Category Archives: Tools & equipment

Empty Balance

Lynne Yamaguchi Posted on by

Collaboration by Lynne Yamaguchi, Connie Rayburn, and Bina Rothblatt

This is the second collaboration I was part of at the WIT eXchange, this one with Connie Rayburn and Bina Rothblatt. In contrast to my first collaboration, Connie, Bina, and I came up with the concept for this quite quickly, right after getting “empty” and “balance” as our words: balancing objects on the rim of an empty, small-footed bowl. We all worked together on the main bowl, then split up to make objects to balance. I wanted to make a raw, chaotic, asymmetrical piece to contrast with the elegance of the main bowl, so I played with a reciprocating carver for the first time (loved it so much I bought one after I came home), then torched the edges. Connie turned a small version of the main bowl and another bowl that we decided to paint green. After playing on the lathe, Bina wasn’t satisfied with any of her objects, but she found a cool-looking scrap of wood burned to coal and cut off the tip to put on the rim. We painted the inside of the main bowl and its mini-me black to emphasize the emptiness, then added the base to emphasize the balance, painting it black for aesthetics. If we’d had more time we would have tapered the base to echo the curve of the main bowl. It took all three of us to find the balance of the objects, but we did—nothing is attached in this piece, all just balanced.

We discovered an interesting surprise after we finished: we had ended up balancing chaos and destruction (my carved object and the coal remnant) against growth and (re)production (the “baby” bowl and the green). The unconscious at work?

New milestones

Lynne Yamaguchi Posted on by

I have some new recent milestones to note.

First, last Monday, I drove solo for the first time since my accident. The weekend before, I practiced driving in a big empty parking lot and on the empty streets of an industrial park. I managed to park and corner and not run Karen over, so she granted me permission to drive myself to the dentist. I am using extra caution—my left-side blind spot really is a blind spot at the moment—but feel pretty good about being back on the road. I won’t be driving a lot or at night anytime soon, because I am not seeing well in low light and am not adjusting quickly to changes in light, as with oncoming and passing headlights, but it is good to know that I am not entirely dependent on others to get around.

Thursday, I finally finished the vessel I was working on when I had my accident. I epoxied it back together and filled the exterior cracks with turquoise inlay. It is now lucky number 13 in the commissioned series.

The vessel that broke and hit me, now repaired and finished.

The vessel that broke and hit me, now repaired and finished.

Another view of the vessel. I like that these sapwood patches look like eyes--and the left one (on the right in the photo) matches mine at the moment!

Another view of the vessel. I like that these sapwood patches look like eyes–and the left one (on the right in the photo) matches mine at the moment!

 

And on Monday, I started the first of the last four vessels in the series—from another highly cracked log. I used the wire guard on my lathe and wore my riot helmet for protection. The wire guard does interfere with seeing the curve I am cutting, so I probably will not use it for the final external shaping, but I will continue to use it for the rough turning of these vessels and while I hollow the interiors. I am pleased with the riot helmet. It is not too heavy. My head got a little sweaty, but that’s not a big deal for me.

Oh, and today, I used my chainsaw.

Finally, it appears that I will pass a major milestone at the end of February: Dr. Harris says the silicone oil in my eye can come out. She will perform another laser procedure next Tuesday just to make sure my retina is securely tacked down, and three weeks after that, she says, I can have the surgery. I was expecting to have to wait six months from the October surgery, but she says I am ready, or will be (it will be four and a half months by the time the surgery happens). My understanding is that she will replace the silicone oil with saline. I am hoping that this will improve my vision. When you compare photos of the retina in each of my eyes, the right is sharp and the left is dim and blurry, because of the oil. I still won’t have a lens, but I hope that what I can see will be a little clearer and brighter without the oil. And after I heal from that surgery, I can be measured accurately for a new lens, so maybe that will happen sooner than expected too. I don’t want to rush—I want to give my eye all the time it needs to heal as much as it can—but I am anxious to see better.

Safety gear

Lynne Yamaguchi Posted on by

For safety, I use the Uvex Bionic face shield, which I bought from the Sanding Glove, and a small 3M 7500-series half-mask respirator with P100 filters (other half-mask respirators did not come small enough to fit my face properly—true for most women, I think). Even though I wasn’t wearing my face shield at the time, since my accident, I have looked into whether I could improve that protection. (I also wanted to find out how much protection my face shield would have provided.)

One of the possibilities I considered was the Trend Airshield Pro, which is very popular among woodturners. I discovered, however, that it claims to meet only the “low energy impact” standard for eye protection (http://www.trendairshield.com/specifications.html) and its stated respiratory protection is also lower than what I already have (and it is not NIOSH approved).

