Hello,
New to forum here and hoping maybe someone could help me with something i’m trying to do. I have a small engine dyno that uses a lawnmower throttle cable. I would like to retrofit some type of electronic throttle control to this however they are out there but quite pricey. I’d like to build my own. With this being said I would have a lever for idle to full throttle that would continuously move the actuator as I run the lever both forward and back. It has to be able to stay in position not just fully retract and extend. I’d need some way to make the actuator work in relative to the lever in and out with the lever motion. I don’t know if potentiometers will work for this or how to even go about this. Also since I’m putting different throttle linkages to this I would also need to be able to have a knob where I could adjust the limit on the retraction to pull the throttle back so far as to not over pull the linkage. basically with actuator fully extended it would be at idle then I would bring lever to full throttle and use a knob (to be able to adjust the throttle limit on the retraction so only allow the stroke to retract so far on the linear actuator. Am I out of my mind on this is it even possible or not a prayer. Any help would be awesome. Simple wiring diagrams components needed etc. I’m not a techy or very good with electronics but I’m very mechanically inclined.
Thank you,
Matt
Hi Matt,
As much as this seems easy to achieve, there are not off the shelf systems that will cover all of your requirements.
To do it, the best way would be to use an actuator that can be controlled by R/C signal and use a Microcontroller to handle the different options needed like fine tuning the throttle.
If you can sacrifice some of your requirements, you could use a simple R/C servo control box with an actuator.
Simple Slider 2 Channel 180° Servo Controller
RC Servo / ESC Tester
If you can do it mechanically, you could use a standard R/C servo as well with a little linkage between your throttle and the servo. That’s how a R/C plane work. (thumb-20.jpg)
All of the Firgelli actuators labeled “PLC/RC” will take direct R/C signal as a position.
Thanks for the reply. I figured it would be more in depth but I know its done on larger dyno’s or at least a similar method. I thought maybe an arduino board and potentiometer to control actuator but I don’t know how to get the fine tune adjustment added nor how to program such things. 
Matt,
You can take a look at this “Arduino Knob Tutorial” it show how to take an Analog reading (with a potentiometer) and control a R/C servo (or a R/C capable actuator).
Thanks! I did see this or something of the like. and thought I could do it like this maybe. But if I have the potentiometer connected to the lever for full and idle throttle. how could I put another potentiometer or knob of sorts to limit how far I want the actuator or servo to extend or in my case retract. idle would be fully extended then full throttle would be retracting but I may not need it to always fully retract so id like to be able to fine tune adjust it.
Matt
Hi,
You can certainly use multiple potentiometers to both control the position of the actuator (by varying the pulsed width of the RC-type signal) and also change the minimum or maximum range of the pulse width.
We made a small example for you to check out doing exactly just this. You can find the code on the Lynxmotion GitHub here for use with an Arduino-compatible board, 3 3-pin potentiometers and a small RC servomotor (you can find some here). It should work equally well for a linear actuator that works in RC mode.
For our example, we used the RB-Elf-82. They come with the cable and are of good quality. We chose to use the BotBoarduino as our board because it comes with extra headers to connect 3-pin analog signals and 3-pin standard RC servomotor connections easily and has screw terminals to power RC servomotors separately, which is recommended.
We hope this helps!
Sincerely,
Ill check that out! Thank you so much! I feel a lil dense as i’m not too savy with this stuff yet figured it could be done some way.
Matt
Hi Matt,
With that setup, you should be almost ready to go by using the code provided and wiring the potentiometers like on the picture.
Thanks. I was wondering if I only use 2 potentiometers one to control servo motion. can I use just the other one to control the limit in one direction so it will extend the throttle fully and only pull back so far even if the potentiometer on the lever is brought all the way on direction. basically acting like a limit switch? And how exactly would I wire this into the board… I’m sorry This is all new to me.Matt
Yes you can. Actually, we updated the sample code so that it is easier to understand what needs to be changed (only one line, actually).
For the wiring, please see the picture in the README.md file in the GitHub here.
Sincerely,
Awesome!! Thank you very much. I may need a simple wiring diagram if I can not figure it all out myself. But appreciate the time and help!
Matt
Hi Matt,
We are currently working on some generalized representation of the BotBoarduino (for use in schematics) and we will be adding a wiring diagram to this project in the near future. We will update this topic when we do.
Sincerely,
Great! Thanks a ton!
Matt