A small update - eventually got round to weighing it, and even with the 2mm plate, it's come in at the top of the designed weight - 1.1kg.This is good news because it means I should be able to hit the designed AUW - with NEX5 and gimbal - of 4.1kg.
With the recommended pack, that will mean a loiter time of around 19 minutes, and mixed flight time of 9 minutes (according to ecalc), This is just below what I wanted, unfortunately - I was aiming for 20 minutes loiter, and 10 minutes mixed flight time. I have some weight saving changes to make before handing over to 3 guys here for independent testing, so I'm hoping for 1kg, including legs, clamps, bolts, and DJI elevator.
The X/Y8 config might be interesting...yes it can do it easily enough, but I'm not sure how 4 x 4,000mAh 6S in parrallel in the bay (theoretically possible with 4m risers) will affect the CoG or the flight times...<laughs evily>. I can't do X8 for jack, but thankfully one of the testers will have more experience than me here!
Still to do before handing over to the testers - 19 different refinements/corrections, including holes for mounting new pixhawk attachments (led and external USB port).This frame is design from the outset for APM 2.5 & 2.6 at the moment, but just need to see what considerations I need for pixhawk.
Comments
Ok, so now the reason it's called Platypus...
Eventually got round to testing Platypus' true purpose - to carry Gimbals. And I'm happy with the result - I now know exactly what holes to pre-cut in the "bill", with the ideal being that the big selling gimbals in the NEX5 range will just bolt right on without mods.
But there are problems. The legs. I will need to increase both the height and length of them. This is not hard - it's just some carbon rods. But that will also mean a redesign of the mounts from a 45' to a 30', to maintain a sensible posture, and the extra length will add additional torque to the mount, which may mean an upgrade to metal mounts. But I can't find any off the shelf, and a custom design will just add to the Bill of Materials. And the weight. Hmmm.
There is also the issue that this RCtimer ASP gimbal is notably heavier than advertised. As if I wasn't running into enough weight problems...:-(
Want one! nice job! :D
@ Hyon : I was asking Euan.
@Euan : Inventor Fusion .. So bad product. Thank you for the information
Still trying to decide whether to release the design, or wait until I release the 550 size version. Same design principles - designed for camera and gimbals with good endurance, good photography flight characteristics and a more flexible internal layout. But smaller (3s-4s).
@Hubert Did you ask to me? or to original author? :)
@ Euan very nice design. I am also building a quad from scratch. I will be using an all aluminum frame. I cant wait for the test flight of your quad.
Which CAD software do you use?
CAD file available?
At the end of the day it's entire up to the user, but I'd recommend something very similar to the lines you're looking at yourself - for X4 something like 5-6S, 14-16" props, 300-400kv, 300-350watts and around 2.5kg thrust per arm. 4 big torque motors + props vs 6/8 medium ones. My personal preference is T-motor's, but if someone else has a preference, so be it.
The Tiger Navigators look good (thanks to you!), as does my favourite the MT3515's. Afterall, this is a flexible airframe for medium lifting of camera equipment (gimbal use has been designed in from day 1), with good duration. It will need big motors if you only have 4.
X8 is also possible, and has also been designed in from the start. However, I'm no X8 expert, so can't advise on best combo, other than the arms are technically rated to 3kg (but will actually take much more).
Re: battery packs: Just because you can fit 4 x 6S 4000's in there with the extended risers, doesn't mean you should....:-) I just used it as an example of what packs this thing has been designed to carry - the battery bay is extreme large (l175mm x w110mm x h63mm with the standard risers) and will take practically *any* pack on the market - the only thing you really need to worry about is CoG. I'd recommend anything in a single pack, upward of 8000mah; personally I'm flying with a 10900 from maxamps, but there are much more cost effective options if you go parallel. I recommend single packs for convenience and weight efficiency, but there's nothing stopping you slapping 2 x 6000mah's in there instead - the bay is extremely flexible and is only really limited by the length of the legs and the length of M3 risers you can get.
Re: the 4.1, this is based on:
- X4
- MT3515's
- 10900 pack
- RCtimer ASP
- Nex5 (standard lens)
- Gryphon octo PDB + 5.5V BEC
- 45amp OPTO ESC's
- 1555' CF props
- APM 2.6 + external GPS + compass.
- R800 Orangerx + 2 satellites.
Once the Rctimer gimbal gets here, I'll do a full weight. The frames you guys get will be lighter - as above, I want to peg it at 1kg if possible.
What's the weight gonna be of 4 packs 6S 4000 mah ? Is it counted in the 4,1kg limit?