Friday, December 29, 2006

library books

I picked up Ice Carving Made Easy, Practical Ice Carving, and Ice Sculpting the Modern Way from the local library. I have finished the first two but am still working my way through the third. So far, I haven't encountered very many insights that I hadn't figured out already, but a few tidbits have stood out.

Ice Carving Made Easy contained a couple of interesting points. One was the description of steam cutting in chapter three. Both Lars and I have been experimenting recently with cutting ice by bringing it in contact with metal tubing carrying hot fluids. According to the book, using steam in this manner is "still preferred by some carvers accustomed to older techniques" despite its slowness.

Chapter One, The History of Ice Carving, of the book includes some interesting details of the ice palace commissioned by Empress Anna Ivanovna in 1739.

"Inside, every detail was carved from ice. The highlight was a translucent clock with all of its interior mechanisms detailed, displayed on an ice table in the middle of the drawing room."

Could it have been a working clock? Considering that the palace was built some years after the invention of the Deadbeat Escapement, I think that it is possible. A clock of the size Lars and I hope to build would have been difficult with the technology of the time, as would a very small clock, but a table-top model would have been the most likely to succeed. Lending credence to the idea is the account of various other functional artifacts of ice:

"Six statues and an elaborate frontispiece graced the front entrance; two dolphins and one life-sized elephant fountain sprayed water 24 feet into the air. Two mortars and six cannons fashioned of ice were working replicas; they fired frequently. An ice-log bathhouse, also functional and used on occasion, completed the grounds."

package for Lars

I sent a package to Lars containing a hot wire ice cutter for him to try out. It consists of a home-made variable power supply (encased in a CD spindle shell) and a 10 inch nichrome wire on a wooden bow. Since receiving it, he has used it for cutting foam but hasn't tried it on ice yet. I'm hoping he will try it in cold temperatures to see if it causes ice to crack.

The CD spindle (with center post removed) turned out to be a great case for the power supply. I used a cheap triac dimmer switch, a transformer salvaged from a useless wall-wart, and a little fuse holder from Radio Shack.

Monday, December 11, 2006

robotic fishing hole carving

I ran across Jesse Hemminger's art shanty projects and enjoyed the read. The CNC lake ice router is outstanding, but I was even more impressed by the simplicity of the hot water pipe technique. I'll have to give that a try.

Monday, December 04, 2006

big, scary lasers

I found this amazingly inexpensive, 25W, 808nm laser on ebay tonight. I was quite tempted to buy it as it appears to be a very complete unit, including power supply, cooling, power meter, and output fiber. Unfortunately, it appears that ice doesn't absorb much at the 808nm wavelength, so I guess I'll pass on this one. I finally found an outstanding data source for optical properties of water and ice. Based on this information, I'd say I need a wavelength of at least 980nm.

Sunday, December 03, 2006

laser cutting

Lars suggested using "high intensity lasers!" in one of his first emails when we started planning for Ice Art 2006. I laughed off the idea at first, but I'm taking it more seriously as time goes by.

Visible light lasers are certainly out of the question; they'd pass right through the ice without heating it. Infrared lasers, on the other hand, have a great deal of potential for ice cutting. Ice has a couple of peak absorption wavelengths at about 1500 and 2000 nm, but it looks like any laser in the infrared band would be worth trying.

I'm guessing that I need at least a 1W unit to do any meaningful experimentation, but the devices I've found so far are quite expensive. If anyone has lead on a cheap IR laser or laser diode (or salvage ideas), I'd appreciate it.

two turtle doves

This weekend brought good weather for ice carving practice, so I asked Emily what she would like me to make for her. "Two turtle doves," she replied. I have them sitting on a turtle shell, mounted on the deck railing by our front door. Apart from breaking off one of the beaks at the last minute, I thought the project went pretty well. I used a chainsaw and chisels on mediocre, home-made ice.