When we left last time, all I had was a fdm 3D printed body and not much else. Much work had to be done still, so this is what has happened since.
My The body is ready:
I asked a favor to get the camera printed in STL resin. To be able to aford it, I had to accept the piss colored resin avaliable, so the camera won’t look fancy yet, but hey, at least I could afford it:
So sharp!
You can see the camera lens sealing ring.
A bit of postprocessing will be required to mate the pieces seamlessly (quirks about resin printing, but it will also help with sealing after everything has been fitted properly, so I’m not gonna complaint)
Not everything was easy, apparently the bodies where a bit fiddly to get out of the printer and got a few damaged ones before having succesful prints:
Anyways, got bodies! /hides the digging supplies/
Next question, please. XD
Power Button & Switch:
As mentioned before, after looking hard for a IP68 micro power switch and not finding anything that had the price of a small car with a kidney on the side, I had to capitulate and go full electronics with the approach, using a soft power button.
I found this circuit on eeVblog:
And proceeded to build a PCB around it. Said board had definite dimensions at 24x14mm (r3 corners) but I should be able to fit such a simple circuit easily (hah!), so, it was Altium time!
Funnily, I kinda assumed I would be able to quickly fit easy to solder 1206 components when I was selecting size:
Ooops…not sure anymore…
But somehow I managed to put everything perfectly:
So perfectly in fact, that I didn’t even have to put tracks for the switches, just direct vias (to be capped off when the component is soldered, so the whole pcb is hermetic in the body)
I know someone will be triggered by the 90º difference between switches. Enjoy! XD
Ordered them from OshPark in after-dark, just for kicks. XD
Heatsink that shit:
First time I powered the camera, I notticed that the whole board was noticeably hot, and the main processor, even more so. I imagine that’s not a problem ina FPV drone flying at 80+ kph, but for a closed body camera, that heat can’t be allowed to accumulate.
I mentioned before the sideplate that would have the main pcb attached neeeded to be made out of aluminium, easier said than thone, ^^U
Just about before milling it, I made a few modifications. I added the studs to hold the pcb, instead of having to add them later and thread in the thin baseplate. That would give me more thread lenght for the screws AND allow me to make the fins 1mm deeper, because the interference between them and the M2 threaded holes was eliminated.
But one thing is making a nice design, and another is to actually build it. That piece could be definitely made with manual milling and some filing, but my trusty 3020 can more or less do aluminium if you are patient enough, so I went with that instead.
Fusion definitely made some pretty swirly cutting patterns that I decided to save, even if that is only going to be seen by me. When cutting the piece, I kinda overreached the speed at wich the router was moving (the motor was fine, the cutting sounds where great) but at some very sharp changes, it definitely flexed enough to make the rounded corners a bit wonky. The studs also suffered from that speed excess, being a bit overcut on some sides. I definitely need to make a new piece someday that doesn’t have those mistakes, BUT, the piece was mechanically and geometrically functional, so I still went with it.
Also, this was my first piece with a double sided operation, wich made me nervous (the first milling was about 3h) but I was feeling confident, and as long as I didn’t switch off the router (or the power didn’t go out) I should be able to mantain the coordinates to process the piece.
First I drilled a very tight pocket where the small square of the plate would fit (had to hammer it a bit, wich is good in this case).
Given the experience with the other side, this time I went very conservatively on the feed, maybe even a bit too much, as the whole piece took a bit over 4h to be milled.
At least the results where really excellent (for the machine) The screw holes where 1.5mm but the heads where 2.5, so, with my newly gained confidence, I made a post program to itnerpolate those from a 2mm endmill. In the model I had made the screw seats about 0.4mm thick, but in the real aluminium piece, even if it’s more resistant, I left it at 0.8mm (remember that for later).
Gorgeous!
I didn’t want to spend more time in the router, so I decided to do the big chamfers in the milling machine, with probably not the best setup for the angle:
In retrospective, I could have done a few things better, like attaching a thick parallel to the side of the triangle to have more resting surface to set the plate, for example, but well, that’s for the next time, I guess. (definitely will be making more than one camera in the future)
Anyways, I did the cuts, and altough I did not make them perfectly simmetrical, at least I did not mess up badly, and you will not nottice once it’s mounted:
Camera beauty shots:
Remember what I said about the screw base thickness being left slightly thicker? if you look closely, you can see, the heads protrude a sliiiiiiiiiightly bit to the side of the chamfer. It’s not functionally a problem, but I know, and you know, and I will definitely change that for a future version, putting them a bit more inwards.
In any case, It’s friggin cool, isn’t it? (It’s my blog, I can say whatever the fuck I want, tbh)
I’m missing the PCB and it’s components. The bodies still have to arrive from Germany, and some o-rings, a micro Li-Po and the power board from china too, so the camera it’s not really near completion yet, but it’s close.
See ya!
The Electronic Mercenary 