I see. It would be a bit fast at 200g, then. It's better to add lightness, rather than equipment, at that scale.

Originally Posted by valiantGLX

I'd go the KK2.0 flashed with openaero2

Thanks. That looks interesting. I'm not familiar with the Atmega324PA - maybe an Atmega328PA with less Flash memory?

Can it be run as an Arduino like the Multiwii's? I'm kind of interested in Arduinos for their own sake, at the moment.

EDIT: I should have just googled it http://www.atmel.com/devices/atmega324pa.aspx - kind of a 328P with more I/O pins. I'm not sure what the other differences are... probably not much.

I looked up that airport, pretty cool, and since it is closed, no problem with air traffic while you do FPV.
But FPV adding 20 grams, wow, my first experiments with FPV back in 1990 added about 3 pounds! And I would lose signal at 1/2 mile, very tense moments to remember...

You could use 2 cells and ESCs without BEC, by throwing in a 3-terminal 5 V regulator, like a 7805, but that HK Rx works up to 9 Volts, so you could just tie it to the 2-cell, but then you must find servos that take it.

Originally Posted by Andy2No

I see. It would be a bit fast at 200g, then. It's better to add lightness, rather than equipment, at that scale.

I guess you're right Maybe I'll scrap the stabilisation idea, and use a smaller battery. the one I worked into my equation weighed around 50g

Originally Posted by Andy2No

Thanks. That looks interesting. I'm not familiar with the Atmega324PA - maybe an Atmega328PA with less Flash memory?

Can it be run as an Arduino like the Multiwii's? I'm kind of interested in Arduinos for their own sake, at the moment.

EDIT: I should have just googled it http://www.atmel.com/devices/atmega324pa.aspx - kind of a 328P with more I/O pins. I'm not sure what the other differences are... probably not much.

Sorry I got no idea about the technical jargon, but it looks like the beez kneez in stabilisation. Auto recover, 3x gyros and fully programable via the built in backlit lcd screen, for a small price. Never used it though. theres a great thread on it:

https://www.rcgroups.com/forums/show....php?t=1708175

EDIT: I just had an epiphany: the 200g weight I estimated includes the mosquito electronics too, so it should be more like 180g including a great BIG battery and all the other bells and whistles. I could also remove the plastic casings off everything and hard wire it all close together to save weight aswell. Also I could do the criss cross thing like on the tail for the best part of the fuselage to save a few g's too

Cool. Thanks.

For a 5V BEC, you'd need an LDO, rather than a simple linear regulator like the 7805. LDO = low drop out, typically 0.5V to 1V, meaning it will still give 5V from 6V, or maybe even 5.5V. The 7805 would need at least 7V, so there's a bit more waste heat, and a smaller safety margin.

If you're running an AR6400, or servos designed for single cell operation, you need 4.2V or less, which can be done by dropping the voltage down from 5V with a diode (more waste heat, but nice and light), or you could look for an adjustable voltage regulator. It's probably easier to just stick with ESCs with a BEC, and disconnect one of the BECs (cut or unplug the red wire), then add a diode if needed, for 4.2V ish operation.

Andy2No,

Wow, I didn't know that, I have been doing this for years, but (luckily) with 3 cell, so this is good to know, thanks.
Do you have any numbers for the LDO version? Just for future reference for me...

Yep, the LD1117AV50, is a cheap way to make a 1A BEC:

5V, 1A low dropout voltage regulator (higher quality than 7805). Marked LD50V, full product name LD1117AV50

£0.25 GBP - about 40 cents? - depends where you buy it

Originally Posted by dbacon

I looked up that airport, pretty cool, and since it is closed, no problem with air traffic while you do FPV.
But FPV adding 20 grams, wow, my first experiments with FPV back in 1990 added about 3 pounds!

that was a major over compensation too. this kit weighs 1g camera + tx: http://fpvhobby.com/143-sub-nano-combo-set.html

Its 2.4 ghz though so Id need a slightly larger 5.8ghz setup such as this: http://fpvhobby.com/96-8ghz-micro-combo-set.html

How times have changed eh!

I maidened the CC panorama at that airport

Originally Posted by Andy2No

Yep, the LD1117AV50, is a cheap way to make a 1A BEC

Datasheet for that series of regulators: http://www.datasheetcatalog.org/data...onics/7194.pdf

Originally Posted by Andy2No

It's probably easier to just stick with ESCs with a BEC, and disconnect one of the BECs (cut or unplug the red wire), then add a diode if needed, for 4.2V ish operation.

Most of that post was over my head but the above I understand thank god you posted that, I would have most definitely fried my servos otherwise

No problem. It's been mentioned before, but this is now a very long thread, so it would take you a while to read it all

The sort of diode you need for sub 1A is 1N4001 or 1N400X where X is "anything". It has to be plain silicon, not germanium, and not Schottky - the voltage drop is too low for either of those.

Andy2No,

I found this at Mouser, a US warehouse that has NO MINIMUM ORDER (Read: wonderful)
and they have this one, I selected out of 100 of them:

Mouser's number = 863-NCP1117DT50G
Mfg's number = NCP1117DT50G
Max Volts input = 20V
Each = $0.39
Dropout Voltage = 1.1V
Max current = 1 Amp

Thanks for the info.

You're welcome, dbacon. 40 cents was a good guess

Andy2No,

Well the 40 cents will be more accurate in a few hours, the way prices are going up. Gas has just recently doubled! We have "quantitative easing" going on, sounds nice, but NOT!

ValiantGLX,

An incredible site for FPV, thanks! The small one combined with Tx, they say good for 3000 meters would take 24 of them to weigh one ounce! We have come a long way...
I just wish there was more info about the range, because it depends on antenna, Rx, Tx, band, and power level.

I found diodes at my local Radio Shack here in Michigan.