Saturday, December 19, 2009

Round 'n' Round

Here's a bit of an unsung hero in my shop, the tapered tenon rounder.

Usually, I try to make all of my tapers on the lathe, where they are done quickly and accurately. But on occasion, especially if the piece is already bent before shaping the tenon, I pull out my rounder. Elia Bizzarri sells a version of this tool, that while adjusted differently, cuts a beautiful tenon. You can see it on his sight

What I like about my rounder, besides being cheap (you do have an old frog laying around somewhere, don't you?), is that it's as adjustable as a handplane. The control that I have over the adjustments overcomes my usual hesitance to use and set up a jig. And the results are dead on. As with most of my jigs, I found a rare piece of water stained poplar laying around the shop for this one, I guess I'll have to find another use for all that exotic hardwood.

It's simple to make. First drill a hole in a block and ream it with the reamer that you are matching. Then, cut the top off the block close to the hole. I like to finish off with a handplane until I get a nice even slot along the top of the hole. Then cut a separate bed for the frog you are using and screw it to the block. Mount the frog and you're just about there.

I like to curve the blade a bit where the tenon enters, this help shear excess material down to the size that will fit in the hole. When making a tenon, I still find it helpful to rough shape it before using the rounder, this helps to ensure that the tenon is centered properly and saves wear and tear on the tool and my wrists! (quick tip: wear those rubber dipped gloves from the hardware store, they'll save your joints)

As you can see in the image, once the tenon exits the rounder, it becomes a straight tenon that equals the size at the end of the tapered hole, with this in mind, you can easily modify this design to make straight tenons as well.

Thursday, December 17, 2009

Your Turn

That's right, I've been posting here for a few years now, and the time has come for me to ask you for your experience. When I set out to make my Crested Rocker in fumed white oak, I found it much easier to work with air dried planks for some of the thicker parts. Air dried wood bends beautifully and not having to wait weeks for the parts to be ready was a real plus. Also, as it happened, I had a great deal of the stuff on hand and it was sawn right down the fiber line. Perfect.
My experience with the air dried stuff was great, but now I am writing an article about the chair and am trying to stretch the material choices to include kiln dried stuff. The only kiln dried white oak that I have was poorly dried and I wasn't at all surprised to see the nasty checks in it after I dried it down. My question is this, have you successfully steam bent kiln dried white oak?

I suspect that there are some kiln operators out there who don't know how touchy this wood can be during the drying process, especially at 8/4". I think that the stuff I have was probably run in the same kiln load as a bunch of 4/4 pine and they just blasted the poor stuff. Perhaps a proper kiln operation would yield a wood that could take the rigors of steam bending, or maybe I'm just tilting at windmills, whaddya think?

Below is a photo of a newcomer to my shop. I decided to work through my design with some of the walnut that I bought from Lou Irion. Boy did it bring back memories, that smell!

It's still quite odd to look at a plank and break it up into pieces, but I must admit that by the end of the day I had all the pieces bent or ready for the lathe. I'm excited to test some new waters.

I did some cutting with my drawknife while roughing out the stiles, what can I say, it felt like I've been practicing for this wood for 10 years.

Tuesday, December 15, 2009

Mr. Happy

No, I don't mean the hairy guy on the right, although he was pretty cheerful! This is Eli (smooth shaven) and Mike Javidi, they were my hosts, along with Mike's lovely wife Karin, for my weekend trip to Boston. Mike is about to graduate from the North Bennet Street school. While normally I am drawn to the canine and caprine, this little fellow got quite a hold on me.
Thanks for the gracious hospitality.

The students at NBSS are of the highest caliber and their motivation is impressive to say the least. I think that the seminar went well, although I underestimated the effect that 8 hours of talking can have on my throat. It felt as though I had swallowed a rasp.
Below is a photo of us playing in the dark. Each time that I did any carving, we turned out the lights and used a raking light. I know that overhead flourescents work well for machining, but I couldn't see the surface at all with them on.

My steady rest, which was meant to protect me from the embarrassment of screwing up a turning in front of 40 eyeballs, worked marginally well. I still got a bit of vibration and it got me rethinking the design. When I got home, I flipped the V block so that the long side was down and it seemed to work well, although it does interfere with cutting directly across the contact point when the piece gets small. I think that the reason that it might be a better way for smaller pieces is that it more directly opposed the ability for the piece to jump up and over the top of the tool.

Then I had an idea. As long as I am not cutting across the actual contact point, why not use a spring clamp to lock in the V block, Wow, what a difference. Who knows, maybe my prejudice against turning spindles for chairs will even change...probably not.

And finally, here's a photo that I couldn't pass up of the initial carving on one of the fan back crest's ears. Too fun.

Now it's up to Curtis to go up in January and show them how to put it all together. Lately, he's been trying to stick around home, but the call to North Bennet Street is just too strong to resist.

