OT? TV Lift: power Ideas?

[DiezMon]

Hey guys,

I'm building a custom TV Lift. I'm thinking of using a motor with high torque that drives a basic block-tackle pulley system. Without getting into electical engineering and power: I was thinking of using either an old cordless drill, or corded drill.

I'm just curious.. How come most cordless drills come with a switch that lets you choose low speed/high torque, or high speed/low torque? Corded drills don't usually have this. Is it simply because the 110v motors can deliver more torque?

It would be cheaper and easier for me to use and old corded drill. But, a cordless type has a more reasonable speed when switched on the high-torque setting. And I imagine since it's geared, the higher RPM may be better for the life of the motor.

Input? :)

Thanks,

Tim

[RicodJour]

Not sure about the weight of the TV and stand you're lifting but how about an electric wheelchair motor and a drive belt instead of a block and tackle setup? Tons of torque and some real low speeds.

R

[Joseph Meehan]

Garage door opener? :-)

[Jmagerl]

a garage door opener motor should lift a tv

[DiezMon]

I'm sure a garage door is plenty strong, but I'm looking for something small.

I forgot to mention that this lift will be mounted inside a cabinet.

:)

[Tony Hwang]

Hi, Generally if the motor is same size, DC motor is more powerful than AC motor. Also it's easier to control speed. Look at Diesel loco. which is driven by DC motor. Small high tourque motor with low RPM.... You can find one at RV shop. They use it for moving front stabilizer jacks up/down. They are pretty strong. They are 12V motors. Tony

[Goedjn]

I should think you'd have better luck using a threaded rod and a big-ass nut. If you want to use cable, don't use a block and tackle, use a windlass.

[Jim Yanik]

"DiezMon" wrote in news:6T%pe.297501$ [e-mail]:

The GEARING multiplies torque.The motor turns the same RPMs for both ranges,just the gearing changes,slower range multiples the torque more.

Corded motors have much more electric power available,thus they can use more powerful motors.

Why don't you try a scissors type lift mechanism(like a scissors jack for a compact car),you have less complexity,drive the screw with your motor.

[Mike Dobony]

4 threaded rods with a chain sprocket and connected by chains. It will go up smoothly and easily by driving any one of the rods.

[HeyBub]

Think hydraulic. One teeny-weenie hydraulic motor and piston can lift TONS.

I've seen hydraulic positioning motors, taken from old mainframe disk drives, used to manipulate an elevator in a hay barn. Motor was about 1/3 hp and it pushed 4000+ pounds up 16 feet.

'Course a piston that long was a search...

[DiezMon]

Well, I seem to have my terminology wrong then, I essentially am using a windlass like this:

Bit I'll have four pulleys, and one driving shaft, if that makes sense..

I'd thought about 4(or three) threaded rods and nuts, then a chain drive.. Would this take a while to lift though? It'll need to lift roughly 3' and I don't want to have to wait 5 minutes for each lift ;) Although, that's just being anal.

[Pop]

[Goedjn]

The time it takes to lift the set is going to be directly related to your mechanical advantage, it doesn't matter how you derive that mechanical advantage.

The drawing shown with the windlass is a bit odd, since it looks like both ends of the rope are winding around the axle, which makes the pulley useless. What I was evisioning was skipping the pulley, and replacing the hand-crank with an edge-driven wheel, of whatever size it takes to get you the mechanical advantage you want.

Sort of like this:

[Bob_M]

[Pop]

"Bob_M" wrote in message news: [e-mail]...

I can't find it right now, but ...

1. Try here; I couldn't be sure it's there because I wouldn't accept the Flash download and the parts charts wouldn't load.
2. Try calling a local Singer Service Center and ask them about sourcing it for you.
3. Here are a couple links, mechanical and electric, from google "sewing machine lift" Sorry, have to run - more later; try google * see if ht helpsas

[nospambob]

[Anonymous]

Go with a DC motor.

Not sure if a windshield wiper motor could deliver the torque to move a TV. If so, they're cheap...$15 or so.

[DiezMon]

Yikes, where to begin??

[DiezMon]

Yep, that's basically what I had in mind, but I'll probably build it to use direct drive. Since I won't be using a gear ratio, like in this drawing, I figured the block-tackle would help with less load on the motor..

Tim

[m4rcone]

It's not useless. It's needed because rope is being transferred from one part of the axle to the other (note that the ends don't go to the same side of the axle). And since the two parts have different diameters, the pulley will be moved up or down (as well as laterally).