Thursday, June 25, 2009
If you are not familiar the Hex Toy is a laser cut building toy, the edge notches fit together to make abstract shapes.
Here’s a new version made specifically made for 3mm and 1/8th in plastic. The notches are larger, and the peices themselves are larger too. The feel is much more substantial.
Check out the Hex Connectors project page for more detail and to download the new design.
Monday, June 15, 2009
In the past there’s been a lot of talk about laser etched/cut moleskine blank books, but it’s come to attention that the PVC outer layer is very toxic when vaporized.
On the other hand, real leather bound journals are great for engraving on and make a great Father’s day gift. This isn’t really a new idea, but it’s great in context of Father’s Day.
I chose an image from “Ernst Haeckel: Kunstformen der Natur” It has fantastic and artfully hand drawn illustrations of various plant and sea life, and better yet, is in public domain. If you have not seen these images it is worth your time. I’ve used the illustrations in many things.
Try a google image search, or you can download the full PDF at following site.
http://caliban.mpiz-koeln.mpg.de/~stueber/haeckel/kunstformen/natur.html
http://images.google.com/images?q=Haeckel+Kunstformen&hl=en&hs=YNS&sa=N&um=1&imgsz=xxlarge
Tuesday, June 09, 2009
Here are my plans for a 3 stage filter, it has a rough filter, a fine filter, and a tray of activated carbon. It uses standard 14x20in home filters and bathroom ventilation fans for suction. The cost is about $50, not including filters.
It’s good for dust, smoke, and fumes at about 100 CFM. It’s great for my shop.
To start you’ll need:
- 2 – 24x48x0.5in plywood sheets
- 1 – 4ft 2x4 board
- 2 – 8ft 2x2 boards
- Screws or nails
- 2 Bathroom style ventilation fans
- 1 Tube of caulk
- 1 Roll of duct tape
- Vent tubes for input and output
- Tools
Step 1:
Cut 1- 14x20in plywood piece, and attach a 14in 2x4 to the far edge, and 2- 17in 2x4 pieces to the side.
Once the base is complete, place the fans and mark where they will be cut though. I used a jig saw and drill to cutout the square slots. Mount the fans to the base as well as you can.
I used duct tape to seal the edges of the fan down to the base to eliminate leaks. Eventually the entire air path will be sealed except the input and output vents.
Use 2x2 boards to create a border around the base, the filters will rest against this frame.
Cut 2-14x14in board to attach 1 to the back of the base, that’s the side that the fans are blowing away from. Save the 2nd board for the front of the box later.
Cut 2-21x14in boards and attach to the sides of the filter, note the caulk on all edges.
Cut a 14in 2x2 board and attach it to the back top of the filter.
Cut 2- 18in 2x2 boards and attach it to the top sides of the filter, these three pieces will be the anchor for the top board. Note the caulk around all edges.
Cut a 15x21in board and attach it to the top of the filter, caulk around all edges.
That completes the main part of the filter, all your have to do to complete the box is make sure that the output air is directed correctly depending on your situation, in my case I used some scrap plywood to create sealed a channel that by output duct will attach to.
About the Carbon filter, I used a cheap air filter and just dumped a big pile of activated carbon granules on it. I used the activated carbon that you can buy at the pet store for cleaning your aquarium water, 3 pounds of carbon cost about $20 and filled the 14x20x1 tray perfectly. This isn't the most effective filter, but is is much cheaper then a “real” activated carbon air filter.
My laser, among other things does not have a air filter, and when I cut things the fumes get to be over-powering.
The filter works great, I estimate that for standard smoke it filters about 99% of it, and for the more acrid plastic fumes are reduced by 60%-70%, which is a big improvement.
Eventually I will buy a “real” activated carbon filter for this box, but they are kind of expensive, so I will make due with the DIY version for now.
Monday, June 01, 2009
My last post was about rapid prototyping with sugar and lasers, it turned out well, but the result is really only 2d. Although with some supporting hardware I think it has great potential for making full 3d objects.
Soon I will be testing a 3d object with finer sugar, but the first step is to get all the 2d layers of a 3d object and semi-manually building up the object layer by layer.
After some research I found Skeinforge, a collection of python tools for slicing and creating g-code for 3d printers like the RepRap and Makerbot. I downloaded the version that’s included with replicator-g, the program that controls those same machines.
For anyone that may be using Skeinforge with Solidworks, the trick is to set your STL export options correctly, I used:
Output as: ASCII
Unit: Millimeters
Do not translate STL output to positive space: Unchecked
Once that is set Skeinforge works great with Solidworks STL files, though you will need to be patient when you are waiting for the output.
Friday, May 29, 2009
I always wanted to start a project for making 3d prototypes with my laser in layers similar to how the legacy Candyfab project did, but never got around to it. With the recent Candyfab news , and the relative success of my Laser Cooked Bacon project, my curiosity got the better of me and I wanted to see what would happen.
I did some research and I wasn't able to find anyone that had melted sugar with a laser, there was some posts on the Candyfab forums, some seemed to think it was possible, and some did not.
So I fired up my laser and got a small dish of standard granulated sugar, all I had to do was fire the laser and see what would happen.
Success! At 60% power (of a 40w co2 laser) and 5cm a second speed, my test text melted right into the sugar as I expected.
The sugar sagged a bit and the melted sugar kind of sank into the sugar below. It was also about 3mm thick front to back, I used my trusty Laser-Cut Caliper to measure.
