Design story 1: shelf supports

New home. If you live with a woman, one of the first care will be the wardrobe’s shelf. By a well-know theorem the women dresses’ number is limited but infinite. And you have to create space.

For the shelves themselves we let to your own creativity. But the supports are a good possibility to use RepRap.

Look around
Ok, we decided that the supports will be in plastic and they will be pleasant to see (and funny to project). Lets see what there is now in the wardrobe:

Old supportOld support


The shape and the idea to use only one point for fixing are good. But with time the nail loose grip and tend to come out. With a screw the problem will be solved. And would be nice that in the end the screw results hide…

To plan
Let begin to make some drawing to clear ideas.
RP support sketch RP support sketch


Build in that way the support hide the screw and you can decide the “strength” with which you put it on the screw. It’s enough loosen or tighten the screw to decrease or increase the strength necessary to put it in the right position (and so avoid that the support turn when the shelf isn’t put on).
The idea seem nice, but which orientation we have to give to the support during the print?

  • Case A) with the bigger part turned towards the bedSupport orientation A
    • Pros: the part that remains against the wardrobe will be smooth, and from the outside the aspect will be more uniform. There aren’t overhang problems.
    • Cons: maybe there will be some problems with the “bridge” printing the first level. But with the correct settings you can avoid them.
  • Case B) print the support contrariwiseSupport orientation B
    • Cons: we’ll have the little part (visible once that is mounted) shiny to the rest.
  • Case C) print with the support flat surface towards the bedSupport orientation C
    • Pros: same of A case.
    • Cons: the piece is more weak. The shelf weight tend to unglue the levels.

So, we choose the A case. The item is little and rounded, so we won’t have warping problems.

To drawn
Now we have to choose the software that we’ll use to project the item. From the moment that we do that to amuse ourselves, we are going to use OpenSCAD. Maybe is less intuitive but it is very powerful and we can define our model in a parametric way. Modify the dimension at the moment permit us to tare the item for the print and to adapt it for every future situation.
The final file is published on Thingverse (http://www.thingiverse.com/thing:12350). There is a little to explain: the best way for understand is open the code and play with it (put a # before the entity to put them in debug and see how OpenSCAD behave). The only peculiarity is to use a polygon extrusion to generate the guide.

rpshelfsupportparamsrpshelfsupport-openscad


Conclusions
A good idea don’t come out from nothing. Is the development and evolution of something that already exist, that has qualities and imperfections.
Comparing with situations already experimented (by us and others*) one can find the right point and the right way to use our creativity to do something original. To be inspired doesn’t mean to copy and not even to reinvent the wheel.

*) the strength of rapid prototipation is that we get a real model of what we have think. So we can verify how it works and which ideas experiment to improve it.

RP shelf supports Making hole Tightening screw RP support assembly Shelf on new RP supports


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