In this video you can see the tuning and restoration of a Stanley 9 1/2 type craftsman block plane to highest possible geometrical accuracy with files, scrapers, straightedge, touching plate and dial gauge as tools. It also shows how to turn a replacement of the original adjustment lever. It is also an introduction to basic scraping and touching techniques and shows its advantages in precision and working speed to the common used sand paper method.
Table of contents:
00:00 welcome and workshop jingle
00:42 feature of the plane
02:29 geometrical checks with a straightedge
04:40 filing the sole
07:02 filing the sides
08:16 cutting image of a file
08:45 self made touching plate
09:07 touching image of the filed sole (shows the reason why scraping is needed afterwards)
09:20 scraping the sole
11:35 touching image of a side
11:55 scraping the sides
13:09 checking the alignment of the mouth plate rails with a dial gauge
13:59 filing the mouth plate
16:25 scraping the mouth plate flat and flush with the sole
19:25 demo of the final squareness
20:43 final touching image of sole and sides
22:27 cross check and demo that the mouth plate runs parallel to the sole
23:33 cleaning the mouth
24:28 tuning the bed with a Barett file
27:24 test cuts and checking the shaving thickness with a micrometer
31:02 tuning the mouth gap adjustability.
31:53 making of a replacement for the adjustment lever
38:45 demo of the final precision of the mouth gap
39:03 final overview of the tuned block plane
39:41 outro and disclaimer
There seems to be a little misunderstanding why to file first an than start scraping. The file is primarily a roughing out process. The scraping is for final accuracy. One of the many reasons is that the workpiece is under pressure of a vice and will change its geometry. so that the file will start to cut at the wrong areas. That is one of many other reasons to start cutting selectively with the scraper. The other fact is that no file is flat. And of course the interpretation of the touching image is easier due to the interrupted cuts. Keep in mind that we are in the micrometrical order of magnitude here! And as always, a deep understanding needs practice.
Sometimes there are doubts about what a highly tuned plane is good for. A true understanding of the reasons is based on a deep experience when it comes to geometric scales that cannot be seen with the keen eye. When you start to control the quality of your glue joints with straightedges and touching plates you will experience the missing link of understanding. If you believe that aggressive clamping and the chemistry of the glue will do the job, you probably will never take care. But once you noticed that there is a step beyond and you will start to use highly tuned tools and see (with the aid of tools) and feel what they are good for, you do not want to miss them anymore. Keep in mind that in most cases the geometrical accuracy of your workpiece will not be higher than the geometrical accuracy of your tool. The only exception is working spotty via scrapping to annihilate systematic errors caused by any technique to cut over the hole surface in more or less one go, independent if this is done by hand or any kind of machine.
By our mathematics teachers we are forced to believe in the lie of an ideal flat surface. This is just a mathematical approximation and has no physical reality. Every surface is a sort of landscape with hills and valleys. The only thing we can do is to give all these hills the same height with highest possible standard, to take care that the number of hills is high enough, and the difference between valleys and hills is very small. And that’s the art which es very briefly suggested in this video.
Scraping is not an out dated craft. It is still bread and butter in the precision machinery industry. The final stages of accuracy can still only be done by hand, via scrapping if it is a cuttable material or via e.g. (diamond) lapping of adiabas touching plates.
Please keep in mind that a steel rule is not a straightedge, and the a plate of black marble or granite is not flat by nature and a smooth surface does not mean that it is flat.
If you are interested to see, how these techniques can be applied to tune up wooden jointer plane please check my video:
If you are interested in tuning a tipped plane blade pleas see https://youtu.be/WgLdzy_yUgM, which is an excerpt of the video linked above
If you are interested in sculptural art work check out my video on carving a gravestone out of an oak tree:https://youtu.be/c4FxTP-d5u0
Post time: Jun-24-2017