(04-Jan-2024, 06:32 PM)SnowLeopardFPV Wrote: Using tweezers to grip the wire on the silicon coating close to the tinned end of the exposed wire can also help to precisely hold it in position over the tinned pad while soldering. If you find it difficult keeping pressure on the tweezers while holding it in position to solder, try some reverse action tweezers which will grip the wire for you automatically. You obviously still need a steady hand to hold the tweezers in position, but this is how I do it and I get precise joints every time doing it like this even on the tiniest of pads.

As already mentioned, drown the pads in flux. More than you think you might need then it won't just smoke away to nothing when you apply the soldering iron tip. It is easy enough to clean off any excess afterwards with isopropyl alcohol and a small toothbrush / Q-tip. I personally find those flux pens useless because they only apply a thin layer of flux which just burns away to nothing as soon as you apply any heat. I have a tub of flux that I spoon/dab onto the pads with a small flat-headed screwdriver, and I also have a syringe of MG Chemicals flux. I use whichever seems most appropriate for the job that I'm doing.

Yeah the flux thing is part of the problem.  This pen kinda works for spot repairs, but it isn't viscous enough for major work.  A tub of flux and a couple of syringes of something more hardcore is probably a better idea. 

I have now stripped pads of two FC, yet when I use the practice boards I have no issue. :/  I think for 14xx or less, connectors are the way.  For anything bigger a 4-in-1.  I ordered some more AIO's with connectors and will keep micro builds to 3S or less. 3 inch or bigger, will use stacks (for ease).

Also my hands are not steady.  i can nullify probably 80% by withholding medication and coffee, but I still have a tremor.  Anyway, I will get there.  Thanks.

(04-Jan-2024, 07:02 PM)mstc Wrote: Plugs are certainly convenient, but they are pretty rare on larger motors. I can only think of the Happymodel 1404s that come with plugs. Maybe solder up a set of race wires/leds with larger pads to a connector, and solder motors up to that instead.

I guess with shaky hands you will have to rely on helping hands/putty to hold the wire in place and apply pressure in the correct direction to set the wire once the solder melts. But maybe breaking the soldering into two steps (join then position) might still work. Hopefully your AIO is still good, the old AIOs seemed to be a lot more hardy than the more recent ones.

I was curious and popped open my build. The solder job looks pretty ugly, but it was functional and flies fine. The 1408 has 22awg wires, and there is decent spacing between wires (mostly). I think if you can get the middle wire on cleanly, then having ugly side wires will still work.

You have better soldering on that board than mine.  I did try and solder to the connector pins as well, with limited success.  Also wondering how you got a 1408 on to that FC, I looked but the amp draw is way beyond 12A on my 1408.

Back in the day, this was released as a 20A board. It seems there may have been a 25A version as well. (Edit: seems 25A is just the burst spec) Question is how did it get turned into a 12A board, revised specs or overstated specs?!

https://www.happymodel.cn/index.php/2020...toothpick/

My build is a light 4" toothpick, 1408-3800kv budget motors. Forget now how high the amp draw went, but imagine it was more than 12A.

A first/second version of the CrazyF411 that they currently sell. I thought the CrazyF411 only recently came out in the last year, but i guess it existed prior to that.

Maybe you are thinking of the CrazyF411 ELRS, that is pretty new. This diversity frsky board came out... 4 years ago in 2020... so pretty old by drone time. But as with all drone manufacturers, giving products same/similar/confusing names seems to be the norm (I think it was originally named CrazyBee v3 something).

Looking back, my 4" pick actually started with 1505 motors and was promptly smashed in a crash and rebuilt with 1408 motors.

Yeah my one is Crazybee V3.1 and it seems the CrazyF411 was the improved version that shipped with Cine8's, manufactured after 2021 (i think). Mine didn't come with the 20A one for some reason, nor the updated OVX306 VTX. But it's fine and still works ok, But not having ELRS does irk me a little. Still I could technically fix the VTX to use the buzzer or LED circuit by remapping, which would open up UART1 for the ELRS. Not really bothered right now to do that.

So made some changes.  The new versions parts are as follows.

The Parts


Datasheet



So it really isn't helpful in this case. The 2750kv was only tested on 4" props. :/ The 4850kv were tested on 3" but still not helpful. Funnily enough the 4850kv motors are what i would like a set of down the line.

Weight




So started work on it again.  I have put the 1404 motors on it, sorted out BF and got it assembled only to be thwarted by one of the motors. So I removed the prop screws and now it flies, but if I do a punch out on these motors without prop screws it will lose props for sure.  It's still twitchy when you first arm, the motors spin up but not uniformly.  When you plug in and it does the startup beeps, it does the first set, twice.  Normally it only does them once.  I don't know if that is relevant.

Could it be an issue with minimum startup speed?  It seems as soon as the gyro works out it isnt level it speeds up the motors and we reach equilibrium.  I wonder if increasing the min speed a bit might improve it.

So this bird uses FrSky D8, so hopefully the whole thing is working as it should, but won't know until I take it out.

I intend to take it out tomorrow if I can, but we'll see.  i don't have anything charged yet.

Hi Pathfinder,

You know, I have found that data sheets are really only valuable for
certain props and more likely than not, they don't show the props
that I want to use. It suggests that they think other props will not
work, but they will. Hmmm. 

Now, the prop screw issue is interesting. From my experience, most
motors come with M2 x 7mm prop bolts. Presumably, because most
props are 5mm thick at the hub. That leaves 2mm into the bell housing.
Sounds ok, but I have noticed that not all prop hubs actually measure 
5mm. Hmmm. There could also be a clearance issue between the stator
and the bell housing inside the motor. With some props, I have needed 
to use 6mm bolts. I would try the motor with a prop bolt, but not fully 
tightened down and see what happens. 

