Hello, I am new to Arduino. I am in Computer Science with little knowledge of engineering. Could you please help me to select the parts? My requirements are as following:
Two-link robot arm with one joint. One link is fixed horizontally on a desk-like platform and the other link is connected to a load of 80-100kg.
The link between the motor and the load is about 5-10 cm long.
If possible, I want to be able to turn the motor clockwise or counter-clockwise using both methods shown below:
a) a remote controller. For example, one button for clockwise turning and the other for counter-clockwise turning. To be used both indoor and outdoor under different lighting conditions (please suggest product also)
b) control via C/Arduino programming
If possible, record the data of the motor rotational angle and which button was pressed when a change in turning direction happened. I think I need to attract an encoder at the end of the motor (please also suggest product)
Could anybody please recommend Arduino board, motor controller that can supplies that much current, motors with gear set, encoder, etc?
It's not clear if you want to lift the load (which would be hard work) or just rotate it which should be easy if the mechanical pivot is well designed.
First thing you need to do is get an estimate of the force needed because that will determine the spec for the motor.
If it is fixed to a desk it sounds like it only needs to rotate through part of a circle. How far does it need to rotate? That will indicate options for how the motor can control the motion and for how to keep track of location.
How fast does it need to rotate - that will also have a bearing on the motor power and mechanical design.
Compared to all this the control stuff should be simple.
A diagram of the proposed machine would be very helpful.
Thanks for the reply. Rotation from 0 to 90-120 degrees is good enough. One end of the mechanism is fixed on a platform while the other end is connected to a load being hanged. I guess if it can rotate for 90 degrees in about 1.5 seconds. That should be fast enough. The setup is like:
P---------M--------
D |
Load
P stands for platform, D stands for a desk and M stands for the motor. I define the current configuration as 90 degrees.
You are not going to do this with a motor connected directly to the load. you will at least need gears. 100Kgm is a lot of weight to swing around. You will even need to know the length of the arm before you can calculate any motor requirements.
While your diagrams might describe to you what you have in your head, they don't do it for others.
petercohen:
Hello, I am new to Arduino. I am in Computer Science with little knowledge of engineering. Could you please help me to select the parts? My requirements are as following:
Two-link robot arm with one joint. One link is fixed horizontally on a desk-like platform and the other link is connected to a load of 80-100kg.
The link between the motor and the load is about 5-10 cm long.
That implies a torque of 100Nm, meaning a gear system is definitely required.
If possible, record the data of the motor rotational angle and which button was pressed when a change in turning direction happened. I think I need to attract an encoder at the end of the motor (please also suggest product)
Details matter here - if the encoder is on the arm it will need more resolution, if on the
motor much less (due to the gearing ratio). Without knowing more about the actual
physical components its impossible to select a product. Note that gear motors with
built in encoders are available.
Could anybody please recommend Arduino board, motor controller that can supplies that much current, motors with gear set, encoder, etc?
First you work out the torque speed and power needed, then find a gear / motor
system that's going to work, only then can you think about the motor driver!
You suggest 1.5s to rotate 90 degrees, which is about 1 rad/s (10rpm), so with 100Nm
torque as the load that means 100W (power = torque * angular velocity). Allowing for
spare capacity and losses in the gearing that implies a motor of 100W rating for
light duty, or 200W for continuous duty I would think. 200W motors with about 0.5Nm
would be fairly easy to find, implying about 300:1 reduction gearing to give >100Nm
at 10rpm.
Reducing the arm length or relaxing the speed requirements would allow a smaller
lighter motor of course.