Wednesday, January 31, 2007

ice chime workshop

I spent most of the weekend working on ice chimes. After a serendipitous discovery during the 2006 competition, it seemed that it would be fairly easy to make rectangular chimes out of ice. Unfortunately, it has been hard to improve upon the original, lucky design. Although it is difficult to produce large blocks of ice in Colorado's climate, recent weather has made it easy to produce slabs of ice by freezing water in shallow, cardboard boxes lined with garbage bags.

I had hoped to be able to make rectangular bars of ice attached at one end, but it has turned out to be difficult to get good tones that way. I've had better luck with bars that are free on both ends and attached about a quarter of the bar length from each end, like the bars on a xylophone. In fact, our music box will probably end up sounding quite a bit like a xylophone.

I made chimes of varying shapes and sizes and digitally recorded the tones they produced. Some handy, open-source software made it easy to analyze the spectrum produced by each chime. With bars free on both ends, the chimes produced tones as expected according to various sources identifying Young's Modulus for ice.

four weeks to go

The Single Block Classic will begin at 9:00 AM on Tuesday, February 27th, only four weeks away! Lars and I have registered and intend to build a working music box entirely out of ice. The sculpture will be based on the model Lars sent me a couple months ago, although we will have to change a few things.

The chimes will be solid and rectangular rather than hollow and cylindrical. The hammer mechanism will require significant modification due to differences of scale (long pendulums swing slowly) and material. We will have four chimes instead of one, enabling a tune to be played.

The tune will be Westminster Quarters, the familiar clock chime tune. As it was originally written for mechanical chimes not unlike ours, it has several features that make it well suited for our music box. For one thing, it only uses four pitches. Another nice feature is that no pitch is repeated quickly. Combined with the facts that it is universally recognized and continues our clock theme, these features made it an easy choice. The sculpture will be called "Counterclockwise."

There is still a great deal of work to be done in preparation for the event. Lars is making improvements to the wonderful power tools he made for last year's competition. I've been working on designing and testing chimes and hammers as well as making hot wire gear cutters.

Tuesday, January 30, 2007

orbital mending plate

I tried attaching a mending plate to my quarter-sheet orbital palm sander, but it didn't do anything but cut my thumb! (The injury was during installation; once in place it was actually quite secure.) I think the problem was that the little sander didn't move the abrasive surface enough in comparison to the distance between points on the mending plate. I think a device with a larger orbit would be pretty cool, though.

Sunday, January 28, 2007

registered

We received an email confirming our registration for the Single Block Classic at the 2007 World Ice Art Championships. It's a good thing too, because I had already purchased my plane ticket. The Multi-Block event is already completely full, so there will be plenty of giant ice sculptures to enjoy this year.

Sunday, January 21, 2007

mending plate

I had an hour to kill at a hardware store a few days ago, so I walked up and down the aisles trying to think of how to put various tools and objects to use carving ice. I picked up a Strong-Tie MP36 Mending Plate and thought it might make a decent, one-handed nailboard. (As my friend, Dave, would say, "This nailboard was mislabeled as a mending plate.")

I tried it today, and it works great! I guess I shouldn't have spent all that time making my wooden nailboard. Attaching a whole bunch of these mending plates to a board would be a very quick way to make a large nailboard.

hot wire gear cutting

Today I tested a new hot wire gear cutter made of balsa, copper, and 21 AWG nichrome wire. I cut an eight inch cylinder of ice with the table-mounted chainsaw and placed the cutter on top of the cylinder. I still need to make an axle-mounted guide to keep the cutter steadily moving vertically without tilting or rotating, but I decided to do the first test without a guide.

As current was applied, the cutter started to slowly work its way through the ice. My power supply was only producing about 50W; it was enough to do the job, but I'd like to find a larger transformer that will cut faster and enable cutting of larger gears.

The finished gear had several flaws due to the lack of a guide but otherwise was beautiful. Making cutters like this one will take quite a bit of time, but the actual cutting time is very short. I think that this will be our gear cutting method for this year's event.

Thursday, January 18, 2007

chainsaw table mount

I tested a new table mount for my little, electric chainsaw tonight. It is made of steel flats and some nuts and bolts, and it allows the chainsaw to be used like a table saw but with more cutting depth.

My first use for it will be to precisely cut experimental ice chimes, but it may be handy during the competition as well. I also hope to use it to mill some boards from any trees I have to cut down this summer due to beetle kill.

The initial tests went very well. If Lars's 10", stationary, ice cutting, rotary bit doesn't make it redundant, I think we will find it quite useful.

It worked very well for cutting arcs and discs by inserting an axle perpendicular to the table-top and rotating the ice around the axle.

Monday, January 15, 2007

gear design tool

Steve Michel wrote to let me know about his amazing Excel spreadsheet for gear design. I probably won't need it this year, but I'll definitely keep it in mind for the future.

Saturday, January 06, 2007

nailboard

I found my new nailboard to be quite useful while making the snowflakes. I used it to even out the 1/2" plates of ice out of which each snowflake was carved.

I made the nailboard a few weeks ago but didn't try it out right away. It works like a mega-coarse grit sanding block.

snowflakes

I carved a small sculpture of three snowflakes to take to a New Year's Eve party. I tried to photograph them illuminated by a small reading light housed in a small cavity in the base of the sculpture, but only a couple of the photos turned out to be useful. I really need to use a tripod for this sort of thing.

The snowflakes were about 0.5" thick and were pretty fragile. I think I repaired thirteen separate breaks while making the things. Fortunately, two out of three snowflakes actually survived the journey to the party! I think the sculpture would have been easier to carve on a larger scale, but I was limited by available ice.

I took a photo with flash as well. It isn't as pretty, but at least it captured details despite my unsteady hands.