Well it's been a year since I built my first quad (selecting APM, naturally), and I've decided to do a bit of an upgrade in the off season, as is the tradition. There were four objectives to the exercise:
- better reliability
- simplify
- reduce weight
- improve performance
1. Better reliability
- added 40A ESC's, giving me 15A overhead (formally 30A on a 25A max draw)
- replaced 5V BEC with a 5.5V, after getting occasion chirp from spektrum telemetry about low volts.
- Re-wired the PDB and the ESC's for better RF
- replaced 1 motor that sounded less than optimal
- ESC's now uprated (if you can "uprate "to HobbyKing...:-)) and outboard for cooling and better security
2. Simplicity
- number of battery circuits reduced from 3 to one. New 5.5V and 12V BEC's used
- Unnecessary LED's dumped. Only retained 4 for orientation on the odd occasion I don't FPV. But they are braincube's and *very* bright! Here is the controller:
- Labelled everything
3. Reduce weight.
- Reduced battery circuits from 3 to 1.
- EzOSD replaced with minimOSD. Also in picture: an FPV camer switcher and the Telemetry junction box.
- LED circuits dumped
- Spektrum telemtry TM1000 dumped
- GPS finder dumped
- Leg components replaced with Carbon Fibre
And did it work? Starting weight: 3.65kg. End weight: 3.62kg. lol. However, if I'd stayed with the quadframe brushless (just refused to tune with a martinez board!) and dumbed the Braincube as well, I would have saved over 200g.
4. Performance
Ok, a big subject...
- Moongel replaced with zeal. Unfortunately vibes actually went up! I now hit the +/-5 "safe" limits in high power flight and maneuvers. However, it does seem to respond to very small commands much better; the zeal is firmer than moongel so I might expect that.
- PID's retuned after 3.0.1, to increase YAW control, and to decrease pitch/roll (only by 7%) to improve video footage. It still handles well, but it's now more "Transit" than "Cosworth" (for our american cousins, this translates to: "it's more light truck than corvette").
- 6S Current sensor added. Means Compassmot can be run in CURRENT not THROTTLE. Flight noticably more accurate, especially in RTL, Loiter.
- Higher GPS pole added. Compassmot reduced from 4% to 1%.
- Quadframe gimbal replaced with RCTimer, and video quality immediately improved. Quadframe brushless gimbal just refused to take a tune, and never performed well.
- Radio diversity added via Orangerx 800 (DSMX) + 2 sats. Each with a 30cm cable. One mounted far out under one arm, one as far down on the leg as possible. It's not perfect, but better than before. Radio now much more reliable regardless of orientation. No more scary moments...
Video TX moved to as far down the legs as possible. Range has improved from 350m to well over 600 with 600mw tx + ibcrazy omni's. Will be pushing out further, as I now have an ibcrazy 5 turn helical to play with as well. Also to come: 1/4 wavelength 433mhz antenna's for long range telemetry. How bad is it? It cuts out before the video does...
Gimbal has had 2 upgrades. I replaced the battery plate with my own design, and I'm happy with that. So happy I'm selling it to anyone who wants one. Also replaced the balls with stiffer ones. I still get a tiny bit of jitter in pitch, but I might need to look at my rx feed into the martinez; it might be noisy.
And finally, dumped the 420 line camera, and went with the 650 line from Security Camera 2000 (the one everyone goes for!). Along with some new low light lenses. Works so much better. Just a pity I can't get minimOSD to overlay on the feed for some reason; works ok on the Gopro feed!
What's everyone else got planned this winter?
Comments
Thanks Bravojul,
It does look like it. But 10 euro feels expensive. I feel like making one of my own diy style.
Cheers
It looks to be a DJI GPS mount
Hi Gunnar,
I bought them some time ago and they work well. I have one installed inside the Skywalker where the spectrum satellite rx is inside the tail just below the rudder.You can buy the long spectrum cables at hobby king here
I am looking for the GPS stand too.
Hi Euan!
Great Job. I am on Version 0.1 on my first Quad completly self build from plywood and aluminum rods. I have two questions. Where did you get the nice GPS Stand for the µblox and where the long cables for the spectrum sattelites.
Thanks and have fun working during the winter - I certainly will have.
Gunnar from the wet and cold Northern Germany
Thanks Euan,
Yeah, I love your Platypus... While it is no where near as cute and adorable as our beautifully unusual Platupus, there was really no other name for your creation, was there!
It certainly looks fit for purpose and I look forward to following the development of this project. If this is not sensitive information, I would love to know how you plan to manufacture the product? Yourself with automated workshop outputting ultra low volume? Using kickstarter for crowdfunding route? ordering pre-milled parts in qty, then assembling into kits? Licence the design? Or finding a low volume manufacturer in China to do the whole thing for you? And will it be available as a basic frame kit, or as a complete kit including all electronics, or as a RTF solution? Will it be open source?
I am miles behind to in the development process. I have attached an image of my balsa test mule below for your amusement, along with a shot showing the small scale of my project.
Looking good quadzi!
This is mine - a little more conventional, but a little different too! It's built to be an "VX8" - a coaxial V, in other words. Designed from the outset for pixhawk, PX4 sensors, Nex5 gimblals, 12,000mah battery capacity and 20 mins flight time.
Should get to market for the spring next year - the "gold" prototypes are out in February, and a few guys here will be doing some beta testing too. Only 32 modifications to build in before then ;-)
http://www.diydrones.com/profiles/blogs/at-last-it-flies
Cool Wiki. Good work Gary.
