Category: Crucible Tool

The Crucible Tool “Chairpanzee Analog Computer” and “Lump Hammer” are now available to order through the U.K.’s Classic Hand Tools (along with the Card Scraper and Design Curves). That’s good news for non-U.K. overseas readers, too, because Classic Hand Tools will ship to most countries.

Both the Chairpanzee and the lump hammer are, in a way, simply returning home; both ideas came out of England. The Chairpanzee is the brainchild of Ed Sutton of FirstLightWorks, and the lump hammer is an idea brought to woodworking by the great English craftsman Alan Peters (that Christopher Schwarz picked up from David Savage).

Classic Hand Tools also carries the full line of Lost Art Press books.

— Fitz

Here’s a short video that shows how to use the Crucible Chairpanzee to work with photographs of furniture to create simple drilling settings for the compound-angle mortises.

In the video, I show how to convert a chair’s “rake” and “splay” into “sightline” and “resultant” angles using the Chairpanzee. Why would you want to do this? It makes the drilling much easier. 

If you have only the rake and splay, then you usually use two sliding bevel tools to drill the mortise – one for rake and the other for splay – and have to obey both tools as you drill. It’s do-able, of course, as I worked that way for years.

By using trigonometry (or the Chairpanzee) to convert things to sightline and resultant angles, you have to obey only one sliding bevel tool. It makes drilling compound angles as easy as possible.

Here’s the video:

There are other ways to use the Chairpanzee. You can use it to design new chairs, stools and tables from scratch. I’ll make a video showing that process sometime in the near future.

The Chairpanzee is available in our store for $16 plus $4 domestic shipping anywhere in the United States.

— Christopher Schwarz

One of the (many) barriers to making staked furniture or chairs is wrapping your head around the compound-angle geometry. And then figuring out how to execute it at the bench.

The new Crucible Chairpanzee ($16 plus shipping) does the trigonometry for you, allowing you to translate rake and splay into sightlines (which create your layout lines) and resultant angles (which is the setting of your sliding bevel).

This allows you to easily design new pieces of furniture with compound angles and to replicate angles from existing pieces of furniture from photos.

The Chairpanzee is a clever sliding calculator that is printed and assembled in the United States. Here’s how we use the Chairpanzee on a chair design (though it can be used for tables, stools or any other piece of staked furniture).

To calculate the “sightline:”

1. On the underside of the seat, draw a line connecting the two front leg mortises (as shown above). This is the baseline.

2. Move the calculator’s slider to the desired splay angle in the top window.

3. Next to the lower window, select the desired rake angle. The number shown in the adjacent window is the sightline angle.

4. Draw the sightline angle on the underside of the seat using a protractor. The 0° on the protractor should be directly on your baseline.

5. Repeat steps 1 through 4 for the rear legs.

To calculate the “resultant:”

6. Confirm that the calculator’s slider is set to the desired splay angle in the top window.

7. Next to the lower window, select the desired rake angle. The number shown in the adjacent window is the resultant angle.

8. Set your sliding bevel tool to the resultant angle and place it directly on the sightline on the underside of the seat.

9. Drill your mortise. Keep the drill bit perfectly parallel to the blade of the sliding bevel.

The Chairpanzee is available for immediate shipment. We hope that some of our retailers will also carry this product for our international customers.

In the coming week I’ll post a video that shows how it’s used.

— Christopher Schwarz

I don’t keep a diary, I just look back at Instagram to see what I was doing on any given day. This is how I know The Chairpanzee was born on 11th April, as nothing more than an idea in search of a good name. That day, in the early stages of my COVID-19 infection, I sat at my desk designing a new low back chair. I used other chairs I admire as a reference point, noting their rake and splay angles to understand the visual effect they generate. Rake and splay are all very well on a drawing, but when it comes to making a chair what we really need are a sightline and a resultant angle for the legs. This approach allows us to drill with reference to a single sliding bevel (set to the resultant) which is positioned along the sightline. It struck me that a simple device to tell us those sightline and resultant angles based on any given rake and splay would be a useful tool to own, which brings us to today.

