Geometry in the carpenter's shop. Main method of obtaining flat boards

This method, I read in a book "The basic tools and wood processing technology"Author Paul Haslak.

The book is written, it is well-known method of Sir George. Whitworth verification on board flatness. I looked on the Internet information about Whitworth. This mainly affects the arms, although there is a brief information about its methods of obtaining accurate flat surfaces.

The method.

For example, there are three rails with relatively straight edges. If you attach two rails to each other, you can see that they are not always in close contact with each other.

You can fit these two slats so that they come into contact with no gaps, but if you take the third rail, it will not exactly fit the first two.

That is, the rack BUT and IN can perfectly coincide with each other, but one may be slightly concave and the other slightly convex, respectively. And if you take the rail FROMThen it can not perfectly adhere to both the convex and concave sides. But if you adjust it to BUT and IN at the same time, then get three perfectly aligned rails.

To put into practice this is possible with the use of colored crayons - an edge rail BUT conduct fine then applied rail IN and gently move it back and forth along the ribs and get on it the mark where it is tight, and where not. Further, a plane or sander remove colored areas. This is repeated several times until the rails are not adjusting accurately. Further, the same is done with the third rail.

In practice, in the wood, I have not yet seen problems where such a method can be used, except for the manufacture of long wooden ruler.

But still a way to fit racks lapping very well suited for the manufacture of boards. Only there is need to adjust the shield elements are consistent and do the layout before gluing, so as not to mix up the order.

Method workpiece alignment rib lapping, I often use small panels before gluing. Instead, apply the pencil crayons, as even the basics using the table bench, on which is placed a sheet nazhdachki.

On this application, I described in the article End cutting board with simple tools

This allows you to precisely adjust the grinding small details and the selection of the texture is almost invisible seam.

Thank you for reading. I will be glad of your support in the form of a husky and a subscription to the channel. And look for other posts on the channel.

Alexander.