176 lines
8.3 KiB
HTML
176 lines
8.3 KiB
HTML
<p>
|
|
... which means it's pretty much as dead as it can be. As I'm typing this, not one of the original wooden elements of
|
|
the prototype has survived, fully delivering on the expectation that prototypes are not meant to last. In this case,
|
|
the beamer arm prototype lasted for a single movie sitting before I realised that it was, on the long run,
|
|
structurally unstable. More specifically, the single hinge took quite a lot of force. The inside
|
|
pin is only 8 centimeters high and combined with the length of the arm, the construction makes for quite a lever. The
|
|
top of the hinge started to come off the back plate, and, more worryingly, the top curl of the hinge started to open.
|
|
Back to the drawing board then!
|
|
</p>
|
|
|
|
<div class="row">
|
|
<div class="col-md-12">
|
|
<figure class="figure">
|
|
<img src="/assets/post/beamer/img/curving.hinge-cropped.jpg" class="figure-img img-fluid rounded"
|
|
alt="The top of the single hinge, coming off the back plate.">
|
|
<figcaption class="figure-caption">The top of the single hinge, coming off the back plate.</figcaption>
|
|
</figure>
|
|
</div>
|
|
</div>
|
|
|
|
<p>
|
|
As a reminder, the current mechanism consists of a couple of parts. A single big hinge that connects an MDF arm to the
|
|
wall. Then, a circle with two fixed side plates on top. The arm slides in between these plates. Below the circle, the
|
|
beamer mount plate is fixed, which can rotate. The whole mechanism would fit in between two shelves in order for
|
|
inconspicuous storage of the beamer.
|
|
</p>
|
|
|
|
<p>
|
|
I wanted to save the old hinge, as it was an expensive part. The obvious thing to do was to add a second
|
|
expensive part (always dig a deeper hole): the same hinge but slightly less wide, which would hopefully alleviate
|
|
the problem of the top of the hinge coming off the back plate. I had to reposition the old hinge, to make both fit in
|
|
between the shelves, with as much space as possible between them in order to lessen the force exerted by the
|
|
beamer arm. Now I could carve out a new arm, which would prove less heavy than the original one (partly due
|
|
to the cut-outs, partly due to the use of a lighter type of MDF).
|
|
</p>
|
|
|
|
<div class="row">
|
|
<div class="col-md-6">
|
|
<figure class="figure">
|
|
<img src="/assets/post/beamer/img/new.arm.unpainted.jpg" class="figure-img img-fluid rounded"
|
|
alt="The old and the new beamer arm.">
|
|
<figcaption class="figure-caption">The old and the new beamer arm.</figcaption>
|
|
</figure>
|
|
</div>
|
|
<div class="col-md-6">
|
|
<figure class="figure">
|
|
<img src="/assets/post/beamer/img/second.hinge.installed.jpg" class="figure-img img-fluid rounded"
|
|
alt="The second hinge, installed above the old one.">
|
|
<figcaption class="figure-caption">The second hinge, installed above the old one.</figcaption>
|
|
</figure>
|
|
</div>
|
|
</div>
|
|
|
|
<p>
|
|
After painting the new arm I was almost done with the new version! All I had to do now was connecting the old
|
|
mechanism (the circle with the two fixed side plates) to the arm and the system would be ready. Consider this version
|
|
to be prototype 2, as I would quickly run into the next hick-up: the two plates connecting to the arm were too tight a
|
|
fit, which was problematic when assembling everything when painted. The paint itself was adding an extra layer of
|
|
thickness. It also added friction when sliding the mechanism over the beamer arm, which would damage paint on both of
|
|
the components. I'd have to do a little bit of work to the mount-plate mechanism then...
|
|
</p>
|
|
|
|
<div class="row">
|
|
<div class="col-md-6">
|
|
<figure class="figure">
|
|
<img src="/assets/post/beamer/img/destroyed.prototype.1.jpg" class="figure-img img-fluid rounded"
|
|
alt="The old and the new beamer arm.">
|
|
<figcaption class="figure-caption">A 'bit' of work proved to be optimistic.</figcaption>
|
|
</figure>
|
|
</div>
|
|
<div class="col-md-6">
|
|
<figure class="figure">
|
|
<img src="/assets/post/beamer/img/destroyed.prototype.2.jpg" class="figure-img img-fluid rounded"
|
|
alt="The second hinge, installed above the old one.">
|
|
<figcaption class="figure-caption">The circle part, after deconstruction efforts.</figcaption>
|
|
</figure>
|
|
</div>
|
|
</div>
|
|
|
|
<p>
|
|
The circle and the two side plates formed a solid block, glued together, which meant that my careful efforts to remove
|
|
the side plates from the circle ended in total destruction of the piece. <em>Fine.</em> Rework those parts as well, and might
|
|
as well make everything slightly better in the process! The beamer mount plate was shaved down a little to save on
|
|
weight and a couple of other dimensions were modified.
