I've been flying a little quad based on this mini frame HobbyKing do. It took quite a long time to get right, and flew really well for a time, but it seems is easy to mess up. See this video for a quick explanation of Mondays flying
http://youtu.be/3Hh2-VJprdQ (http://youtu.be/3Hh2-VJprdQ)
So I've tried to take a virtual step back and had a think about the compromises I was having to make to get everything to fit onto that frame. I really didn't have much of a choice about where to put a camera, I could only use a small 800-900mah 2s lipo, and I was having to use a micro VTX that a) was very hard to get rid of the lines that would appear as I increased power, and b) used the boscam frequency which meant I had to drag around an external VRX and tripod to fly a tiny thing.
So here's the quad as it stands right now -
(http://farm6.staticflickr.com/5523/10706433336_1dbe993e2c_c.jpg)
I haven't done anything yet, other than rip off the components from the other frame. I intend to reuse everything I had (luckily I had a spare motor). I'm not using any science here, I'm just going with what "seems/feels" right - so this post is more about a statement of directions.
The tiny lipo annoyed me, with a max flight time of about 4 minutes, I want something more. So this new quad must be able to take a 1600mah 2s
(http://farm6.staticflickr.com/5508/10706418084_9dd1064bcf_c.jpg)
I want to be able to use an immersionRC VTX so I can just take my goggles, radio and a quad. Most importantly is the fact that this quad is for flying stupidly. I like to flip/roll around, and fly through gaps where it can't possibly fit. So it will break/crash a lot. So I've decided to go with some of the ideas I used when I built my tricopter from the rcexporer.se plans.
In fact, I'm going to build it out of bits of spare/broken tricopter bits.
(http://farm4.staticflickr.com/3751/10706610333_043b544a4f_c.jpg)
Other than the fact that I've decided on an H design, the rest will be made up as I go. That's all for now, more as I do things
Well, I'm working from home today, so at lunch into the garage I went with a saw and started hacking pieces of wood. I came up with a rough idea of how I wanted stuff laid out - mainly based on the length of the lipo I want to use and the 5" props. I came up with this -
(http://farm8.staticflickr.com/7357/10708784006_186a4e53c4_c.jpg)
I wanted to apply the same mounting technique for the motors as used in the Tri build, i.e cable ties. However a DT750 is a large motor and it's easy to get a cable tie through several holes to keep it rightly in place. Not so on these tiny things. Anyway, I made a guide hole for where the shaft slightly overlaps so it didn't rub against the wood.
(http://farm8.staticflickr.com/7366/10708786096_577a5f81e3_c.jpg)
That's pre-sawdust removal :) Next I filed some notches into the underside of the arm so I would be able to get a cable tie really tight.
(http://farm4.staticflickr.com/3716/10708787516_23a88710b2_c.jpg)
Then I tried one of the motors as a test.
(http://farm3.staticflickr.com/2827/10708702875_b1df9cb5d2_c.jpg)
It's on there pretty tightly, you can slide the motor using brute force - the question is will it be able to move around with normal flying (and thus vibration). Don't know, I'll be trying it to see. All the motors have varying lengths of wire, and I need to decide how I'm going to connect these to the ESCS's - whether to extend, or keep short and have longer ESC power wires.
Next thing I then messed about with was the layout of the "bottom" plate, which I eventually came up with this
(http://farm6.staticflickr.com/5549/10708774044_7ab50f8fbe_c.jpg)
That bottom plate gets kind of boxed in with some other sections -
(http://farm3.staticflickr.com/2851/10708793686_e89fac30f3_c.jpg)
I'm keeping the KK2 board so I can get to it, it's slightly protected as it stands here, but it will be being raised up on pads to absorb some vibes.
My plane then was to have the lipo on top of those 2 bits of wood, like this -
(http://farm4.staticflickr.com/3712/10708976283_2a6371b9f4_c.jpg)
However, in retrospect I'm thinking it's too much of a squeeze on the KK2, and I'm a little worried about the balance lead flying away and making contact with a prop, so I'm thinking that using the underside of the bottom plate is a better place - although I might need little legs to keep it off the ground slightly... which possibly over complicates the simple design.
