The Y shape and the bright light at the front made the orientation very easy to spot whilst flying out a reasonable distance - much much better than with the hex!

[Robert Longbottom]

Yes, it does look good, though I do like the raw electronics look as well.  I was a bit worried the GPS wouldnt word as well under it, but it seems okay, 12 satellites in the garden, which is pretty much as good as it gets.

At the minute my locking pin is a bolt with no nut on, but the hole is too tight for it to just slide out and it wouldn't vibrate out even if it was.  I'm thinking of a smooth metal rod the L shape of an Allen key that you push in from the top and then clip the end under something to keep it down in place would work well and might be easier to get in and out.

Though I think the folding arms on the hovership have saved me damage in a number of crashes.  Its all about the type of flying you're planning on doing with it really.  I take a lot more care to stay away from things with the y6 because  I know it will break I'm a crash, whereas with the hovership I'll be a bit more adventurous!

I also need to find a source of bright LEDs because the ones I've got just disappear in any kind of daylight.

--

[Robert Longbottom]

Well, after two flights, it seems that the shell doesn't seem to make any difference at all to Alt Hold.  So I'll have to look into other things.  Though right now, I don't know what given it used to work just fine on the quadcopter.

[Damian Axford]

ah - bummer...  well at least it looks nice :)

[Robert Longbottom]

Indeed :-)

On 06/04/2015 22:05, Damian Axford wrote:

ah - bummer...  well at least it looks nice :)

[Robert Longbottom]

I seem to have fixed my Alt Hold, I'm not 100% sure what fixed it because I changed a few things, but it was one of more of:

 - More parameter tuning on Throttle Rate P, which I think fixed the pulsating throttle problem.
 - I discovered that the shell was touching the top of the APM and I think that was causing high levels of vibration so I've improved that.
 - I've also put some tape over the foam covering the barometer - apparantly they are sensistive to light (?!)

Alt Hold and Loiter now seem to be working well again.  Though I need to see how it handles in the wind because it was fairly still when I was flying, but it was clearly much better than before.

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[Damian Axford]

excellent - and interesting to note the light sensitivity on barometers - wtf?!  

my new props arrived this morning, so looking good for flying on Sunday :)

[Robert Longbottom]

Yes, that's certainly an odd one, but it would fit because on my quad which would alt hold just fine the APM was hidden in the middle and I used tape to stick the foam on so it doubly covered.  Whereas on the y6 its on the top only covered by semi translucent pla.  Until now!

On 10 April 2015 21:50:13 Damian Axford <dam...@axford.me.uk> wrote:

excellent - and interesting to note the light sensitivity on barometers - wtf?!  

my new props arrived this morning, so looking good for flying on Sunday :)

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