How to control pan & tilt head with a 2-axis joystick & 2 knobs?

Help & Support Robot Parts
1

I’m new to this forum, very excited I found such forum and here is my question hoping to find the answer:

I’m building a pan tilt head for my camera . something similar to this one:

robotshop.com/productinfo.aspx?pc=RB-Sct-128&lang=en-US

I will be using same motors : 20 rpm - 12v - 1 A stall current and of course two of them one for the pan and other one for the tilt.

I don’t know how to control those motors in a similar way as above pan tilt system in a way that I will have a 2-axis proportional joystick controlling both motors plus a knob for each motor to further fine control its speed and smooth motion.

For the joystick I thought of using this 2 axis type:

robotshop.com/productinfo.aspx?pc=RB-Sct-283&lang=en-US

and both motors will be same as:

servocity.com/html/20_rpm_precision_gear_motor.html

I thought of choosing this dual DC motor speed controller which I’m not sure if its useful or overkill:

robotshop.com/sabertooth-dual-regenerative-motor-driver.html

in conclusion: My budget is very limited in a way that the head controller box which includes the joystick and 2 knobs with their wirings and requirements should not exceed $ 120.

Your support is highly appreciated.

Regards

2

guys,any one can help please?

3

Thanks CBENSON for the reply.

from what I understand from those motor controller is that I will end up having proportional joystick control on each motor which is ok.

But I need further fine speed control on each motor which should be controlled by a knob for each motor. to reduce the speed interval of each motor while using the joystick,as shown in most of Pan Tilt head systems, they have one 2-axis joystick controlling both motors and also a speed controlling knobs for each motor controlling its speed interval as it is a required thing for better filming.

example 1:
servocity.com/html/mpt1100-ss_pan___tilt_system.html

example 2:

in this example there one knob for further tunning the speed of both motors:

thecinecity.com/eshop/Proaim-Jr.-Pan-Tilt-Head-with-Joystick-Control.html

example 3:

creativevideo.co.uk/index.php?t=product/glidecam_glidecam-vista-head

thanks for the support

Regards

4

I’m really sorry, But i still didn’t understand how to do it properly and how many parts I should buy?

(I forgot to mention that I’m a civil engineer and I hardly passed my physics 2 course related to electrical stuffs :confused:)

So I attached this diagram for easier answer so that I will understand :slight_smile:

pan tilt project diagram-dashti1767.jpg
pan tilt project diagram-dashti1767.jpg1275×1650 346 KB

5

You’re on the right track. The motor controller you chose is more than enough for the two motors, and there is the option of analog control (so you can connect each of the channels to one of the outputs on the joystick). You can certainly choose a less expensive and less powerful Analog DC motor controller (5A max per channel for example like the Sabertooth).

6

The setup they have is a bit custom, and there are two ways of doing it:

  1. electrically (the knobs provide resistance which reduces the maximum speed - you can simply wire these with the joystick
  2. use a microcontroller for full control; the joystick and knobs would connect the the analog inputs and you would create code to combine the two and output the desired signals to the motor controller.
7

Adding two analog potentiometers (one associated with the joystick, the other associated with the knob), the voltage will be reduced as compared to if you had just one. You should be ok wiring the outputs together, as well as the V and GND.

8

We cannot make the design for you unfortunately, however, you should be able to make the proper connections using the products documentations.

The principle behind using a potentiometer is to make a voltage divider that will create a voltage analogue to its position. The signal is the used by your motor controller to drive your motors accordingly. Wikipedia is full of resources about voltage dividers and you can find many readily made examples on the internet.

9

I see …
Which approach is more accurate and which one is easier?

I was thinking to go for first approach ; Electrically to wire two knobs to the joystick reducing the maximum speed. so can you please help me choosing the proper knobs and how to connect them to the joystick ? considering that I will go with motor controller you suggested me earlier: sabertooth Dual 5a 6v-18 v and for the joystick I will use the 2 axis joystick :
robotshop.com/productinfo.aspx?pc=RB-Sct-283&lang=en-US

thanks again for the prompt support…I really appreciate it.

Regards