Looking good Wayne
Personally I would have mounted the lipo underneath so you had access to your screen and buttons for tuning without removing the battery every time ;)
I agree with Coyote - it'll also make the CoG lower giving it more stability.
Also don't forget there'll be wires+connectors coming out of the VTX so it won't be able to be flush against the lipo like that.
You are both absolutely right. The lipo has moved underneath - it had to really. I did lots of soldering on Monday, I'll get some more pics up soon
I did some more work on this on Monday. Usefully some nuts/bolts and silicon wire all arrived through the post so I could get on with things.
First I drilled holes so I could get the nuts/bolts in and make sure it would all kind of go together. I also cut out little sections in the wood supporting the "shelves" so I could route my cables through there
(http://farm4.staticflickr.com/3795/10835050845_b1416deb09_c.jpg)
Next thing (get ready to recoil in horror at least half of you) I bulleted the motors and ESCs so they could seperate without pulling the motor wires apart. This was a bit messy as two of the motors already had nasty stubs of wire left after the previous crashes.
(http://farm4.staticflickr.com/3804/10835223444_9770419963_c.jpg)
I decided I didn't have room for a power distro board (and nothing to make one from) so I decided to just get all the wires collected together and solder them in. (This is 4 esc wires and the power for the VTX)
(http://farm8.staticflickr.com/7372/10835225264_84398a4027_c.jpg)
Slightly relieved that it fitted together, and looks quite neat. This is a copy again from the rcexplorer Tri wiring, but we're dealing with thinning cable here, so it wasn't such a squeeze
(http://farm3.staticflickr.com/2824/10835126706_a647d14ffc_c.jpg)
I then laid out the escs as I needed. At this point I realised I was a bit non-committal in where I wanted the ESCs to go, so they ended up a little in the middle. A better idea would be to have them laying longways with the frame and making that frame section slightly longer to accommodate. I find the best thing to do when discovering an oversight like this is to say "well, this one is just a proto-type, that'll be fixed in the final build". Which it kind of is - work it out while you go, and take note of things that aren't right.
(http://farm4.staticflickr.com/3676/10835227864_14be337719_c.jpg)
The great thing about covering up, is that you can pretend that the mess underneath doesn't exist :)
(http://farm8.staticflickr.com/7451/10835129216_eb4214d1bd_c.jpg)
....and here it is with KK2 and some of the other gear installed (lipo strapped underneath).
(http://farm6.staticflickr.com/5494/10835061905_d55ff55333_c.jpg)
And once again, another mistake I found when putting the KK2 on and finding a power lead coming from it. I use the KK2's own lipo alarm, but had forgotten about this when I made my power harness. Big oops there. Never mind, as I'll test it for weight before anything else. The VTX is a dummy (dead) before anyone panics about not having an antenna on, and I still have to lengthen the power/video cable from the 808, so that's not on yet.
I just tried a motor startup, but motor 4 didn't spin. I found one of the motor wires broke off..... at the bullet connector (lalala, I'm not listening *puts fingers in ears*)
I'll try and sort that tonight and see if it hovers without 100% throttle
looking good mate...but i'd have given it a quick coat of paint first;D
Quote from: Brod on November 13, 2013, 12:19:55 PM
looking good mate...but i'd have given it a quick coat of paint first;D
Proto-type... will get some black paint for the final build and pretend it's carbon :D
always gunna be prototype,always modding like my homebrew quads..
;D
That`s looking good now :)
love it wayne :)
This looks great, will follow this with interest as I want a small quad for indoor practice, but building seems more fun than just buying a Hubsan for £40! :D
I'd certainly recommend the building aspect iwan, it's lots of fun. To be fair though, unless you have a really big house/rooms, a Hubsan X4 is a lot better for practicing indoors. The idea of this one is a take anywhere/fly anywhere quad... especially silly places where you are bound to crash :D
Anyway, I did my quick solder fix tonight, and took it to my lounge for a very quick maiden - just to test the weights out. My KK2 is still setup for it's previous incarnation which is quite different in weight distribution. Quite weirdly what I found (without any tuning) is that self level was very solid, and manual was too twitchy... normally I find getting self-level to get stable is hard, but manual is silky.
