Boyd Guitar Works - Thickness Sander
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Thickness Sander

 

A useful tool for guitar building is a thickness sander.  
This is used to thin the sides and back  pieces to the required uniform thickness.
Commercial models are available, but I decided to build one as a temporary solution and now I use this on all my guitars.

The thickness sander has a motor driven "drum" that is covered with sandpaper.  Below the drum is a height-adjustable
table that can be raised or lowered to sand different thickness of wood.  The main use is sanding thin pieces like guitar sides
that are one-tenth of an inch thick.  But you can also use this tool to sand solid guitar bodies and other pieces. It works
great for sanding wood bindings.

Two bearing units hold the shaft that is inside the sanding drum. These are known as pillow block bearings.

A pully wheel connected to a motor provides the rotation.

The bottom of the drum should move toward the operator, and the wood is pushed into the turning drum.


If you want to build this tool, please take look at my version and modify as needed it to work for you.  




Here is a little trick to make a single piece of 2 foot square plywood create the two sides of the tool:

 


Details:

  • Sides cut from one piece of 2' x 2' 3/4" plywood
  • Bottom is 3/4” plywood.
  • Cross braces are 1 x 4 pine.
  • Assembly is done with glue and screws, pre-drilling as you go.
  • Pillow block bearings are from e-bay (about $20 with shipping)
  • Motor is from $40 1/2 horsepower bench grinder  (1/2 inch shaft)
  • Sanding drum is about 10 "donuts" cut from cedar 2 x 4 with 3.5" hole saw. Stacked and glued on 1/2" steel
    shaft.  Use wood filler to fill in any gaps, this drum will be sanded perfectly round after final assembly.
  • Sanding table is particle board shelving material (doubled for stiffness) hinged at back cross brace
    and height is adjusted via 1/4" bolt that is mounted on front cross brace with T-nut.
  • The sanding drum is not perfectly round to start.  The sanding drum is "trued" using sandpaper
    covered board to very slowly sand down the high spots. Seal with lacquer.
  • Afterward the sanding drum is round, adhesive backed sandpaper is applied to sanding drum and wood to be thickness sanded
    is gradually sanded to desired thickness.
  • The machine had a lot of vibration that was traced to the motor mount; I now use the weight of the
    motor to create most of the belt tension.  The motor is mounted to a small board that is held in place
    by two bolts with wing-nuts to adjust final tension.
  • Motor RPM 3500, pulley ratio 2.5, shaft RPM 1400.  Drum diameter is 3.5" so the sanding surface is
    about 21 feet per second.

I created a 0.035" thick piece of mahogany on the first trial run. The dust collection system is in progress...

Many thanks to the great folks at the MIMF for their ideas.  (www.mimf.com)









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