Johnholiday09:
I need to figure out how to program an arduino board to accomplish these design specifications, for a winch listed below:
No load retract speed of 5 fpm.
Dead load pull of 250 lb.
Variable pull force controller by a microprocessor with 5%.
Used braided cable designed for pulling with a factor of safety of at least 5 based on working load.
No overhead pulling, horizontal only.
Length of the cable 5 feet.
The motor is a Tenshock RC906 1750KV 6 Pole Brushless Motor For 1/14 1/10 Axial Wraith Crawler Black Dia 3.175mm.
Can anyone please help point me in the right direction? I'm unsure how to start and what all I will need in order to accomplish this. Thank you.
I built a crane almost from scratch to lift a solder pot out of a soldering machine. The first thing you need is a drum to wind the cable on. And then a way to drive it with your motor. My drum and motor are mounted parallel in an aluminum frame with ball bearings on the drum shaft. The motor drives the drum with a chain drive. The solder pot weighs about 50 pounds.
You cannot use the motor shaft and it's bearings to pull something. Particularly if the motor bearings are sleeve bearings.
Using a BLDC without Hall sensors is going to be tricky, they don't hold stationary.
Basically you need servo control loop, current sensing, position sensing and suitable gearing.
To be able to sense pull force using the motor current the gearing has to be efficient and not too high a ratio, with a 5% tolerance this could be tricky (you need friction to be small or very constant).
You wrote:
4) Used braided cable designed for pulling with a factor of safety of at least 5 based on working load.
That implies you are using deep sea fishing line. Will it be made of copper wires?
Braided cable will not lay properly on you drum, as it winds in. Round cable will slip beside the previous turn and lay flat on the drum. Especially if the cable is lubricated.
My crane uses 1/16 inch steel cable rated for 90 lbs. Your project will require at least 1/8 inch steel cable.
The calculations all change if your cable begins a second layer of turns on your drum, because the radius is now longer.
That looks like a bare motor with no gearbox. You are going to need some serious gear ratio to make that work.
There must be dedicated winch gearboxes available. Maybe with the drum and motor included. Keep searching.
Variable pull force controller by a microprocessor with 5%
5% of what? You want the pull force controlled to within 5% of a target? That is surprisingly difficult to do. It is relatively easy to control the drive current to the motor to high precision but the force on the cable is only somewhat related to the motor current.