Tuesday, 26 January 2016

an unconventional lever cap

It has been a while since I have made a lever cap from scratch, but given the complex geometry and really odd final shape needed for the badger plane, it was the only option. Besides, sometimes going back to your roots can be a lot of fun.

I had made several test lever caps for the first badger plane, so I was not starting totally from scratch. One of the wooden mock-ups fit the new badger plane quite well - well enough that I could use it as a pretty accurate template.

The reason I am posting these photos, is to show a process and a methodology using very simple workshop tools and woodworking techniques. Starting with a rectangular block of metal and turning it into an accurate, complex shape. I have often joked with people that metal is just a strange wood with strange properties, and this lever cap is a perfect example of that mindset.

I made a set of card stock templates from the wooden model and transferred them to the blank.

 You can see the outline of the lever cap scribed on the blank.

I am often asked why on earth I do so much of this by hand. The reason is fairly simple - I look at all the hand skills as having a cumulative effect. One skill leads to another which impacts another. Taking the time to hand cut all the dovetails for our kitchen drawers was really over the top, but it was another lesson to teach myself how to ‘feel’ when I am sawing level and sawing accurately. It is such a simple thing, but the time taken for all that work has had a tremendously positive impact in many other areas of work - including the shaping of this lever cap. I do not need a reference line on the opposite side - I don't need to stop sawing to check if I am close to the line - I just know where it is, and when it feel right. That sense is transferable to filing as well - and all sorts of other aspects to plane making and woodworking.

The outline of the lever cap, and the waste below.

It also helps to treat yourself to a brand new hacksaw blade.

I cut the outline first to waste out as much material as possible. This greatly reduced the amount of sawing for the profile. I drew the profile with a sharpie and cut some vertical kerfs,

and then started cutting the profile. Just like using a chisel to cut a small notch in a piece of wood to register a saw blade - I saw a small kerf to give me something to register against for such a shallow cut in metal. 

Taking 1/16" off the height here is way easier now that the outline has been defined. 

I only cut part of the profile so I would have more area to clamp while tapping the hole for the screw. The flat surface also gives me a reference face for checking 90 degrees.


Once the screw was fit, it was time to shape the other half of the profile. The two sharpie lines represent the two different shapes on the sides of the lever cap. They are quite different reflecting the dramatic rotation of the lever cap in the plane. 

I cut the angle of the lever cap first - again, to reduce the amount of sawing during profiling. Wasting off this angle was a more efficient way for me to work. If you click on the image, you can see another benefit of hours and hours using a hack saw - being able to saw very close to a line. This greatly reduces the amount of filing later on.

Sawing thin, tapered slices to reflect the two different side profiles and the rotation of the lever cap.

The (rough) profiled lever cap. 

At this point, the top surface of the lever cap has been fully shaped by way of files. I need the profile to be the final shape in order to accurately start fitting it into the plane.

I measured the angle on the wooden test model and transferred it to the lever cap, took a deep breath, and started sawing. With each cut, the risk increases dramatically. I did not cut exactly on the line for this cut - I left about 1/32" so I could further refine the angle during the fitting process.

The fitting process is a lot of back and forth, lots of direct lighting for clarity, and careful file work. I used a wooden hand screw in the blue vise to position the edges of the lever cap level. Positioning things level and/or plumb is always worth the extra few seconds of time, and allows you to take advantage of the muscle memory you have built up.

The screw was a little too long so I cut it down and re-shaped the tip.

A much better screw length.

The next few shots show the odd angles of the sides of the lever cap as well as the overall wedge shape. 

The lever cap fit to the plane. The next step is to drill for the cross pin, and I have to confess.... this is going to require a few antacids.  


Blogger Mike Davidson said...

IG just doesn't do this process justice. It's one thing to register 90 degrees to another surface but quite another to make such a complex shape by hand and have it all fit perfectly. This should confirm why hand work is so important and machines have no sole.

Attempting to draw out the shape in a CAD program then setting up the CNC machine to make the various cuts would have taken far longer and I would suggest the results would not have been as nice.

Every woodworker should experience the thrill of effortlessly pushing a S&S custom hand made plane across a piece of ill behaved exotic wood. The sensation is so intoxicating you just might think it's illegal.

Now my mind is consumed by thoughts of selling as many tools/body parts/etc. as possible just to get my name on the list of lucky owners. BTW, this feeling is still with me from Handworks.

26 January 2016 at 15:14  
Blogger Konrad said...

Thanks Mike,

I was wondering if anyone from IG would wander over here! Nice to see a familiar name, and now I know who the maddog really is:)

Glad you enjoyed the post and that it was worth posting in addition to IG. IG is pretty new to me, and I am still adjusting to the speed of light response times.

Thanks too for the kind words and glad that feeling from HandWorks is still there. It is a tough one to shake... look what happened to me:)

best wishes,

26 January 2016 at 22:45  
Blogger Kevin Brehon said...

Do you get your bronze for the cap in bar form? and if so, where?

29 January 2016 at 09:27  
Blogger Konrad said...

Hi Kevin,

Yes, it was in bar form - you can see the chunk sitting on the bench beside the plane in the first shot. You can order it from a place like the metalsupermarket, or in my case, call your friend Stan who has all sorts of off-cuts like this:)


29 January 2016 at 09:30  
Blogger Steve Kirincich said...

Hi Konrad,
I feeling like I am looking at some funky modern art. I think this plane belongs next to the MIT Stata Center:


Thanks for blogging!


29 January 2016 at 16:24  
Blogger Konrad said...

Hey Steve,

Thanks for reading the blog.

I guess by that description, it would be a 'deconstructed lever cap' :)


29 January 2016 at 16:26  

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