I solved the problem of the weigt of the casing and the battery being to weak, by placing the camera module, without its plastic casing, in the battery bay, that way it is nice and protected, and i put an 610MAH battery underneath the lb with velcro. It still hovers with half power now, weighs some more than 40 gramms though. WIll make some pics later on

Originally Posted by Wartexx

WIll make some pics later on

Hope to see some detailed pictures soon - sounds like a good idea to put the cam in the battery tray. What is the weight of the 610mah battery, what type is it? I've tried to fly mine with two of the original 240mah parallel and tx5805 - but it's 51g then and that's too much for the lb. You can hover but do not have enough power for flying and also flight time does not increase much.

Originally Posted by ralfrcgroups

but it's 51g then and that's too much for the lb

If you want to fly more than 3-4 minutes, you really have to keep it under 40 gr...
With a 400mha lipo, I can fly 9 min. and auw is 38.6 gr (buzzer and 120° lens included)

Brilliant idea to solder the motor leads directly to the frame, saves some gramms?? I can now fly 8-9 min on half throttle. What exactly is the buzzer used for? You can flip a switch to find the model again??

Edit, some pics of my mods



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Any request photos?

The buzzer is linked to the green led... Fmod will activate it when lost in the bush

ah oke, I programmed the Gear switch to power that port on the lb ( for a night flying ladybird casing, turning the leds on and off) I actualy dont plan on losing it (A) but I think I will make one of those asswel, ( got some bussers laying around anyway)

Why did you btw solder that wire to the - terminals ? Was the trace on the circuit board nog thick enough for all the power you asked from your motors? Will not the possitive supply have the same thin traces?

First of all, I like am inspired by everyone's efforts of innovation and augmentation to the not so impressive factory formed walkera fpv system. I know this thread started as an fpv "mini multi rotor" discussion, but given the knowledge of the active participants I will pose my plan here. Over the past week i have had some considerable improvement with the devo f7 system and have been able to maintain solid crystal clear fpv transmission over 325m, up from the dismal 30m of broken signal i was getting in factory form. By adding a rpsma connector to the the f7's video receiver i am now able to switch between my foxtech clover leaf or patch antenna. The other mods include replacing the walkera tx 5803s 200mw video tx's whip antenna with a foxtech clover leaf antenna and modifying the walkera plugs to allow my go pro hero 3 to be incorporated as the fpv cam and recorder. While these distances are a huge improvement, I am now hoping to get to increase the range by modifying a band e foxtech 400 mw vtx to match my devo f7s band b vrx. Here is a photo of my foxtech vrx and and I just recieved the incredibly tiny 0402 1k resistors. I have read instructions for the placement of the resistor, but I wanted to run this operation by you folks for any input or advice before make my second attempt of soldering this resistor via a fine point traditional iron.

Another question to the group. Has anyone found the 3.5" LCD to be too small to effectively fly fpv with? I have been thinking about ways of mounting a 7" LCD display module to the devo f7?

Originally Posted by Wartexx

ah oke, I programmed the Gear switch to power that port on the lb ( for a night flying ladybird casing, turning the leds on and off) I actualy dont plan on losing it (A) but I think I will make one of those asswel, ( got some bussers laying around anyway)

As you can see, my LB is a V2... the missing chips on this version make the Gear switch ineffective... that was the only solution I found to have a trigger switch on my LB

First the good answer: You don't need your 0402 resistor!
You can just place a solder blob on the two pads, so that they get connected. For a 0402 size land pattern this shouldn't be any problem at all.
Just place a blob across for the BX Pin 4, and your module will send on Band "B".

For explanation:
That the channel selection pins do have some resistors, is as I said earlier probably due to noise rejection reasons. But the 1k resistors directly at the pins 1,3 and 4 are not optimal. A zero Ohm resistor (bridge) would be better. The reason why it wasn't populated like that is very probably, as you don't want just for that to add another part on your PCB. When you design for SMD placement, you always try to have as few different components as possible, even if it isn't optimal. The reason are the setup costs of the SMD placer.
As 1k also still works for such a bridge, they probably used these same 1k resistors as for the channel selections pins, also for these pins.

