Trying to build project...need to know what kind of motor to buy

[scratch17]

I am building a project that will need to lift a very thin sheet of aluminum (12" X 18") up and down at set time intervals. Any ideas or what type of motor this would be. Hopefully very small? I am a complete rookie when it comes to this..... I would really really appreciate any help!

 

[Sceadwian]

Very thin is a relative term, not a metric, 12x18" is a metric, no way to determine weight without a specific thickness though. 'up and down' again it's a relative value not a specific orientation vs the flat plate you're referring to. Moving a 'flat' plate up and down against it's major dimensions as opposed to it's ends will be a VERY different situation relative to moving the same plate up and down if it's oriented on end. And more important WHAT you want to do might help us suggest things that you may not have considered.

 

[KeepItSimpleStupid]

We need to also ask if the "up" and "down" limits are fixed.

 

[ronv]

Don't know where you are located but there are some cute little "DC Gear Motors" on Ebay.

 

[scratch17]

Thanks for getting back to me! I have been away for a few days. I am building a project that is very hard to explain but I will try my best. It will be a shape of a rectangle box about 2 foot long and 1 foot wide (to give you an idea.) On both of sides I will cut out a side that will look like doors. Put them on hinges of some sort and need to them to raise up and then back down. The weight should not be much at all since it will be aluminum, do not know the exact width but the thin enough to bend easily. I will have a cable or line attatched to the cut out piece. When it raises, it will pull it up the bottom of the door, where a side is open to the inside of the box. When it goes down, it would be flush to the outside of the box. This is my first time to try something like this but I am very interested in learning about this. I am really just looking for what type of motor would be the most simple and inexpensive. Sorry its vague

 

[ronv]

Usually they are cheaper than this.

**broken link removed**

 

[KeepItSimpleStupid]

You still didn't say how high is the lift and how fast. Synchronous motors work nicely at low RPM and medium torgue. They have 3 wires and a capacitor. One wire is common terminal and you apply HOT to one or the other side of the capacitor to get a change in direction. Speed is inherently constant.

How do you plan to drive this thing? Common mechanisms are "rack and pinion", "linear bearings, gear and chain, a linear actuator (usually way too expensive), hydraulic (very heavy loads), air cylinder, Pull from a drum.

The pain is usually the "linear bearings"

This is where "how far" comes in. Is it 10" or 10 feet?

 

[jpanhalt]

I would just use a cheap hobby servo. They are easy to control, and positioning accuracy for even the worst would be as good or better than you are likely to get with a continuous rotation direct-drive or gear motor.

John

 

[OlPhart]

Cable and windlass offer flexibility in direction of force, even multiplication by block and tackle methods. Limit switches can be actuated by a cable clamp or higher tension on an idler arm. <<<)))

 

[KeepItSimpleStupid]

Remember counterweights can be used too.

 

[colin55]

Buy a windscreen motor from a wreckers.

 

[scratch17]

Thanks a lot. That helps. Length should be around about a foot or so. I am trying to have it stay open for time intervals like 4 hours and shut. May be too tough to pull off but thats what I am looking for. Thanks again!