Thursday, March 07, 2013

Beginners or Experts?

Who should I make tools for?

I have always made the tools that I like. Some of my first needles were polished like jewels. They were slippery and I found them unpleasant to use. So early on I found that annular striations around the tip facilitated a gansey needle pulling a loop of yarn through a stitch. This made it easy for me to learn to use gansey needles with a knitting sheath.

Over the last few years I have become a better knitter. I can now use gansey needles with highly polished tips.

Last night, I picked up a set of the old gansey needles with the annular striations around the tip. I happily used those needles to knit a gansey in 9 days a few years ago, but now I find that I can knit faster without the   annular striations. This morning, those needle tips are smooth and polished. A beginner would find them hard or impossible to use. If I had been presented with those polished needle tips when I was beginning, I would have given up in despair  However, now I want something faster.

When one is making specialized tools, how does one compromise the needs of the beginner with the needs of the expert?

Makers of wood turning tools have a similar dilemma.  Wood is abrasive, and even the best wood turning tools have to be resharpened frequently.  Does one tell one's (new) customers how to get the best professional edge, or do you tell them they can do a "good enough" job of sharpening with a bench grinder?

Robert Sorby stands up and says, "This is how we recommend that our tools be sharpened."  It is an approach that requires a large capital investment, but results in a very high quality edge, saves tool material, and saves time.  Hamlet on the other hand, declines to make a definitive statement about how to sharpen Hamlet tools, and mumbles something about bench grinders being "good enough", fast, and inexpensive.  I feel sorry for owners of Hamlet tools that are not informed as to the best practice for sharpening HSS.

In wood turning, the burr raised by a bench grinder is ephemeral and will quickly be worn away by the wood it is cutting.

Any burr that can be raised  on a HSS scraper edge with a manual burnisher is ephemeral and will quickly be worn away by the wood it is cutting.  The cutting edge of a HSS scraper edge with a burr raised by a manual burnisher is not as sharp as a HSS scraper cutting edge honed with a diamond card.  This is a combination of tool engineering, metallurgy, and physics. I am amazed that people that would rather work with dull(er) tools than admit that I am correct.

Yes, it takes longer to sharpen a wood turning tool with a fine, slow speed, wet grinder, but the cutting edge lasts much longer than the cutting edge produced with a bench grinder.  So the slower sharpening system actually saves time in the course of a full day of high end wood turning. And since less tool material is removed, the very expensive turning tools last longer.  Thus, over all the system is less expensive.  The even more capital intensive Sorby system removes even less of the wood turning tool, and thus for somebody doing a lot of wood turning, the Sorby approach is even less expensive, because the big cost in wood turning is the cost of the wood turning tools that are ground away in sharpening.

Wood turning tools do not need to be hollow ground.  In fact, flat ground bevels are less likely to catch, and stronger. And, flat wood turning chisels with flat bevels last longer.

On the other hand, a bench grinder will very quickly produce a reasonable edge. And just as quickly, it will grind that expensive HSS into a pile of worthless gray powder.  Then, Hamlet can sell another set of  expensive HSS tools.


Holin Kennen said...

Whether you are making tools for a beginner or expert, I can tell you that I received my size 1 needles from you today, and they are, in every way, perfect. I can't wait to start working with them. Thank you so much for making such wonderful tools!

Aaron said...

I am glad you like the tools. I make the tools that I like. I know about the theory of QA/QC and consistency in manufacturing. However, I can look at a set of needles that I have made, and can tell you what kind of yarn I was knitting the night before.

My training in industrial engineering says this is terrible, and I should make up jigs so all are exactly the same.

Then, my work as a craftsman comes in and says, "Make the tools that you want to work with NOW, not the tools you wanted to work with back when you made that jig.!"

A friend is writing the definitive book on hand spinning linen, and she has a big deadline coming up.
We are going to celibate by taking a day off and I will teach her swaveing. Part of it is making her a kit of all the swaving tools. It is interesting for me because that toolbox is an essay on everything that I know about swaving today. Then, I can copy all the data into my shop book. I like the shop book approach because I do not mind crossing out a number and writing in a better one.