The sugar stuck to the edges of the text a bit blurring out the outline. I also tried cleaning up the letters with a bit of water, but without just the right technique the sugar dissolved very quickly, but it did help some with the edges. That technique is probably impractical with this size of construction.
The second test was at 80% power and 15cm a second speed and was 75x75mm in size. The resulting construction was much thinner, about 1.5mm and fairly fragile. If I were to make a 3d object with layers, I would use a power lever similar to this. The sugar was only slightly discolored, and there was very little sagging. The construction ended up breaking when I was measuring the thickness.
The third test was at 80% power and 5cm a second speed, this object is 50x50mm. The result was very solid and durable for sugar, but had quite a bit of sag and was yellowish on top. If I were trying to rapidly crank out some custom sugar treats I'd go with this power and speed.
Since the sugar never comes into physical contact with anything else, it should be safe to eat. I couldn't resist and sampled a bit of the last test, and it tastes exactly like caramelized sugar, no big surprise. If the sugar was mixed with another powdered flavoring (like cinnamon or coco) you could get some more interesting (tasty) results.
I may make some custom sugar treats for my next house party, they might go good on top of a cupcake or in a drink.
Another interesting side-note, when hitting the sugar with the laser, the sugar flared up a bit with a light orange flame, but with no smoke. I'm not exactly sure why that is, but it seems relatively harmless.
Eventually when I rebuild my laser into a larger frame, I will try to make some previsions for making 3d objects in sugar with a special sugar tray and layer leveling device.
Thursday, May 28, 2009
I was looking for inexpensive things to engrave at the local department store and came across these cool “Key Tags”. They are a thick paper chip with an aluminum protecting ring around them with a keychain ring already inserted. The Avery 11027 pack has 25 in it for about $3.50.
It turns out these are perfect for engraving on and handing out as trinkets, the paper chips mark easily, but are thick enough that a low laser power setting doesn't instantly cut though them.
I put these together for a short film release party. You can see that film, and others I’ve worked on over at a3o.net.
Wednesday, May 27, 2009
Todbot has posted an excellent tutorial on how to setup and use the minimal Arduino, which is the bare minimum you need to run a ATmega chip and the Arduino bootloader.
Todd goes into detail about how to get the bootloader onto the chip as well as how to setup the Arduino environment to use it.
Even if your not interested in building an Arduino from scratch, It’s a good read if you are interested in the technical aspects of what makes the Arduino work.
http://todbot.com/blog/2009/05/26/minimal-arduino-with-atmega8/
Sunday, May 24, 2009
When building the Jansen Walker I coated the feet for better traction, I didn't go into much detail then but I wanted to show the whole process here.
Laser cut acrylic parts are pretty slippery, especially on hard surfaces and fabrics. For parts that need good traction, like legs and wheels, it’s nice to have a little extra something.
I used plasti-dip, it’s a rubberizing dip that’s designed for dipping tool handles and it works great with laser cut acrylic.
I used 3 coats and dried them hanging up, the tricky part is hanging them without touching any other parts.
The dip shrinks considerably after drying, it’s thicker then latex paint, but not by much. I used three coats to build up a good base. Above is the wet size, below is dried.
The final product seemed to work great, I'm sure I’ll continue to use this technique on future projects. It’s easy and cheap.
_thumb.jpg "IMG_2046 (edited)")
Friday, May 22, 2009
It’s been a while since I’ve posted anything PSCombine related, if you are not familiar here is a short blurb:
PSCombine is a program that will import your collection of images or photos and randomly combine them in Photoshop with a random blending, opacity, and filters. I like to think of it as "Computer Assisted Art".
It’s free to use, all you need is photoshop, go check out the PSCombine project page for more detail. If you have a PSCombine gallery let me know, I would love to see it.
John just posted a new gallery on flickr and I wanted to post my favorites here.
Wednesday, May 20, 2009
I’m starting on a project that I’ll be using stepping motors and belts, and after looking for cheep parts online, I thought I could do better by stripping down some old scanners.
People are excited to get rid of there old computer stuff, the great thing is it doesn't matter if the old scanner works. Even if it doesn't turn on likely the motor and mechanical parts are still good for salvage. I posted a ad on Portland’s craigslist in the wanted section and got several responses, in a week I had a bunch of scanners for free, I only had to pick them up. I found that putting in the ad that you would be reusing the parts for a robotics project people were very interested.
Scanners are easy to take apart, they are pretty simple machines and generally there are some catches, and a screw or two around the edges of the top cover.
Once the cover is off, you can start stripping parts, the valuable and easy to use parts are the stepper motor, linear slide, belt and gears. There may also be an optical end-stop sensor, and some buttons that are easy to re-use. You can get more hardcore and try to salvage parts on the actual circuit board, but that takes a bit of research to figure out what is useful.
Here are the parts from two example scanners, both have similar parts and took about 10 minutes to gut.
From all my scanners I salvaged at least:
- 1 Stepper Motor
- 1 Linear slide bar
- 1 Timing belt
- 1 Set of gears for the belt
- A few buttons and LED’s
If I were to buy those parts I would be spending at least $20-30, and they are all in good usable condition, just for the stepper motors alone it was worth my time. Also most of not all of those scanners would have went to the landfill. I was able to recycle most of the electronics, and I put the plastic shells in the city recycle bin, that’s something you can’t do while the electronics are still inside. That’s a net win anyway you look at it.