Here's my progress on my DIY screen.

I got the screen material from here.Linkage

The screen material is 72 X 116 and that gives me up to a 132" diag. screen. So no problems with 4 X 3 or wide screen formats.

I used 1" EMT for the tube, 1 1/4" would have been better.
The screen material was surprisingly heavy and I have about a 1/4" droop in the center. So I'll be coming up with a center carrier bearing this weekend. I would have never though that the screen material would have been that heavy.

Edit:
Dohhhh! forgot the drive unit, battery drill, is temporary. I'll be using a battery operated screwdriver, should be more than enough torque.
I'll try to get to the limit switches and final drive unit this weekend.

Lookin good man! I assume you are going to attach the screen in the same way the old vinyl window shades were attached? Also, the drill is just temp I know but would that be enough power for the long haul? If so, how easy would it be to break down one of those and house the motor and all inside a small box on the end of the emt? I see drills all the time at yard sales and fleamarkets for like $2-$10, that would be a pretty cheap engine.
Cant wait to see how this turns out!

The backplate for my screen base is 1/2 X 3 X 130" ply.
The blocks that the screens support tube is attached to is aprox 1/2 X 3 X 3 1/4" pine with a 1/4" brass bearing that the 1/4" steel rod goes into. The blocks are attached to the backplate from the back with wood screws.
The temporary battery drill I'm using will be replaced with one of those yard sale battery operated screwdrivers. You know what I'm talking about, the tool every dad gets for fathers day.
A battery drill or screw gun is needed because you need the low torque. That low torque is what will hold the screen in place either up or down.
Variable speed drills are best because you can set the speed easily. Also your not stuck with that grip on the drill. That can be cut off and the batteries repositioned.
The screen and drive unit will all be housed together. The screen's 116" long and the backplate is about 130".

EDIT: One note of caution about those ni-cad batteries be very careful! If shorted they can cause sever burns and can explode!

Personal experience?

No, watching other peoples experience.

ey phil how heavy was you total screen? im think about doing the same, and did you order the screen any longer than u needed it?

I would say the screen material is around 6-7lbs. The shipping tube had 9. something on it, it had a very heavy cardboard shipping tube.
I cut about 8-10 inches off the width of the cloth but left the height as mentioned before. I wanted excess material for attachment to the tube and a bar on the bottom. It's real easy to have too much screen but a real bummer to be short in any direction.
I've had to put the screen on the back burner for now I decided to make a section of the basement a projection room. So I'm in the middle of making storage cabinets and a storage room for the wifes treasures.
I really want to get back on this project, but first things first.

yeah im looking into getting almost the same material i finally found a place for my pj to be permenant, and i need a huge scrren but its gunna bein the way so im looking into makings a pull down type of deal

That screen material looks promising. Have you done any side by side testing with BO cloth?

It's better than BO cloth.
I don't have a meter to do a real test.
But using the Mk One's it is an improvement especially in dim lighting situations.

I have gotten my limit switch and motor worked out.
But I'm going to have to come up with a carrier bearing for center support of the tube.
I'm using 1" EMT that's about 117" long.

This is a really good idea I think im going to do this (as soon as I get my PJ built ), how well does it work? Any action shots.

Hi,
Thanks for posting this project. I have been planning to do exactly this and I happened to see your post. I have one question. How do you suggest that I attach the screen fabric to the metal and/or vinyl tube so it doesn't keep sliding/slipping over it when it is rolled up? Did you actually do this?

I want to end up with a roll-down screen - and I do plan to use a electric drill to control it.

Anyone else with any other recomendations?

Thanks a lot!!

I used 2"wide masking tape, worked fine.
Get the tube you going to use setup and plumb.
On one end of your tube suspend a plumb line from the end on the tube.
Get some help and hold your screen material up to your tube. With short pieces of tape start hanging your screen material.
Measure from the side of your material to your plumb line to get your screen square to your tubing.

Hope this helps, good luck.

A motor with great torque is a windshield wiper motor from an auto junkyard (about $10). They're quiet, run easily on a small 12 VDC car battery charger, and usually have a threaded spindle. Use a two-way, twin-lead toggle switch (about $3) to reverse directions and a simple rheostat to slow it down.