The Torture Brolly! (Patreon)

Howdy, wonderful people!

This one's going to be publicly available, but I'm posting it here regardless! :)

It's amazing what 3D printers can handle!  But let's put things to the test with an umbrella that folds and extends with all sorts of complicated linkages, sliding components and folding bits, all of which prints assembled, without supports, and is ready to go, right off the print bed!

Now, how much torture is involved in printing this?  It's actually not that bad.  The toughest thing by far is making sure your bed adhesion is up to the task, though the Torture Brolly has been refined through many, many iterations to be as friendly to bed adhesion as possible (well, in relative terms, at least!).  All the angles are nice and civilised, and the tolerances on all those moving parts are quite generous.  However, if even one of those moving parts is compromised then the whole thing will fail to operate!  So, while it's as printable as it can be it's still quite sensitive to print issues in general.

It also has tassels!

Here it is folded! 

And extended all the way!

There's also a stand, and it'll hold the umbrella at an interesting intermediate point:

I did start typing up a description of how the brolly works mechanically, but it's much easier to just say "print it and you'll see!".  There are sliding bits and linkages that pull folding elements closed, and so on.  

Interestingly, the most complicated design element in the whole thing is the mechanism that stops the top folding the wrong way!  There's a whole complication there of parts that need to collide at the start of the fold to push panels upwards, but then move out of the way so that the folding panels aren't hindered in their movements.  Combined with the fact that the linkage end is rotating outwards with respect to the panels, that whole thing took a while to get right (and involved a lot of chopping up of prototypes with side cutters)

Print Description

This one's a regular style print.  Infill won't matter too much, since it's mostly perimeters!  It's really only the handle that'll be impacted to any great degree.

Print Dimensions

The Torture Brolly occupies 184mm x 164mm on the print bed and is 172mm tall.  However, it can be rotated to fit neatly on a Prusa Mini's 180mm x 180mm bed.

Supports needed?

No supports needed!

Scalability

You might get away with scaling this down a little, but bed adhesion will get increasingly more difficult the smaller you get!  At some point, too, the hinges will be impacted as well.  

This is a torture test, though - how small can you print it successfully and still have it function? 

Print Orientation

The Torture Brolly prints upside-down, like so:

The stand prints right-way up:

File location You'll find this one at at 653 Torture Brolly

Link to dropbox post: https://www.patreon.com/posts/31697592

Further Thoughts

Some designs really are a journey, and it won't surprise you to hear that this was one of them!  

When it comes to motion in print-in-place designs it's often fairly achievable to predict the way something's going to behave, but the more parts there are the more slack there is in the system, and things start to move around a bit more than might be expected, leading to all sorts of jams, collisions, and unexpected movements.  What that did mean, though, was that every prototype was a mixture of fascinating and frustrating, and I never  knew quite what I was going to find!

These things are only possible, though, because of your wonderful support, and I really do count myself very fortunate that I get to play around with these crazy ideas! :)  

xoxo

Sven.