Hi everyone, I picked up a tricopter frame on clearance through HobbyKing and I need some help getting it in the air. I have a control board, motors, Rx, etc. The issue I'm running into is that I can't figure out where to solder the servo wires on the control board. I'm using this controller: https://store.flitetest.com/hobbywi...-flight-controller-combo-hwa38040302/p1008932. Any assistance would be greatly appreciated.
Assistance needed with a tricopter build
- Thread starter doc_mat
- Start date
Hi @doc_mat ,
I've got a few too many tricopters in my hanger to not be considered an addict, so I will try to help. What frame did you pick up? Pictures are always cool! Some of the details you are looking for will depend on what firmware you plan on running, the hardware design of the flight controller, and the type of servo (analog vs. digital). in general, you do not want the servo channel to be on the same clock/interrupt as your ESC motors. Servos do not respond as quick and usually run between 50 and 330 hz, and ESCs run up to 4Khz. So unless you want to run the ESCs at a really low update rate, they must be kept on different timers/interrupts. I am not familiar with that flight controller, so some research may be needed to determine what PWM outputs to put the motors and ESCs on. Analog servos can only run 50 hz update rate or less. Digital servos can run up to 400hz, but are usually 330 or less depending on the specs of the servo. You will also need a seperate voltage regulator (ubec) to power the servo. The 5V supply from the Flight controller and ESC boards are not rated at a high enough amp rating to drive a servo. You should use a 5V/2A supply at a minimum.
Cheers!
LitterBug
I've got a few too many tricopters in my hanger to not be considered an addict, so I will try to help. What frame did you pick up? Pictures are always cool! Some of the details you are looking for will depend on what firmware you plan on running, the hardware design of the flight controller, and the type of servo (analog vs. digital). in general, you do not want the servo channel to be on the same clock/interrupt as your ESC motors. Servos do not respond as quick and usually run between 50 and 330 hz, and ESCs run up to 4Khz. So unless you want to run the ESCs at a really low update rate, they must be kept on different timers/interrupts. I am not familiar with that flight controller, so some research may be needed to determine what PWM outputs to put the motors and ESCs on. Analog servos can only run 50 hz update rate or less. Digital servos can run up to 400hz, but are usually 330 or less depending on the specs of the servo. You will also need a seperate voltage regulator (ubec) to power the servo. The 5V supply from the Flight controller and ESC boards are not rated at a high enough amp rating to drive a servo. You should use a 5V/2A supply at a minimum.
Cheers!
LitterBug
I'll have to get some pics when I get home from work. It's not even on the HobbyKing website anymore. Lol. Unfortunately, every web search came up with places where I can purchase the control board (FliteTest was at the top a few times.) Even the HobbyWing tech support was at a loss on where to solder the servo wire.
It is an analog metal gear servo. It's a smaller one, as the hole on the turning mechanism is rather small. Once I get home from work, I can add in what model servo if that helps.
It is an analog metal gear servo. It's a smaller one, as the hole on the turning mechanism is rather small. Once I get home from work, I can add in what model servo if that helps.
kpixels
Antigravity or bust...
On my old Naze32 tri and a dRonin tri, I have the servo hooked to the yaw/rudder channel of the flight controller (all 3 leads). I consider LitterBug the tricopter expert tho, so now I'm wondering if Ive been doing it wrong. Hi LB!
The biggest concern I have is that the flight controller looks to only have 4 PWM outputs. It uses the BetaFlight OMNIBUSF4SD target, which I have similar boards laying around, so I should be able to figure out if it will work and come up with a channel mapping plan.
Servo: Metal gear is good, Analog... Meh... It can fly and will work. It should actually be OK for a long boom tricopter frame like the one you have. The small "race" tricopters I have do better with the higher speed servos. Just make sure you set the servo PWM update rate to 50Hz and no higher or the servo will probably burn itself up. Do you have a UBEC (5v voltage regulator) to use for powering the servo, or do you need recommendations. It should not be powered off the ESC or flight controller boards. They do not supply enough current to drive a servo and would most likely brown out if you tried to.
