Hi all, in response to all of the discussion sparked by the tensioners in my post (@blurfl, @clintloggins, @dlang, @Keith, @ScrumdyBum, @bar), I figured I should shed some light on how they work.
Firstly, I want to establish the core relationships of certain parts of the maslow in relation to one another during normal operation, from which I derived the system.
At its core, the system relies on this:
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When a chain is at it’s greatest extension, the maslow (gravity acting on sled) can provide the least amount of force in the opposite direction that the extended chain is pulling.
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When a chain is at its greatest extension, the slack in the chain is at its minimum length.
From those two observations, I arrived at my current design:
The “Block and Tackle” setup uses the relatively small movements of the chain slack to greatly increase and decrease the length of the elastic cord depending on the sled’s position on the work area. One block (top one in diagram) is attached to the frame – the other to the blue paracord, and when the chain is fully extended, and the slack is pulled up, the pulleys pull apart, tightening the elastic cord on the opposing side.
If you mirror the mechanisms, you get this:
I understand this is all a bit confusing, but essentially you’re just using pulleys to magnify the chain slack’s movements on the opposing side of the frame to increase tension in the desired direction when it is in the corners.
As an added benefit, the tensioners also relax when the sled it towards the top of the work area where they are not needed, since the slack in the chains is longer when in the raised position.
I did some more testing this evening, and was pretty pleased with the results when running the calibration test code. I’ll post a video later this week to show the system in action in the comments here if anyone is interested.
@clintloggins No worries! I’m glad to add my drop to the magnificent bucket of effort here in the forums.
Thanks guys!
-J