Friday, December 11, 2009

Steady Rest Detailed

Here are the details of the steady rest that I made the other day. The dimensions work well but don't consider them as written in stone, I was just wingin' it.
*I've made a couple of advances in this design that can be seen in the "Mr. Happy" post*

As you can see, the construction is simple, it's a housing (like a book with no pages) and two pieces that float in it, a wedge (which rides on another wedge that is part of the housing) and the V Block. As the wedge drops in, it pushes the V block into the workpiece.

It's important to note that the floating parts need to be slightly thinner than the fixed wedge so that they move freely. I also eased the edges and waxed all the rubbing parts. After some experimentation, I noticed that the weight of the floating wedge is critical to achieving the desired pressure on the workpiece. I made the crude move of drilling a hole in the top of the wedge and jamming an old auger bit in for extra weight. A more elegant and adjustable solution would be to put a nail in the top and stack washers on it as needed. The correct pressure will hold the piece firm but not burn as it spins, remember, it's there to stop major deflection of the piece, not slow down the motor!

The other feature that seems to help is that the V notch is not simply a 90 degree notch set evenly in the side of the block, but is offset to lower the apex. I did this to more directly oppose the force of the cutter. The spinning of the work piece helps the notch climb into place and lock on.
It's also helpful to ease the edges in the V notch, to make sure that the contact isn't just made at the edge, of course it will just wear the edge away quickly in use, but everything will go smoother if you get there first.
Watching the wedge lower as you cut across the contact point is pretty fun but don't forget to make something while you do it!

Wednesday, December 9, 2009

Steady as She Goes

In making choices about the tools and processes that I use, I try to reconcile whether I am going to continue learning and enjoying working that way and if my skills and chairs will keep developing. For instance, using the skew for the finish of my turnings, as opposed to sandpaper, took quite a while to conquer, but now it's great fun and the work keeps getting better and faster.

The same has gone for steadying vibration on the lathe. I've taken some steps, such as weighting the lathe with cinder blocks and bolting it to the floor and wall, but I've always tried to manage vibration with sharp tools, reasonable cutting pace and my hand steadying the piece when needed. I figure if I can turn on my little rumbler, I can turn anywhere. When demonstrating at Peter's Valley Craft School, I even pulled out their ragged old Delta benchtop lathe and let the Oneways sit idle. Just like home!

But this weekend I'll be demonstrating one of the toughest turnings I do, which is the fan back side chair post. It's long, thin and detailed. Now I could practice and probably get pretty proficient, but I don't make many of these and I just don't see it happening. Plus, as Curtis said when asked about demonstrating this turning, "I could try, but everything has to be just right".

With all this in mind, I set out to make a steady rest. Most designs out there seem like a pain to make and set up and they rely on contacting multiple points, which means more set up time and less time turning, plus they get in the way of cutting.
Then, I remembered a steady rest concept that I'd seen and even used almost 10 years ago. It's simple and it works. Basically it's a V block that's held against the spinning piece by a wedge and gravity. It's easy to make, self centers on any size spindle and beyond that, you can cut right across the contact point and the wedge drops deeper and the V block advances giving constant support. That's right, you can cut right across the piece at the steady rest, AWESOME!

Below is the rest in position. First I removed the wedge and V block from the base and placed it about 1" behind where the work piece. Then, I clamped it to the lathe bed with a couple of little C clamps. Next I cut and smoothed an area for it to make contact. I put a little wax on as well for good measure. The V block is made of a very dense exotic that a student gave me (you were right Peter, it does come in handy!).

Here you can see that once I turned the detail intensive parts, I was able to rough out the long "vase" right across the steady rest.

Once the entire piece is turned, I go back and remove the V block and wedge and skew carefully across the contact area to finish the piece. Below is another image of the rig with the V block and wedge in position.

I'm going to make some measured drawings to post, but I just couldn't wait for them to be done to share this. Now instead of spending the entire time worrying about the wood climbing over the top of my tool, I am able to focus on the quality of the shapes and surface, it's a compromise that I can live with.

Monday, December 7, 2009

Hunkering Down

Yep, the cold has finally come to New York and we are all running around making sure that we are ready. Mikey seems pretty secure with his room full of hay, and not a moment too soon.

We decided to give the chickens run of the garden, after taking the last mint out for some ice cream. These are the girls that we got last year, and I'm happy to say that they are still laying, although slower because of the short days. They have been working the compost pile over and nipping away at the last remnants of greens.

This week is all about turning. I'll be teaching turning this weekend at North Bennet Street and am getting warmed up by making parts. Turning often is the best way to turn well, and I'd hate to be rusty in front of a crowd. I made couple of jigs to help things along at the lathe. A steady rest, which I'll detail in the next post, and this little handy center marker shown below.

I used an old hacksaw blade that I ground to a knife edge on the back and sunk into a saw kerf. It really comes in handy when I trim my roughed out blanks and need to recenter. I know that you can buy one, but it seemed like a perfect candidate for a shop made solution.

A couple of hammer whacks and rotations and you've got it.

I've found it particularly helpful when recentering a piece that is dried and gone oval. I just use a few more rotations and don't expect the lines to all meet in the center, instead, they leave a little vacant circle right in the center.