I'm using pad "1" for the Servo with a PWM rate of 330Hz.. (Digital Servo running on 7.5V) From there just wire up the motors as you would any Quad.

Granted, this can also be done using Betaflight but from my own experiances with Beta, its not too Tri friendly. Specifically, tuning is a major pain, especially with a custom rig like this. PID's have to be kept low and worked upwards as even the slightest increase cause instability. You can surmise that this takes a long time and thus is not for those new to tuning.

The updated frame and tilt-mech are super stiff. Just waiting on the PDB to arrive for the rebuild ising the new Akion 4-in-1 esc. The last ESC from DYS could not handle basic dShot without desyning like crazy.

Quality 20 x 20 gear is difficult to find and in short supply everywhere.

Here is the new frame and tilt-mech.
https://www.thingiverse.com/download:6609360
https://www.thingiverse.com/download:6604648

sounds like your design's been let down a bit by electronics, and idk man, there are a few really excellent 20x20 4 in one escs, I've seen people have good experience with ones like the ori and even my own cheapo spedix 20x20 20a is holding up good with 2205 2450kv motors on 5152 props which is a pleasant

A few things about why...

I'm residing in Germany so my access to gear is a bit more limited. The build is further restricted to FC's currently supported by dRonin. (Matek F405 / Kakute F4) From this, i need to find something that supports 20 x 20 form factor and can safely drive a servo @ 6-8 volts.

I had considered using gear thats focused towards Betaflight but i know from experiance that its not very Tricopter friendly.

Right now the big hold up is this thing...
Lumenier Mini 4Power + Plus PDB (20x20mm, 5v/8v Reg, 100A Curr.)

Note: 5V for the FC and 8V for the Servo.

Have had it on order for over a month and its not shown. Word is that its been discontinued.

may i make a sugestion. brushless esc will run a brushed motor you have a spare ,
use it to run the servo , it can be done,

I took a look at this concept and was only able to find stuff on Arduino thats very dated. (May no longer be relivant considering how much our hardware has changed)

This I next saw this... https://www.instructables.com/id/Simple-Electronic-Speed-Controller-ESC-for-Infinit/
Unfortunately, this is also driving the Servos direction rather then allowing the Servo to be controlled directly via PWM. (No feedback wire either)

Do you have a link showing how this can be done using BLHeli ESC"s ?

just use it as the power supply

So how?

Unless I've missed something...

Most ECS's dont have BEC's, at least not in the range of 6-8v. Those few that do work as BEC's only work to 5v and are rated to 0.5-1.0 Amps. Keep in nind that most servos can easily draw 3-5 amps stall current.
Side Note: Other then using a dedicated BEC / UBEC, I've also used this... http://flyingfolk.com/BEC-Mini-Spannungswandler-FREI-EINSTELLBAR-fuer-FPV-Step-down-Voltage-Regulator

My aproach would be to take the output from 2 phases of the esc . add a couple of zenner diods and a cap .

That may cause issues for the ESC as it would be expecting the EMF feedback.

Then there is also the issue where the Servo feedback wire wouldn't be tied directly to ground. This Feedback wire allows the Triflight algorithm to sence the physical position of the Servo / Tail-Mech providing for a smoother flight. The sensed voltage is tapped from the Servos internal potentiometer, showing the differance between the center pin voltage and ground. (based upon the position of the Servo) This output is usually 2-3 volts output depending on the input supply for the Servo. Now, if the ground were floating, this value could be off signifigantly. Likely resulting in a loss of control of the Copters Yaw.

I've worked with electronics a bit, having retired from the Naval Lab. There "we" test, service and repair everything from Fluke DMM's to Jet engine test cells. Sometimes its fun stuff as we get to mess with pretty much everything.

Would a digital servo suite

Yeah... far as i know of what currently have is Digital.

Pros: Faster, less jitter, higher PWM rates , often better torque.
Con's: A bit more expensive

Best to run the Servo at the highest voltage and PWM rate it can handle. This allows the response, torque and stall current to be much improved. I try to run at 7 volts / 330 hz if the hardware permits.

BLUEBIRD BMS-101HV

Digital Controller 12-Bits ( 4096 Steps ) / Frequency：333Hz / Neutral：1520us, 6.0V ~ 8.5V input.

New frame is very good. Can hardly bend it, yet its so thin.

Thus far its much stiffer than the earlier 2” whirlygig and has tons of power. So much so, i have to scale the motor back by half. Yet still the TWR is 4:1 !

Only issue i have this far is that the DYS 4-in-1 F18 ESC is garbage. Dam thing has had issues from the very first moment. Everything from it not keeping Sync with any protocal other than dShot-300 to motors that sputter in flight. Will replace with an Aikon unit tomorrow. Motors ohm out fine so i dont really have any other option but to toss the DYS.

Edit: Powered up the Aikon ESC alone to have it short out instantly! (WTF)

Brutal.

Ok got the ESC issues sorted out and installed the new frame. This frame is reenforced with Carbon-Fiber inside the Nylon. While this is a little more expensive to have printed, its basicly indestructable, short of jumping up and down on it.