Toad Craft 03

In the last issue we looked at the machining of the heater module holes. Now, we'll continue on the lathe to finish up the next two processes that'll bring these cherry wood blocks closer to their final forms.

Back on the lathe again to drill out and bore the battery hole. I start with a drill bit to remove as much material I can.

Because this will be a flat bottomed hole, I switch over to an endmill to finish the hole closer to it's final inside diameter and depth. This will create an almost flat bottom that'll need to be cleaned up in the next step.

By using the endmill, not only do I get the flat bottomed hole, but It also puts a lot less outward pressure on the thin walls compared to a standard twist drill.

The endmill is followed up by a boring bar to bring the hole to it's final dimensions. Because the walls are starting to get quite thin now, I take a light cut to minimize any distortion. A sharp carbide insert makes a beautifully clean cut at the bottom of the hole to create a flat and smooth surface.

The depth of the battery hole is set with a wooden block, just like we saw for the previous heater module holes.

Finished holes.

Each Toad requires centering in the chuck, one pass with a drill, one pass with an endmill, and then a final pass with the boring bar. Due to the thin walls I set the tool to advance through the cut quite slowly... so these can take upwards of 15 minutes per hole. On a large batch of Toads, this adds up to days of work.... just for this unassuming little hole.

In the early days I explored other ways to improve my hole machining speed, but after much experimentation, I think I've dialed it in to be as fast as possible with manual machine tools.

It's easy to look at a hole in a block of wood and think, it's just a hole... But, if you want these holes, well... there is no shortcut.

The next step is the most difficult machining operation of the entire build. The Toad bodies are flipped and mounted back onto the lathe to machine the stem hole and O-Ring groove.

This process is difficult for one reason, alignment. The stem hole needs to meet up with the heater module hole. If the two holes are misaligned, the entire block will be ruined.

This is where the previous steps really come into play. Because these blocks are perfectly flat/square they can be remounted on the lathe and aligned using those outside faces for reference. If a block was out of true... it would cause a misalignment during this step and that would be the end for that poor Toad.

I'll be clamping onto the thin walled sections with the lathe chuck jaws so I use a purpleheart plug that fits snugly into the battery hole to prevent the walls from distorting under the pressure.

One last, critical, alignment procedure using the ol' boxwood block. Being a little more careful with this one. That tiny gap between the tip of the tool and the edge of the boxwood block is my guide.

As before, a drill does the rough work.

This is the dial that sets the location of the cutting tool. Each mark on the dial equates to .001" of movement at the tool. I use masking tape and a pencil to mark off my stops for where I need to set the tool locations. I have three settings for this process. 1, Sets the internal diameter of the stem hole. 2, Sets the internal diameter at the bottom of the stem hole. 3, Sets the depth of the O-Ring groove.

After each block is machined I check all the measurements to confirm I'm on target. Re-adjustments will be made throughout the batch if my measurements start to drift.

Each Toad takes their turn, dancing with the 700 lb cast iron brute. The clacking rhythm of the drive belt, dials turning, gears whirring. The hum of the motor drones on and on. An unstoppable force with the power to turn a piece of wood into a blur of splinters in one terrifying instant. And yet, the old beast floats across the dancefloor, sending wisps of cherry wood flying like ribbons of silk. All I do is pick the music, hit play, and hope that I chose wisely.

After cutting the stem hole I swap out the boring bar for this custom made O-ring grooving tool.

Once again, the depth of the tool is set with a wooden block.

The groove is cut and an O-ring is installed to test the fit. I do this test every 5 or so Toads, just to make sure everything is going smoothly. This groove can't be modified later, so it's important to get the fit right.

The moment of truth. I check to see if my holes line up... and yeah, it's pretty much perfect.

There is a step-down right at the point where the stem hole meets the heater module hole. You can clearly see the step in the photo above. This is also where the stainless steel diffuser mesh will sit.

The O-ring groove.

Much of the wood has been removed at this point, and these blocks of wood feel a whole lot lighter.

In the next issue we'll switch it up, the lathe work is getting repetitive.

Spring is here, so I'll be getting out to collect more lichens before the bugs come later this month. Perhaps I'll get working on the buttons, it'll be a nice change of pace!