Yeah, this is the Roma F1 1104(6) 7500kv motors.

It’s flying great, except for vertical power. As I said before, I don’t need to be able to throttle punch to the moon, but, I do need to be able keep it from smacking into the ground.

I’ll definitely follow your suggestion and try a 3s battery before swapping out the motors (as a side note, I knew I should have added motor connectors to this build- I swap components around far too much to direct solder).

I’ll have to make a 3x 1s harness tomorrow, all of my batteries are 1s or 2s.

These motors are only rated for 2s, so I’m guessing I’ll have to monitor motor temp after flights.

If the do overheat, I’ve got some used HGRLC Flame 1105 6000kv motors on the way that are rated for 2-3s. So, lower kv but faster on 3s than the current motors on 2s. I was planning on using them for a 3” build after I finish the Sector25CR, but they can go on this little guy if needed.

My 2.5 inch GEPRC Phantom (analog) has 1103 8000 Kv motors and I run 3s (both 650 and 1100 mAh) batteries all the time without any motor heat up. I figure it will be ok, but check motor temp anyway.

By the way, I use connectors on my motors most of the time because I, too, tend to change things a lot. For small motors and FCs that have the connectors on them, I use the same JST 1.25 3 pin connectors as linked in a prior post. In fact, some of the smaller motors come with these connectors already attached to the motor wires.

For the larger motors I use standard 3-pin servo connectors. Yes, they are a bit larger, but work fine and fit ok on a 4 inch build. 

Also, I made both a 2 x 1s to XT30 and a 3 x 1s to XT30 connectors a long time ago because I have a bunch of 1s batteries for my tiny whoops which I do still fly {mostly in the house}.

In fact, I use connectors for just about everything which makes it a lot easier to repair, upgrade, or just change components. Since I wire all of my XM+ and R9MM receives for SBUS, these two receivers use the same connections so I can interchange them freely by simply unplugging one and plugging in the other.

Here is a picture of the electronics package of my Tiny-Black-85 whoop build.

The 26x26 diagonal whoop mounting format AIO boards have gotten powerful enough {actually more powerful than many stacks} to power 4 inch and even 5 inch quads as well as whoops and toothpicks, I have pretty much standardized on that format. I generally have a few of them rated from 25 Amps to 55 Amps in my parts bin. These boards fit my whoop builds all the way up to 5 inch builds. Well, one of these whoop boards is going in a 7 inch build. So for me, the "whoop" format AIO FC board is pretty much a UNIVERSAL fit...use it in anything.

Some of the bigger whoop boards are a little tight in a 65mm whoop frame, but still work. Now, on an 85mm whoop frame {which fits 2 inch props} all of boards fit just fine. 

So, it really doesn't matter what I decide to build next, I always have an FC board in the parts bin that I can use. 

Again, this is just me, but I only buy boards that have the extra UARTS which are the F405 boards and any F7xx boards; that way I always have enough UARTS for a GPS unit, TBS Crossfire receiver, or what ever else I want to add.

I’m all for connectors/plugs. I’ve got a pack of those same ones that I usually solder to my whoop boards that don’t come with plugs. I wish I could find them with silicone wires.

I’m thinking I need to stick to aio/whoop/toothpick style boards for these builds. I bought a stack for the Roma because I was intentionally trying to over complicate it, but…

The Roma F1 is having some serious overheating issues. I’m getting core temp warnings and it’s heating up to the point where it’s almost too hot to touch. I reached out to the manufacturer and they think it’s just not getting enough airflow.

I don’t have any other 20x20 FC options that will fit in this tiny little guy, but, I do have a GnarlyFPV Sub Atomic frame which is almost the exact same thing except it has 16x16 FC mounting pattern and was designed to use a JHEMCU ghf13aio. I’m going to check tonight to see if it has enough clearance to fit the Roma F1 prop guards, if it does, then I’ll probably get a ghf13aio in my next parts order.

Yeah, it would be nice to find the JST 1.25 3-pin connectors with silicone wires, but so far I have not found any. If you find some, please let me know where. On the positive side, I have never had an issue with the ones that I have.

Sorry to hear about the "over heating" issue with the Roma F1. That is an iFlight Succex stack...very interesting. It does look a little "packed" in there. 

First, if that "shield" plate is still there, remove it. It is covering the FC board and NOT allowing air to flow over the board. Basically, it is holding the heat in.

You know, I haven't had an FC board overheat, BUT the VTX generally gets REALLY HOT which might just be heating up the FC board. So...just as a test...You might try relocating the VTX     

You could just mount it off to one side and let it hang out (at least as a test). 

