Screw Drive/Worm Gear

You cannot do it. This is a job for the Gate-makers. Call them.

Nope!

Together, we can do anything...

Remember it only weighs 2200lbs and from horizontal it only needs half of it's mass to be picked up.

All of the other suggestions, including the squirrel, will work, but, a simple application of a 12v 2000lb winch will do the trick, applied as per Chris' pictorial.

See!

Easy.

Stu.

First, counterweight the bloody thing. Then put a chain drive off a gearbox.

A simple system of pulleys, wire rope and a 2 ton winch will do the job. The drum of the winch will have 2 lines (1-each side) attached to the top corners of the door. As the drum turns, the 2 wire ropes will wind (or unwind) equally to raise or lower the door. The wire ropes will be guided through pulleys (sheaves). There are more complicated (expensive) ways to accomplish this, but this is the cheapest way.

Do you think that it could be counterbalanced, and driven by a squirrel in a cage?

Please send me a PM with any further suggestions.

Welcome to the insanity.

ronseto's suggestion should work well for you in many ways. If you can counterbalance it some, the winch can be working less, and be of lower power. If, you have electricity,so much the better. But, if not, you can use a gasoline, or diesel powered winch.

If you want to avoid cables and pulleys on the gate- to leave the sides of the gate open when it is dropped, use a system of counter weights (driven by a ball-bearing screw system) attached with a hinge to rigid "up-rights" (when the gate is down) and a cable attached to the inside wall of the gate and to legs attached to the drive motor assembly.

As the ball-bearing screw moves the counter weight away from the gate, it will begin to raise the gate and the uprights with the screw-drive motor attached will begin to rotate toward the horizontal. As they move away from the wall, the cable will pull the top of the motor backward, causing the ball-bearing screw and the weights to maintain a horizontal position. At the end of the gate lift, the counterweights will be fully extended and nearly horizontal, near the ground.

Lowering the gate will draw the weights back toward the gate posts, allowing the weight of the gate (which will be about 85 degrees from horizontal) to cause it to begin to fall back down until it is fully down at 5 degrees below horizontal and the weights are fully retracted near the posts attached to the gate (now at 85 degrees from horizontal).

Paper machines move large rolls on arms to move them from one position to another. Up to 10 tons or more. They use large quadrant gears at each end and a large gear ratio to an electric motor. A parking brake is used on the motor so the arms (your door) doesn't move in intermediate stopped positions. If a variable speed drive is used a regenerative or dynamic braking system is usually required. If the gear train used a worm reduction that couldn't be over run then the brake is not required.

Long screws could also be used, or a rack and pinion arrangement.

If counterbalanced properly could be open and closed by hand.

Counter balancing weights, dampened by simple hydraulics. (for safety)

i.e. a hole in contained pistons to slowly release the air / oil / whatever
to control the speed of fall, even with the restraints broken.

With the correct weights and bearings it could be a pleasure to use!

Just my sort of "cow shed" engineering. (plenty of room for error.)

jt.

It's not the quantity you eat, but the amount you enjoy, that counts.

And, if you are limited by what size motor you can drive your wench with... check out paragraph 6-7.

JavaHead

For driving a wench...battery power!

for driving a winch battery power. for the wench - praise, money and jewelry.