Category: Crucible Tool

We are in the final stages of producing our latest tool, a Crucible Planing Stop that is easy to install, looks similar to a traditional hand-forged stop and is reasonably priced (about $49).

I hope this tool will be out by the end of the year, but we are at the mercy of our supply chain, which loves to whip us almost every day.

Here’s why I think the world needs another planing stop. 

I love blacksmith-made planing stops, which are embedded in the end of a block of wood that is about 2-1/2” x 2-1/2” x 12”. The block is friction-fit into a mortise in the benchtop and moves up and down with mallet taps.

For me, the planing stop is as important as the workbench’s face vise and has almost-endless uses.

My main problem with a blacksmith planing stop is that it can be tricky to install. You need to drill a stepped hole in the block of wood or heat up the shaft of the planing stop in a forge and burn it into the block. And there is always the risk of splitting the block during the process.

Also, some people think that blacksmith stops are too expensive (I disagree), which can cost $100 to $300.

The Crucible Planing Stop is made from ductile iron, so it can take a beating. Hit it with a metal sledge, and it will not shatter (unlike typical gray iron). The teeth and the angle of the head of the stop are based on A.J. Roubo’s planing stop from the 18th century.

And – this is important – it is easy to install. Here’s how you do it: Buy a 5/8” (or 16mm) spade bit (less than $10). Drill a full-depth hole in the block of wood and remove the sawdust and chips. Drop the shaft of the planing stop into the hole and it will stop about 1” from the bottom of the hole. Knock it with a hammer a few times and the stop will cut its way into the hole and bed itself in place. Done.

It’s a dirt-simple tool, but getting to this point took more than a year of experimenting with hand-forged stops, developing the casting patterns and (where we are now) developing the risering so the liquid metal goes where it needs to go.

RIght now we are trying to get on the foundry’s schedule as soon as possible. We will let you know when the wheels have started moving.

Making stuff is hard.

— Christopher Schwarz

We have a decent-sized batch of Crucible Type 2 Dividers up in the store today, ready to ship. This is the batch we managed to get done before an end mill decided to go supernova in the mill (no one was hurt, thank you for asking).

I use these dividers every day. Above is a snapshot of me adjusting them one-handed to transfer mortise locations to a chair seat.

The bonus with this batch is it contains Megan Cooties. We had to sharpen these by hand before sending them to the warehouse. Cooties are no extra charge.

— Christopher Schwarz

If we had a company motto, it would be something like this: “If it were easy to do, then every idiot would do it.”

It’s something we say to ourselves when we’re fighting to find enough cotton cloth for a run of books, or a vendor for hinges for our dividers, or looking for damn Chicago screws without a burr on the underside of the head that has to be machined off and who does that and why am I not able to finish this sentence like a normal person?

And so we look to Craig Jackson for salvation. 

Craig is the machinist we use for a lot of parts. He’s like if Matlock and Columbo had a baby. He’s easy to underestimate because of his Kentucky accent, and you do that at your own peril.

Anyway, for the last few weeks, we’ve been wrestling with the tips of our Crucible dividers. They have been getting bent in transit, and we’ve tried lots of strategies to stop the damage. All through the process, Craig kept saying: I can show customers how to heat-treat the tips at home.

But we ignored him. At our peril.

Finally, we came up with a solution with the CNC mill that would strengthen the tips. Craig said it would work, but he also sent this message:

“Heat treating the tips now.”

OK, because we live in a litigious society I have to say: Don’t do this, you fool. It’s a joke. You will hurt yourself badly (but please tell us if the tips increased in Rockwell hardness).

— Christopher Schwarz

We have just put up another load of Crucible Type 2 Dividers up for sale in the store. They are $110 plus domestic shipping.

These dividers are certified chicken-fried. The hinges are made in Tennessee. The legs are machined in Central Kentucky. And the screws are “new old stock” from somewhere in America’s great industrial past. They are assembled by the chicken-eateningst crew in the state.

The last few loads have sold out within two or three hours. So order soon to avoid disappointment.

A Cool Divider Trick

One of the cool things our Type 2 dividers do is they allow you to return easily to a previous setting. And you can do it with a pencil.

Here’s how to do it. Set the dividers to your initial setting (say, the distance of a half-pin when laying out dovetails). Take a sharp pencil and mark the position of one leg onto the interior of the other leg. Now adjust the dividers to the second setting (say, the spacing of one tail and one pin).

The pencil line will not be erased when you move the divider’s legs. The tool’s friction is up at the hinge – not on the leg recesses. So you can mark multiple settings on both sides of the tool. The pencil lines are easily removed with an eraser. (Thanks to tool designer Josh Cook for pointing this feature out.)

So now one pair of dividers can do the work of two or three. I guess I’m a terrible salesman because now you don’t need to buy two or three tools.

— Christopher Schwarz

Today I reviewed a big batch of Crucible dividers for quality control problems and sent them on to our warehouse in Indiana. Barring some delivery stupidity (it happens), they should go on sale on Saturday.

These dividers are the most complex tool we make and are difficult to manufacture, especially considering the $110 price tag. If they were $300, we could lavish a couple hours of polishing and tuning on each tool and still come out in the black. But that’s not what we’re about.

Instead, these tools are manufactured – like our books. Yes, there is a lot of handwork, hand-assembly and tuning involved in these tools. But a lot of the skill to make them is in programming the robots and ensuring the processes are foolproof so that even I can assemble them – even though I’m not a skilled machinist. And so far, I’ve assembled quite a few of them.

Because I’m not a fan of hype, I’ve tried to downplay these dividers quite a bit (maybe too much). They aren’t like an infill plane or a blacksmith-made fretsaw. But when I pick up our dividers and use them – as I have every day for the last six months – I am tickled by their presence. Despite the fact that my personal dividers aren’t cosmetically perfect, I carry them around all day like a nice pen. I hold them when I’m thinking or on the stupid phone.

I open them and shut them over and over, and think about the mechanism inside. It looks so simple, but the angles and tolerances have almost broken my head a few times. But still they make me think. And now that we have the mechanism (almost) perfected, we’ve been designing other tools that use it.

(EDIT: When I say “almost” perfect, I mean that we are improving the hinge to make the assembly process easier. Right now we have to do a couple extra steps to get the hinge working perfectly. Nothing leaves our hands that isn’t 100 percent functional and meets our standards for fit and finish.)

Books have authors, but there is always a team of people behind them that makes the thing look good and read well. Tools are the same way. And so I will continue to call out the people who have made this tool really work: Craig Jackson at Machine Time and Josh Cook, a mechanical designer. Thanks guys.

So look for the dividers on Saturday. And if we sell out, know that we now are making hundreds more. Our goal is that everyone who wants one can get one.

— Christopher Schwarz