[lotus197]

I need to know if a wiper motor can lift a 3 foot wide wood interior (hollow) door. They weight around 50 pounds. Anyways, The goal is to make a door slide open by hoisting it upward, I tried a standard winch but its way to slow, I would have to make something to bolt onto the motor gear to turn a spindal to retact and unretract line. If the wiper motor won't work, any ideas???

 

[vonroll]

I need to know if a wiper motor can lift a 3 foot wide wood interior (hollow) door. They weight around 50 pounds. Anyways, The goal is to make a door slide open by hoisting it upward, I tried a standard winch but its way to slow, I would have to make something to bolt onto the motor gear to turn a spindal to retact and unretract line. If the wiper motor won't work, any ideas???

Wiper motors have gobs of torque so I would think it would work for your purposes. The ones I ordered...i forget from where were 15 bucks surplus each and have two speed operation depending on which terminals you use on the motor.
Also, the wiper motors have an end (knob) on it for attachment but, you can drill that out easily so that the bar it uses has a hole instead.

 

[CaptnJackSparrow]

50 lbs 'mate? I be disinclined ta agree wit' Vonroll.. 50lbs be quite a weight, even thru several block an' tackles, savvy? Now, if'n ye was ta use a hollow door (abt 20lbs), might possibly work..

 

[Ugly Joe]

I believe wiper motors generate about 12-13 ft/lbs of torque, so if you have a small spindle to use instead of a winch, a wiper motor may very well lift a 50lb load...slowly (Cap'n Jack is on to something with using a lighter door).

Something I'd suggest is counter-balancing the door.
If the door's sliding vertically, is there room to just add another rope to the top, run it through a pulley, and hang a 25lb weight plate on the other end? You're effectively reducing the weight of the door by 25lbs, and the wiper motor may be able to move that load quick enough to make your prop work properly (heck, add 60lbs to the other end of the rope, and make the winch/wiper motor PULL the door into place - so when you release it, gravity will simply pull the door up and out of the way as quick as you need).

 

[vonroll]

yeah...I'm thinking there is no way that door weighs in at 50lbs. Those hollow doors (interior doors) are fairly wimpy and light. I can't even picture how this is moving the door though so, I could be over estimating the wiper motor's capacity. My tests just messing with mine, I was quite shocked at the torque. YMMV.

 

[dna1990]

Not worrying for a sec about if the motor can lift it...is this a doorway that folks will walk thru? If so, then 50# or even 10# suspending overhead is quite dangerous. Be certain to build in some failsafes, safety chain, something...

Does it even have to be a real door, hollowcore or not? Could it be made from foamboard or even cardboard? I assume this is not an existing regular door, if you plan to 'slide it up'.

 

[Clad In Shadows]

I believe wiper motors generate about 12-13 ft/lbs of torque, so if you have a small spindle to use instead of a winch, a wiper motor may very well lift a 50lb load...slowly (Cap'n Jack is on to something with using a lighter door).

Something I'd suggest is counter-balancing the door.
If the door's sliding vertically, is there room to just add another rope to the top, run it through a pulley, and hang a 25lb weight plate on the other end? You're effectively reducing the weight of the door by 25lbs, and the wiper motor may be able to move that load quick enough to make your prop work properly (heck, add 60lbs to the other end of the rope, and make the winch/wiper motor PULL the door into place - so when you release it, gravity will simply pull the door up and out of the way as quick as you need).

You will need a counter weight in order for the wiper motor to work good.
Personally I think the wiper motor won't have enough torque to pull the door up by itself and only because of the power you'll supply to the motor , unless you'll be using a high amp power supply.
Something to check into.

 

[redrom]

Seriously good comments. Looks like the heavier-than-door counterbalance is the way to go, so that the motor cranks the door back down, but opens swiftly. Hopefully that gives you the effect you need. Takes care of the safety issue too. Best to keep the counterbalance at the minium weight to do the work to take it easy on the motor and 12v power supply or battery.

 

[Frosty Don]

You will need a counter weight in order for the wiper motor to work good.
Personally I think the wiper motor won't have enough torque to pull the door up by itself and only because of the power you'll supply to the motor , unless you'll be using a high amp power supply.
Something to check into.

Ditto on that. If you get the counterweight just right the door will be practically weightless and it will also be a lot safer to walk under. I also agree with the others who say that a foam door would be a better idea in case it falls. Crap happens!

Don

 

[redrom]

Your winch might work too if you could somehow rig it to do this.