Mini Arrow Power, control, and FPV systems

[Robert S]

Anyone have any tips (or pictures) on how to stuff all of the Power, Control, and FPV stuff in the the Mini Arrow?

I put the ESC back in the power pod just in-front of the Motor but, those wires are pretty long and they make it a tight fit one they are all carefully bent to fit. I'm thinking of cutting and reordering them shorter so that they take up less space. I was afraid they would pull apart and short as I stuffed them back up in the power pod so I put some shrink tubbing over them to hold them together and to give me some peace of mind.

I'm thinking that I'll put the FPV transmitter in one of the wing bays and the Aura 5 Lite board and a Spektrum RX in the other wing bay. The only problem I see is that the Aura has to be mounted in a permanent sort of way so that it always knows which way its pointing relative to forward and level flight. I also need to be able to access the buttons and the USB port without having to un-mount it and/or move it around. When I plug in the servos and throttle, it makes the whole thing so thick that I can no longer mount it in a way that seems to satisfy all of my other mounting requirements and shut the door so that its flush with the wing.

I can't be the first to do this and, I'm not too proud to ask for help... or to shamelessly re-appropriate a workable solution.

 

[JasonK]

it is possible that you might need to enlarge the electronics bay to make it all fit.

Putting what electronics you can out in the wings is a great solution. I agree that the Aura would probably need to end up in the main pod because of the servo headers.

One thing you could do, would be to remove the servo headers and swap them for some 90deg ones, so the extra space would be horizontal instead of vertical, perhaps that would get it flat enough to fit in your bay.

 

[PsyBorg]

Anyone have any tips (or pictures) on how to stuff all of the Power, Control, and FPV stuff in the the Mini Arrow?

I put the ESC back in the power pod just in-front of the Motor but, those wires are pretty long and they make it a tight fit one they are all carefully bent to fit. I'm thinking of cutting and reordering them shorter so that they take up less space. I was afraid they would pull apart and short as I stuffed them back up in the power pod so I put some shrink tubbing over them to hold them together and to give me some peace of mind.

I'm thinking that I'll put the FPV transmitter in one of the wing bays and the Aura 5 Lite board and a Spektrum RX in the other wing bay. The only problem I see is that the Aura has to be mounted in a permanent sort of way so that it always knows which way its pointing relative to forward and level flight. I also need to be able to access the buttons and the USB port without having to un-mount it and/or move it around. When I plug in the servos and throttle, it makes the whole thing so thick that I can no longer mount it in a way that seems to satisfy all of my other mounting requirements and shut the door so that its flush with the wing.

I can't be the first to do this and, I'm not too proud to ask for help... or to shamelessly re-appropriate a workable solution.

I am fairly sure the Aura can be side mounted but you would have to connect it to the computer to change the orientation. That way you could stand it vertically next to or close to your receiver.

 

[whackflyer]

Anyone have any tips (or pictures) on how to stuff all of the Power, Control, and FPV stuff in the the Mini Arrow?

I put the ESC back in the power pod just in-front of the Motor but, those wires are pretty long and they make it a tight fit one they are all carefully bent to fit. I'm thinking of cutting and reordering them shorter so that they take up less space. I was afraid they would pull apart and short as I stuffed them back up in the power pod so I put some shrink tubbing over them to hold them together and to give me some peace of mind.

I'm thinking that I'll put the FPV transmitter in one of the wing bays and the Aura 5 Lite board and a Spektrum RX in the other wing bay. The only problem I see is that the Aura has to be mounted in a permanent sort of way so that it always knows which way its pointing relative to forward and level flight. I also need to be able to access the buttons and the USB port without having to un-mount it and/or move it around. When I plug in the servos and throttle, it makes the whole thing so thick that I can no longer mount it in a way that seems to satisfy all of my other mounting requirements and shut the door so that its flush with the wing.

I can't be the first to do this and, I'm not too proud to ask for help... or to shamelessly re-appropriate a workable solution.

On several wings I've made, I've put the ESC on top of the pod stuck down with velcro. You just tuck the battery wires in at the back of the hatch cover. I'd mount the Aura right in front of the power pod and the battery should go clear in the nose if the CG is the same as mine were. Put the receiver in one of the wing bays. Hope that works!

 

[Robert S]

Thanks for all of the suggestions!

So, I was able to fit the ESC and all of the wiring into the power pod in a neat and clean sort of manner. I topped it off with an extra piece of foam board and added some tape to it so that if I pull on any of the wires, like as I'm changing batteries of fiddling with it, the the ECU and motor wires won't pull out of place. I also cut the back of the center section where the power pod fits in so that the wires look cleaner.

