Simple procedures

It's funny to me how complicated the simplest procedures can be sometimes.

In this case, I had to cut an arch for a detail piece on a built in that I'm installing soon.

First, I had to consult the Internet to remember formulas for chord length. I knew how long the chord length was, I needed to use that to chase back and find the radius of the arch. The radius I came up with was 15' 6".

Then I needed to make a trammel beam that would hook to my bench on one end, and mount to the jigsaw on the other.

Fifteen and a half feet is a long distance for an unsupported beam, so I brought out the trestle rails.

Last but not least was sawhorses, and a box beam to clamp to.

In all, about two hours of setup time. Two minutes later, the cut was done.

Cutting dados with the cutting table

Using routers with guide rails is nothing new. But I like this setup for two reasons. If you want to run dadoes at a fixed distance from one end or the other, this is, again, easier than a table saw. And, I find the depth with a router cut dado to be more reliable than with a table saw. Sheets flex, it's hard to keep them firmly down. And cross- cutting dadoes with a table saw on long pieces like this requires either a really big sled, (ie, bigger than mine) or alternate but similarly excessive techniques. So, this table is great for production work in that direction.

Another little time saver is this router starting block. This is the first piece that gets cut with the router on the first pass. It tells you exactly where the router will enter the wood. Simply align your layout markings with the actual cut, and go. That saves a LOT of time that would otherwise get tied up in fussy measuring techniques. Good stuff. And, again, this doesn't have to be quite so fancy. Using something simpler for the rail, and routing with a laminate trimmer would work, too. And the top picture above shows a simpler production fence than the Kreg setup: just some plywood and a clamp. I went with the Kreg because I think it's more robust and precise, but hey... Whatever works.

Cutting table Part I
Cutting table Part II
Cutting table Part III

More on the cutting table

I pulled out my DW circ saw to demonstrate the point that this table isn't just for Festool junkies. It's for anyone who needs to break down sheet goods cleanly, to reliable, repeatable dimensions, but don't want to use a table saw, either because...

-They don't have room for in feed and out feed in their basement shop.
-This whole setup is cheaper than a table saw.
-Moving a circ saw over a table is easier on the back than moving a full sized sheet of ply, and more controllable.

I've seen methods for making a zero clearance plate for a circ saw. Some involve bolting on a piece of Masonite, or filling the plate with bondo. However you do it, with a zero clearance plate and this table, the veneers on both sides of the sheet will be supported. That means you can cut a finished edge in one pass.

For my next trick, I'll be using a router with this table, to make identical dadoes in multiple pieces...

Cutting table Part I
Cutting table Part II
Cutting table Part III

Festool cutting table

A couple of years ago, I got a look at a cutting table over on the Festool Owner's Group message board, and I thought it was really cool. I bought a bunch of plywood to build a version of my own, but I stopped short. I looked around and realized that what I really wanted was the space, not more stuff, and so I shelved the idea, until now. The main difference between what I had planned to build then, and what I actually built today, is that this is just a work surface, not a full table. We have a 4x8 assembly table/plywood cart in the shop already, and eventually I realized that I could simply make an MDF top, and put that surface away in the plywood rack when it wasn't being used.

The idea is simple: the Festool track registers against two points, that hold it square to a fence that's equipped with a production stop and a ruler. So, rather than measure and lay out every piece, and clamp the fence down for every one, I can set the stop and make the cut. Done. And because the MDF is supporting the underside of the sheet, the veneer doesn't get ripped up so badly.

The reason to make this is simple, for me. I have a lot of 8' long pieces of plywood that are too wide to fit in my cross cutting sled. They're destined to be cabinet parts and shelves, but they need to be cut to length, and that with efficiency. Given the half a day that I lost throwing this together, the efficiency part may not be in evidence on this particular project, but I suspect that future projects will vindicate my decision.

For the average woodworker with a 'normal' circ saw, this is still something that can be approximated. There are clamp-on guide fences that can be used instead of the Festool track to do basically the same job. If you use a lot of sheet goods for production jobs, this might just save you some time, and make things easier on your back...

Cutting table Part I
Cutting table Part II
Cutting table Part III

The chair is finished...