Another option would be to zip tie the VTX to the rear vertical standoff column similar how I have mounted the VTX on my Katana-LR4 build (picture). Since your VTX already has mounting holes, I would consider just zip tying it on the rear column.

If you are top mounting the battery, you could mount the VTX  under the bottom frame plate. Now, I realize that you wouldn't want to leave it there, but you could try it just to see if the FC board runs cooler. 

If moving the VTX solves the heating problem, then that means the VTX is what was heating up the FC board...and...that the stack is probably ok.

Hrmmm, good suggestions, thank you. The shield isn’t in place, but it is awfully tight in there. I’m hoping that you’re right and it is just the vtx- it would make sense as the top plate above the vtx gets really hot to touch.

I’ll check to see if there’s a place I can safely strap it on to. I also need to fix my settings and reload the vtx table so that the irc tramp thing actually works. It isn’t currently, and prior to it having heat issues I was using the button to try to change it to raceband 1- I’m willing to bet that I managed to crank up the power at the same time. If that’s the case, I may be able to leave it where it is.

Thanks for pointing me toward the vtx, Harry. I accidentally had that thing at way too high of a power level. I’m gonna put a few batteries through it tonight, if I still get a heat warning then I’ll find a place to strap it away from the stack. If it still overheats after that, yeah, it’s the stack and a certain manufacturer owes me a refund or replacement.

Side note: without doing a significant amount of sanding and hacking, the Roma F1 prop guards will *not* fit on a GnarlyFPV Sub Atomic.

I’m getting started on the Sector25CR build tonight. Semi-final component list:

-Diatone Mamba F722 MK1 AIO flight controller (I picked this up for $36 at RDQ on clearance- I wish I would have bought a few, but I’m glad I got one before they sold out). This build was going to use a JHEMCU GHF420 AIO, but I decided to save that for a 3” build I have planned after this that doesn’t have a 25x25 mounting option.

-Flywoo Robo RB 1204 5150kv motors
-Rush Tiny Tank VTX
-Runcam Nano 2 camera
-Speedybee vtx antenna 
-RX: Jumper R1, Flit10, or an XM+. XM+ if downgrading its firmware allows me to actually bind to it, but if I get frustrated it’s getting one of the other two rx.

I decided to try hydro dipping the Sector25CR frame. It was my first attempt at hydro dipping, and it was a spur of the moment kind of thing. I saw some vinyl frame wraps on the google and thought, “hey, I wonder if I could…”

The results were… well, let’s just say that I should have practiced on something other than this frame first. I initially tried using some pearlized acrylic airbrush paint that I have. It was too thick at first and once I thinned it out it was too thin- I ended up just using nail polish. Apparently what I should have done prior to adding the acrylic paint is thicken the water with corn starch or carrageenan powder.

I ordered a cheap hydro dip kit from Amazon that includes paints that are made for this to try on a future build.

We’re just gonna say that this frame now looks unique. I’m not saying it’s ugly, but I’m not saying it’s not.

The good news is that the paint didn’t add any measurable weight.

I put 4 batteries through the Roma F1 without getting any heat warnings or having any part of the frame or outside edges of the stack heat up to an uncomfortable level, yay! Winning!

The Sector25CR is coming along slowly, I’ve got lots of wires to splice and things to solder. Compared to the Roma F1, this thing has *so* much room. It’s nice.

Hi Lemonyleprosy,

I am glad changing the VTX resolved the heat up issues with the Roma F1 build.

Personally, I like the way the Sector25CR frame turned out. It looks pretty cool 

Now, you are going 

I’m making slow progress on the HGLRC Sector25CR.

We’re not gonna talk about the shitty xt30 cable solder connection. I’m usually better than this, I swear.

Everything for the Sector25CR is wired up. It’s gonna sit for a bit while I fly other things so that the conformal coating can dry.

I haven’t tried to bind the xm+ yet, but I did downgrade its firmware. If it still won’t bind, I’ve got some ELSR gear on the way and it will get that instead.

I really struggled with soldering onto this flight controller, and I’m not sure why. I’ve got 2+ decades of soldering experience, I’m more than capable of through hole and surface mount soldering, and I prep all of my surfaces appropriately- rosin on wires, boards get hit with 99% isopropyl alcohol and then liquid flux.

I’ve got a more than decent soldering and desoldering station, however, my fine point soldering iron is a cheap pos- I’ll probably use this as a valid reason to buy a better fine point soldering iron (anyone have any suggestions?), but I think it’s probably more likely that the manufacturer just used some weird alloy for the soldering pads.

Also, the Sector25CR is gonna use another caddx ant nano- I bought a cheap one from someone’s bench clearing sale, and I figure I should use the highest resolution camera I have available for each build.

