Grabcad (www.grabcad.com) recently challenged their community to help ULA (www.ulalaunch.com) design a piece that would be utilized on their newest rocket ship model.

More about the challenge can be found here. 

ULA provided volume design constraints as well as weight restrictions and material restrictions.  It was an excellent opportunity for me to branch out and design real life products for other market sectors.

This challenge pushed me to focus on different design constraints.  For example, weight is a very important limitation because costs rise as weight increases.  A full summary of my design is included in this post (see "ula-bracket-report_final.pdf" at the bottom of this post).  I've also included an engineering print of the design as well at the bottom of this post.

Part of my design included running finite element analysis (FEA) simulations to ensure that the bracket could withstand the expected loads.  My proposed design can hold up to approximately two times of the expect load.

The video on the right shows the stress distribution as the load increases.  Check it out!

I encourage you to check out grabcad's site for future challenges that you can participate in yourself!  It is a great opportunity to learn about other market segments and you could win some fast cash or other prizes at the same time too! :)

Leonardo da Vinci was a prolific inventor and artist who had a keen sense of the world around him.  While most of his flying machine drawings illustrated an attempt to mimic the wing movements of birds, he made one drawing of a helicopter type flying machine, which he called an aerial screw, since in his vision it would have screwed into the air.

​Leonardo understood that air had mass, and so it could be screwed into, hence his design.  We know that there would be some technical difficulties as the rotation began, since as soon as the canopy and base lifted off, there would be nothing solid for the pilots to push against, and the rotation would stop (and gravity would take revenge).  I can't find any accounts of information about his design being tested.  I understand that he was somewhat secretive in his inventions though, so he may have, and I just never found out!

There are two theories on how the aerial screw worked.  In one possibility, the pilots would have stood on the inner platform and pushed the handles on the pushing drum.  This drum would have been attached firmly to the mast and lower base (a base under the one they were standing on).  The pilots hold onto the drum and push with their feet on the rungs of the inner platform, facing the left.  This would set the base and outer ring in motion, and the canopy structure that is attached to it.  Once moving fast enough the canopy would bore into the air and the canopy would lift off.  The top canopy would slide off the mast in this case (meaning the canopy is not attached to the mast as I have it here, and would stand on its own).  Where my collar is tight, the collar in this case would be loose and slide up the mast.

This has good potential, if the structure could be turned fast enough, but then the inner platform they are standing on would have to release somehow, to allow the canopy to rise without them.  It would then slow down and return to Earth.

​In the other case, the men would face the opposite direction and would actually move around the mast.  The drum would attach to the mast and outer ring.  As the canopy got going fast enough it would lift off.  Then of course it would fall since there would be nothing solid for the men to push against, and with no steering ability, it would tilt over and fall down, with ensuing scrapes and bruises.