Sunday, 23 October 2016

Laser Cut Cryptex

This is my laser cut cryptex. It features 28 different characters and 9 rings, giving a total possible 10.5 Trillion different combinations. I took a bit of time developing the design so that I could add some nice features. This cryptex file is laid out so that you can have any number of rings in your own design. The best feature is that the codeword is changeable, each locking ring has an outer letter ring that can be placed in any one of the 28 different positions. Once the rings are back in place the ring locking bars can added and they prevent the rings from being modified until the box is open again. It's a bit hard to explain so I made a video showing how it all work (svg here)

It took a long time to assemble this so I lived with my initial design choices but if I were to remake it I would adjust the file to make the ring locking bars out of 6mm ply and maybe put some blind holes onto the code rings to prevent the code being brute forced.

Friday, 30 September 2016

1000 sharks in the making

The 1000th project for this blog very much took on a life of its own. I knew I wanted to make something big and impressive so the idea of making 1000 of something had a lot of appeal. The laser makes it very easy to churn out 1000 identical items so I also wanted to make something that needed assembly, something where I had specifically touched all 1000 things. So I built this little shark model, it had a few iterations and eventually ended up with five ribs and a flexible tail.

I managed to tessellate 60 onto a sheet of poplar ply and I set the machine to cutting out 18 sheets, each sheet taking just over an hour to complete. In between sheets I would pull the parts out of the laser and scoop them into boxes for later assembly. I spent many nights sat in front of the TV assembling parts and in full flow I was assembly one every 45 seconds, so it was roughly another 18 hours for shark assembly. This left me with two,80L crates full of sharks and lots of time to figure out what the next step should be

Arranging the sharks into some kind of sharknado was appealing but it would need a sturdy framework. Suspending 1000 sharks inside a fish tank would be cool but there would be a lot of strings so I hit upon the idea of sticking the sharks together to form a larger shark. One big thing made from lots of smaller things would look pretty good so I set about making one giant shark from all these pieces.

The first step was to create a former to make sure I got the right shark shape. Thankfully with a laser cutter you can change the scale of things pretty easily and in no time at all I had a full sized model form corrugate card. This allowed me to check it for size in the final tank and gave me something to work around. I just started gluing sharks into location on the side of the cardboard, putting them between the ribs and making sure that the shark picked up the right shapes in the right proportions. Because the card was flexible I was about to add a bit more shape into the design as it evolved.

Each shark was built in several stages and took about 40 hours each to complete. The first half of the shark was built against the cardboard former. All the sharks were packed as tightly as possible and hot glued together. Two more layers of sharks were added on top of that giving the body some shape. Next the fin was added to the top and sides and the tail made last. Because the tail was the thinnest part it was the first thing built on the other side when the cardboard was removed. The flexible corrugate spine allowed me to add some curves into the body shapes.

The first shark only used around 500 of the smaller sharks which left me a problem, I had to build a second shark to use up all 1000 sharks. The second shark was built in the same manor but it gave me a chance to put the shark in a different pose.

To make the shark tank I took the laser crate from a Greyfin laser cutter and very carefully extracted the laser trying not to dismantle the box. I secured the lid back down and had full access through one of the side panels. In the walls of the tank I cut holes for the portholes and screwed them in using Dome nuts to give them an extra nautical feel. I used the large Just Add Sharks Stencil to spray paint the company logo onto the side of the tank taking care to mask off the red and black areas as required.

The inside of the tank was painted white to hide the footprints and marks left from the laser cutter and the whole thing was illuminated with a water effect lamp. The sharks were suspended from the ceiling using fishing wire and hooks screwed into the sturdy points of the roof.

1000 Sharks

This is my 1000th laser cut item. It's nearly my fifth blog anniversary and I wanted to make something epic so I built this shark tank and housed 2 large sharks inside it. Each shark is made from 500 smaller sharks so over the last few weeks I have cut and assembled 1000 of the smaller laser sharks, 1000 things for my 1000th item. Portholes into the tank allow you to see the sharks from all different angles.

Cryptex Ring

I set out this evening to make a cryptex, it was fairly ambitious given that I also had to pack for New York. Instead all I managed to achieve was a single ring prototype but I figure that is most of the hard work done. This cryptex features a ratchet to make the ring rotate in a single direction. 27 digits, I view the blank character to be equally as important as the other 26, and as this cryptex will be infinitely extendable you could have multiple words in the code. The central section is square which means it doesn't have to be made from 100s of stacked layers. 

Most significantly there is an outer ring containing all the letters. The letters are glued into place using a jig to ensure they are all square on the wheel but the wheel can be rotated in relation to the keyed slots, this means the code word is actually going to be changeable once the cryptex is assembled.


Thursday, 29 September 2016

Wavy Bowl

I made some bowls before but I lost some of them at the Newcastle Maker Faire this year, as I'm bringing my 'A' game to New York, I thought it was quite sensible to make another one for display. I chose to make another wavy bowl from a single concentric stack. This time the layers had guides to show you where to glue the next layer (svg here)

Wednesday, 28 September 2016

Counter Mechanism

I finished the counter mechanism, I doubled the size of the wheels to make them easier to run and I added a detent mechanism to ensure that the smallest wheel falls into place and it also stops it spinning wildly. (svg here)

The geneva mechanism was rebuilt using a layer of 2mm ply, this allowed the two different gears to sit half a step out of sync with each other and eliminates any clashing as the gears rotate.

The detent mechanism gave me a few headaches, typically these mechanisms usually look like a rounded ratchet. The rounded end allows the lever to slide in either direction. The trouble with laser cutting and wood is that the edges are a little bit rough and I really struggled to make this design work in the reverse direction.
To solve the problem I got thinking laterally, I put some 0.8mm ply in side ways to press against the sides of the decagon. I put in 2 bars to create even pressure on both sides of the wheel. As the decagon rotates it flexes the two bars outwards and that helps it bump over into the next detent. The rough side of the decagon rubs against the smooth surface of the 0.8mm ply and there is no sticking.

Tuesday, 27 September 2016

Church Window 2

I made a church window a long time ago and I was never very happy with the way some of the layers were offset. The perfectionist in me always knew the glass layer was a bit awry from the rest of the framework. Given that it is well received at most events I figured now was the time to redo it and make a 'perfect' one this time around. It's a pretty straight forward layered design, the only real tricks are engraving on the pillars to add some depth and make it appear like there are bands around them and the perspex layer is a dodecagon, rather than a circle, to prevent it from rotating within it's hole.