Power Pocket Door!? Help needed!

[thejava1]

Hello all, as you can see i'm new to the forums, but i was hoping there will be some creative people here to help me with my "problem". In any case, what i'm trying to do is make a pocket door (a door that slides in/out of the wall) opperate on its own! There are kits to do this, such as for handicapped people, however these kids are Very expensive, so I was wondering if anyone out there has solved a simmilar problem before, or at least where to even start.

My vision was to have the door open as I approuched it, however i'm also attemping (in the works) to build my own touch sensitive buttons (capacitance... maybe resistance if i can't figure it out :P) so button activation would work too... The door does not have to be super responsive, i'm doing it for the cool factor, i'm not handicapped myself. (starwars, perhaps startek effect).

One last thing, the area has only just been framed, so i have an easy area to work with. I have also considered a type of mat to go under the carpet. But turning it on/off is not my entire problem, mainly, what should i use to move the door? Obvious problems are that the door needs to open if the power is out, so hydralics could be problematic. I've wondered perhaps ways to do it wiht magnets, as the break down rate would be minimal, and they would be sighlent. hmm... lemme know what you guys think! price is sorta an objective, i cant blow hundreds on it, so stay a little realistic with your creativity Thanks!

[HayZee518]

ok, first I am thinking to use a chain and a couple of pulleys connected to the door with a counterweight with enough of weight to open the door. to close the door use an air cylinder. BIMBA makes a lot of thin cylinders. for detection maybe you could make use of an outdoor motion sensor - use the sensor to open the door [de-energize the cylinder] and a timer to close the door. an electric eye at floor level could detect a body or object to stop the motion. and upon removal of power the counterweight will open the door.

[thejava1]

good idea!

a pully system would be easier to install than a spring most likely... could you direct me to what type of BIMBA part i would need, i know next to nothing on how they work, power wise... thanks! good idea!

[HayZee518]

I'll put together a rudimentary diagram with microsoft "paint" and post it. the bimba cylinder can work with hydraulics or air. I was thinking using air, because the force needed by the counterweight to retract the door under no power conditions would be the weight of the door plus the air exhausting out of the cylinder.

[thejava1]

thanks!

awesome, i eagerly await!

[buckofdurham]

awesome, i eagerly await!

Me too !!!!!!!!!!!!!!!!!!!!

[HayZee518]

the cylinder uses air to move a piston inside the cylinder. the rod connects to your door. a two way valve would be required. upon energizing it air would go into the cylinder extending the ram and with it the door. with no air supplied, air would exhaust out of the cylinder upon action by the counter weight pulling the door open. so the cylinder is set up into a fail safe open condition. the cylinder is supplied air to keep the door closed. to make the closing operation smooth a throttling valve for speed is used so air is supplied gradually not all at once. [flow control valve]

[HayZee518]

Power door

In its "normal" state, the door is kept closed by action of air and the cylinder ram. When the solenoid is de-energized the counter weight pulls the door open acting against the ram and retracts the ram into the cylinder. when the motion sensor timing circuit times out, the motion detector contacts open an auxillary relay's spring loaded contacts close, energizes the solenoid and admits air into the cylinder and the ram extends closing the door. when the motion sensor detects an object, its contacts swap closed and the aux relay is energized which disengages the power to the solenoid and the counter weight opens the door. this is FAIL SAFE open function so loss of power would automatically open the door.

[buckofdurham]

I've got to try that. I just have to figure where my wife will let me.

[thejava1]

Thanks!

Hmm.. i really like this idea, in fact the only flaw i see with it is the compressor. I've posted on other forums, and they are generally suggesting mechanical means, how much pressure do you think will be required? Again i've never used a pneumatic cylinder before, but when browsing sites i can only seem to find max 6" stroke, am i looking for the wrong thing? I assume the "stroke" needs to be >28"... thanks again for you help, wonder paint drawing!

[thejava1]

hmm

would something like this work well?
Chelic 39" movement pneumatic piston DN40/1000 - eBay (item 190231945512 end time Jun-30-08 13:52:17 PDT)

[HayZee518]

I looked on an industrial supplier site and found the stroke of a cylinder of 28-36 inches. the bore was 1 1/4 inch and I'm assuming the ram's rod to be 3/8 inch. the force needed to open the door again I'm assuming would be about 12 pounds through the flow control. how is the compressor a problem? once it's up to pressure it shuts off and if you have no leaks it should maintain pressure. when the cylinder operates there may be tiny leaks around the packings but other wise nothing hazardous. about the only loss in air is once for each stroke.

[thejava1]

response

Its not a huge problem, just the noise it makes mainly. I think I'm going to try a 2 gal compresser that I already have. THe door is in the basement actually, so i'll have to run a line through the ceiling (Floor joists) that way i can leave the compressor in the garage. I was just wondering how large it should be is all, thanks fo you help again, i'm going to try looking at tractor supply and see if they have anything good.

o and is this the right type of cylinder? It doesnt appear to have a spring recoil, but the weight of the door should push it back...
Chelic 39" movement pneumatic piston DN40/1000 - eBay (item 190231945512 end time Jun-30-08 13:52:17 PDT)