Need help finding hardware

[Joe Willmann]

I built some bookcases into a sliding wall. It hides a "secret room". The book cases hang from barn door hardware and are guided by a short track on the floor. With the wall/door closed you can not tell there is a room behind there. The problem is when you fill the book shelves with books they get heavy. I want to motorize the door. So I am looking for possible hardware.

I have thought about using a screw type garage door opener. The concern with this aproach is the range of door movement. I need about 5 ft ove movement. Can the standard door openers be adjusted for that small amount of movement?

Does anyone know of any sources for this kind of hardware?

[mel]

door openers have a trip switch that mounts to the track that limits the range of movement.

[Robert Bonomi]

This is a relatively trivial "build it yourself" job.

I just built an 'opener' assembly, from scratch. components, and approximate pricing:

6' 3/4" threaded rod this is the screw drive $10.00 "long" (roughly 2") hex nut the 'follower' $ 0.75 2 pillow-block ball bearing supports 10.00/ea 2" dia drive gear (3/8" 5tpi cog-belt drive) 17.00 1/10 hp, 1500rpm, _reversable_ motor *surplus* 9.95 w/ 3/8" 5tpi drive gear 3/8" 5tpi cog belt 5.00 low-voltage control system 20.00 metal hobby enclosure 12V transformer rectifier (couldn't find AC relays, use this w/ DC relays) 2 relays (one for run/stop, one for open/close) two 'limit switches' 3-way switch power cord

misc hardware 3.00

Total cost, about $85.

I could have saved $25 or so, If I'd felt up to fabricating my own supports for surplus ball-bearing races, rather than buying new industrial- grade, and v-belt instead of cog-belt drive.

And likely another $5-10 on the 'electronics', by shopping discount/surplus sources, vs just bying all at Radio Shack. But they _were_ conventient. :)

This opens/closes a 4-1/2' spam in about 30 seconds.

For your application, I'd gear down further, or use a more powerful motor. 1/4hp might run $20, and 3/4 hp ones (from treadmills) were going for around $40, at the same source I got my 1/10 HP one from.

Note: for those into 'gadgeteering', and not familier with the place, "American Science and Surplus", online at , is a *dangerous* place. Ditto for "Surplus Sales of Omaha", online at

[Charlie Groh]

[Bored Borg]

in uk

I've used these

GBP

as the GBP has plummeted like a stone, it might even be worth an import - or I can jiffy bag you a packet over at cost.