(26-Aug-2021, 04:49 AM)Lemonyleprosy Wrote: I really struggled with soldering onto this flight controller, and I’m not sure why. I’ve got 2+ decades of soldering experience, I’m more than capable of through hole and surface mount soldering, and I prep all of my surfaces appropriately- rosin on wires, boards get hit with 99% isopropyl alcohol and then liquid flux.

I’ve got a more than decent soldering and desoldering station, however, my fine point soldering iron is a cheap pos- I’ll probably use this as a valid reason to buy a better fine point soldering iron (anyone have any suggestions?), but I think it’s probably more likely that the manufacturer just used some weird alloy for the soldering pads.

Hi Lemonyleprosy,

I suppose anything is possible, but I have never had any problems with the pads on FC boards.
The Diatone Mamba boards are generally pretty good boards. So, I would assume the board to be ok.

However, several members who are very skilled at soldering have had issues with "bad" solder.
It seems some of the "off" brands either have the wrong mix of lead/tin or the mix is not consistent.

It sounds like you have plenty of soldering experience...so you probably don't need a tutorial.

Anyway... Here is how I solder...

I use a cheap $15 60W AC soldering iron that I have had for years. I have the temp set at 425 C degrees and the temp setting wheel is taped so that it doesn't move. I like it HOT. Yeah, sometimes I catch some flack about that, but it has always worked well for me. I like things to heat up quickly, solder quickly,  get out quickly.

     Some people say that you will burn the pads off if the iron is too hot, but that just isn't the case.
     You burn the pads off by leaving heat on the pad too long. The longer that iron is on the pad,
     the more heat dissipates to other components. The hotter the iron, the less time spent on the pad.

I use a conical tip for everything. Yeah, I know, a lot of people like the chisel tip, but I like the conical tip better. I like that the tip is pointed rather than flat. For me, it is easier to focus the contact point of the tip without getting too close to other things. Now, I have tried those really thin "needle" like tips, but do NOT like them. For some reason, they don't seem to transfer the heat as well as the conical tip that I use. The conical tip works for me.

I also use Kester 63/37 .020" (.5mm) solder which is very thin, high quality, and has a precise melting point of 183 C degrees. The .5mm size is extremely thin and easier to apply to tiny pads than the thicker solder. For tiny electronics, this solder works better than any other that I have used over my many decades of soldering.

Yeah, plenty of flux. I use a flux pen on the FC boards, but have other "paste" type flux for wires and such. 

I  always tin everything first...pads, wires, what ever.

I tin the pads by touching the solder to one corner and the tip of the iron to the diagonal corner. When the solder melts {in about a second or two}, done. Some of the smaller pads do require a bit of finesse. 

       I really like those notched side pads...they are easy to tin and the wire sinks in nicely.

I set the tinned wire on top of the pad and use the tip of the iron to apply very slight pressure. The hot iron melts the solder and wire sinks into it. Done.

Just in case you want to take a look...

[Tutorial]  How to Solder - Principles, Technics, Etc.  

It’s possible that it’s the solder, I opened a new roll recently. Haven’t had any problems with the brand in the past, but that doesn’t mean much.

I also like my iron *hot*. I’d much rather be in and out quickly than have to sit on a pad. I also prefer 60/40 or 63/37. I tried using lead free stuff for audio gear a few years back, it was horrible to work with and started growing whiskers.

So, my shopping list is now new solder and a new fine point soldering iron with replacement tips.

I was really hoping I could do the maiden flight of the Sector25CR tonight, but it did not work out how I planned.

After downgrading the firmware on the xm+, it still wouldn’t bind to my transmitter.
Yesterday my order of an ELRS tx module and a few receivers arrived, so I decided that the Sector25CR will be my first elrs quad. So, most of my night was spent setting that up.

ELRS was surprisingly easy to set up- it only took me a few hours of screaming at my computer, telling  it to just do the damn thing.

But, now my tx is talking to the rx, so, winning.

It’s a bit of a rats nest of wires, but once I decide that yes, this is the FC, vtx, and motors that will live on this quad then I’ll trim things down.

As a side note, my second attempt at hydro dipping a frame came out really well- but it’s not part of either of these builds- I’ll add pics on my next build log.

Hi Lemonyleprosy,

It looks good to me.  

I really like those prop guards 

Yeah, I generally have a bunch of extra wire to stuff in somewhere, but that doesn't bother me. Sometimes, I just stuff it in there; other times, I fold it up and tape it down. I am more about how it flies than how it looks. After all, I fly between 300-400 feet...so can anyone really see it up there...yeah right