Boards are back, loaded, tested.

I am in an extremely good mood. The board works with only one minor (haha) issue.

It's overweight at minimum by 6.2 grams. For the volume of helium I'm thinking about using, the gondola can weigh no more than 14gr.

I did the super swift service from @oshpark - ordered on Monday, had boards back on Saturday. Boards look nice, I'd forgotten to put in a pull up resistor (charge light doesn't light) and there's that weight issue, but otherwise, pretty happy. The ESP8266 is not designed in yet, it's just on the scale to be weighed.

NEXT REV:

Shave ~6 grams off of PCB.
Investigate diode on Vreg (drop is too high)
Add pull up resistor to PIN CE
Make connection points for batt and motors thru-hole

Discussions

Sophi Kravitz wrote 10/31/2017 at 03:22

@davedarko I made a log just for you :)

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davedarko wrote 10/30/2017 at 12:53

Could you please add the weight of the PCB alone and the parts alone? I'm curious about that :)

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Sophi Kravitz wrote 10/30/2017 at 23:03

Hello! The PCB alone w/ no parts shown in the pic weighs 10.7gr., but I'm making a new one with massive cutouts now.

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davedarko wrote 10/30/2017 at 23:29

so 60% of it need to be cutouts, to shave off, nice. looking forward to see the updates, even purple renders ;)

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Sophi Kravitz wrote 10/30/2017 at 12:11

@davedarko I like what @Radomir Dopieralski did! Was that to save weight? In this case, large holes will have better airflow/ less friction than a lot of small ones.

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deʃhipu wrote 10/30/2017 at 12:38

Actually I made the first hole just in case I need to route some additional wires between the sides, and once I did, I kinda got carried away, since there was all this empty space under the display...

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Sophi Kravitz wrote 10/30/2017 at 12:49

LOL

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oshpark wrote 10/30/2017 at 06:11

Very interesting! As @Laen commented, our 2 layer 0.8 mm thickness service saves a good amount of mass: http://docs.oshpark.com/services/two-layer-hhdc/

My neck definitely prefers it for PCB name badges :)

-Drew

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Sophi Kravitz wrote 10/30/2017 at 12:24

will def check it out! thanks!

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deʃhipu wrote 10/29/2017 at 19:49

You could remove the shield from the esp module. Also, you could have a separate adapter board with the USB plug, and use a plastic plug on the board.

It looks great, I can't wait to see the thing flying.

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deʃhipu wrote 10/29/2017 at 20:20

Also, are you using a Shottky diode? They have very low drop. Something like MBR120 should work.

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Laen wrote 10/29/2017 at 18:51

Try the 0.8mm service? Should be half the weight (but twice the wait. :)

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Sophi Kravitz wrote 10/29/2017 at 19:06

oooh! I will check it out. I plan to add large cutouts in the center of the board, which should cut down the weight significantly too.

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davedarko wrote 10/30/2017 at 09:47

do it like radomir did ;) https://hackaday.io/project/25256/gallery#b351bb1746913ab13f1528803679fd25

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davedarko wrote 10/29/2017 at 20:16

also twice the copper though ... although I don't see a ground plane, so that should be fine. May be add some drillholes?

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Sophi Kravitz wrote 10/29/2017 at 20:19

there's a ground plane :)

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davedarko wrote 10/29/2017 at 20:49

I can't see one on the picture, is it on the backside only? anyway, the thinner pcbs at oshpark have twice the amount of copper, 2oz instead of 1oz for the standard boards. drillholes where no pcb is needed probably helps more.

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Propeller Sizing

Rev 2 (posting for @davedarko)

Discussions

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