I have been flying mostly wings lately and have not been keeping up with the Tricopter scene lately. I have been playing with them a little on the bench, and have gotten away from the current status of the TriFlight software. I may have to do some digging on that front, but for starters, you could probably just set it up on BetaFlight to get everything going. I really really need to get my fleet flying again. Most of them are currently unflyable due to not being completely configured. I had been beta testing the latest triflight software and migrated some of them to new flight controllers, but never finished setting them up and flight testing them. Two of them still have the Old RCExplorer F3 flight controllers and I will probably roll back to a known working firmware and configuration. The other two, I need to get set up with the latest triflight firmware.
Cheers!
LitterBug
Servo: Metal gear is good, Analog... Meh... It can fly and will work. It should actually be OK for a long boom tricopter frame like the one you have. The small "race" tricopters I have do better with the higher speed servos. Just make sure you set the servo PWM update rate to 50Hz and no higher or the servo will probably burn itself up. Do you have a UBEC (5v voltage regulator) to use for powering the servo, or do you need recommendations. It should not be powered off the ESC or flight controller boards. They do not supply enough current to drive a servo and would most likely brown out if you tried to.
I have been flying mostly wings lately and have not been keeping up with the Tricopter scene lately. I have been playing with them a little on the bench, and have gotten away from the current status of the TriFlight software. I may have to do some digging on that front, but for starters, you could probably just set it up on BetaFlight to get everything going. I really really need to get my fleet flying again. Most of them are currently unflyable due to not being completely configured. I had been beta testing the latest triflight software and migrated some of them to new flight controllers, but never finished setting them up and flight testing them. Two of them still have the Old RCExplorer F3 flight controllers and I will probably roll back to a known working firmware and configuration. The other two, I need to get set up with the latest triflight firmware.
Cheers!
LitterBug
I could use recommendations for a UBEC. I'm a massive newbie when it comes to control boards. I still piddle around with my old Versacopter that has a Graupner Rx in it. Lol. I'm not planning on using this as a racer. More along the lines of a camera platform. The servo I purchased for it was as close to the "recommended" servo that HobbyKing had listed for this frame as I could get my hands on.
I run these for the UBEC on my larger tricopters.
https://www.readymaderc.com/products/details/rmrc-3a-power-regulator-5-to-6-volt-ubec
https://www.readymaderc.com/products/details/rmrc-3a-power-regulator-5-to-6-volt-ubec
Still trying to figure out if the Flight Controller can be used for a tricopter. From what I am seeing, the Timer and output mappings make it impossible since there are only 4 outputs, and they are paired up between two timers. Servos and Motors can not share a common timer.
The only option might be to remap an alternate pin like the LED output pin for the servo.
Hmmmm..... Found this from someone using another variant of the OmnibusF4SD and mapping the servo to the LED
DEF_TIM(TIM3, CH3, PB0, TIM_USE_MOTOR, 0, 0), // S1_OUT D1_ST7
DEF_TIM(TIM3, CH4, PB1, TIM_USE_MOTOR, 0, 0), // S2_OUT D1_ST2
DEF_TIM(TIM2, CH4, PA3, TIM_USE_MOTOR, 0, 1), // S3_OUT D1_ST6
DEF_TIM(TIM2, CH3, PA2, TIM_USE_MOTOR, 0, 0), // S4_OUT D1_ST1
The only option might be to remap an alternate pin like the LED output pin for the servo.
DEF_TIM(TIM4, CH1, PB6, TIM_USE_LED, 0, 0), // LED strip
Hmmmm..... Found this from someone using another variant of the OmnibusF4SD and mapping the servo to the LED
I think the cmds would be along the lines of:
resource led none
resource servo 1 B06
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I'm also looking at a setup like the old Versacopter that uses a receiver, but finding a way to use the control board along with the receiver. So I don't have to worry about soldering the servo wires, but then I'd have to find a way to get the Rx to talk to the control board which will be dealing with the battery and camera, etc
It all really needs to be controlled by the Flight controller. It should not be too bad to hook the servo up to the Flight controller on the LED out pin. You should be able to make a Female pin-header that takes the output of the UBEC, and the LED pin for the signal, then just plug the servo into that socket.
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