So here is the story: I am making lightweight doors, just because. the constraints are:
- I don't want flappy fibres doors
- I want the windows to slides up and down as normal because I live in the montains, and well, it gets cold up here and very warm in summer. so I want air in the car.
basically, I got my hands on extra crispy doors, I have stripped the outer skin, will be replaced by aluminium sheet. and I will strip as well the interior panels.
Now here is the catch: if I get rid of most of the interior panel, I have to get rid of the winder mechanism, which by the way weights a metric ton, more or less.
So I am making leather pull strap, and in this post, I'll detail how I get there.
first thing first, got 2 sacrificial windows for a few bucks, scratched and all, but they will do fine for the purpose of the experiment:
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the first thing to do with leather strap is to engineer a stop at the bottom of the window. if by any chance you let go of the strap, it will get at the bottom and potentially damage your door skin.
so I made little aluminium brackets:
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and they will sit at the bottom of the door, like that. pay attention, there is not much clearance between the bottom of the window and the outerskin, so keep a few mils, but that's it.
here it is:
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now since I got rig of the gutters under the window, i have to make a new one. here aluminium sheet and profile are your friends and I found one that just fit well. it's however very thin (5x5x5mm outer dimension) so it will not stand much traction without help. so, I made captive screws to attach thicker aluminum plates to attach a leather strap.
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so here is how it looks when all assembled:
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there are 3 sections attached to the thin gutter: the main one is the one with the strap attached. Since I did not have the strap, well, humm, I used my own belt for the purpose of demonstration.
the central one will thus have as final the leather strap rivetted (here I used shorted screws and washers. I do like that belt.
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the external triangle are there to compensate torsion on the gutter:
when the strap is pulled, it pulls on one side of the gutter. the counter plate in the center helps, but if you have extra pad pressing on the inside of the window (so, the same side that pulls), interior of the car, so to speak, it will compensate torsion.
and here is how it looks window up!
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Now if you want to do it too, there is a catch that need to be addressed: the window in not balanced: it has a triangle shape. so originally, i aligned the pull with the center of gravity (and yes, I'm a nerd). turned out it's a bad idea:
the friction with the seal on the rear hand of the window is much worse. as result, if you align on the center of mass, the window falls forward. so it is better to align it to the middle of the large section of the window. then it is balanced and works well:
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and finally here it is from the inside!
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and window down:
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ok now what's left to do:
- repair the crusty bits of the doors for sure
- cut the interior panel
- but insert a diagonal aluminum section to get more rigidity
- and insert a vertical strap that will old 2 nuts for the final belt.
those nuts will have to go through the door card. so i have to figure out a way to make it elegantly.
a couple of final tips:
there is a company that makes door cards similar to stock one, but you can ask them not to put the hole for the winder manivelle, so this is sorted out :)
there are door strap kits available for Porsche 911 that I can use but I might do my own, I havent' decided yet.
you have to replace the inner top door lip but something that looks more like a sheet metal seak (similar to the one you find on edge of metal to avoid cutting yourself, not sure how it's called) it's a rubber with metal inside anyway. the reason is that the strap will tear the inner lip. the good news is that the strap do apply pressure on the window and therefore, even if half open, I don't expect it to flap.
Not sure I will keep the windows. the guys from plastic4 make apparently decent poly window and it might be easier to pull.
that's it for today, hope you like it ! :)
Edited by Benoit_Dupont, 10 August 2019 - 07:18 PM.