Low Cost Bending Machine by Bo Walker

 
 Holstein/Walker Low Cost Side Bender

This side bender was collaboration by LINT members Steve Holstein and Bo Walker. It was inspired by the Fox bender and an innate desire to make it CHEAPER and functional. These attributes seem to appeal to most LINT members!  

Our original inspiration was Steve’s enthusiasm for immediate gratification as far as bending was concerned. His first shot at this was on one of my new guitar designs and I saw that he was really motivated to create a cheaper concept. His sides came out beautifully so I decided that I would try to refine it and write it up for LINT.                

Part A Heater Base

The bender consists of two parts which are the heater base and the mold. The heater base is easy to build, durable and cheap. Heat is provided by three 150W watt clear light bulbs. After several tests I think that using clear bulbs seems to deliver more radiant heat than frosted bulbs
The heater construction details and dimensions are available in the complete drawing pages 3 and 4.  One element to highlight is the sliding lamp assembly.    

The bulbs are wired in a parallel circuit which when assembled resembles a train with cars. The bulbs can then slide into any one of three ndividual dados which allows for height adjustment relative to the mold being used.

Parts List

Item Price Total
1 ea  light switch (20A,110VAC) 2.72 $2.72
3 ea ceramic light sockets 1.23 $3.69
1 ea switch cover 0.47 $0.47
1 ea 15ft.two conductor extension cord 2.25 $2.25
2 ea wire cap nuts 0.5 $0.50
12 ea #8x1" cood screws 0.83 $0.83
2 ea draw latches (National n208-561) 1.53 $3.07
3ea 150W clear light bulbs 1.88 $5.64
1ez 2'x2'x 5/8" particle board 2.97 $2.97
8 ea #8x1" tapping screws 0.83 $0.83
Grand Total   $22.97

A countdown timer switch as used for bathroom ceiling mounted heaters could be adapted for setting various heating cycles. We found that 20 minutes was a required heat up time before loading the wet wood. That was followed by a 20 minutes bending time and a 1 hour cool down period before removing the sides to an assembly mold. It worked great! No cupping and no scorching.


MODIFICATIONS IMPROVEMENTS
We even thought to use a three way bulb and sockets so the heat would be adjustable from 100-300 watts. In this way each type of wood could be controlled individually….but it added cost….maybe a later improvement.

PART B - THE MOLD


Each mold is individually customized using particle board and ∏” aluminum rod. The total cost for ours was about $17. The only instruction we could offer is:

  1. Space the rods around the mold pattern at 2” intervals.
  2. Adapt each mold so that it clamps as shown in the first photo. This way one heater accepts all body shapes.

It could also be cheap enough to dedicate a bender to each instrument shape and even trade them around within LINT….but that sounds like a commune doesn’t it?