Lots of people on the internet asking about this one, but not so much info out there. I purchased a single blind today to disassemble and see how difficult it would be to cut down to size to fit my particular windows, and had great success.
In my case, i purchased the smallest blind available, 23", and I needed to fit into a 21" window. I was able to remove approx 2 1/4 inch, but i think that was about the maximum easily available.
first step is to simply remove the battery compartment. There is a small ribbon cable connecting it to the motor, which can be removed with the help of some pliers, or a flathead screwdriver on the clip.
you can see the “smart” control board in the far end of the battery compartment, along with the battery power connection.
Project for another day, I’m also planning on running some 18 guage wire under the window trim, so i can provide the 7.4V via an external power supply instead of the batteries, at a later time…
Next up, remove the aluminum bottom channel by popping one of the endcaps off, and sliding it off the blind material. That will expose the strings on the bottom, which are just tied in a knot. you can now easily un-tie that knot, and slide the blind material out of the top housing.
that this point, i used some gaffer tape to hold the strings and cable out of the way, and removed the slightly over two inches of body from the frame (using bandsaw, but hand hacksaw would work just as well)
Depending on how much you remove, the battery compartment plastic has a chunk of plastic in the middle which might hit the end of the motor bar. In my case, i had to remove some of that plastic to make room.
Here you can kind of see the bar, with the battery compartment installed.
Cutting the fabric, i just tightly wrapped in some tape, and a utility knife left a perfect cut. cant tell the difference of this side from the factory side at all.
(I did pull the plastic insert pieces to the side and cut them separately.)
now putting it all back together. You are going to need more length of string to thread the fabric before you slide it back into the housing, so connect the battery and the cable. CAUTION here.. when you connect the power, the motor starts retracting the string (going to the open position). grab the strings and just hold them. The motor will sense the resistance and stop pulling the strings in. Then you can press the down button, and allow the motor to feed you out a couple feet of string.
To get the string back through the blinds, I used some 18guage wire folded in half like a big sewing needle.
once threaded, just slide the fabric back into the housing, while pulling up the slack on the string. Once in place, use the up button to have the motor suck the extra string back in until there is just enough left to re-tie the string.
One note here, i did find once completely re-assembled, when going from full open to down, it would sometimes be lopsided, as the blind isn’t perfectly balanced now, having removed material from one side, the strings aren’t centered. I used some gaffer tape on the bottom (inside the bottom track) to secure the strings in their “balanced” position, and so far so good.
It’s all working well, paired up with my zigbee stick, and talking to Homeassistant like a champ!
Now that i’m confident in the process, will be working on the other windows as well.