Discussion Beta85 ELRS quad and General Discussion Thread

[Pathfinder075]

You know it might be worth doing one. There's a badge for reviews as I remember. (Not that i'm wanting to become a badge whore)

Probably won't be a video one, I hate talking and hate cameras even more. Maybe I could do a MuteFPV style no talking, just text on screen type video. More things to think about.

What do you know about adding caps to the power leads? I am thinking of doing it on the Beta85 eventually because I get so much noise on the feed and if i'm doing it to the 85, I might as well put one on every other quad I build or buy. I read Oscars guide on it and from what I can work out a 16v 220uf capacitor should suffice for both 2S and 3S. The 3" will use something bigger since it will have 4S capability.

[Pathfinder075]

Also if you wired up that DVR inline.  So wire the camera to the VTX but piggyback a second wire off video out and send it to the DVR, so it isn't inline any more.  It runs almost parallel to everything else. 

My reasoning.  I was reading Ronin's thread from a couple of years back when he had a video freeze due to a Runcam Split board on his drone.  That type of situation could be avoided by sending video back to the DVR, but not from the DVR to VTX.  So it records footage, but doesn't send anything back to the VTX.  Since i'm kinda new to this, i'm just wondering if that would work. It would give a safety net in case the DVR ever died mid flight.

   

[iFly4rotors]

You know it might be worth doing one.  There's a badge for reviews as I remember. (Not that i'm wanting to become a badge whore)

Probably won't be a video one, I hate talking and hate cameras even more.  Maybe I could do a MuteFPV style no talking, just text on screen type video.  More things to think about.

What do you know about adding caps to the power leads?  I am thinking of doing it on the Beta85 eventually because I get so much noise on the feed and if i'm doing it to the 85, I might as well put one on every other quad I build or buy.  I read Oscars guide on it and from what I can work out a 16v 220uf capacitor should suffice for both 2S and 3S.  The 3" will use something bigger since it will have 4S capability.

Hi Pathfinder,

First, I have a couple of those DVR units. I have a mount for it on my Rescue Quad, but
that build is still in getting off the ground, but I will likely mount it at some point. So far,
I have not used the RunCam DVR, so the Rescue Quad will be the first test of it.

Caps...Ah Caps... WELL...I put caps on everything regardless of the craft. In fact, some
may say that I use larger caps than necessary, maybe, but they always seem to work.
On 4 inch and larger, I use a 1000 uf 35 Volt capacitor. I will use smaller ones on lesser
sized craft, but always use one. 

Now, where or how to wire in a capacitor. Well, there are a few different "theories" and
I don't say that lightly. There may also be a bit of difference between the purely technical
specifics and the practical application. Manufacturers seem to mount caps everywhere.
Some quads come with the cap mounted at the XT30 battery connector which seems to 
work fine. Some mount the cap at the battery pads on the FC which is where many FPV
builder/pilots say it should be. Some say that the leads should be as short as possible. While
there is a technical rationale for this, in practice, I have not noticed any difference between
this an any other method or location. I have mounted caps at the XT30, in the center of the
battery leads, and at the FC {sometimes with short leads of the capacitor, sometimes with 
extension wires}. In fact, I often use a connector for the cap so that I can change it easily. 
I have not noticed any difference in one method or another. While there may be some 
purely technical differences, in practice, this appears to be insignifican and it just doesn't 
seem to make any difference. Having the capacitor is better than not regardless of the 
connection method or location. Another consideration is where the capacitor will fit. On a 
small quad there is less space and the capacitor might need to be at the XT30 or with wire 
extension that allows the cap to be put where it will fit and be able to be mounted effectively.

Use a cap on everything, connect it somewhere on the battery lead {either end or even in
the middle, it really doesn't matter}, use extension wires if necessary to place the capacitor
where it will fit and be able to be mounted, and don't sweat the small stuff. Do what works
for the particular quad and application. It will work. Just do it.

[Lemonyleprosy]

Also if you wired up that DVR inline.  So wire the camera to the VTX but piggyback a second wire off video out and send it to the DVR, so it isn't inline any more.  It runs almost parallel to everything else. 

My reasoning.  I was reading Ronin's thread from a couple of years back when he had a video freeze due to a Runcam Split board on his drone.  That type of situation could be avoided by sending video back to the DVR, but not from the DVR to VTX.  So it records footage, but doesn't send anything back to the VTX.  Since i'm kinda new to this, i'm just wondering if that would work. It would give a safety net in case the DVR ever died mid flight.

I can’t think of any reason why this wouldn’t work. You’re basically just putting a splitter on the video out.

Regarding caps- I put them on everything except for my 1s whoops. Get low ESR ones from a reputable seller.
Other than added weight/size, there is no downside to using a cap that well exceeds your needs. I typically run short jumper wires to a cap from the fc- I don’t like just having it hang off the back of fc. If I don’t have room in the build then I’ll stick it on my battery connector. If I’m going the battery connector route, I usually use WaFL’s Cap Caps, because they make life easier and make things look cleaner:
https://pyrodrone.com/products/wafl-s-xt...p-set-of-4

[Pathfinder075]

I'm looking at Panasonic 16v 220uf as they were mentioned in Oscars article and seem to be widely available.

I decided to pull the trigger on that semi built drone too. It's on order along with a FrSky ELRS board and a dipole antenna since it comes with some random bare wire looking antenna which doesn't bring about feelings of great success or quality. Also some random soldering bits and solder. Going to try with my mains soldering iron for now. Also will probably order a v1 Runcam DVR board tomorrow for testing and if it works, probably get another for the Beta85.

Everything is once again on track.

[Lemonyleprosy]

That’s exciting!

I didn’t even know FrSky made ELRS rx’s. Yeah, that little wire doesn’t scream, “quality!”.

All of my removable (non-ceramic) antenna rx’s came with two different lengths of “T” style antennas for me to choose from, except for my Matek R-24D, which came with two fat dipoles (it’s a diversity rx, so it uses both dipoles. Well, sort of- it’s switching diversity rather than true diversity. In case you’re unfamiliar with what that means: true diversity would have two separate rx circuits on the board, each with their own antenna- the rx circuit with the strongest signal is used. Switching diversity would have one rx circuit on the board and two antennas, the antenna with the strongest signal is used. Then there’s antenna diversity which is just one rx circuit and two antennas, and it uses a mix of both antennas.)

My apologies, I got off track there. Anyhow, my ELRS rx’s are all Happymodel, JHEMCU, or Matek. I wonder if that little whip antenna on that FrSky rx would effect range at all?

That cap will do you fine on 3s and below.

I’m looking forward to hearing your thoughts on that semi-prebuilt plug it all together and fly quad!

[iFly4rotors]

Me, too.   

[V-22]

I think this has been mentioned before, but actual testing has shown little benefit to having a cap installed at the battery connector. It really needs to be attached to the ESC pads to provide a benefit. Also, it is helpful to keep the ESC leads as short as possible, and to use heavier gauge wire if you need to mount the cap away from the ESC. Further, it doesn't seem like low-ESR caps make a difference. Any cheap electrolytic cap of the appropriate voltage/capacitance should work.

See here some testing from Jye Smith here (also covering TVS diodes):
https://docs.google.com/presentation/d/1...cnB6U/view

and some discussion from JB and itsblunty here:

[Lemonyleprosy]

Thanks for the clarification, and especially for the test results, V-22!

[Pathfinder075]

Well I discovered that HobbyRC sell the v1.1 DVR board, so I ordered one.

https://www.hobbyrc.co.uk/runcam-mini-fpv-dvr

I also ordered some caps. I'm still going to throw one on the main power input. I like to test these things myself and if I see no difference between having and not having then I probably won't bother in the future. Although i did wonder if I could put it actually between the VTX and the FC. Since the noise is at that point, would smoothing the power to the VTX defeat the noisy video signal issue? I don't know, but I do intend to experiment.

Also ordered a bunch of other random bits, since the postage is the same. A tube of TBS solder, 2x Panasonic 470uF 25V, 2x Panasonic 1000uF 25V, 1x NewBeeDrone Practice Soldering Board, 2x XT30 Male w/ 16AWG Silicone Wire 200mm, 1x TBS Smoke Stopper. I wanted to order some motors for one of the other builds, but I need more of the basic stuff as well. This order is more solder bits orientated. Getting that part squared away, opens up other possibilities and allows me to start building properly.

[brettbrandon]

I wonder if they got the weight wrong in the specs. It shows 3.5 grams when the HappyModel Diamond 25x25 25-200mW 5.8GHz VTX w/DVR is 3 grams and it records at a higher resolution...

[Pathfinder075]

I don't know. On Runcams site it shows the weight as 3.5g. On Gal Kremer's comparison video, he weighs it at 3.42g (for the v1.0 board). The Diamond is brilliant if you don't have a VTX, but the drone kit i've bought comes with a 400mW VTX, so it makes more sense to use the Runcam on this build. Also the camera is a 480p 4:3 Ant, so 720p would come out stretched. For the same reason, if I put one on my Beta85, I would probably use the Runcam since it outputs 4:3 and 480p is a better resolution.

https://youtu.be/TWuey9bJ6YI?t=90

[Pathfinder075]

So I cheated. Due to my lack of skill and general lack of confidence in my soldering right now, plus the fact my soldering iron has a tip like a builders trowel, I decided to grab a cheap Radiomaster T8 Lite from HobbyRC, since they are on at £25 (in Special Offers). The radio will eventually go to my nephew, along with a copy of FPV Freerider, so he can learn the basics of flying and a D8 whoop will follow by Christmas (or maybe earlier).

Good news is I have almost all the stuff here (still waiting on some practice boards), except a usable soldering iron. I ordered a cheapo 60w from ebay with many tips, similar to iFlys iron. Turned out my Draper iron was only 25w and obviously not designed for small electronics. The new one comes with smaller tips.

I have two sets of solder now. 5m of cheapish 60/40 No Clean 0.5mm (could be anything but came from a fairly reputable electronics shop) and a small tube of TBS solder (which is what I will use for the drones).

[Lemonyleprosy]

I wouldn’t call it cheating.

Knowing the current limits of your skills and tools is a good thing. I have a habit of trying to make whatever tool I have on hand work, regardless of how suitable it is- it doesn’t usually end well for me.

[iFly4rotors]

Personally, I like things that have plugs and all you have to do is literally
PLUG Them IN and they work.