Just as a test, you might try nylon bolts, but don't over tighten them,
just snug them up and see what happens. This is just a test as I have
never used nylon bolts on the props to actually fly since they would
shear pretty easily if the prop hit something. Anyway, just a thought.

Later, iFly  

I see you have only one prop screw in the photo, probably not a good idea as that may throw the motors out of balance. It may depend on the batch, but my HM 1404s shafts fit extremely snuggly on the prop and even the 3500kv on 4S with 3.5" props don't need prop screws to hold them down, but unfortunately the shaft will snap in a crash instead so the prop screws are needed to prevent that. And it is odd you say one motor will not spin with prop screws installed? Maybe your prop screws are too long and double check you have not damaged the windings. Did your 1404s come with super long motor wires?

It will be interesting to see if you can get it to fly on 3S, it would probably have a very high hover point and not enough thrust. For a few more grams I'm guessing it will be happier on 4S.

I'm using something by 7mm screws. Same prop screws I use on the 1202.5's without issue. I guess they changed the depth on the screw holes on the 1404.

I have some pan heads that I could try that might shave 1mm off them. The one screw per motor was just for the hover test. I have since had it hovering on a 3S. Hover point for 3S is about 35-40%, but not an unexpected level. I intend to fly some 3S packs as well. On 4S it should be lower, but not sure I want to hover stuff in my bedroom on 4S. 3S is sketchy enough.

As to the long wires, yes. WTF level of long. i wrapped them around the frame about 5-6 times to get rid of it all. The other thing i need to be careful of with this build is the antennas, as I have like one spare beyond this. but I have them arranged now in a T shape on the top so should get good coverage. Also the RSSI value is working, but not dbm, so I should have an idea of signal strength while flying.

But on the whole I think this build will rock on 4S and be more sedate on 3S. I usually like to start with sedate for a couple of flights then go to hardcore level after that, so it suits me. I will do some final checks and stuff tonight, but all being well I will take it out for a spin tomorrow. But it's cold here so no idea what sort of flight times i'll get.

So while reading random threads on twitching motors, the consensus seemed to be to increase idle by 5%. So i have no clue how to do that, but I know there is a minimum throttle setting in ESC Configurator, so I went there and it was set to 1148. So I increased it to 1200. Most of the problem is solved. There is still one motor that twitchs a little bit. A number of threads also said to switch demag compensation off, but I don't know what this actually does, so i left it at Low. I think I still need to increase Min Throttle a little more, maybe a couple of notches.

So the amps used element is basically wrong I think. It reckoned I used a max of 7A on 3S and 4S to hover. Even given voltage to amps scaling it seems off. But it does hover. At around 50% on 3S and 30% on 4S.

I look forward to testing it out tomorrow. Charging packs now. I will be taking 2x Tattu 3S 450 Lipo, 2x CNHL 3S 550 Li-HV and probably 4x CNHL 4S 450 Lipo and maybe some 4S 450 Li-HV. Ideally I want 8-10 packs.

(08-Jan-2024, 03:03 PM)mstc Wrote: It may depend on the batch, but my HM 1404s shafts fit extremely snuggly on the prop and even the 3500kv on 4S with 3.5" props don't need prop screws to hold them down,

I actually thought the same until I was ripping Flea in misty rain, like drizzle, did a throttle punch and popped a prop (at around 30m up).  Been using screws ever since.

So this quad has no cap on it.  I was going to but it means desoldering the power leads and given my propensity for destroying boards I decided not to risk it.

twitching prop means it cant figure out bell position.
at very low rpm, voltage is super low.

1. magnets damaged or demagnetized from heat

2. back emf voltage resistor network damaged (maybe resistor not 100% soldered.

3. motor wires bad cold solder joint.

As soon as I add throttle to it, it goes away, so is that more low voltage?

1. Brand new motors. Unlikely.
2. Unknown. Possibly beyond my skill level / pay grade. Sounds like the sort of problem Lemony would know how to fix.
3. Maybe, but connectors came on FC straight from the factory, so no idea, it's not my work.

Would increasing minimum startup power in ESC Config, from 0.5A to 0.75A be worth a try?

So I took it out for a spin and the motors on the left side definitely have issues. For testing I will remove the 1404's, replace with 1202.5 and see what that handles like. If it still has issues, then it's probably the ESC's.

One weird thing I noticed. My first packs were 3S and it didn't spend all that long in the air, but it did fly for a fair bit, with minimal problems. But on 4S the problems really started. Most of the time it seemed to not make it off the ground. Maybe it is a bad solder joint on the connectors or maybe the motors. Can't see a way of checking without removing the connectors and then putting them back could be interesting.

Another problem is the VTX is too high and one of the props is hitting the plug for the camera. Need to maybe move from using the tall gummies, to using the smaller ones.

I will put some videos up later. FTR, it did fly, just not the way I wanted it to.

2750kv is very very low for 2,5inch. i commonly use 8000kv on 3s or 6000kv on 4s.
i believe thats the issue. uncommon use might need uncommon settings.

i believe you need to choose 24khz, motortiming to high and screw up the startup power step by step, maybe up to the max possible.

i use the 4800kv version of the ex1404 on 3s batteries and 2,8inch props on my cinewhoop. i like them.

sadly the board can only handle 4s batteries, i would fly 2750kv with 2,5" to 3,5inch on 6s :-)
two 3s batteries in series, two 550mah 3s is a lot energy that might fly very long if gently on the throttle.

maybe give the motors a try on a 6s capable board?