Anyway, here's my 1 minute maiden - would have gone for longer, but I realised I'd only hand-tightened the prop nuts in when I was checking motor direction. The hover point is slight over the 50% mark on the throttle, maybe 55-60%, but it is much heavier. I want to take it into the garden when it's not raining/pitch balck and hover for a whole lipo so I can check out the state of the motors and ESC's afterwards.
Mini H-Quad indoor maiden (http://www.youtube.com/watch?v=xIr4pNvuNO0#ws)
So on the to do list, put in a proper working VTX + antenna, wire up the KK power monitor and little speaker, and will remount the KK as it's slightly wonky. Mount the 808 on something squidgy, and lengthen the usb cable so it can reach the VTX/rx, and add some more velcro underneath so the lipo has a bit more support than just some glued in straps.
Spot on Wayne :)
Ok, so my little prototype is finally finished - I redid some of the annoying wiring, and lengthened the camera cable. It's not easy to get non-shaky footage from an 808 on a multi. I'm having a try of some vibration absorbing ideas. This first one is mounting it on some quite soft flexible rubber hose, and also routing the video cable through this, as the ones that come with the camera have quite stiff cable and could easily pass the vibes on
(http://farm6.staticflickr.com/5473/10923308034_9647071c32_c.jpg)
So here's the finished article. Annoyingly, I found I had no right angled SMA connectors, and only straight scews, so it's having the suffer a rubber duck at the moment.
(http://farm8.staticflickr.com/7352/10923234296_62eca49c35_c.jpg)
It has had it's FPV maiden and it performed pretty well. I literally only had about 5 minutes to have a quick go - I think there's a little tuning to do on the gains. I was just taking it easy for that little flight - but flying in that style was pretty good.
That video to follow....
Here's the quick fpvhub cut (i.e I will make a longer YouTube whoring one later :)) I thought at first I was getting defocused from some vibes, but having looked a few times, I think my lens just got a bit blobbed by fine fine drizzle we had.
Some exterior shots provided by FlyBoySee, using the patented Tri-shoulder-cam
http://youtu.be/0_OnAY-sq0Q (http://youtu.be/0_OnAY-sq0Q)
Thats awesome, looks like it flies pretty well!
I've convinced the wife to get me the parts for christmas, so thats my 2 weeks off sorted! Although I may try a tricopter build rather than the quad.
Nice and simple build , got a zmr coming to do a similar build myself , might be going h frame at a later date.
don't know if you've seen it but theres a very neat/cheap diy mini h quad design on rc groups.
solves the jello by mounting the battery/camera/electrics on an isolated plate .
http://www.rcgroups.com/forums/showthread.php?t=1965226 (http://www.rcgroups.com/forums/showthread.php?t=1965226)
http://www.myrcmart.com/zmr-xpower-4axis-quadcopter-barebone-frame-motor-esc-propeller-mwc-multiwii-lite-p-6321.html (http://www.myrcmart.com/zmr-xpower-4axis-quadcopter-barebone-frame-motor-esc-propeller-mwc-multiwii-lite-p-6321.html)
Very impressive Wayne, especialy as you are using fairly cheap kit! and your flying is awesome M8.
Cheers, ;D MIKE.
Thanks Mike :)
Just to finish off this thread (for now at least) I put a video together of the build... which mostly rehashes what I've already put on here...(though a few more FPV flights at the end) but I will pretty much sell my soul for another 10 view on YouTube :D
FPV Mini-H Quad build, maiden and initial testing (http://www.youtube.com/watch?v=o2fIZ4iznss#ws)
Tuning needed. I say that, but I've a feeling something might be amiss with one of the motors. The original Mini quad was pretty smooth, but started shaking around on the flight I managed to destroy it on, so I think I need to take some time and see if all the motors are performing in the same way