|
|
</p>
|
|
|
|
<div class="row">
|
|
<div class="col-md-12">
|
|
<figure class="figure">
|
|
<img src="/assets/post/beamer/img/new.circle.mount.plate.jpg" class="figure-img img-fluid rounded"
|
|
alt="The old and the new beamer arm.">
|
|
<figcaption class="figure-caption">New bracket and mount plate.</figcaption>
|
|
</figure>
|
|
</div>
|
|
</div>
|
|
|
|
<p>
|
|
I reworked the circle with two metal brackets instead of gluing the side plates, which alleviates the problem of the
|
|
<em>pinching</em> plates, making it easier to slide the arm between them. It's a bit less pretty, but it's at least
|
|
functional and can easily be adapted without tearing up the whole block. I only had to finish the rough edges of the
|
|
wood with smoothening paste (Polyfilla), paint the elements and hope everything fit together...
|
|
</p>
|
|
|
|
<div class="row">
|
|
<div class="col-md-6">
|
|
<figure class="figure">
|
|
<img src="/assets/post/beamer/img/painting.base.jpg" class="figure-img img-fluid rounded"
|
|
alt="Base paint of the circle.">
|
|
<figcaption class="figure-caption">Polyfilla + base paint of the circle and a side panel.</figcaption>
|
|
</figure>
|
|
</div>
|
|
<div class="col-md-6">
|
|
<figure class="figure">
|
|
<img src="/assets/post/beamer/img/painting.side.panel.jpg" class="figure-img img-fluid rounded"
|
|
alt="Side panel lacquered, Duplo for the win!">
|
|
<figcaption class="figure-caption">Side panel lacquered, Duplo for the win!</figcaption>
|
|
</figure>
|
|
</div>
|
|
</div>
|
|
|
|
<p>
|
|
All parts were ready for deployment, and thankfully no measurement errors popped up at the very end. I could install
|
|
the mount much easier and more precise now, and after a bit of tinkering with the wiring I managed to get a pretty
|
|
clean final system in place. Easily adjustable in each possible axis, the mechanism locks in place after deploying it
|
|
in its <em>view</em> state. The only axis which is not locked yet (the angle of the main arm) can easily be
|
|
manipulated by hand. I could have it be locked in place as well, adjustable and all, but as it's easy to do by hand it
|
|
does not seem to be worth the effort.
|
|
</p>
|
|
|
|
<div class="row">
|
|
<div class="col-md-6">
|
|
<figure class="figure">
|
|
<img src="/assets/post/beamer/img/finished.undeployed.jpg" class="figure-img img-fluid rounded"
|
|
alt="Undeployed, everything tucked away.">
|
|
<figcaption class="figure-caption">Undeployed, everything tucked away.</figcaption>
|
|
</figure>
|
|
</div>
|
|
<div class="col-md-6">
|
|
<figure class="figure">
|
|
<img src="/assets/post/beamer/img/open.state.jpg" class="figure-img img-fluid rounded"
|
|
alt="Deployed, from the side.">
|
|
<figcaption class="figure-caption">Deployed, from the side.</figcaption>
|
|
</figure>
|
|
</div>
|
|
</div>
|
|
|
|
<div class="row">
|
|
<div class="col-md-6">
|
|
<figure class="figure">
|
|
<img src="/assets/post/beamer/img/finished.top.view.jpg" class="figure-img img-fluid rounded"
|
|
alt="Top view.">
|
|
<figcaption class="figure-caption">Top view.</figcaption>
|
|
</figure>
|
|
</div>
|
|
<div class="col-md-6">
|
|
<figure class="figure">
|
|
<img src="/assets/post/beamer/img/finished.deployed.jpg" class="figure-img img-fluid rounded"
|
|
alt="Deployed, from the back.">
|
|
<figcaption class="figure-caption">Deployed, from the back.</figcaption>
|
|
</figure>
|
|
</div>
|
|
</div>
|
|
|
|
<p>
|
|
Finally I can put this project to bed, it took me a while but I'm happy with the results. A couple of things I
|
|
learned:
|
|
<ul>
|
|
<li>Never use a hinge by itself.</li>
|
|
<li>Don't glue together prototype parts like they have to survive two apocalypses.</li>
|
|
<li>Don't leave MDF out in the sun for too long: it curls up and deforms.</li>
|
|
<li>Don't get sunburned by cutting wood the whole day.</li>
|
|
<li>Listen to sheep, for they are wise.</li>
|
|
</ul>
|
|
</p>
|
|
|