Thursday, 18 March 2010

The first A7 - part I

It is hard to believe that this is the first adjustable shoulder plane I have made - but here we are. Several people have asked about them over the years, but there were a few “issues” I needed to resolve before I was comfortable saying I could make one. The adjuster and the threaded sleeve (and top screw) were the biggies. Building the pair of Rebate mitre planes solved both of these issues, so it was only a matter of time before the A7 shoulder plane came to life.

I have kept my camera close at hand this last week as there were a few sequences that I thought might be interesting.

The first one is rather generic - but it illustrates the manner in which I work.

After the shell has been piened together - I measure the gap between the sidewalls. As long as the sides are parallel to each other - I don’t really care what this number is. Well... unless it is 1.124" and I am making a 1-1/4" wide plane - then I would have a problem. Although Riley would be happy... he would be all over the “scrap” bronze! Anyway - the plane is .002" wider than 1.000" which is a non-issue for me.

(front of the infill, bottom)

Because this is what matters to me. Early on in the planes construction - each part becomes specific to that particular plane. The front bun to “identical” planes are not interchangeable - they are individually fit. There are variations from one plane to the next - measurable in thousandths of an inch - but still variations. I have no interest in going the extra mile (or charging you to do so) to get rid of the .002" of extra space between the shoulder plane sidewalls. I care that the sides are parallel to one another, square to one another and that the fit between the infill and the metal shell are gap free.

(front of the infill, top)

(back of the front infill)

These three measurements are taken from three different points on the front infill. They are close - and slightly over sized. Perfect! It is kinda hard to tell from the photos - but the two readings from the front section are the same and the back portion is slightly narrower.

One of the true joys of woodworking is knowing your tools so well that you know how many passes it will take to remove .002" from the front of the infill and taper it back to the desired thickness. Once the piece has been made parallel - I can start working on the overall thickness. And that is how all the infill pieces are “fit” to their corresponding shells - on everything from this shoulder plane, to a 28-1/2" long jointer.

Here are a few photos to show the keeper (the bronze plate that supports the top of the wedge and registers the threaded sleeve).

The sleeve houses the bronze screw that engages a small cup that is inlayed into the top of the wedge. The cup is offset so the tip of the bronze screw works as a drawbore - as it is tightened down, it pulls the wedge in.

The two tenons of the keeper.

The underside of the infill showing the recess for the shoulder on the threaded sleeve.

The keeper and the bronze sleeve.

The next sequence shows the shaping of the back of the rear infill. I apologize - there are a few steps missing here. In the above photo - the back of the infill is still “off the bandsaw” and needs quite a bit more work.

I use the bandsaw to cut the above radius and then refine it with rasps files and sandpaper. I have always found it is worth the effort to maintain square edges, clean transitions and smooth lines. Most of this clean radius will be removed during final shaping, but I am convinced that going through the process of working accurately prepares my hands and mind for the next really critical steps. Having clean crisp edges is also crucial because those are the reference edges for all other layout lines.

Here are the layout lines for the compound radius on the bottom edge of the rear infill. If you click on the photo - it will be easier to see the line on the side of the infill - graphite does not like to be photographed.

This is about 8 minutes and two files later. I start with an 8" half-round and then finish with a very fine half-round. From here I proceed to some sandpaper wrapped around a hard rubber form.

The last sequence shows the shaping of the front infill section.

Here is a shot showing the front infill section already pinned. At this stage - I have already started refining the arc of the front infill that transitions from being flush with the bronze sidewalls into the raised section that houses the sleeve. Note that the infill is still quite rough at the front of the plane.

This shot shows the refined radius in front of the keeper and the keeper now flushed with the top edges of the sidewalls. This was slow delicate work with files and then finished with sandpaper. Again - note the crisp lines of the edges.

This is a photo taken from the back of the plane looking forward. I use a paper template to layout the radius across the back of the front infill.

Here I am using a specific radius template to define the other side of the compound curve. When I was in design school - part of our kit included this great set of ellipse templates. They range in size from 1/8" to 2" and in projections of 10 degrees to 80 degrees in 5 degree increments. I cannot believe how many times I use these in my day-to-day work!

(a quick shot to show the Pickett ellipse book)

Here are the layout lines and some blue tape - just in case the file wanders a bit.

The first stage of shaping with the 8" half-round file.

Another view to show the end radius taking shape.

After the second file - it looks like this. I used a 6" single cut, mill bastard file for this work. From here it is onto a bit of final sanding.

And here is a shot showing the fully shaped and sanded section. You will notice there is a fair amount of sunlight in many of the photos. Good strong light is a key to shaping complex curves. Watching the light roll across an arc is a very fast and accurate way of judging if the curve is right or not.

I am not sure where this last photo fits into the order of things, but it was a good shot to show the fit between the infill and the shell.

That is it for now, but part II should follow in a week or so.


Blogger teal and gold said...

speechless. Can you call a plane sexy? thanks for the detailed steps.


19 March 2010 at 11:28  
Blogger tomausmichigan said...


Thanks for the brilliant series of photos! I feel as if I were in your shop, looking over your shoulder.


20 March 2010 at 14:23  
Blogger Konrad said...

Thanks Tyler. I hope one can call a plane sexy... I have been doing so for years now:)

Best wishes,

20 March 2010 at 15:58  
Blogger Konrad said...

Hey Tom,

you are most welcome - that was the desired effect.


20 March 2010 at 15:59  
Blogger Tico said...

Hi Konrad,
I really enjoyed this post. It's chock full of good information. That book of ellipse templates is a revelation.
Do you use scrapers in shaping? Also, what grit size do you work up to with your sanding?



21 March 2010 at 08:42  
Blogger Konrad said...

Hi Tico,

Glad to hear the post was useful for you.

I do use scrapers - but not that often to be honest. All the shaping is done with files and rasps and then finished off with sandpaper. I start with 220, then 320, 400 then 600. 600 wears very fast and I suspect it acts more like 1,000 grit in very short order.


21 March 2010 at 08:51  

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