After that, I played with different mounting positions but, I finally decided that there was enough room to mount the Aura on the bottom and pushed all the way back up against the power pod. I can still get to the USB port for programming (just barely) and there seems to be enough room for the RUNCAM Phoenix 2 Cam I intend to put in the nose while still having room to move the battery a little forward and back so I can adjust for CG. The FPV transmitter will go in one of the wing bays and the RX will go in the other

Last thing I did tonight was set the throws. Tomorrow after work I'll finish the wing tips, gluing the paint stick on the bottom, and I'll finish mounting the camera and hooking up the FPV. Hopefully she will get a maiden Saturday Morning.

Only took me a week. Josh did this all in just 40 minutes on the video. Lol.

 

[Robert S]

I think this is about all there is for this thread but, I'd like to finish off with this thought that I had when I was gluing on stabilizers to the end of the wings tonight....

As I was cutting the wing tips flush before gluing on the stabilizers I was thinking, "Josh makes this look easy in the video. This should be no sweat!" Then afterwards as I was looking at my crooked cuts I was like, "How am I going to make this work?" So basically I glued the stabilizers on so that they were flush and perpendicular to the wing based on the straight part of the wing that I didn't have to cut, , I and then let the glue dry. Once it dried and it looked like the geometry was about as good as it was going to get, I filled in the gaps with hot glue and then used a scrap piece of foam to wipe off the excess and make it look like I wasn't drinking (yet).

Afterwards, I heard something in my head that Dad told me when I was a kid. My Dad was a Trim/Finishing Carpenter and he used to say to me while helping with side jobs on the weekend. He would say, "A little caulk can cover up a lot of sins." Well, a little hot glue can apparently cover up a lot of sins too. Once I paint it, you'll never see it... uh, as much.

 

[Robert S]

A lot of firsts here. First Scratch build. First foam board build. First wing. First FPV.

I already ordered another one. I'll fly this one (the MK-1) for awhile, and then when I think I've gotten the bugs all sorted out and I can fly it with at least a little proficiency, I'll build another and incorporate all of the lessons learned from this one.

I'll save the paint for the second one. My 12Yro Daughter is taking Digital Art in school and I've tasked her with coming up with the artwork for the MK-2.

 

[slowjo]

cool pilot

 

[Robert S]

I was going to wake up early and go to the park to maiden her today but, Mother Nature decided that she wanted to have freezing rain instead. Since I haven't installed wing de-icing yet, I decided to re-do my control rods.

I appear to be somehow incapable of making a decent Z-bend the way its shown in the build video. I tried and tried but, they all looked horrible. I finally got some that looked bad, had (what I thought) was too much slop but, that I thought would work. That is what I was going to use this morning. Since I had the time, I changed the rods out with some that I bought that had adjustable ends like the ones on my foam plane. They are also (very) slightly thicker and stiffer so that should help with control authority.

So after I got it all done and re calibrated the static setting and the throws (way more precise than the rods with the z-bends that I made), I put the prop on and then decided to op check the camera, control surfaces, and motor. I meant to just nudge to throttle a bit to show that it worked but, I didn't realize just how much freak'en thrust this thing produced. It wants to fly and it wanted to have the Maiden right there in my basement. See below. This one can go in the blooper's reel. Broke one side of prop right off. I still have not found where it landed.

Its supposed to stop raining and get back into the 40s this afternoon here in NoVa. I plan to stop by Tower Hobby and grab some more props and another battery to on my way to the park.

 

[Robert S]

The picture says it all. If I wanted easy, I'd have bought a Parrot Disco or some other BNF wing.

Oh well, time to fire up the glue gun!

 

[JasonK]

how hard did you crash that thing?

 

[Robert S]

This was the end of the second flight. Unfortunately, I was alone the first time. The first flight went OK but it was real nose heavy. I got the CG all wrong and I had to run the trim all the way up to get it to fly with out a lot of fighting.

After that I went back home and tried to add some weight to the rear. My wife came the second time and shot video.

It was even more touchy the second flight. I also don't think the gyro was working. After I glue it back together, I'll go into the control board and make sure the gyro and stuff is on and set correctly.

 

[Robert S]

There is a better than average likelihood that pilot error was involved as well.

You hear me laugh at the end. My wife later asked why I laughed and I said, "It flew!" She said, "It crashed." I then told her that it was flying before it crashed so something was working. Had it just crashed right away I would have been more upset but, it was flying and controllable to a certain point, so, now all I need to do is figure out why it was so touchy.

Next time it will be better and I will be better.

