I am trying to make a winch that can pull about 1 to 3 pounds about 6 feet of vertical distance as quickly as possible. I have found a winch for a servo and a servo that I was thinking about using.
I have no idea whether the servo can pull 1 to 3 pounds. Do you think it can pull one to three pounds?
If the specs are as stated, the servo can pull up to 3lb with an 18cm pulley mounted in place of the servo horn. This will be the fastest way of doing it.
Nor do I know long it will take it to pull the 1 to 3 pounds 6 feet. How quickly do you think it can pull 1 to 3 pounds? How long will it take it to pull it about 6 feet?
A shade more than 2.5 seconds (again if specs are for real).
Can the winch I selected even hold 6 feet of rope?
There's no reason to buy the winch kit at all, just make or buy a pulley that can be mounted on the servo.
How much "rope" a given pulley can hold depends on the diameter of said "rope", but for 3lb, a heavy polyester sewing thread will do. If spun thread makes the load spin too much, get some braided thread instead. For max strength vs diameter, us either carbon fiber thread or an aramide like Kevlar.
You are aware that you'll have to disassemble the servo and modify it to make it continuously rotating, as well as to provide a servo signal for running it?
You sure chose some expensive parts. Vex parts are expensive which doesn't surprise, but close to $80 for a servo from a Chinese site is ridiculous, especially when you factor in their usually very overrated specs and their up to several month delivery times and it's probbly a clone rather than a genuine Hitec part.This servo
is around twice the strength, which means you could double the diameter of the pulley and get down to around 1.25s for the 6' lift - and it's $11 cheaper.
This one will need to be modified as well.
Any particular reason not to use a gearhead motor (which will be stronger/faster) rather than a servo?
A better way to solve whatever it is you're trying to do, is to specify what you need (In empirical terms rather than approximations and subjective values), i.e. max 3lb (if that's the max) in n.nn seconds.
When the numbers are in place, you pick the servo (or whatever you need) that does this for the least amount of money.
Since you don't reveal the purpose, your options for powering it, or whatever's gonna drive it, I cannot say if this is the best solution.