The safety standard for eyeglasses and face shields is specified in ANSI Z87.1-2010, which includes general specifications and impact specifications. It is the general specifications that the Trend Airshield Pro meets. My Bionic face shield is rated for the high-impact Z87.1 specifications.

I did the math (see below) and realized that, measured in kinetic energy, the mesquite missile that hit me delivered about 30 times the amount derived from the high-impact Z87.1 specs. Surely, my face shield would have absorbed some of that energy, but I almost certainly would have been injured anyway. Polycarbonate isn’t supposed to break or shatter, but all that energy would have had to go somewhere. Could I have escaped with bruising and a concussion? Would my face bones still have broken? Would the impact have contacted my eye? Does anyone have any experience they can share?

Anyway, I went further with my research and looked into ballistic face shields. These are expensive and heavy and seem to me like overkill (they are also not readily available to civilians). But they did lead me to riot helmets and face shields, regulated under the NIJ 0104.02 standard, with about 15 to 27 times the impact resistance specified under ANSI Z87.1. I ended up buying the lightest one I could find, the Max Pro RD1002X; it weighs 2 lb 3 oz, just a little more than the Trend Airshield Pro. Others weigh 3 lb or more, which I thought might be a bit heavy for prolonged wearing. I should receive it in a week and will report on how it feels.

Max Pro RD1002X anti-riot helmet

Max Pro RD1002X anti-riot helmet

You may notice that the impact resistance of the riot helmet is still not equal to the impact I sustained in my accident; at best, it is 15% too low. I balanced the impact resistance against potential comfort (weight) and cost and also reasoned that damage to this helmet would still mean considerably reduced damage to me.

My intention is to wear my Bionic face shield with my respirator when turning most things (most of what I turn is small and light), but to wear the Max Pro with my respirator when turning heavier pieces, especially when working with cracked wood. I also installed the wire guard that came with my Jet 1642 lathe and will see how that feels. I have read that others don’t like using it, but I’ll try it to see if it interferes with visibility or tool use.

The wire guard on the Jet 1642 lathe.

The wire guard on the Jet 1642 lathe.

For the technically minded among you, below is a summary of the kinetic energy figures derived from the specifications and my calculations. I give the foot-pound equivalents for kinetic energy for those more familiar with the units used in ballistic specs.

KE Unit Accident Z87.1 High Velocity Z87.1 Penetration 0104.02 Impact 0104.02 Penetration
Joules 127 4 6 111 88
Ft-lb 94 3 5 82 65

Formulas:

  • velocity of falling object = √(2 × height from which dropped × acceleration due to gravity)
  • kinetic energy = .5 × mass × velocity²

My accident:

  • 1-kg piece from a 10″- (.254 m–) diameter vessel turning at 1200 rpm
  • velocity = (.254 × 3.14 (pi) × 1200) / 60 sec = 15.95 m/sec
  • 1 kg traveling @ 15.95 m/sec
  • .5 × 1 × 15.95² = 127.201 joules (93.82 ft-lb)

ANSI Z87.1 tests (Bionic face shield):

    High velocity:

  • ¼-inch steel ball (.001046 kg) traveling @ 300 ft/sec (91.44 m/sec)
  • .5 × .001046 × 91.44² = 4.373 joules (3.23 ft-lb)
    High mass impact:

  • 500 gm (0.5 kg) pointed projectile dropped from 50 inches (1.27 m)
  • velocity = √(2 × 1.27 × 9.81) = 4.99 m/sec
  • .5 × .5 × 4.99² = 6.225 joules (4.59 ft-lb)

NIJ 0104.02 tests (riot helmet):

    Impact:

  • 5.1 kg traveling @ 6.6 m/sec
  • .5 × 5.1 × 6.6² = 111.078 joules (81.93 ft-lb)
    Penetration (pointed striker):

  • 3 kg dropped from 3.00 m
  • velocity = √(2 × 3 × 9.81) = 7.67 m/sec
  • .5 × 3 × 7.67² = 88.243 joules (65.08 ft-lb)

This is a simplification, of course. The numbers don’t take into account air resistance, drag, pressure, or other factors. They just gives me a means of meaningful comparison.

Addendum

Australia and New Zealand have higher impact standards. (Their medium impact standard is close to the ANSI Z87.1 impact standard—at least for eyeglasses. Cannot find their face shield specs.) Their test for high velocity uses a 6.35-mm (¼-inch) steel ball traveling at 120 m/sec. This yields a kinetic energy figure of about 7.5 joules, compared to 4 joules under Z87.1. The Triton Powered Respirator meets this higher standard, and its shield is indeed thicker than that of the Bionic face shield. I did not check the helmet or respiratory standards for this device.

Oops! The Triton respirator may no longer be available: I can’t find it even on the Triton web site.

