I thought I would put this picture up for the benefit of the customer who is buying it. I plane all round for truing up. As you will notice I have chosen to do all my planing on the milling machine as it will plane true without any tearing when it comes to the more difficult grains. I achieve more accuracy this way than I would do on an ordinary planer/thicknesser.
T21 Transitional Dovetailed Jointer Plane
Boring and counter boring the hole in the bun blank for the fixing stud.
T21 Transitional Plane
I will be working to finish the blog on the T21 today, so I thought I would leave you with these pictures in the meantime.
T21 Transitional Plane – Bushing
There are 2 single bushes and 1 pair in this plane. The bun and the rear handle have one each and a small pair for the adjuster. Following are a few illustrations to give you an idea of how they are made – once fitted they are invisible though vital.
The purpose of these bushes is that they spread the load into a greater contact area. I use a coarse thread on these which is cut on to both the male metal portion and the female wooden counterpart. These bushes are permanently cemented into position with an epoxy resin.
It is possible to break the bond on the metal parts. When the bushes are cemented in position they are less likely to rotate due to the mechanical properties of the flats you will have noticed in the photographs (in the above photo I am about to cut the flats on to the stud for the front bun, not one of the bushes – but the principle is the same). However, as during the fixing process the epoxy resin is forced in the fibrous texture of the wood providing an additional mechanical key these will not break down.
T21 adjuster
The adjuster for this plane is of the well known Norris type. As with all my Norris style adjusters they have some revisions.
In these pictures you can see two small holes which are used to secure the adjuster body. One of the larger holes is for the rotating nut and the other is an extra hole to assist in work holding when machining (as in the second picture).
Gunmetal fittings for T21
This is parting off my spider hub (for want of a better name) from a prepared bar.
Once these are parted off they need to be trued up to the precise length.
INTRODUCTION TO TRANSITIONAL PLANES – T21
Having made some comments on the instability of wood in infill planes and now that I have successfully made metal planes without infills of my own design; I felt that there is a sector in the market that looks longingly towards wooden planes. Having used some wooden planes myself I feel that there is a sweetness in the way that these planes glide which adds to the plane’s charm. There is the metal plane with a greater accuracy (well some of them) and the smooth operation of the wooden plane. When you try and put the two together to get an infill plane you can lose the advantages of both types of plane. This leaves the transitional.
Instead of putting wood into a metal plane, I put metal into a wooden plane. The advantage here is that I am not interfering with the integrity of the wood. Of course there is going to be a lot more wear and tear on the wood but any settlement due to differences in environment is easier to deal with.
You will find in my designs of this plane that I have kept all the character of the wood and yet introduced the fittings as found on a metal plane (the adjuster and lever cap).
All these fittings including handles have been thoughtfully integrated into the wooden body. Items such as handles and adjuster use brass bushes. I have used brass bushing in these areas rather than using an ordinary wood screw. This is a considerable leap forward; the wood screw is just one step up from a nail.
I put some pictures up earlier on in the year which are here if you want to look back: http://www.holteyplanes.com/blog/category/transitional/
Holtey Transitional Jointer Plane – 2
As there have been comments about this dovetailed jointing system I realised that I should show the pictures of the dovetailing in progress.
There are a few who know the dovetail puzzle of using a cube made up of two contrasting woods showing one dovetail on each side. In the case of a square object you cut the angle of 45 deg for the path of the dovetails (two) so that the joint slides into position with this angle, which gives an even sized dovetail on all four sides.
Once you start altering the dimensions and the number of dovetails then it becomes complicated. If it was not for my CNC it would be a nightmare.
The first cut for the dovetailing is done with a plain cutter so that I can reduce the mileage on the dovetail cutter.
Holtey Transitional Plane
For some time I have had a fascination for transitional planes. Since I have made two planes that are mainly made from metal it seems fitting that I should now make a transitional plane.
The designs that have had the greatest influence on me are John Gage’s planes, but of course I feel the need to upgrade on the metal working side. I like the lightweight and low profiles of these planes and believe they could find favour with quite a few people.
I also have some interest in ECE Primus planes but again I don’t like their metal work. I do, however, like the laminated sole very much. I feel I could improve here by dovetailing the hardwood sole instead of grooving. It will be technically superior as the mechanics of this jointing system is not totally dependent on glue.
There are some problems in the making of this dovetailed system but I have overcome them with a considerable amount of thought and work. I will be very dependent on the use of my CNC machine. It could provide quite a challenge for the home constructor.
As you may have noticed from a previous post I have already jointed and glued the bodies and they have been settling in my workshop for the past three months.
The timber that I am using is Quilted Maple, for its beautiful figure and light weight. I have a choice of two different woods for the sole; one is a Cocobolo rosewood (Dalbergia retusa) for its density and oiliness, or the Guatemalan Rosewood (Dalbergia cubiquitzensis) which is also dense and oily.
Though I have had considerable interest in these planes I am not taking orders until I can price them.
The picture shows the plane body being flushed using a face cutter in the milling machine. This is not just the only practical way of planing this very difficult wood because of the character of its grain, but I am also applying a high degree of precision.
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Commentary – T21 Transitional Plane
I have been quite impressed about some of the comments on forums about my T21 plane and I would like to make my contribution to these discussions.
There was a reference made about the brass kicker pads being in the wrong position i.e. cutting through one of the dovetails. I have to assure everyone that I think long and hard about the positioning of everything. Sometimes I can ponder over these decisions for months. This kicker pad is there to assist in the lateral positioning of the blade, which works in conjunction with the adjuster. In the case of castings there was usually a pip in the pattern to do this job. The kicker only has to endure very light side pressure. However its positioning is important if it is to be effective.
An interesting comment, on my blog, was that someone noticed the positioning of the five pins in my spider hub and worked out the reasoning.
The most interesting point is discussion on the stability of wood. When it comes to wood stability we will always be losers. I have always had a fascination for transitional planes probably because I am more of a woodworker than engineer. Where possible I like to combine woodworking with metalworking. Engineering is not always all about metal. However, for stability and reliability metal will always win.
The reason I decided to laminate the sole is so I could chose a light weight wood for the body, something pretty like the quilted maple, and laminate it with a harder wearing wood. With laminating in this application straight forward bonding would not have been sufficient because of the oils in the wood I chose for the sole. This is the reason for using the jointing system like ECE have on their primus planes, except I chose to dovetail whereas ECE had a tongue and groove system.
The difference in movement in different materials would be cross grained and most of it will be tangential. Over a distance of 3 3/8” it should have a minimum effect. Whether these dovetails run at right angles, longitudinal or diagonal I would think would be irrelevant and it would seem that it hasn’t affected the ECE planes. The use of the dovetail joint is it is more positive than the tongue and groove and of course there is just that little bit of vanity.
I feel that I have made some inroads with the fittings that I designed, and I would like to make this plane again in smaller sizes and in a one piece stock i.e. without the laminated sole.