Cuboctahedron

Three pics of

the cuboctahedron from

Geodesic math and how to use it by Hugh Kenner.

Struts laid out, then

transfered to acs10 matting.

End result with tools etc.

Ta-Da!

Hi, Last time in this series, I built a six strut tensegrity, and this time I am building the next structure in Mr. Kenner's book, the cuboctahedron.  If you think its getting complicated you are right, if you think pic 3 above shows a mish mash of units which is a mathematical blasphemy you are right.  But I am plodding on with these things.

To start with I got my 3d printer going, made 24 of the orange rod ends, then stuck them on to some sawn-off pieces of fibreglass tent pole.  The fit wasn't quite right, so I bulked out the rod ends with sticky tape, and hey presto, a nice fit, and 12 struts are ready. Finished making the struts last night.

Next, replacing tendons with rubber bands, I lay out the struts minus the top and bottom rows of rubber bands, which would cause it all to collapse (pic 4).   To complete the assembly I tried rolling that lot around a bucket which failed causing rubber bands to fall off.

After a bit of thought I tried a different approach and laid everything out on Ventisit or ACS10 which  is a mesh material I use to cover recumbent bike seats.  Then the struts were cable tied to the mesh, and the mesh rolled around in a circle, extra linking rubber bands linked up, cable ties removed, and finally, the acs10 rolled up a bit tighter and removed.  Hey presto, all done!

But still confusing!  Not sure how what I've built relates to a cuboctahedron, but I will investigate. And from pics 3 and 4 it looks like the pattern could be changed with 3 or 5 or 6 sets of 3 struts.

Next step in Kenner's book is icosidodecahedron which both looks and sounds fiendish.

regards

Steve Nurse

Fringe Furniture Opening

Wearing a red badge, one of my sculpture components.

Convent entry looking....

very glamorous on a warm September evening.

Opening speeches and prizegiving.

Tahl's exhibit...

And blurb.

Tensegrity table

Christine and my exhibits which were....

also immortalised in film.

Hi, here are a few pics of the Fringe Furniture 32 opening night. My friend Tahl from uni was exhibiting, and I also saw Marinos, a uni acquaintance and Paul from Airies Inlet whose daughter Bella was exhibiting.  I took Christine along the next day, lots of fun, everyone very friendly. Its on for another month or so, don't miss it if you are in Melbourne.

regards


Steve Nurse

Delivering to Fringe Furniture

My Wife Christine........

took a photo of me leaving from home with my small table......

on my leaning trike for Abbotsford Convent where.....

Kristina was.....

delighted to receive them for Fringe Furniture 32.

Regards

Steve Nurse, thanks to Christine & Kristina

PS..... Same time last year I was doing something similar, click here to see last year's bike blog post. On that occasion a whole wooden trike was on display at fringe and the commute involved carrying a Bickerton folding bike in the luggage area to ride back home on. Not stressful but more stressful.

Six Strut Tensegrity

Jig for making the model

1st attempt, quite unstable. Pic and text from Mr. Kenner's book in background. There are meant to be 24 tendons which are 0.6124 times the length of the struts but I have 6 rubber bands instead......

bit more stable but not very colorful, 24 rubber bands on this one.

And the final version for tonight anyway, Colorful, Stable, Able to support a beer bottle as long as you are hovering close by and don't mind it spilling!

Hi

After a bit of a break and some diversions, I have got back on the horse, and kept on going with what I set out to do at the start and build some Tensegrity structures from Hugh Kenner's book.  Here are some pics of what I built today from page 11, I had printed enough of the 4-way rod ends to make this thing a few weeks ago.

The little jig I made to put this together worked well to hold things in place while I started off assembling, but because I was skimping on the assembly by using only a few rubber bands, it fell apart a few times. Ok now, but.

Will plod on with this, Regards

Steve Nurse

Alien Sculpture

Hi, for a while I have had a small sculpture hanging round the house, it is made from 3d printed parts I made at home on my 3d printer, and soon I'll make the computer files used to make them(STL's) available for upload. Anyway, the sculpture has a red, rear bikelight inside, and a white one outside, and they can flash, or have constant beam or be off (very special, that last one!).  Tomorrow I take it all of 2k's down the road for it to be exhibited in a local design exhibition,  Fringe Furniture 32 .

Anyway, during the week, my regular weekly copy of New Scientist arrived, and it had an article about Keri Bean from NASA in it. She was involved in getting the Opportunity Rover to take a selfie of itself using a dodgy camera, as recorded on the internet here.  Here is a quote from the linked webpage "it was all I could do to not burst into tears. Yes, it was fuzzy – but not as fuzzy as we thought it would be". So in that exciting spirit, I decided to let my model take a few selfies and have even out-nasa'd Nasa by taking a movie as well.

Anyway, quite a few different possibilities for selfies as you can see above, which were all taken with 12 seconds delay from pressing the button to taking the photo. There is the model lighting, the camera flash and the bathroom lighting which can all be played around with, and the escape hatch can be left open.  See you at Fringe Furniture, Regards

Steve Nurse

Tensegrity Prisms etc 4

Christine with the wind up frame model car in its discharged state.

Top view, discharged, see the video

Side view, wound up or charged.

Top View, Charged, see the video

Hi, I will start this entry with just a basic description of this latest model from my 3d printed, one-part wheel construction kit detailed last time.  (The model can be downloaded for free from this site) Really you have to go back to the start to see how this machine evolved out of a way of making tensegrity prisms, and what tensegrity prisms are in the first place.

So from my last posts here and here, I showed a 4 wheel steering model car and a rubber band driven model car, and from some studies I had been doing, knew about the concept of energy being stored in the frame of a vehicle.  So the designs all whooshed together, and I came up with the model shown on this page.  The sticks which are the frame and the power source are very flexible, green, late winter growth twigs just about to burst into flower.

Ok, not the most refined thing, but I think printing them in schools and seeing what kids would come up with would be a great practical way to introduce energy storage and conversion. In 2040, Norway plan to have all their planes electric, so in the next 20 years, the storage of energy in lightweight structural materials will become a major development goal.  The storage may start in batteries that come with solar panels, then evolve through batteries for bicycles and velomobiles and cars, until, finally, the entire frame of airplanes do double duty as a battery.

So what about the future for the Wind-Up-Frame-Car I've made?  I have some plans to go big and go slightly less rough with the design.  Will keep you posted.

Regards

Steve Nurse