Preparing for a show

Lynne Yamaguchi Posted on by

I have a major show coming up in just a bit over three weeks, so I’m trying to get in gear and get productive. This is just one of the business aspects of trying to make a living as an artist. It requires a different mindset than simply creating what is in my heart. Unlike many woodturners, I don’t have a production line, which means I don’t make the same item or type of item over and over. I do have to consider the marketplace, however, and make sure that when I do a show, I have available a wide range of vessels, in terms of price, size, shape, style, etc.—mostly so that I can offer customers choices, but also because variety makes for a more-inviting display.

Variety also, of course, keeps the creative process fresh for me. Even when I am focused on producing a lot of work efficiently, I still want every vessel to be uniquely itself. I want the process to remain one of creation, not one of mass production.

The upcoming show also means that I need to put off solving some equipment problems I’ve been having—chiefly with my chucks. The spindle on my old lathe was 1 inch; that on my new lathe is 1¼ inches, which meant that I had to change the insert on my old Teknatool Supernova chuck. The insert had seized, however, and in removing it, I appear to have damaged a jaw slide, as the slides no longer meet snugly at the center (and jaws don’t close properly either). The damage isn’t readily identifiable, however, and I’ve already spent one afternoon trying to pinpoint the problem. That chuck used to be perfectly centered, with perfect repeatability when I would remove and replace pieces. My new chuck, a Supernova 2, isn’t perfect, but I can’t spare the time right now to tweak it either. I’ll let you know what I figure out when I finally have time, after the show. In the meantime, I just have to make do. To quote Tim Gunn, “Make it work!”

Correction to my last post

Lynne Yamaguchi Posted on by

The Steve Russell article on the Center Saver that I mentioned was actually in Volume I of his DVD, an e-book, not in Volume III as I originally stated (I have corrected the last post), and the article is also available on his website. Had I spent a little more time with the DVD I would have discovered that Volume III, which is a DVD video, actually has a video chapter on using the Center Saver. Now that I have viewed it, I’ll try again.

I also discovered in reviewing both the Kelton instructions and Russell’s article that they contradict each other on the height of the cutting blade. The Kelton instructions say, “Adjust the height of the tip so that it is EXACTLY ON OR JUST BELOW CENTER. (If you have the tip above the center, the tool will tend to buck and jerk when you commence cutting.)” Russell says, “The tip of the blade should be set at centreline, or slightly higher.”

I followed Russell’s recommendation and had the blade slightly higher than center—mainly because the tool post is too long for my lathe’s tool rest, so I couldn’t get the blade down to center without cutting the tool post, and I was too impatient to try out my new toy to stop and find a hacksaw.

Let that be a lesson to me. I will cut the post down and try again, at center and slightly above and below, and report back on what I discover.

Playing with new toys

Lynne Yamaguchi Posted on by

An interesting week, not terribly productive in terms of finished work, but I did make progress in less direct ways.

I tried out my new McNaughton Center Saver. It wasn’t quite as straightforward as I was expecting. The biggest complaint I have is that the system comes with insufficient documentation. There isn’t even an illustration of the setup of the unit. And the instructions on how to use the Center Saver are minimal. I’m lucky: I have seen Mike Mahoney demonstrate the McNaughton system, so I had some idea of what to do, but without that experience, I would have felt pretty lost. I think Kelton should include at least a brief video of its use (on CD or DVD)—or at the very least make such a video available for free online. I know that Mahoney has published a DVD on using the Center Saver, and I trust that it’s good, since he is an expert with it, but it’s also $25. Instead, I used a helpful article by Steve Russell as a guide to using the system. (Kelton does provide a shorter version of the article on its website; I suggest you print it out to have on hand as you try out the system. The version I used came from the DVD Woodturning with Steven D. Russell, Volume I.)

I prepped two pieces of wood, one mulberry, the other eucalyptus. Both were heavily checked, and this may have caused some of the problems I had, though ultimately that didn’t appear to be the case. I started with the mulberry and the least curved of the curved blades, trying to remove the largest possible core. I cut the first couple of inches without problem, but then the blade began to catch, and catch hard, so that the lathe stopped altogether, and this with minimal forward pressure. I tried systematically adjusting as many variables as I could identify—widening the kerf, changing the angle slightly, pushing even less, making sure the blade was up against the cross brace, etc.—but the blade kept catching.

I finally switched to the eucalyptus chunk and fared better. I got much deeper without a catch, then when the blade did begin to catch, I was usually able to back off a little and resume without the lathe stopping dead—though it did stop a few times. Eventually, I was able to cut the whole core out. Woohoo! The wall thickness of the outer bowl was even fairly consistent, so I had followed the outer curve pretty closely.

