Passover!

This Passover is special for me — it is the first Passover that other families will be using my Seder plates.

It is such a thrill that the years of preparing the tools to make these plates have enabled my handiwork to add to others’ Seders.

Thank you.

If you need a Seder plate for this Passover, I have a few ready.

If you want a plate made specially for your table, there may still be time, although time does draw tight.

Again, thank you for making this a special year.

Valentine’s Day

I’d like to do a “romantic” carving for Valentine’s day. Yes, I know it is a Christian holiday, derived from the history of Saint Valentine writing letters to people encouraging them to love each other. Somehow that molted into the lavish statements of Eros we have today.

I added “Valentine” to the key words on the “Heart of David” carving on Etsy. I am curious to see if it attracts any interest.

DSC06416

By the way, the chorus I sing with is selling Singing Valentines. We send a quartet anywhere in the Boston area and express love to a boyfriend, girlfriend, spouse, or probably even and ex. You pick the place, private or public, workplace or during a special dinner. Check out our Singing Valentine’s site. Carvings by Carl has no association, but I’m the co√∂rdinator this year.

Aesthetics

I showed a Seder plate to a shop manager today. Great feedback, which underscored the value of letting people help create their own look.

For instance, the letters in the item locations are all rotated so that the PESACH is at the center. Many Seder plates have the labels parallel, so they all can be easily read from one place. When I’ve asked about this feature, I find that about 60% of people prefer the letters to line up with each other, and 40% prefer them to radiate from the center. With some customization interface, this could be determined as part of customizing a plate.

Custom carving to order caries more obvious value, and it could be more fun for me, too. I like making things specially for people who want them. It may soon be time engineer the user interface that enables selecting options, and quickly renders images with the particular selected collection of features.

Sunday, Sunday…

Sunday I should be back in the workshop. I have some new wood to try — Spanish Cedar. It doesn’t have the aroma of the cedar for a closet, but it does have a rich, golden color — like roasted almonds. If even a few things go right, I’ll be working with it tomorrow.

I’ve went over my machine. I checked the servo-motor brushes (no visible wear) and the spindle brushes (maybe 25% wear). The first wave of intense use loosened some parts and changed the alignment. After strengthening the parts that needed it, the leg length dimensions changed by a tenth of an inch or so. I was delighted — it was time to calibrate!

I had already written new calibration code to better estimate the construction measurement errors, and wrote last weekend new code to sample the data the calibration routine needs. The calibration code is exciting because it take advantage of modern computers to do a better job than my old calibration code. The code now runs multi-threaded and multi-core, pushing my Intel I-7 processor to the limits. It simultaneously estimates all seventy-two (72) simple sources of error, and does so based on a much simpler and more automated data capture system.

More importantly, though, I took a hard look at the results from my first calibration (something like three to five years ago), and saw that the results were terrible! Points that I know are (nearly) co-planar were deduced to be over an inch out of the common plane. I would have been far more accurate using my measurements than the results of my previous calibration.

So tomorrow, I may not be running with a completely calibrated machine, but it will be far more accurate than I was using before.

Now, will the accuracy actually make much difference? Probably not, since my process compensated for many distortions — including internal position errors. Tomorrow should reveal the difference.

Back to the Spanish Cedar… it has a great deal of harden pitch in the wood. I may choose to finish with oil diluted by mineral spirits, or perhaps I’ll go with shellac. I’ll check my references. I still want a stain resistant surface — it won’t do to have beet juice from the red horseradish stain the plate.

Time for the Left Brain

Hello, and thank you for being here.

We’re deep into Channuka now, so why am I still talking about Seder plates? It turns out that Limmud brought me a custom order for a large Seder plate. I make my own variations, but hadn’t formalized the process with someone else, so I had to set up the work flow to make that possible. The process is pretty simple, actually. We talked about the desires for the design, and I made an electronic mock-up. The customer reviewed the design, and gave approval to proceed. I sent frequent photos showing the work in progress. That is all in order now, the Seder plate has been delivered.

Now, my attention turns to the technical aspects of this — specifically maintain, improving, and calibrating the machine I built.

