Ever since I first saw a lithophane in a YouTube video I have thought they were really cool.  I have made cylindrical lithophanes previously with my CNC machine.  When I bought my 3D printer I thought I would give printing lithophanes a shot.  I tried working lithophanes into Christmas ornaments with marginal success (See some of the ornaments here).  After a little refining I printed some pictures on a cylinder and a night light cover.  I removed the original night light cover and replaced it with a 3D printed version.  The nightlight worked out well since it was a purposeful back light for the lithophane.  Below are some pictures of the results.  The cylinder is back lit by a battery operated tea light candle (the pictures are the front and back of the same cylinder).  I spent a bunch of time making the STL file only to find that there are utilities that other people have made available for making cylindrical lithophanes.  Here is a link to one I found on Thingiverse: Customizable Cylinder Lithophane Lamp.

This is a collection of bottle openers that I made from 16D common nails.  Some of them work better than others but I tried to incorporate a variety of designs.  The plaque hangs on a wall and the bottle openers (nails) are held in place by magnets (neodymium magnets from hard drives) installed in cutouts in the back of the plaque.  The YouTube video embedded above shows each of the openers in action.

Here is the basic process that was used for each of the bottle openers. My son Derek (age 9) did all of the hammering for the pictures shown below. (I worked the torch and held the nail with the pliers)  The Anvil in the pictures is also Derek’s.  I have a chunk of railroad track but Derek wanted the anvil shape so he asked for an anvil for Christmas last year.  He thanked his Grandpa for the anvil before opening it (the weight gave it away).

Start with a nail (16D common):

Heat the nail up, in the area to be bent, with a Propane torch:

Hammer the nail (or bend with pliers) to achieve the desired bend and repeat as required:

The nail can also be flattened to achieve additional features.  Derek has even flattened nails and added a twist for decoration:

In the picture below the shape of the opener is complete:

To increase the strength of the nail we heat it up and quench the nail in a cup of water.  This is needed to varying extents depending on the design of the bottle opener.

That completes one bottle opener. Time to put it to use:

The embedded video above shows closer views of the other bottle openers and includes video of each design opening a bottle.

A couple of years ago Fran posted a really interesting video demonstrating friction welding. Fran used a cheap harbor freight rotary tool and some plastic (styrene) rod from a craft store.  Her demonstration showed how strong friction welded joints are.  Friction welding has been bouncing around the back of my brain ever since.  Lately I have found a couple of applications for the friction welding technique.  Having recently purchased a fused filament 3D printer (PrintrBot Simple Metal) I have some failed PLA 3D prints laying around. I also happen to have some ABS scraps and some 3mm injection molded ABS rods from another project.  Experimenting with these materials I have found that friction welding works well for both ABS and PLA.  As part of my experimentation I repaired a failed Maker Faire Makey figure. The following video captures the process.  (I have since printed a successful Makey Robot on my Printrbot simple Metal)

After some experimenting with 1.75 mm PLA and 3 mm ABS I have come up with a few friction welding tips:

• 3 mm filament can be used in a standard 1/8 inch collet.
• 1.75 mm filament can be used in a 1/16 inch collet (available at most hardware stores. usually in a set of four Dremel collets )
• You could also use a Dremel chuck to hold the filament if you have one.
• Don’t run the Dremel at full speed.  I try to keep the speed as low as I can.  If the Dremel tool wants to jump away from the part you are welding increase the speed.  (thicker filament requires more speed)
• Don’t let too much filament hang out of the collet.  Too muck filament will start to whip around and break off.
• The filament will wear away quickly.  Stop to extend more filament before the extended length of  filament gets too short to grab and pull out with a pair of pliers.  Otherwise the collet nut will need to be completely removed to pull more filament out.

In addition to repairing failed prints friction welding can also be incorporated into the assembly process.  Smaller parts can be welded together to form larger structures.

For example I printed 20 hexagons and friction welded them together to form a truncated icosahedron (same shape as a buckyball).  In this case the finished part would have fit inside of my printers build volume but the same process could be used to create much larger structures.

Friction welding is a quick, strong and easy way to join plastic parts together.  The great part is that welding the parts together eliminates the need to add additional adhesives keeping the part a homogenous material.  Additional structure can even be added if needed for strength.  For extra strength prints could even include bevels for strong traditional weld joints.

