Wow! Just Wow!

Wow! Thanks to everyone for the support. Thanks instructables and Epilog! All sorts of new things to make...

http://www.instructables.com/contest/epilog4/

Laser 3D Printer - Stereolithography at Home

It's working! It is a bit of a work in progress still but so far it is working pretty well. This is mainly an experiment which started as a Delta Robot Stereolithography Printer but ended as a more traditional Cartesian Stereolithography Printer. For how it was built, check out the instructable here.

"I'll be honest, we're throwing science at the walls here to see what sticks. No idea what it'll do." - Cave Johnson

Stereolithography (SL or SLA from Stereolithography Apparatus) is an additive manufacturing process using a vat of liquid UV-curable photopolymer "resin" and a UV laser to build parts one layer at a time. On each layer, the laser beam traces a cross-section pattern of the part onto the surface of the liquid resin. Exposure to the UV laser light cures, solidifies the pattern traced on the resin and adheres it to the layer below.

I have wanted a 3D Printer for a while now and there are some very reasonably priced kits available like the Makerbot, Ultimaker and the RepRap project. I could have just bought a kit and started printing things but at the time I had not seen great resolution or print quality from those. I started looking around at the other 3D printing technologies and found SLA made some amazing quality prints, so I decided to try making my own. Since I started this a while back those projects have come a long way and they can make some beautiful prints now. There are also people working on a UV resin and DLP projector 3D printer which is showing promise. 

Octopus

It just crawled from the depths of a resin vat...

Delta Robot 3D Printer. Sounds cool doesn't it?

Alright, I've been meaning to post an update for a while now, I was just hoping to have finished the rebuild by now... Anyway, I have been working on a UV/Visible cure resin 3D printer using a 405nm laser. I started off thinking if I could mix a Delta Robot and a resin printer in one it would be ultra double awesome. While it was pretty darn cool and fun to build, it just didn't work great.

I first started with a dynamixel servo based delta robot design thinking they should have a decent resolution.



Then after I built it, I found that was not the case, at least for 3D printing purposes. Also the controller started resetting every couple of moves so I probably fried it somehow.

At that point I did some more research and found some people working on a delta robot for use as a reprap printer. Following their design I used steppers and gears. The gear ratio was chosen mainly for what would be easy to cut on the taig mill. All worked out on paper it looked like it would have a decent printing resolution. My brother drew it up and we got to work cutting it.

We made the Z axis pretty much out of scraps and it didn't work the best. (linear servo... what was I thinking?) It was good enough to test the theory though.

After assembly and mangling the reprap firmware into a usable shape for a delta robot we were ready to go.



Yeah, it printed an awesome lump! It was supposed to be a small hexagon.

So, what went wrong? First off I think that shooting a laser at a shiny aluminum plate is going to make the laser reflect all over... Yup, also I think dye needs to be added to the resin to help with the reflections and diffraction. The delta robot worked alright but I just didn't feel it would make the best quality prints. There was a little too much backlash and the inverse kinematics is not my thing.

So now we have redesigned, again, but this time back to the tried and true (but boring) Cartesian robot. Here is the X and Y axis, still working on the Z axis redesign but hopefully soon we will have more acrylic lumps cool 3D stuff printed.

Brass Sign

Here is a video of cutting a brass sign for a Christmas present. It was the first time I cut brass on the Taig mill so I went pretty slow. The video has most of the cutting sped up 4x so it is a little more interesting. Merry Christmas Brian and Amy!

 The first picture is what I was given for the layout. The next two are output from the design I made in VCarve Pro.  

To hold the sign in place during the through cut I used the Tabs feature in VCarve Pro. Then I used a hacksaw blade to cut the tabs and a file to remove the rest of the tab.

Mario Bros. costumes with Sound Effects

This year the boys wanted to be Mario and Luigi. Kind of boring right? Well my wife didn't think they were ready for throwing real fireballs so we did sound effects instead. I wanted them to make the Mario jump sound when they jumped and be able to make the fireball sound too and maybe a few others. So I took a Wii Nunchuck, an arduino, a set of portable speakers and a birthday card to make this.

The Wii Nunchuck has an accelerometer in it so I used that to tell when they jump and also for them to control the rest of the sounds. The Nunchuck is connected to the arduino using an adapter that you can make or buy so you don't have to cut the cable.

For the sound recording and playback I found a birthday card that you can record 4 sounds on and playback the sounds by pressing each button. After tearing the card apart I found that it ran on a 3V battery so I used an arduino pro mini 3.3V for one and an arduino FIO which is 3.3V for the other. This way the arduino could directly control the sound board and power it too.

I have an instructable I made for this located here.

Halloween Firefly Costume

Last year we asked our sons what they wanted to be for Halloween and they both wanted to be fireflies so of course that was what they were going to be. It went without saying that they had to light up so my wife started working on the costume and I worked on the lights. Of course there wasn't much time until Halloween so it had to be pretty quick and easy.












For each costume I started with a cheap high powered LED flashlight and took out the LED assembly.

Then I took 2 AA batteries and put a piece of jumper wire at one end with some foam tape to hold it in place. On the the other end is the wire that goes to the battery connector and to the LED assembly. I soldered the wire to the LED assembly leads.

To make them able to light the lights when they wanted to I soldered a tiny switch and put heat shrink on it. I used the battery connector so the switch could be ran inside the sleeve of the costume and be removed from the light and the rest of the costume without having to pull the wire and switch out.

Here it is assembled. I don't have pictures of the rest of the costume parts but for the firefly light I cut out a sort of oblong half circle shape from thick styrofoam and cut a hole in the middle for the light. The battery pack was stuck to the styrofoam with 2 sided foam tape. My wife sewed a bag from yellow fabric and to make it keep it's shape she put fabric interfacing on the inside.