I am trying to control an actuator (firgelli L16-50-150-12-S). I have the “S” model (bought to test the output force only) and will need something with feedback “P” I believe. The motion I need to create is:
move to position upon power up
using a push button, move out at desired rate (to a maximum allowed distance of travel or until button released)
return to start position when button is released
The current test unit I rigged up is as follows:
115VAC to12VDC wall transformer 500mA connected to
PWM led light controller connected to
automotive power window rocker switch
this gives me speed control, movement based on rocker switch only. The end goal is to mount the actuator in a handheld case similar to a fireplace butane lighter. If I could contain the control in the case, that would be great but it could also be in the wall transformer. The final plan is for different end of arm jaws at the tip of the handheld. Having it battery powered and cordless are on the wishlist too.
Any help to source components would be great!
Thanks
Hoping for something smaller than the LAC from firgelli (50mmX50mm footprint). I am new so pardon my ignorance.
You’re best opting for a -I version which can be controlled using a normal RC servo signal. We offer some pretty small servo controllers:
robotshop.com/en/servo-controllers.html
Alternatively you can use a small microcontroller instead (programmable and you can connect buttons etc):
robotshop.com/en/microcontrollers.html
It appears the servo controller might work with a joystick board and is small enough. I have no experience with phidgets but it looks like they need to remain connected to a computer to function. Is this the case?
after a little more research, it appears that I need a microcontroller to do what I need. The nano is small enough to fit in the handheld body and am trying to find what I might need to drive the actuator itself.
after searching further, would an Arduino Nano 7-12V, 2A Dual Motor Controller
suffice for running the actuator? and does the -I version track position?
It can run a basic 2-wire actuator, and you can somehow connect the potentiometer to an analog pin, but it’s really not great.
The -I internally tracks its position so you can simply assign it to any extension, much like you assign the angle to an RC servo.
so if I have a nano, what else would be best for handling the current to the L16?
If you still want to use the -S model which you have, the Arduino Nano cannot provide the necessary current, so you’ll need an intermediate brushed DC motor controller.
If you want to use the -P model, you’ll still need a brushed DC motor controller, but you can then also connect ground and the potentiometer wires to the Nano to get positioning.
So, with the -P option actuator, would this suffice to drive the actuator?
Pololu Dual DC Motor Driver 1A, 4.5V-13.5V- TB6612FNG
robotshop.com/en/pololu-dual … 12fng.html
and if so, I think I would need the following to have programmable control over the actuator
arduino nano (mainly for sizing)
motor driver (above)
L16 -P actuator
also, a push button or some kind of switch
The L12 only needs 0.65A at stall, so the 1A motor controller is fine.
The rest looks good, and the last things you’ll need will of course be power and wires.
I ordered all the previously mentioned components and also picked up a wall-wart (120 vac to 12vdc 1.5A) adapter for power. The output of the adapter measures 14.2V and while in range for the arduino, it is above spec for the motor driver board. Any problems with using as is? or suggestions if not.
If it’s out of spec, it’s really a matter of how susceptible the board is to voltage just beyond what’s indicated. Honestly don’t know, but the 14V may be an absolute maximum for fully charged 12V batteries.
Got the breadboard circuit wired and enough program to move the actuator with a pushbutton. Nothing smoked as of yet and I also noticed the sparkfun version of the driver board is rated at 15V, the same as the chip. I don’t know how long it will work with the higher voltage but it is working for now. Just gotta dust off my programming skills now.
I am working on the code for operating the actuator and am finding that when I try to stop at a position (actuator has potentiometer output (0-5V)) I blow by the position. What would be the best approach to stop at a given location? If I reduce the PWM signal, it is better but won’t stop at a position. Firgelli L16 actuator with Pololu TB6612FNG motor controller and Arduino nano.
Your code should always be reading the position and then stop the controller as soon as it is reached. If you want something smother, as you get to within a % of the desired position, start slowing down.
According to the truth table for the motor driver, there are 3 short brake settings and stop. Is one better to use than the others? The % away is a good idea. First time using one of these. It works, just need better control.
We see the “short brake” under H-SW, but the manual does not give any details as to their differences, so unfortunately we cannot provide any input in this regard.
The “stop” function (high impedence) may be more powerful than the brake, but you’ll just need to test it.
Ok, I will try it. Thanks.
