DC motor for heavy blinds

Hi all,

I need piece of advice, maybe someone had similar project.
I have bedroom blinds but those heavy aluminum behind PVC windows (as seen in attachment).
I'd like to make controller to open them and close remotely. I have a cat and I'd like to close it when she comes home at night and I'm not there (I have camera for now, will work on sensors also, rain, ultrasonic, PIR?)...

My question is, what kind of motor I can use to roll those blinds? Motor also needs to hold blinds weight when powered off.

I estimate those blinds have no more that 10kg

thank you!


Dc motor with a worm drive gearbox. If I remember correctly any ratio over 40:1 will prevent motor running back under load when switched off. Also gives heaps of torque. Basic limit switches such as microswitch at each end of the travel.

put a small knot in the rope,
tie in a second rope and connect to a bucket
fill with water until the blinds lift
put bucket on scale.

worm gear motor on amazon

check e-bay... this shape motor comes in many voltages and many gear ratios (speeds)

you can find quite a number of worm gear motors and more straight or spur gear motors with very high ratios and low RPM, the lower RPM, the more torque. figure what size you have to work with.

and remember, you cannot power ANY motors from the Arduino power supply. but you can control ANY motor if it has it's own power supply and/or driver with power supply.

For short time (month) I was pulling it using big 1m actuator and H-bridge .. today that bridge is no longer working for some reason.. I get voltage but not current, can only hear some small buzz in actuator .. I used external 12v 1.25 amps dc power (seemed more than enough).. that setup could pull just 1m so it was just enough for cat to go out and fairly close it. Obviously that some quick dirty and temporary solution.

For a quick note, I tried to use MG996R 55g Gear Servo Motor (just for sake of it) ... and it rolled it down nicely but pull was just not enough.. little hand pull and it was going.. so if by that anyone can estimate torque needed...

I'm really new at this.. I can use modules, very good in linux and all sort of devices, but mechanic part is low to none.

I was thinking maybe use motor of hand drill, would that work? I've pulled apart power-tool drill, it has some 9,6v motor inside, but I guess H-bridge would need some current regulator of sort?

Automotive window winder motor will more than likely suit your needs.

Low voltage, plenty of torque, worm drive gearbox, all self contained.

Just need a decent sized mosfet H bridge and power supply to get you up and working.

Size of both latter items depending on load.

You can measure that on site before connecting to any control gear.

Just hook it up to a car battery.

so this?


I cannot find how this actually works.. it winds some cord?

edit: found it!

this looks great and just what I need. thank you! :wink: