combining two PWM signals

Hello,
im producing a servo controlled variable pitch rc chinook heli for my dissertation. I'm using 6 servos to control the pitch of the blades and a single brushless motor to control speed (which will be fixed) iv programmed an old rc controller and spliced in some lines and managed to get the 6 servos controlling cyclic pitch correctly but I need to add the elevation (collective pitch) element of the pitch to these servos.

The way control works is when elevation is changed all of the servos will raise or lower by the same amount depending on the input direction. The RC transmitter communicates this value fine to the rc receiver, which outputs a PWM signal ready to be plugged directly into a servo.
Is there a way I can input the PWM signal from the elevator and add it to the six other servo PWM signals individually and then output these new signals from an Arduino.

I was thinking maybe to convert the mapped PWM signals all back to digital values and sum them together, then re output the new signal on the PWM pins of the board. But am unsure whether this would work/how to do that? id rather not create an adc externally using a capacitor and resistor as it means id have to wait for components to arrive in these times of strife.
Im using an Arduino Uno r3 atm but will be transferring onto an Arduino Micro shortly, don't think this should make and issues as they both have 6pwm pins.

thank you in advance

You’ve posted in the wrong area , this is a project problem !

Conventionally this is done at the transmitter end where the analog signals from the sticks are combined as required , the result is then used to generate the pwm signal for each servo .
That is the way to do it ! ( you can buy this stuff )

Given the complexities of heli’s in general where you might need gyro stabilisation too , it seems a bit of a pointless exercise to try and do it at the RX end and will be hard to make work. Have you made/flown a dual rotor heli?

If it’s “homework” , you need to have a go yourself rather than get others to do it for you , then post specific issues , in the right section