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[Craig1111]

I'm a new member and this is my first post. I'm looking to automate my horizontal pleated blinds (Graber) which are about 7' wide by 7' high. The only problem is the pull system. It's a rope loop which has gear reduction of about 7:1 which means it takes almost 50 feet of pull to fully move them. The pull effort is fairly low, though.

I like the Add-a-motor 800DR, because it's the most cost-effective. However, the specs on it specify max. 15 ft. of pull and 60 lb. max. fabric weight. I was wondering if either of two options could be made to work: 1) disable the built-in limit switches to let it pull 45 ft. and use a timer to control run time (max. 45 sec.) or 2) fabricate a 1:3 pulley system to get 45 ft. of pull from 15 ft. of 800 DR movement. I know that this will cut lifting capability by at least 3x.

What do you think?

[Ralph]

It would have to be the pulley ratio setup. The 800DR uses mechanical triggers to turn it on and off, they rotate with the gear as it turns to open and close the blind. Tabs on that mechanical will come around and hit a switch and toggle it left and right to turn it off as it comes around clockwise, or counter clockwise.

I can't reccomend physically altering a product as it would completely void the product's warranty as well as remove any chance of return.

[Craig1111]

Ralph,

Thanks for the quick reply...I really think it's great that you have this forum and offer this type of service.

I understand your reasons for your recommendation...while I'm sure that the modifications to the 800 DR could be made to work, there is the warranty issue.

Regarding the pulley method, I still don't have a good understanding of the pull capability of the 800 DR. A 60 lb. fabric weight rating sounds more like a "thread count" rating than the ability to create 60 lbs. of pull force on the cord. I haven't measured anything, but let's say that it takes about 5 lbs. of pull force (worst-case) to lift the blinds. If I use a 1:3 pulley system with minimal friction, it would now take a 15 lb. pull effort on the cord going around the 800 DR. Do you know if it could generate that force?

Thanks in advance.

[Ralph]

Their fabric weight refers to the actual weight on a scale, not thread count or other descriptive content. It is purely a measurement of pounds of fabric.