The files for the truncated icosahedron can be downloaded here:

• Youmagine: Friction Welded Truncated Icosahedron
• Thingiverse: Friction Welded Truncated Icosahedron

Update 12/26: Why stop there below is a quick GIF of a dodecahedron made from pentagons.

I have been playing with making spherical lithophanes with my new 3D printer (PrintrBot Simple Metal).  I wrote some Java code to read the image data and then map the image to a sphere.  The thickness of the sphere is determined by the darkness of the image.  Below are some pictures of the results.  I illuminated the bulbs by drilling a small hole in the sphere and sticking a Christmas light into the hole.  My Christmas tree lights are colored resulting in the bulbs appearing colored when illuminated.

Here is a shot of some of the bulbs without illumination.

I would like to add features to the balls to make them look more like traditional Christmas bulbs but the mesh that is produced by my Java program is so large that I have not been able to perform even the simplest Boolean operations on them.

When my kids and I went to Maker Faire Kansas City we made a Maker Faire themed cover for the hitch receiver on our minivan.  For Kansas City we used the themed graphics right from the Make web page.  Well this weekend we are heading to Maker Faire Milwaukee.  Unfortunatly Make does not have any site specific graphics for the Milwaukee faire.  So I made up my own graphic for the trailer hitch.  Makey the robot with a cheese hat.

Here is a picture of our first hitch cover for Maker Faire Kansas City.

I have been sporadically experimenting with my electric micro foundry setup for almost a year.  Recently I have been trying different crucibles.  My first crucible was a mini terracotta pot.  (I don’t know where the pot I used came from but I have not been able to find another one the same size without a drainage hole.)   I have also used a porcelain crucible (from Ax-Man) and a ceramic shot glass that I picked up in Las Vegas.  The terracotta pot has some significant cracks and chipping after a couple of furnace runs so it has been retired from use.  The porcelain crucible shows some chipping on the top edge.  Probably from being manhandled by a pair of pliers during the pour.  The ceramic shot glass seems to be holding up the best so far.  I don’t see any structural damage after a couple of runs in the furnace.  Before I used it I was a little concerned about the design on the side of the shot glass being a starting point for a crack but so far so good.

Casting small parts in sand is a little more sensitive that larger parts.  At least it seems that way since the small imperfections are a more significant portion of the end casting.  I tried the small toy airplane (red) in the picture above a couple of times.  both times the plane was only partially formed.  The tails were too short on one and the wingspan was too short on the other.  I will see if I can’t work out some of the bugs in the future.  Below are some pictures of my micro furnace in action and some in process pictures of a Yoda and toy plane.  I am using old aluminum nails, that I was given, for the raw material in my my micro foundry.  Most of my other scrap aluminum would need to be cut down significantly to fit.

I thought it would be interesting to see how well a simple hot glue gun with standard hot glue could produce injection molded parts.  Although the parts did not all turn out perfect I thought the results were pretty impressive considering the simplicity of the method used.  Here is a video of my trials.

After my initial trials I poked around on the web a bit and found that this is nothing new. There is even a company that sells an “Injection Moulding Pack” Mind Sets Online.   The description of this You Tube Video even talks about polyethylene in the shape of glue sticks.

For more details on the molds I used for these tests and to find out about my homemade plastic injection molding machine see my Home Injection Molding web page.

G-Code Ripper Version 0.05 is now available.  The new version can export tool paths read from a g-code file to a DXF or CSV (Comma Separated Value) file.  The new features are located under a new G-Code Operations option called “Export”.

In the exported DXF file rapid moves and controlled moves are written to different layers with different color indexes. The rapid moves can also optionally be omitted from the G-Code Ripper DXF output.

All of the arcs (G2/G3 moves) are converted to multiple linear segments for now. I will include arc output to the DXF file if there is interest as time permits.

I uploaded version 1.33 of F-Engrave, it is available on my web page. (F-Engrave 1.33)

Changes in Version 1.33:
– Added option for scaling input image height as a percent of the input values (rather than imputing the height as a length unit). This new feature should help people that combine more than one image together in a project. The new option is “Set Height as %” which allows scaling the input image by a percentage rather than setting a size(in or mm) for the height. Setting the height % to 100 will result in the image being the same size as the imported DXF file.

– Fixed batch mode…again. (I should really check that it is working before each new release)