Monday, February 13, 2012

Tabling in Motion

Every woodworker has to come to some accommodation, practically and philosophically, with what sort of equipment they use. Obviously cost plays a role too! There are $6000 hand planes and there are $6000 power planers. Some woodworkers avoid hand tools like the plague, and see everything as something to be glued up and sanded, then sprayed. This describes the vast majority of commercial woodworkers and likely the majority of amateur woodworkers. Others avoid machines like the plague, preferring the quiet satisfactions of hand saws, chisels and planes - this describes a vanishingly thin slice of commercial makers, and a minority of amateurs. Other woodworkers fall in between these two poles, using machines for some things and hand tools for other things.

I'm one of those who fall in between. I like cutting joinery, planing wood and I like using hand tools - indeed, many of the joints I like to cut cannot be dealt with effectively other than by hand cutting. I also like using machines too, both of the portable and stationary form. Sure, they can be noisy and make a mess, and they tend to be expensive, but, if well set up and adjusted, they can get a lot of work done at a high level of quality. I am thankful to have a large jointer and bandsaw at my disposal particularly, and that I have access to a planer and tablesaw when I need to use them.

I do a lot of work with routers, and like the high level of repeatable accuracy which is possible with them. I say possible, for getting ultra accurate work out of your router involves a lengthy learning process of dealing with all those things which contribute to inaccuracy - non-square, twisted or bowed stock, jigs which are misaligned or permit slop, surfaces for the router to operate upon which are not flat, issues with run-out at the router collet, router bearing issues, concentricity to templet guide bushing inconsistencies, inconsistencies and slop with plunge router mechanisms, depth set rod problems, router bit sizing irregularities, and edge guide problems - and I could list further factors besides.

Now, if all you do with a router is trim the edges of boards, make profiles, and so forth, it is likely that most of the aforementioned issues will remain more or less invisible and dare I say it, irrelevant. It is only when trying to obtain high accuracy, consistent results in the range of +/- 0.005", do all these minor little factors start to affect the outcome.

Some would assert that there is no need for that level of accuracy with wood, since it 'moves'. Wood does indeed move, however it is also true that if a fit is sloppy when the pieces are first put together, there is no point down the line where the fit will be improved by the vagaries of wood movement. The first place I worked at in Canada after returning from Japan in 1999 was a log and timber company on Vancouver Island, a company which exported most of its products to Japan. There I was told that the mortise and tenon should have 1/8"~1/4" of slop, because it 'made things easier to assemble and take apart'. I was also told there that a jointer was unnecessary since 'a tablesaw could cut things straight'. How does that sound to you?

I've seen a fair number of youtube video clips showing people putting things together with mortise and tenon joints of various sorts, and usually the fit achieved appears rather loose - to my way of thinking, a tenon would not simply slide into a mortise unaided by anything other than gravity. On the other end of the spectrum are people pounding the living bejeezus out of a joint, 2-ton come-alongs assisting, and that clearly is too tight.

Somewhere in between 'swimming' and 'bludgeoning' then is how an all-wood joint should fit. Some seem quite satisfied by a fairly easy fit and depend upon glue to do the rest. But even glue requires an ideal amount of space - too loose and the glue will not effectively bond the two pieces, and too tight and one risks forcing the glue out of the joint in assembly creating the 'starved joint'.

Some woods have a certain ready 'crushability' and can be fitted in a wider range of fit tolerances, while other woods are most unforgiving, and if the joint is too tight by a few thousandths, something will crack.

So, I guess the questions for the artisan, in deciding what sort of fit is to be sought, are in relation to the material worked and how sensitive to the material are you choosing to be? Is solid wood something that must be subdued at all costs, or something which reveals its particular secrets and nuances to you over time and with increased experience and observation?

In the past couple of years I have been moving more and more towards joinery without glue, and I think this challenge has intensified my perceptions in regards to the material I am working (often quite dense hardwoods) and the processes I use to cut those joints.

One tool I have been making a fair amount of use out of over the past several years is a router table. Years back, I made my own table and stand out of MDF, based on an article in FWW magazine. That table served me well enough, however having to go under the table to make height adjustments, or remove the router every time I needed to change cutters got old after a while. And MDF, with a router hanging off it, deforms over time. A non-flat table does not give pleasing or accurate results in the cut out.

So, my next router table was a commercially available one, made in Canada by Jessem. It sported an aluminum stand, phenolic resin top, CNC machined lift components, side-mounted crank handle to move the lift up and down, and an indicator wheel on the table top which showed height changes. I also obtained Jessem's fence, and a few other accessories, including the large P.C. 3hp. router slug - by the time I was done I think around $1700 left my bank account. I used the table a fair amount over the past 5 years, however in the end it developed some issues with the lift mechanism and the phenolic top was no longer flat. I was frustrated to discover these problems, especially as I was in the middle of a job when they came to light. I have been compensating by using a secondary table across the top to bridge the irregularities.

For the past few months I have been thinking about what I would do in order to to replace/upgrade my router table. There are any number of options. Most of the commercially-made router table tops out there are made of MDF with a melamine casing, and the router lift is a component which drops into the table. I had no interest in those types of tops. Another option was a cast iron top made by Bench Dog, which also accommodates one of those drop-in aluminum lift mechanisms. I considered that option for a while. My reservations about that product were two-fold:

-how well would it fit to my existing router stand and fence?
-how flat would a ribbed cast iron table top stay over time?

I've had more than a few woodworking machines in which the cast iron top has warped or cupped significantly - and this issue seems to affect machines from any country or era of manufacture, so I had some apprehensions. Also, the Bench Dog lift did not feature the convenience of a cranking handle built in, though it did allow for bit changes from the top and seemed well made. The Bench Dog lift also had a lock on it to prevent any movement after bit height had been set.

