foam packaging prototypes

Here’s an industrial job I did for Polyfoam, Inc. Lots of interesting uses for expanded polystyrene foam on their site, as well as some impressive recycling stats. They were working with a window manufacturer to design packaging material for windows and needed 200 sets of prototype parts to test the design. They provided blanks and I cut the recesses in them. Here’s the before and after:

 This foam is a bit different to work with from the sheets of pink or blue foam you get at the big box lumberyard, which has a smooth skin on it. That smooth skin is pretty impermeable, so when you apply a vacuum to the bottom to hold it down it pulls down tight. The white foam allows some air to move through it, so in order to hold it down securely you have to move a lot of air away from the bottom side, which required building a special vacuum fixture. Here it is with the parts in it after machining:

 Wow, is that stuff white! It’s hard to take a good picture of it. Here’s the board without parts:

 The blotchy orange stuff is some thick shellac to seal up the MDF material the fixture is made of to prevent air leakage, and make sure all the air is pulling down the parts.

Here’s a closer shot showing the rubber gaskets:

 The black rectangles are pieces of foam which push the parts into place to make sure they are accurately positioned.

new samples

I’ve encountered some interest in address number signs, so I’ve made some samples. I put this one on my house, I like the font and the gold colored numbers:

The darker of the two boards underneath it is a special kind of MDF called Extira. It’s basically just hardwood sawdust pressed together with a waterproof phenolic glue and heated to set the glue. It’s sold for exterior signmaking and also used for exterior trim on houses. When properly finished it holds paint well and lasts for a long time.

Here’s another sample with a frame (I believe the proper term of art might be “bezel”):

This photo shows the bezel flipped:

By painting the parts separately and then gluing them together with boatbuilding epoxy I avoid the fussy painting which would be required if they were carved from one piece. Still not that excited about painting. I’d rather just cut the parts and hand them off to someone who loves to spread colors, but I am getting better at it and I have found some high performance acrylics that don’t stink like good old fashioned oil based enamel.

lotus step

A local wellness clinic (link here) was looking to make more efficient use of the space and wanted to use the display area at the front of the shop as a bench, so I constructed the step which you see above.

Here is a detail of the mortise and tenon joint which joins the legs to the top.

I carved a stylized lotus flower design into the top.

stair stringers

Samples to show to a builder/remodeler I’m talking to tomorrow. It could be a little challenging to explain CNC and how it can build his business, but I’ll give it a try. Anybody who’s cut these on a jobsite knows how tough it can be to get them identical.

The Kontraptionist

To characterize Andy Baker (aka “The Kontraptionist”) as “insanely great” might be a bit of and understatement. He and his small band of highly intelligent misfit henchmen swat off rats in a cramped shop located in a seedy part of Brooklyn and build stuff that’s absolutely brilliant. Andy’s blog is a frequent source of amusement and inspiration. His shop does full service design/build for artists, galleries, individuals, and industry.

Here’s a picture of his shop dog “Bandit” relaxing on the table of the CNC router which he designed in Solidworks and built himself. That’s a nice small cyclone dust collector in the back with a full six inch duct right to the cutting area. The piece of metal on the table with all the square holes in it is what’s left after making parts for a large ipad charging station.




My router has comparable aluminum cutting capabilities.

clean cuts in pine

Here are a couple of parts made from plain old pine from a big box store. The board they were cut from looked a lot like the curly board they are resting on. The beauty of having a brutally powerful vacuum pump is that I can pull a board like that flat and make good parts out of it.


 Here’s a closeup. These parts are straight off the machine, no sanding has been done. Chipping and cracking on the corners and tearout on the holes has been prevented by picking the right bits, keeping them wicked sharp, and clever programming. The holes in the ends were drilled with the cross dowel drill fixture.

cross dowels in use

On the left is a cross dowel installed, with a screw threaded into it.  In the middle is an uninstalled cross dowel, and on the right is the drill fixture I built to drill the holes in the edge of the part which the screw goes though on the way to the cross dowel.

Here is the hole being drilled.

Here is the joint assembled. Sill more finishing to do on the Baltic birch parts being joined.