Addendum: BTW. I just received notice, that only now, my new RC305 has been shipped. Seems like it didn't make it before chinese new year...so it will be a bit longer...

Addendum2: As you know, I use my own made DC/DC regulators (as I have the equipment, and am a weight fanatic, so I made a switcher which is e.g. lighter than the Pololu ones). And as I said, the filtering is sensitive. So up til know, I used quite some ceramic high caps.
But the switching+LDO design of the TX5805, which I ranted about, seems to be able to get out with just 3 33uF caps.
So I also evaluated a new design, and it is smaller and lighter than my original design, and doesn't need now, such a lot high caps (which are quite costly). So my excuse for this rant about using a switcher+LDO for the design. But my rant, about the terrible big and heavy design still remains. Also the switching voltage of 4.5V is way too high. It just burns too much energy in the LDO. I for example now use a LDO with 0.13V drop voltage (in a 3x3x1mm package). So with some safety margin, I go to 3.6V intermediate voltage. So that in total I only have to burn 0.3V, instead of the 1.2V of the Walkera version.
And the good thing is, they intend to soon publish a 2x2mm package version, which would make the total solution still smaller.
All in all, one can tell, that the VTX chips are extremely allergic to even small voltage fluctuations. E.g. at about 2mV noise, you start to see it in the picture. At about 5mV you can see it very clearly. And already at about 20-30mV you will have heavy picture distortions.
For those interested: I now use a LM3668 as switcher, and then a TPS73733 as LDO.

Edit:

Another question to the group. Has anyone found the 3.5" LCD to be too small to effectively fly fpv with? I have been thinking about ways of mounting a 7" LCD display module to the devo f7?

Lol, why then continue with the F7 at all???
Then I would rather use a standard transmitter and a separate FPV equipment (the F7 has a terrible programming interface...).
As I said earlier: IMHO the F7 doesn't really make sense to buy for most people. It is intended as an all in one solution, for people not capable/wanting to solder a bit. But unfortunately it is quite a bad solution, due to the ridiculous VRX-antenna placement, which unnecessarily limits it to very short distances.
For anything more, you will have to mod it, as you did, and then you quickly are in a situation, where you needed more work to do, than using a standard separate FPV solution, and you will also have spent more money for that.

Problem to be solved now... Increase the devo7/ lb transmitter range.... After about 150 m the signal seems to be lost and the lb keeps on flying without me being able to cut the throttle.... Someone knows how to change the fail save settings of the lb? Or how to increase range?? its now at 20-15 transmitter power.

Unfortunately I have no experience with a Devo7. I got a Devo10 with deviation.
Doesn't the Devo7 lack the additional TX-amplifier? I think so.
But first I would try to have a different orientation of your RX-antenna. Like it is in your picture, you will have problems if the LB is pointing it's front or it's back to you.
Make the antenna point upwards or downwards so that the donut shaped radiation pattern is properly used.
Also always remember that carbon fibers are electrical conductors, so they shouldn't be in the radiation area of your antenna.
Also the antenna length on the LB can be wrong. This also happened on a few of my Walkera helis. This will also make the reception worse.
You can also add a patch antenna to your TX, this should help a lot, and they are cheap.

There are both 10mW and 100mW versions of the DEVO 7 (and almost all DEVOs).
If you can set the tx power to 20dBm, then that is a 100mW version...

So mine should be 100mw, then range should be no problem at all, except the street im flying is crowded with 2.4ghz wifi routers... I will try the different rx antenna position, hope that ll work ^^

BTW check your fail safe values, because the default is "servo hold", so it won't cut the throttle when it loses signal!

I ll have a look for the manual tonight cuz I dont want it to fly away .. love it too much ^^