 

[Robert S]

Yesterday, after my first flight, I went home and tried to add some weight to the back of the wing to get the CG closer to the build recommendation. I had a big camera in the nose and I could not move the battery further back because the control board would not go back any further. Instead of putting weight just in front of the engine, I thought I could use smaller weight if I was able to get back further back. So I hot glued two washers at the rear inside corner of each wing. It brought everything right into CG.

The post crash investigation showed that 1 of the washers I glued on fell off (Post Crash 5). After I took this picture, I pulled the other one off with my fingers with not much effort. Its my guess (who really knows) that when the missing washer fell off, all of a sudden not only was the wing suddenly nose heavy, the CG was lop-sided.

Also, when I plugged into the control board, I discovered that did not turn on and/or configure the Aura 5's gyro when I setup the profile. Had that been configured correctly, it still might have crashed but, maybe it would have been more controlled and a little less catastrophic... or not.

Its all back together now. (Cue the 5 Million Dollar Man theme music). I re-did the power pod and moved it back out the back of the wing about an ~1/4 inch, That let me move the control board further back and therefore gave me more room to move the battery around. I also changed the camera that was in there out with another I had that was 4 or 5 grams lighter. I had to put a hole in the top to allow me a way to push a USB cable into the board in order to tweak it later.

Now the CG is right where the build instructions recommend. The Gyro is now functional too (see Gyro Test). The Gyro turns off when I go to low rates and turns on with high rates.

Its been raining all day but, tomorrow it should be dry and warmer. Can't wait to try it after work.

 

[Robert S]

Four flights tonight. The first flight tonight was less than stellar. The nose still felt heavy and it took a lot of up elevator to keep it in the air. I trimmed the up elevator up as far as it would go and it still seemed unstable. During the second time around the circuit, I lost sight of it in the sun and flew it into a tree as I tried to keep it under control. After I recovered the wing, I discovered the wing looked ok in general but the power pack had pushed way up into the body and pushed the battery out the top.

After I went back to the truck and fixed the power pack's position so that it was further back then it was when I started. I then did a quick op-check and tired it again. I moved way out into he field so that even I could not hit anything. When I flew it the second time i was able to keep it under control for a few laps around the field but I still was not happy so I landed.

I took it over the truck again and plugged my laptop in to see what the gyro was set on. I then remembered that I put the gyro on a switch and then, low and behold, the gyro was off on the first two flights. Just for the hell of it I set the Aura to 6 AXIS (instead of 3) and went out to try it again.

The third flight was awesome. With the gyro turned on, Its crazy stable compared to what it was. Actually too stable. I had the maximum angles set too low and so I could not do a loop or alerion roll if I tried (and I did try). It just would not let me do it. That being said, it would currently make a hell of a sensor platform for farming or stuff like that.

I then had to charge the battery for a while and in that time, at dusk, a cold front was moving in and the wind was blowing pretty good but I wanted to see how the gyro did in wind. Needless to say, it was great! while turning perpdicular to the wind I expected the wing to do something dramatic but you could see the control surfaces fighting to keep things under control until I was either going up wind or down wind.

By the time I went home, flying was more or less a casual, no drama event. I really wanted to try the FPV but I didn't have a spotter and I didn't want to go under-the-hood without a second pair of eyes keeping a watch on the big picture.

 

[Robert S]

I'm going to start calling my Arrow "Timex." It takes a licking and keeps on ticking. Who ever designed that thing did a good job of making it so that it can take a beating!

 

[Robert S]

So... I got a new tool and its inspired me to makes make some "minor" changes. The good news is this thing is going to look great. The bad news is, it now may be too heavy to fly at anything less than full open throttle!

All of the FPV is attached to a removable hatch so that I could print a second hatch that will not have any FPV.... and all of the extra weight that FPV brings. I printed a different, lighter, type of Vertical Fins as well. The ones in the picture are great but, I needed to shed some grams. Once I porotype all of this out, the plan is to build another new set of wings and then reprint the components out of LW-PLA once I finally get around to buying some.

Big thanks to the designers below for posting their designs...
https://www.thingiverse.com/thing:1972543
https://www.thingiverse.com/thing:3033273 (I used his fins)

 

[Robert S]

Assembled. (W/ battery)
With FPV: 399g
With out FPV: 362g

 

[Robert S]

Made a small change to the hatch...

I can't figure out how to get Matter Control to save the modified file. Each time I save it, the resulting file is just the normal hatch without the lego part. I've made sure to group the two individual components but that didn't seem to matter.

 

[Robert S]

Keeps getting better and better.