Cheers
I live in Sydney, Australia. Winter has virtually no impact on my hobby, so flight and development continues all year round. With that said, I do have a pet project which I have been investing an extraordinary amount of time on.
After building 3 multirotors (a 450 irregular quad, followed by a 370mm octocopter and finally a 250mm quad), I formed the view that the ease of use, cost and amount of trouble free fun I could ultimately have seemed to be inversely proportional to the AUW of the craft I was flying.
This set me on the path to designing my own airframe which I hoped would integrate a range of proven methods, while providing a platform to practically test a few (potentially) novel approaches to addressing things like isolation and/or attenuation of rf and mechanical noise sources. The design of this airframe remains fairly fluid , as I am still working through the process of modelling in all the electronics, rationalising the wiring hardness, pushing down the AUW, etc.
I am also constantly chopping and changing everything from the centre plate diameter to the standoff heights, arm lengths... based on everything from the most economical division of the supplied lengths of raw CF materials, to various prop options (4025, 5030, 5030 tri, 6030), the proximity of various electronic components in relation to each other, the position of transmitter and receiver antennas, etc. My hope is to explore as many possible outcomes, resolve as many issues, and refine as much as I can in the virtual world before I move back into the practical stuff.
Project Name: Blue Ring
Project Objectives:
* Accommodate market leading autopilot PX4FMUV2.3 or APM 2.5/2.6 (running Ardupilot) and all relevant sensors to provide full feature platform with fully autonomous flight.
* Feature Super Strong All Carbon Design - Be a true miniature, not merely caricature... and NO Plastic/ABS/etc. (ok, maybe Nylon fasteners)
* 8 Rotors - For maximum redundancy over 3, 4 or 6 designs (protects investment in electronics and, in particular, the GoPro)
* Payload Isolation System - Full isolation between electronic and mechanical noise generating components (sandwiched between the lower chassis plates) and sensitive payload electronics (located up on the backpack, above the battery). Maximising use of onboard weight through design to maximise ratio between 'sprung' and 'unsprung' weight (wrong terminology, but you catch my drift).
* GoPro compatible brushless motor driven gimbal (I am yet to test the selected motors, this could take some weeks to perfect. I am also trialling options for a BLGC which is more compact and utilises 5V mosfets)
* Use of motors with low torque, low moving mass and small props with low tip speed, rather than big props, in order to significantly minimise risk of injury and property damage in event of collision, particularly in urban areas.
* Made from zero bespoke manufactured parts, only off the shelf items and CNC milled CF components. (possibly nylon fasteners, as it could shave in excess of 50g or 5% from the gross flying weight)
* Offer option for tether assisted close range (<25m) flight and aerial view footage capture (with easy breakaway functionality) in order to facilitate significantly longer flight times for close range aerial video footage capture (also useful for longer range flyers, as it allows setup and testing of flight condition not to draw down the on board battery until it is required to depart the immediate prominently of the launch location). NOTE - Tethered flying proved to be perfectly functional with balsa version, even using thick and heavy gauge cable exiting the side of the centre plan and way off balance. Great in the backyard and great in the living room!!!
* Obligatory FPV camera with OSD and VTX
* Generous dedicated switching PSU with excessive filtering and choking providing second power supply in addition to Power Module.
* Isolated upper camera mount enabling removal of lower gimbal and legs for dedicated FPV flight with longer flight times.
* Weight no more than 1000g (It is over this at present, and will likely blow out another 3-5% once I am finished tweaking and factoring for extra weights not currently factored with accuracy - such as the lid and legs... but could come back down some way by replacing the brass standoffs and stainless steal fasteners.)
* Cost no more than $1000 (A goal forgotten long ago)
Numbers & Battery Options
Ecalc - FPV Configuration with 7800mAh
Ecalc - Gimablised GoPro Configuration with 7800mAh
Yes, this is the PRO QUAD, with 25mm arms. I choose the 325mm version.
The gimbal is a RustiCWave gimbal mounted under an UAP damper kit. All this is attached to the Jakub plates through 4 nylon spacers and standoff. I had to remove the biggest tubes that are on the way.
Euan, please enlight me on your GPS+Compass wires ;)
@ Bravojul: wow, almost identical! I think you've gone for the new "Pro" with the 25mm arms - my 21.5mm arms would exceed Jakubs recommended 3kg loading in X8. I like your ideal of using the main arms for the DJI mounts - I should do this too and some some weight!
PS how is your gimbal mounted? I do a CF plate which makes the mounting of popular gimbals much easier, and it doesn't flex like the quadframe plates.
@ Wavey: Yes, they are multistars OPTO's and 3508-29's- they perform well enough - at least as well as the t-motor 30A's they replace, but run cooler. I was tempted with a SimonK reflash, but they fly perfectly well as is. I did find the multistar programming card a PoS though, and the boot up boot sequence is not the same as most other ESC's.
For the motors on 6S and 1455 props, you'll exceed the max wattage above 90% throttle. They perform very well up to 90% throttle; after that you don't get any more thrust/rpm's, just a notably bigger amp draw, and they get hot very quickly. With a 10900mah 6S, you'll get in the region of 23 minutes flight time at "video shooting" pace; go "big sticks" and it'll be nearer 15 minutes, and everything gets warm/hot.
re: the extended GPS/compass cables...these are actually the standard ones! Yes, 3DR should definitely make longer ones, or at least allow us to use "standard" versions, such as 5/5 or 6/6. The 5/6 cable they insist you use reeks of "tie in", and is needlessly propriatory. I'd prefer a 30cm version of each, so I can twist the cables (reduces RF), and route them up the mast for a tidier build.
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