DC motors

[bhargo6516]

hello all

I'm currently designing a winch like product that will use a small DC motor to tighten the coiled material. My question is will the DC motor allow the material to be pulled by hand in one direction to then be tightened in the other direction by the DC motor or should I seek an ac motor as induction will move more freely?

 

[waross]

My question is will the DC motor allow the material to be pulled by hand in one direction

It depends.
With a permanent magnet DC motor there may be some cogging. How difficult that will be to spin will depend to a large extent on your type and ratio of gear reduction.
Without a lot more information it is not possible to give a better answer.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[bhargo6516]

Understood the idea is that this device would be pulled out in one direction to a certain length then tighten the rope or strap on the object securing it to a flat surface applying a certain amount of downward pressure to secure it. using a high power low torque motor with a decent amount of gear reduction would that elevate the cogging problem and allow for the motor to apply that downward force on the object?

 

[waross]

decent amount of gear reduction would that elevate the cogging problem

If there is a cogging problem, that will make it worse.
We have no indication of the forces involved.
You may not have any issues at all.
But the higher the gear reduction, the harder it will be to pull slack.
Many electric winches have a mechanical clutch to allow slack pulling.
Some electric winches must be drive in reverse to pull slack.
Have you considered a starter and ring gear salvaged from a small motor cycle?
The winch could free-wheel and the motor will only engage when it is energized.


--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[bhargo6516]

Thats a great idea that would solve the main issue I'm facing, have it only power on when it needs to be tightened and free moving when it's not engaged. also, a locking mechanism to keep it from coming loose until the person using it needs the thing that is secured. one more question if I were to use a starter motor with it only being used let's estimate 29-40 times a year would a rechargeable battery be an option let's say if it's placed in an area that doesn't have easy access to an outlet? keep in mind it would only need to pull 1 to 5 feet of slack per use most of the time. appreciate the help!

 

[waross]

I had two twenty horse power outboard motors with electric start but no charging system.
I used a 12 Volt automotive battery.
The battery easily started both motors for the summer season without a recharge.
One summer we spent about 30 days on the Yukon river, travelling from Whitehorse YT to Dawson City YT, plus a side trip up the Pelly river and a couple of hunting trips up McClintock Creek.
Other summers saw a lot of recreational use.
Based on that I estimate that your battery solution would work.
You may want to consider using a current limiting controller.
With a full 12 Volts applied, the torque may be excessive when the line tightens and the motor stalls.
You may consider a pawl on the starter flywheel to hold the line tight, if you use the starter option.
Release manually or with a solenoid.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!