There are published tables available to use as a reference, but for this product I went back to first principles, enlisting my older brother (an Engineering Ph.D.) to do the hard bit. Shortly after, armed with lines of data, the first prototype was born. An important concept from the beginning was to return both the sightline and resultant for a single setting of rake and splay, which led to the double-sided design. Every good product needs a memorable name and, having christened an earlier product the Bevel Monkey, it seemed only right to continue the simian DNA line. My son George eventually won the pun-off on a family walk, coming up with the perfect name: Chairpanzee.

Collaboration is a key aspect of product development; it leads to ideas being challenged and ultimately creates a better end product. A good idea is also worth nothing without a route to market, so with both of those principles in mind, Chris Schwarz and I formed an alliance to develop a product that would become part of the Crucible range. We pulled apart the flaws in the first prototype, which was too big and suffered from racking sliders that jammed. We also needed to scratch an itch that Chris had: the thought that a wheel-type gauge might fit the bill. We got to a wheel gauge eventually and I still have a fondness for its Fibonacci-like pattern of holes, but it would have been too big and too expensive to produce. You have to be willing to drown a few ideas in the river on this journey.

By prototype three we were zeroing in on the concept of a double-sided slider, which could be produced to a high quality at an affordable price. We made an important step toward a printed product, which allowed us to reproduce detailed graphics and fine data on a durable surface. Laser engraving had been a useful development tool, but ultimately too costly as a production solution. Following creation of the graphics and layout, we arrived at the end of the story with prototype number four, which looks exactly like the product you’ll be able to have in your hands very soon (pictured at the top of this blog entry).

— Ed Sutton, FirstLightWorks

With all the new books we’ve released in 2020 (five new titles, with two more about to go through the publishing baby-hole), I haven’t done a good job of discussing the other tools and apparel we are working on. Some will be released soon. Like, next month. Which is October, I am told.

Apparel aka Clothing

First, I’d like to mention that we have the chore coat available in all sizes. If you have been waiting for cool weather and for us to carry your size, today is your day. You can order one here. I wore mine today for the first time this fall, and it was like pulling on my second skin. Un-molting as it were.

With vests, we are switching colors this year to a nice brown moleskin from the same British factory. I’ll publish some photos when they are available. But these are being sewn and will be ready in October. Like our green vests, these are being made by hand in Cincinnati by SewValley.

The big project that designer Tom Bonamici has been working on is our workshirt (shown above). This shirt is based on an old Swedish army shirt that Tom wears when woodworking. 

These shirts are made from a 5.5 oz. Japanese solid indigo chambray. Like the chore coat, we had special buttons made that are embossed with “Lost Art Press.” I suspect the shirts will be $165, and we will begin selling them by the end of October. Again, these are being made one at a time in Cincinnati by SewValley. 

Also on down the line, Tom is working on our third bandanna design. We came up with some crazy ideas after a couple beers. We’ll see where they lead (which will probably be not crazy).

Crucible Tools

Until recently, most of my effort with Crucible has been keeping our current tools in stock during material shortages and labor shut-downs. We’re also moving production of the Bevel Monkey and Big Protractor to the United States from Great Britain.

Recently I found a little oxygen, and we have been working on two new tools. One I hope to release by the end of the year.

Ed Sutton of (FirstLightWorks) and I have been working on a simple calculator that will calculate sightline and resultant angles for the rake and splay of almost any chair. It’s devilishly clever and will eliminate the need for you to perform a trig function or consult a table. We hope to show you the prototype next month. 

In the metalworking department, we are prototyping a cast planing stop for a workbench. This will look like a blacksmith-made stop, but it will be made from ductile iron, so it will be less expensive than a hand-forged one but function just as well. 

Also, I have spent a lot of time trying to simplify installing the planing stop into a block of wood. Traditional stops require you to drill a stepped hole in two different sizes. Or to torch the shaft and burn the stop into the block of wood.

I’ve done it both ways. But I always thought there must be a simpler way to do it. The solution came to me in the shower. This planing stop will be easier to install than any other commercial stop I know of.

We are in our second round of prototyping right now. And there is a long road ahead of making the wooden pattern and/or matchplate. But it should be ready in the first half of 2021.

I’m sure you have questions about pricing and 100 other things I didn’t mention, but above is everything I can say right now. 

— Christopher Schwarz