I was exhausted by the effort, however. I went home early, and I was ready for bed by 7 p.m. that night, whereas (as some of you know from my posting times) I’m usually a real night owl. And I was clearly using muscles I wasn’t accustomed to using, because I had pain in my hand, my elbow, and my shoulder!

I haven’t given up on the Center Saver by any means, but I do have to set it aside for a while as I concentrate on preparing for my next show, which comes up in just a little more than four weeks. My inventory is still low from my fall shows, so I need to get in gear and get productive. In the meantime, if anyone has any suggestions on improving my Center Saver technique, please share!

Also this week, Pat and I rearranged the studio, relocating my old lathe to the opposite end of the room, in front of the garage door. I also finally installed pegboard on the divider behind my lathe, so I have my tools better organized and at hand, which will let me be more efficient. Of course, that means that the shop photos I just posted are already out of date. Ah, well.

I’m back . . .

Lynne Yamaguchi Posted on by

So many changes have happened over the last four months.

I’m comfortably installed in my new studio. And now I have a brand-new lathe for my new studio, a Jet 1642, with a 2-hp, 230-v, reversible motor and a 16″ swing. The speed is also variable from 0 to 3200 rpm, with two different belt settings, unlike my old lathe.

Don’t get me wrong. My old lathe, also a Jet, the 1442, served me well for almost five years of full-time turning—and I haven’t retired it yet. It is a little workhorse, but I have worked it hard and push its limitations daily. What are its limitations? Well, the speed is variable only at fixed steps. The lowest speed is theoretically 450 rpm, but actually measures closer to 700 rpm—not slow enough to safely turn very unbalanced pieces. It also lacks reverse. And though 1 hp does the job most of the time, I can stall the motor if I cut too agressively. It has been a very good machine for me for a long time, though, and I would stand by it as a solid choice for an inexpensive first full-size lathe.

My new lathe is, I think, the best deal around for the money. It costs little more than half the price of a comparable Powermatic (I paid $1439 on sale!), and it feels rock steady. I’m actually astonished at how quietly and smoothly it operates. I feel as though I can turn anything on it. And, although it may not be a lifetime lathe, I have no doubt I will get years of service from it.

Brad Smith’s studio (Wednesday, July 11)

Lynne Yamaguchi Posted on by

On the way back from the Esherick Museum, we stopped by the studio of a furniture maker that Peter knows, Brad Smith, of Bradford Woodworking. He makes furniture from turned axe handles, croquet mallet handles, pitchforks, and more, and he has two 100-year-old-plus lathes to do his turning.

Stacked stools and bedposts.

Detail of pitchfork bench.

Pitchfork tables.

This belt-driven lathe duplicates the form installed in the foreground. By using a set of dado blades as the cutter, Brad gets the ridge pattern characteristic of the axe handles he uses in his furniture.

Turning axe handles.

The axe handle being turned.

As we were preparing to leave Brad’s place, Jean-François noticed the red dirt bared by an excavator and collected some to try in a finish.

Jean-Françoiso collects some red dirt.

Another day

Lynne Yamaguchi Posted on by

Jean-François made an attachment for the hollowing tool to resist the torque from the curved tip, making the tool easier to control. Jean-François says he learned this trick from Alain Mailland. He later painted the handle black.

Two views of the attachment Jean-François made for the hollowing tool.

Making travel plans cut into the work day.

We took a break at lunch to plan our travel schedule. Siegfried bought pizza from Paolo’s to ease the process. It took a couple of hours of phone calls and emails, and we’re still trying to finalize plans. Among other places, we will be visiting Washington, D.C.; Wilmington, Delaware; and various spots in Pennsylvania. I’m hoping we can squeeze in a trip to NYC before the end too.

Sean continues work on the burl vessel.

Sean continued to work on the burl vessel. Note the inner spherical vessel he is hollowing inside the larger bowl. He has wrapped the entire outer bowl with shrink wrap to keep it from coming apart as he turns.

Jean-François turns a tool handle.

Jean-François was still trying to get to turning a bowl. First, though, he had to turn a handle for his bowl gouge. By the end of the day, he had at least mounted and rounded a chunk of ailanthus for a real piece.

Siegfried starts a vessel from a silver maple burl.

After tinkering most of the day with the vacuum chuck, the electric chainsaw, and the bandsaw, Siegfried prepped and started turning a glorious chunk of silver maple burl. Check out the inset. Siegfried usually works with less figured wood; he thinks that whatever vessel he turns from this, the wood itself will be the most beautiful aspect.

Sean works on carving a freeform scupture.

Sean took a break from turning to carve. He has assembled the framework of what will be a freeform sculpture from various scraps lying around the shop. Woodturners will recognize the corners removed on a bandsaw for turning.