Stuck figuring out my first quad build...

outthayr

Active member
Do you have a picture of the frame that clearly shows the FC? Looking at the end of the video I see the screws in the 30x30 FC mount holes which would mean it needs to be at a 45 degree angle. The 20x20 holes point forward.

LB

I see what you mean now. My FC board is 45 degrees facing to the front left (as per the instructions from FlexRC)

cranialrectosis said:
Put the yaw back to normal and reverse yaw in your transmitter.

Okay, I'll try that.
 
Last edited:

LitterBug

Techno Nut
Moderator
Yaw reversal in my TX seems to only affect my sticks.

315 or -45 does not align the quad - 180 on the Yaw is the closest to responding correctly. At some point I hit reset settings and now even when I enter the info back in as I had it the BF 3D model still isn't responding with the movements of the quad.

Try 135 and 225 then....

Cheers!
LB
 

outthayr

Active member
I think I see your over lap with the things you are trying to do with switches. Try setting them this way.

Thanks, I'm actually just now seeing this. I managed to separate my 2 free channels by switching them on the transmitter. Now I'll try to work with them in BetaFlight.
 

outthayr

Active member
Wow!

Got my first smooth flight in. Perfect. Felt good. Although, the power has cut out completely two times now - just for a split second and then motors get power back. The quad will freefall for a foot before lifting again. Any idea what could cause the power surges?
 

LitterBug

Techno Nut
Moderator
Wow!

Got my first smooth flight in. Perfect. Felt good. Although, the power has cut out completely two times now - just for a split second and then motors get power back. The quad will freefall for a foot before lifting again. Any idea what could cause the power surges?

AWESOME! Glad you are making good progress! Is anything getting HOT? Ie motors, ESCs? Can you catch it on video and post it up so we can have a look at what it is doing?

Cheers!
LitterBug
 

outthayr

Active member
Nothing seem so to be getting overly hot.

Here's a video of the power drop.


*Just cut the D settings in half and changed ESC to DSHOT150 from 300. Flew for a couple minutes without a power drop.
 
Last edited:

outthayr

Active member
Flew two batteries today and although the power drop isn't happening as frequently it's still happening. I feel something is amiss as the battery drains too quickly. Suggestions?

Maybe some bad soldering on the 5v stepdown?
 
Last edited:

PsyBorg

Wake up! Time to fly!
I would look more towards signal interruption. If it were 5 v loss the FC would stop and reboot. That looks like a fail safe and a re connection to control to me. If it were power related the quad would reboot. Start by checking the antenna wire on your receiver. Maybe move away from electrical devises that radiate any type of signal like things talking on wifi and such. Also check antenna placement. I can't see how you routed them in the video. Straight up off the top is preferred straight out the back secondary. Under slung on a quad not such a great idea specially when low to the ground due to multi-pathing and other wave propagation. Oh and also check the solder connection for the signal wire to the FC from the receiver you could have a cold or cracked joint there.
 

outthayr

Active member
Oh and also check the solder connection for the signal wire to the FC from the receiver you could have a cold or cracked joint there.

This seems likely as I was a little timid at first with my soldering. Once I did a few and figured out I could boost the heat of the gun my connections got better. I'll revisit the signal connections.

I thought it might be something to do with the Spektrum RX - as I read something about it functioning on 3v and not 5v, but I also read it doesn't matter as much going over, you just can't be under 3v. On the Sirin FC I think there is a 3v connection somewhere? Should I try to route the Spektrum to the 3v instead of the 5v?
 

ElectriSean

Eternal Student
Mentor
I thought it might be something to do with the Spektrum RX - as I read something about it functioning on 3v and not 5v, but I also read it doesn't matter as much going over, you just can't be under 3v. On the Sirin FC I think there is a 3v connection somewhere? Should I try to route the Spektrum to the 3v instead of the 5v?

You definitely should be giving it 3.3V. 5V may work for a little while but it will eventually fry it.
 

PsyBorg

Wake up! Time to fly!
Yes if you hooked that receiver to 5v and it requires 3v that would certainly cause problems and possibly fry the unit. That is more then likely the issue now that you say that. If things are heating up they will fail.
 

outthayr

Active member
You definitely should be giving it 3.3V. 5V may work for a little while but it will eventually fry it.



I see 3v marked on the board, but I'm not sure where exactly to connect to. Would I attach the red wire from the Spektrum RX just below where it says 3v? I can power up and poke around with my meter just to make sure ...



IMG_3668.PNG
 

LitterBug

Techno Nut
Moderator
That is a bridge pad. You need to take a soldering Iron to it and remove the blob going between the center post and 5V and then lay a blob down between 3V and the center post. Double check the manual for the FC though. I have not used one of those boards, but that is normally how the RX voltage is set.

Cheers!
LitterBug
 

outthayr

Active member
That is a bridge pad. You need to take a soldering Iron to it and remove the blob going between the center post and 5V and then lay a blob down between 3V and the center post. Double check the manual for the FC though. I have not used one of those boards, but that is normally how the RX voltage is set.

Cheers!
LitterBug

Eek, I don't know what or where the 'center post' is. I metered the 3v pad and it read 3.3 so I hooked up the Spektrum hot wire to it... should I change that? Is center post the hole next to it?
 

LitterBug

Techno Nut
Moderator
Eek, I don't know what or where the 'center post' is. I metered the 3v pad and it read 3.3 so I hooked up the Spektrum hot wire to it... should I change that? Is center post the hole next to it?

There are 3 pads there not just a 3v pad. Looks like ||| on the board with no solder. Two of pads (Center and 5v) are soldered together so it looks like O|. If you drag a hot soldering iron across it, it should lift the blob that is shorting the center and 5v pad. May have to dig through box of FCs to find one without the blob to post up....

Cheers!
LB
 

LitterBug

Techno Nut
Moderator
Here's the documentation from the Sirin web sight. I circled the section of interest in yellow.
Untitled.jpg
Which UART is the RX connected to?

Cheers!
LB
 

outthayr

Active member
LitterBug, I think I see what you mean. Although I believe the 3v pad is actually a rectangle and not a square. So it's not touching the neighboring 5v. Is that what you mean?

Or wait no, you're saying there's another pad under the 5v pad ... and I need to solder that away then bridge center to the 3v.

And so would that mean I need to solder the RX wire back with the other wires. Because I soldered it directly to the 3v pad...

*UART 3
 
Last edited: