Someone sent me a link to
this video saying it copied my 3d pantograph.
But the pantograph carving idea actually pre-dates mine.
But it gave me the idea of trying to build something like that out of lego, especially
because I recently bought a big lego set
for something else.
But crayons are tricky to carve because they aren't flat, and then I had the idea
of trying it on chocolate instead.
After thinking about it for a while, and figuring out what gearing I needed to spin a
cutter fast eno`ugh, I set out to build the pantograph. It took about an hour
and a half of tinkering.
No lego part itself was suitable to use a s cutter or "router bit", but I had the idea of
breaking off a piece of a scalpel blade and sanding that to just the right width to fit
inside a lego shaft coupler. I pressed it in with a pair of pliers (see photo at right)
Used the tight fitting connector pegs for the pantograph hinge points instead of
shafts or the loser fitting connector pegs to eliminate play.
At right, the result of my first test. I followed some letters I wrote on a piece
of cardboard attached to the pantograph.
It worked surprisingly well! But there were bits of chocolate stuck in the
grooves that wouldn't come out. I needed the chocolate to be harder, so my next test was
in a cool room in the basement, just 10°C
It also really helps to lubricate lego shafts and gears to cut down on wear. I used
some mineral oil, which is actually meant for human consumption as a laxative.
That way I didn't have to worry about trace amounts of it ending up on the chocolate.
I wanted a slightly pointed stylus for following my line drawings. The easiest way
to accomplish that was to put a piece of lego shaft in a pencil sharpener.
My next test in the cool basement room worked much better.
There was very little residue left in the grooves.
But the chocolate was brittle at that temperature and didn't consistently
break between the squares. So I used a bandsaw to cut the squares instead.
With valentines day coming up, what better to carve on a piece of chocolate than
The text came out quite legible despite being small on the chocolate square.
I then cut out the outline of the heart on the bandsaw.
A bit of hot air from a heat gun was enough to slightly melt the surface,
smoothing everything out a bit.
I showed the result to Rachel, who was quite happy to eat it!
With a bit of practice from the first attempts, I was able to make
a better one, which I decided to save until February 14th.