Well, it's been finished, I just hadn't had time to post it. The base finished up nicely, and refinishing the rest of it turned out well.

I'm really grateful to have had this project. One of the interesting aspects of cutting the semi- mitered joinery was that there was a LOT of precision involved. In the end, the blanks were out of square just enough after the jointer, planer and table saw, that the sliding table saw wasn't able to cut accurately enough. I needed a hand plane to get the blanks to be just so,

After that, all of the shaping work reminded me of just how skilled I am, and how much I'm able to rely on my hands when the limits of the ability to work accurately with machines is reached. Cool stuff.

There was a very strong element of 'be careful what you wish for,' in this one. I've had a yen for complex curves and complicated methods for a while, and, well...

:-)

The Cadillac Man has left the building...

Even after spending as much time as I did on tracing a 3-d shape into 2-D patterns, and even after all the time I spent getting the mating faces and miters cut perfectly, shaping this chair base has turned a lot of things upside down. The entirety of the thing is made up of complex curves, but there are ways to lay those out, if you have precise reference surfaces to work from. But once I'd sawn rough shapes in two dimensions out of the blanks, there wasn't a lot that I could do to hold everything in place on a router table or shaper. That's not to say that I didn't try, but the harder I tried to force the process to work, the less it worked. I had roughly sawn blanks, but I couldn't get the precise reference surfaces that I wanted.

14 years ago, I worked for a company in Houston that provided Remote Operated Vehicles for offshore use in the Gulf of Mexico, and around the world. The vehicles were basically robotic submarines, connected to the ships and/or oil rigs with long tether cables, and piloted by operators on the surface. Operators 'flew' these remotely operated submarines remotely, and operated the robotic arms when required. Some of the more advanced models had various functions that are roughly analogous to cruise control, including a position holding function. Because he loved his cruise control, and the ease of use that it allowed him, one of my co-workers leisurely announced one day that "I'm a Cadillac Man, you know?"

One day, a job called for more accurate position holding than the computer could really handle, given changing currents and computer processing speeds. (This was 1998.) Cadillac Man told the boss it couldn't be done. Someone else stepped up, and said he thought he could pilot the sub well enough to do what had to be done... And so he did. Cadillac Man left the control room in shame. He'd traded aspiration to skill for reliance on machines.

I spent so much time messing around with patterns, figuring it would be easier for me if the machines could give me the reference surfaces that I wanted. I wanted identically smooth surfaces, and I didn't want to have to make them myself. This, despite my years at North Bennet, and learning how to do things by hand. And finally something snapped. So I pulled out the drawknives, and spokeshaves, and commenced to make a hell of a mess... and to shape some very attractive chair legs.

 I gave up on the notion of doing this with precision, because the truth is that even if I'd gotten precisely milled surfaces, there was only so much that this would give me,  and sometimes the only way forward, is 'blindly, with doubt and faith.' (I'm NOT the religious type, believe me.) I remember thinking to myself 'Elvis has definitely left the building on this one...' But at the end of the process, it was actually a lot easier, and a lot more controllable.

The not-quite epilogue... I spent part of today sanding down the new legs for the chair that I'm rebuilding. They look good. There are spots here and there that don't look perfect to me, but I'm a neurotic perfectionist sometimes. That's why I'd rather leave it to the machines, it's less nerve wracking. I say not quite, because there are still a few things that need to be done, including inserting dowels into the legs to re-distribute some of the interior stresses, drilling for the seat post, and notching the ends of the legs for the hardware. 

Head scratcher of the day

This week I've been making a new base for an Italian-made office chair, as the original legs are splitting. (Bad hardware design.)

The base is made of four saber legs, joined in the center with some really funky nonsense. Basically, two opposing legs butt-jointed, end to end, but at 30 degrees to horizontal, I'm presuming with dowels inside to hold everything together. (That's how I'm gonna do it, anyway...)

And then two more coming into the side, with a weird half-miter, again at 30 degrees. 

So, the drill is, mill the blanks, and cut mating surfaces while there are still reference surfaces to use, drill for joinery (dowels) and then shape.

It's taken the better part of a day and a half to get the mitered surfaces cut...

Oy.

Shaping starts next week.