Need choosing flight replacement stack for 90mm self built Quad

[DevilWAH]

Hi, I built the Quad bellow but I need a new flight stack for it, the one I have is running 20A ESC but and keeps crashing (i mean the software locking up not my flying!) It was cheap and as I can now tell nasty.

The quad is 90mm, weights about 150 grams, I looking to run 3s batteries and RX1105/B 6500kv motors.

So I wondering what is a good 10amp 4in1 ESC (motors are designed to run at 10amp continus current) and a good FC3/4 Betaflight compatible FC.

I also find the motors run very not at the moment, not sure if this is FC, Tuning or some thing else but the quickly reach 80 degrees + in just a 30-16 second hover.

If I can get this flying nicely I will post the Cad file and parts list , It is designed so that the top plate can be removed and you can run it as an open prop quad where it weighs around 110-120 grams with battery.

EDIT!! - Forgot to say I am running a DSMX / DSM2 radio gear, but I have a satalight receiver so dont need to be part of the FC stack

Oh and 20mm mounting holes for the FC

 

[PsyBorg]

It is very common to have motors run hot when not tuned properly. I ran into the same problem with my Gremlin build when I was flying a fat 187 grams on 3s batteries. I could hover for maybe 20 to 30 seconds and have to let it cool a bit while I changed settings. Took a few days of that before I found a happy place where it ran reasonably warm while being in the air for the full duration of the flight battery.

It is nice having things in a stack but that also limits air flow to keep esc's cool. Then as the esc in the stack heats up that in turn heats the flight controllers. More then likely the AIO you have is going into thermal shut down to protect itself. This is one of the reasons I stay away from AIO esc's. The other is that if one dies you have to replace the block of four and not a single esc.

The Femto board that is in the Emax power pack is an F3 controller but does not have mounting holes. There are stl files that people have made to 3d print mounts for them so they can be put in a stack though. Other controllers such as the ones Litterbug is working with for Dronin support are also very good. I have no idea about those though so you would have to ask him for specifics and recommendations.

As for AIO esc's the only ones I know of are the KISS aio's and I am sure they are in the 30 x 30 package formats.

 

[ElectriSean]

I run a Sunrise Cicada 12A 4 in 1 ESC on my Creampuff, works well so far on DSHOT600. The Racerstar's on Banggood are the same, just rebranded and a little cheaper if you don't mind the wait from China. I'm also running a Micro Lux F4 FC but I wouldn't recommend it... No vbat monitoring, can't bind speksat rx's and you need to plug a battery in to power the Rx. I had a Furious PicoBLX in before that, but I'm pretty sure the 3.3V regulator was spiking and killing my receivers, so I can't recommend that one either. I have one of these on the way to try out, can't go wrong at over 50% off https://www.banggood.com/Micro-20x2...ted-with-BEC-OSD-p-1132495.html?rmmds=myorder

 

[DevilWAH]

thanks for the thoughts,

can i ask in what way did you find you had to aduject pids to solve the issue? up or down?

 

[PsyBorg]

Beta flight pids have such a huge swing where they can be effective. I first thought I was getting a better tune going down. The after some reading and videos I saw they can sometimes be up in the 70's. Each controller and quad set up will be different so specially on something small trial and error is the only way.

Just be sure to set your rates before trying to tune they are more important then pids some times on different gear.

My entire process is documented and all my settings are posted in my build thread for the Gremlin if you want to take a peek. I suggest the rates for any quad as I use them on all my set ups now. There is also some auto level settings for Horizon mode that really softens the movements when using leveling mode.

The pids may or may not help with your set up so I still recommend you working them up yourself rather then copy mine.

 

[DevilWAH]

Cheers for the input guys, i will carry on having a play then to see if I can reduce the temps. When you say setting Rates, any hints on what to look for in rates these are not some thing I have played with much do you know of any guides of where to start with these, tune them down?

I had tried tuning down, and tweaking the filters but with not benefits. I was reading that lowering D can help but not in this case.

Think i need to find a good document for tuning rates and pids..

Aaron

 

[ElectriSean]

Rates and expo are a pretty personal thing, they are easy to adjust and play with though. I find the default betaflight rates to be pretty tame, but they can still go down (or increase expo a lot) if they are too much.

Tuning PIDs can take awhile to figure out, but here are a couple guides I've found useful:

 

[PsyBorg]

Sean is spot on with either of those videos for tuning. Personally I like Skitzo's better but that requires an hd cam for the finer points. Stingys method is ok and gets a decent tune. I only tried it once so far. I don't agree with him stopping so early on the p gains though. Of course I fly different as I do freestyle AND race on my Alien so I need a happy medium between smooth and tight.

Rates how ever I use the same rates on all my quads now. here is a picture of my rates and pids. You can try those pids but when that tune was done my Gremlin was a pudgy 187 g so they were adjusted for a heavy bottom. You will probably have to go higher I gains and maybe lower D gains on a lighter Gremlin size quad.

You can see a very nice shape on the graphical representation of the rate profile I use. Very soft at center stick and really snappy at full deflection. I like yaw with zero expo and pretty high degree per second. Makes tight fast turns very easy yet graceful for freestyle still. You have plenty of wiggle room in the expo but I seriously doubt you will need much more then.15 -.20 at most.

 

[DevilWAH]

Hi, sorry for not replying been out of the country for a few weeks. I will have a look though this over the next few days. When you talked about rates I was thinking you wher suggesting specific rates to reduce temp but i get you now

Cheers for the help.

 

[DevilWAH]

I was just looking at blheli config and i noticed that all the motors where set as 1180us min and 1872us max (i think it was), I assume I am correct in setting this to 1000 - 2000 to match betaflight?

 

[ElectriSean]

I was just looking at blheli config and i noticed that all the motors where set as 1180us min and 1872us max (i think it was), I assume I am correct in setting this to 1000 - 2000 to match betaflight?

I believe those numbers are set when you calibrate the ESC's, I wouldn't mess with them.

 

[DevilWAH]

Numbers don't change when calibrating. they stay to what ever they re set to in BLheli calibration tool.