I also considered the option of buying an old shaper and modifying it to accept a router, however most of the shapers I've seen do not have great fences - and then there's the cast iron issue again.

In the end though I reflected on the existing investment I had in the stand and fence for the router table, and the positive features of the Jessem product and began to think of some way in which I could make the best of the situation. After reading something on Pat Warner's site about an aluminum drill press table he made, I considered the idea of making my own aluminum router table. Aluminum plate can be machined with carbide, so I know I could saw and cut it with my existing equipment. I realized that aluminum can leave a mark on wood, so I knew I would need to get any top I made anodized. I then remembered that some of my Italian bicycle parts are 'hard-coated' aluminum and that they had stood up very well. Looking into it a little further, I found several companies in Massachusetts that offer hard-coat anodization. Cool! I was getting excited by the prospect.

I then took a look at Jessem's website again and discovered they have a brand new version of my lift now in production, a 'Mark II':
It seems that they have reconfigured the lift mechanism substantially, making it more direct and robust. The lift also now has a locking mechanism and under-top stiffeners. And it is still made in Canada, eh. Hmmm....

I contacted Jessem and asked them if they would sell me the lift mechanism separately so I could make my own aluminum top. They then told me about a hush-hush prototype they were working on which I found most interesting. After further discussion they will be sending me one of these prototypes which, as part of our agreement, I will be testing and doing a detailed write up on here on the Carpentry Way. How cool is that? I should receive the 'top secret' material later next week and should have something posted up by the middle of the following week or so (by the end of February anyhow).

I have so far refrained from commercial endorsements or advertising on this blog and have tended to stay away from making specific recommendations about tools. I do however get a lot of emails from people asking me for my recommendations, especially in regards to Japanese hand tools. So, reflecting upon that, I gather there is a fair amount of interest out there in the woodworking community in regards to tool reviews, and I've decided that I will start doing those this year. There are several brands of tool which I have very positive regards for, and if I can bring some of those tool companies on board here in some capacity, I think it will be a net positive. I put a lot of time and energy into this blog, along with my two online study groups, and find it very rewarding to get people fired up about woodworking and helping them gain knowledge and skills. So it only makes sense that I find a way here to advocate for those tool suppliers, both manufacturing and retail, whom I would support and recommend in any case. We'll see how it unfolds.

Thanks for dropping by!

10 comments:

  1. Hi Chris:
    I will ask you this question, and i need your help.For you
    What do you think is the best 3d cad on the market for artisans on wood ?
    Personally i hate these two, autocad and sketchup.
    Autocad is for everything and sketchup is very limitated.
    Rhino 3d and solidthinking ?
    Sketchlist ????
    Freecad ?
    ecabinets v6 ???
    The type of furniture i make, is all different from the last, so i need a hybrid cad ?
    Could you make an extensive post in your blog about all this stuff ?
    SORRY FOR MY ENGLISH.
    I follow you every post.
    thanks so much.
    anxo mosquera
    anxomosquera.blogspot.com

    ReplyDelete
  2. Hi Anxo,

    good to hear from you. I am not an expert in CAD drawing by any stretch, nor have I used a tremendous range of products on the market. You may wish to drop Tim Moore (see the links bar)a line and ask him as he is more experienced. I've heard ProjeCad is good, but there are so many options. Rhino makes a lot of sense if you are going to do CAM later. Another choice I've heard is worth a look is Autodesk Inventor.

    ~Chris

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  3. Hi Chris,

    This seems like a natural development for your blog and one that the woodworkers among your readers could probably benefit from too. Your thoroughness and objectivity in relation to reviewing tools would be welcome in a world where reviews are most often tainted by interests of a less savoury nature.
    Also regarding tools, for a long time I have been wanting to ask you about the old 1943 survey of japanese carpenters tools a lot of us have read about. The kit consisting of 49 chisels, 40 planes, 12 saws and so on, required to do traditional japanese carpentry. This is mentioned in many places, but exactly what chisels, planes, saws and so on were they. This information I think would be interesting, especially for the hand tool affectionados, but as far as I know the details are only available in japanese. Maybe with your knowledge from Japan this could be a subject for a blog post some day.
    Thank you for your always enlightening and thorough posts.

    ReplyDelete
  4. Per,

    I greatly appreciate your comment. I'll think about the topic you mention for a future blog post - good idea!

    ~C

    ReplyDelete
  5. Stumbled upon this post after searching for router table info - could you shed some light on this 1943 list? I had never heard of it before, but that's not surprising, LOL. Interesting it was produced during wartime. Darrell

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    Replies
    1. I'm sorry I have no idea what you are referring to - the term '1943' does not appear in the above post anywhere. Are you referring to another post perhaps

      ~C

      Delete
  6. Sorry - it's not in the post, it's in the comments, immediately above mine. The one by Per Hansen about the list of all the tools needed to be a carpenter in Japan, apparently compiled in 1943. You mentioned in your reply that you thought that topic would make a good subject for a blog entry, but I guess that never happened?

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    Replies
    1. Darrell,

      thanks for clarifying. I appreciate the prodding in regards to the above topic.

      ~C

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    2. The survey was taken in 1942-3 by the Japanese Ministry of Labor. Coaldrake mentions it in his book The Way of the Carpenter, chapter 3. There is a copy of the Japanese text at the Library of Congress, and Princeton University, however I won't be down that way for some time. Next time i'm in DC i'll make a point of checking it out. Coaldrake summarizes the survey in his work mind you.

      ~C

      Delete

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