Cabinet Curves

 
Rachel’s cabinet was fun to build in part because I used a technique that is new to me.

Like most furniture makers, when faced with a design for a cabinet including curved sides, I would have fabricated stiff sides that provide structural strength when joined to the front and back of the cabinet.  

 
 In this case I approached the construction more like an airplane builder or a boat builder.  This approach is described in Fine Woodworking, by Judson Beaumont, a Canadian designer/maker of intriguing, whimsical furniture. 

The front and the back of Rachel’s cabinet were shaped in two steps.  First I made a template with nicely finished edges from 1/4“plywood. Then I rough cut the front and the back from a good grade of plywood. 

 

I applied the template to the rough cut pieces and, using a router with a form following bit, made the front and back into exact replicas of the template

 


















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 The front and back were initially joined together with the struts that carry the drawer guides.  These joints were made with floating tenons (Festool Dominoes) and provide ample strength for holding the cabinet together.

The next step was to add closely spaced ribs following the curved edges of the cabinet. 

 


A thin skin of bending plywood was clamped, glued and nailed to the edges of the cabinet and the ribs. 

When the glue dried the carcase of the cabinet beautifully followed the planned contour and had wonderful structural integrity and strength.

Gumball Machine 3: The Electronics

Gumball Machine 3:  The Electronics
 

Some projects are simply more fun than others.  This secret knock gumball machine, designed by Steve Hoefer, was such a project for me.

 

Click here to see the gumball machine in action

 

 Assembly of the electronic components was not easy for me. 

The machine’s actions are controlled by a tiny microprocessor called Arduino.  The code for these operations was written by Steve Hoefer and was easily downloadable from the internet.  Not quite as easy was the assembly of the circuit containing the sound sensor, the Led lights, and the servo mechanism.

Here is the wiring diagram.  It looks simple but every wire and pin in the circuit required a solder joint.

This is what the bench looks like in the thick of soldering.  Here are some of my problems.  My hands shake.  That is addressed by using a vise and small clamps to hold things together.  The parts to be joined are small and hard to see.  That is addressed with the magnifying visor.  Soldering is a skill and I have little experience.  This, and all the other problems, are addressed by actually working at it!

Some of my solder joints: They are sloppy but they work!

The assembled circuit and the Arduino microprocessor ready to be joined.  The Piezo electric sensor is the machine’s sense organ.  The device converts an electric current into a vibration (it buzzes) but it also converts a vibration into an electric current.  So, the piezo device converts the "knock" into a series of electric pulses.  The pulses are then evaluated by the microprocessor.  If the knock is correct the microprocessor activates a servo mechanism and a gumball is released.

The electronic components are assembled and ready for testing.

Adding the electronics to the case.

Now, adding the "knock Board" with the piezo sensor attached.

Voila! Ready to dispense gumballs!

    Click here for the "back Story".

    Click  here for cabinet construction.

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