Barrel Sander (M002) Wooden Slat

The inside of the barrel tumbler needs a polygon (made from wood) in order to (a) give enough “traction” to turn the contents, and (b) protect the barrel from repeated impacts.  I’m going to use Oak or Maple to do this.  Based on the width and thickness of available material, I chose a 9-sided polygon.

Here is a picture of the CAM operation prepared using Fusion 360.   I will make nine of these with just a fraction of an inch extra that I can remove on the jointer while getting a tight fit.

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Stain Dipping Machine Cable Winding Pulley

The cable winding pulley was the most complicated part of the machine due to it’s multiple set screws, flat surfaces, precise bore, and threading.  One set screw holds the pulley on the shaft.  The other set screw holds the cable firmly attached to the pulley.

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Here is a picture of the pulley mounted to the DMM Tech Servo Motor.  In the background you can see the cable go up through the top of the machine, over the free pulley, and back down to hold the main slider mechanism.

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Stain Dipper Machine – Lathe Work

In the Stain Dipper Machine, we have a top pulley which is mounted on a 10mm shaft that is seated in 10x26x8mm bearings.  In the last post on this topic, I showed the pulley holder assembly.  In this post I’ll show the pulley and the final assembly.

Here is the finished pulley, made from a 1″ long by 1.5″ diameter piece of brass.

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Here is the pulley mounted on the top of the machine.  This is a satisfying point in the project because of all the ways this could have been solved, we chose an elegant, smooth, and accurate one.  You can’t buy this specific part anywhere in the world – we designed and made it just for this purpose.

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Here is a picture of tapping the pulley for a M5 set screw.

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This is a picture after the first operation was complete.  Now we need to turn it around in the lathe, recenter it, and finish the other side.

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Here is a picture of the part in the lathe.  Notice the difference in surface finish?  The shiny area is freshly cut.  The dull area was original surface.  The semi-dull area was shiny just an hour before, but oxidization got to it that quickly.

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A view of the spinning 4-jaw chuck and quick change tool post.

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Stain Dipper Machine Top Pulley Assembly

One of the key components in the Stain Dipper Machine is the top pulley assembly.  It is crucial that it normalizes the unspooling location of the cable so it does not put lateral forces on the slider rod below.  To this end, we designed and created 3 components out of UHMW (Ultra High Molecular Weight Polyethylene).  It’s a nice plastic to work with, and super tough.  It cuts like butter but has a lot of strength too.  This is a 10mm hardened shaft with two bearings pressed into the UHMW.

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Here is a picture of the 3D model.  As you can see I haven’t trimmed the shaft yet.

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Stain Dipper Slider Guide

In my last post I had an image of one of the guides and the slider in the background.  The slider is an aluminum extrusion and the guide is 0.75″ thick Oil Filled Nylon.  Nylon is resistant to stain and other chemicals we are using as well as having a low friction coefficient.

Here is a close up of the 3D Assembly taken straight from my computer screen.

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Here is a photograph taken with my phone of the actual part that has been machined and installed.  There is something satisfying about designing something and then making it exactly (within tolerance) to the size and shape you wanted.

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Stain Dipper Parts

Here is a screenshot of some of the parts we’ve designed for the Stain Dipper.  All of the mechanical parts are in the design and correctly positioned and all the hardware has been ordered…

Here are several of the parts from Fusion 360

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Here is a servo motor mount and custom made pulley.

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Here is a small piece of Nylon used to connect a 1/16″ cable with a aluminum tube.

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Stain Dipper Upper Pulley

The Stain Dipper is taking shape one component at a time.  We have the servo controller, servo motor, brass for pulleys, bearings, blocks of UHMW Polyethylene for supports, taps, set screws, aluminum rods, shafts, an Arduino Mega, buttons, switches, power supplies, wire, and more…

Here are some views of the upper pulley system.

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