Here the emphasis switches from smoothness, sanding, and finishing, to bearings, beams, and variables. We move from wood working to engineering — from art to math.

Another Thing that can Go Wrong

Using a unique, home-built high-tech machine has its own challenges. Since I designed every piece, built it myself, loved every joint into place, and wrote every line of code, every failure is my fault. I have caused everything that has gone wrong — and surely there have been plenty of problems. Mercifully, fewer as the machine and software mature, but I am specially responsible.

A few months ago, I eagerly accepted a commission for a customized design, delivered on a tight schedule. It was for a simple customization to one of my large Seder plate designs.

I designed the special variation, the customer reviewed the artwork and gave approval to go ahead.

The customer wanted the design carved in Cherry. I had a piece of Cherry large enough for a large plate, but when I pulled it out to use, I saw a small knot which would be right in the middle.

0.3″ knot in a nice piece of Cherry

The knot was about 1/3″ on one side, and less that 1/4″ on the other. The knot might look really good, or it might be a problem. Since the work was needed quickly, I didn’t want to take that chance.

From my blog entry you may see that I received a large piece of Cherry. It was rough sawn, not planed or sanded smooth. This forced extra steps. First, I modified the tool path to penetrate 1/8″ into the material, deeper than any surface variation. Second, I rough sanded the front so that the surface calibration could find the real surface, rather than the rough original surface.Wood clamped and smoothed

I set up my machine, loaded the design, and set it to cutting. It was looking good, so I came inside to see my wife for a few minutes. Later, I went out and saw an unexpected bump in what should have been a flat region.
A Z-axis discontinuity, caused by the wood cracking and shifting. I assumed that something had gone wrong with the machine, or with the constantly changing software, and the Z-position had been compromised. My heart sank as I anticipated debugging my system, hardware or software, quickly enough to meet the customer’s need.

Looking closer, I saw that the wood had an open a crack from the end. The crack had split and shifted the wood, and that shift had caused the problem.Cracked from one end of the wood deep into the plate.

I chalked up the problem to unseen stresses in the wood that were concentrated as the thickness was reduced. I prepared the next position on the plank, clamped it more tightly with better support, and cut it without incident.

That bit of wood became firewood.

Wood is a natural material. Each piece is unique, and it is always challenging. Finding the right wood is hard, but knowing how any particular piece of wood will respond is, for me, nearly impossible. As an engineer, I like to anticipate problems. As an artist, I accept that materials have their own, inscrutable behavior.

Wow! What a Day.

Thank you, everyone came by to talk and see my work today at Limmud Boston, 2012.

Special thanks to those who liked something well enough to make it theirs.

Talking with you all today made me itchy to bring the store up to the level of my work. I’ll be completely redoing the store, and items will be appearing shortly.

Again, thank you for a wonderful day.

Opening hour at Limmud

I’m set up, and ready to rock. So many people to talk with.


The day is here, everything is set up. If you are in Boston, consider coming to Limmud. The conference is in full swing, with activities throughout the day. Walk in registrations are welcome. And, when you come, stop by and say hello.

Will I see you at Limmud Boston?

Limmud Boston is coming this weekend, beginning with Shabbat eve activities spread throughout greater Boston, and culminating is a full day of intense and varied Jewish learning.

Limmud Boston is the first time I’ll have carvings with me, and have a chance to meet you in person.

Over the forty years of my professional life, I’ve developed many products, and attended trade shows in the US and Europe to personally discuss these products with customers. Every time I come back with ideas. Every time I’ve come back energized and excited.

Every time, I’ve gone with total confidence that the products were valuable, and the best that we could make. This time is not different. I am proud of my product. I’m confident that others will see the value.

Yet, this time I am acting on my own. I designed the carvings. I designed, fabricated, and programmed the equipment. My hands have performed the final steps, applied the finishes, caressed the wood as the surface seems to soften under each finer grit of sandpaper. My eyes have witnessed the wood come alive under finish. Without a team, other than Barbara, I will stand alone at my table, eager to meet each of you face-to-face.