Motorised roller blind?

Hi
I'm hoping to build my own motorised roller blind assembly. It's actually for a home cinema projector screen which I want to recess into a ceiling.
I've a reasonable amount of experience with electronics (well - I know which end of a soldering iron to hold) but know little or nothing about electric motors.
I would assume that the motor needs to have some sort of cut-off mechanism for the top and bottom of the operation and would prefer to have something that can be mains operated.
Any suggestions for models or suppliers?
thanks
Tommy
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 23 Nov 2003 15:51:08 +0000, Tommy Gilchrist

On a similar system at work we have microswitches in series with the forward and reverse supply to the (low voltage) reversible motor. these are operated by an a pair of eyelets punched into the edge of the material of the blind at opposite sides, one for the fully wound in condition and the other for the fully wound out. The actuators on the microswitches are modified to take the form of a two pronged fork, cunningly sized so that the screen/blind material will slip through but when the eyelet arrives the actuator is operated. The bottom edge of the blind is weighted with a steel rod along it's full width which also keeps it flat.
A Maplins or a model shop should have the bits for you to be able to cobble something together along these lines.
DG
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Do not bother with model motor and gearboxes. The teeth will strip real easily. I'd suggest Maxon units. They are expensive but very high quality...used on the recent OU Mars probe. Also suggest protecting the motor with a auto reset thermal fuse.
wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 23 Nov 2003 15:51:08 +0000, Tommy Gilchrist
I just went to google.com and entered a search phrase of "motorised blinds uk". Several likely looking options came up immediately.
PoP
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 23 Nov 2003 15:51:08 +0000, Tommy Gilchrist

You can buy the motor and roller assembly from Somfy.
www.somfy.co.uk
.andy
To email, substitute .nospam with .gl
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 23 Nov 2003 15:51:08 +0000, Tommy Gilchrist
Good. If you build something ugly out of Meccano, it will still be more reliable than the commercial sort with the motor inside the drum. These things are expensive, yet horribly unreliable - especially if frequently used, as they tend to overheat.
A worm drive from the roller shaft to a pinion wheel will allow you to fit microswitches for limit stops, despite the multiple revolutions to unwind the blind. You'll also need two relays, which you can get from the same scrapyard you visit for a car door electric window motor.
-- Die Gotterspammerung - Junkmail of the Gods
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.