|Project by Oldtool||posted 11-11-2013 06:48 PM||1343 views||1 time favorited||6 comments|
Conventional wisdom suggests that band saws be taken out of tension when not in use for long periods of time, a philosophy to which I subscribe. However I often find myself second guessing as to whether or not I performed this function after leaving the shop, so after many trips back to check for this at all hours of the night, and one day’s visit only to find that the saw was under tension for a prior couple of days, I decided to do something about it.
Ebay purchases consisted of one (1) sewing machine flexible lamp, for about 14 dollars, and ten (10) micro-switches for about $5. The lamp was chosen because it contained a magnetic base, a flexible arm, and most importantly (to me) it is an LED lamp, which means low power consumption (0.5 W) – yet still pretty bright.
The micro-switch selected was chosen for the flexible activation arm with a roller on the end, and a much higher power rating than I need at: 15 Amp / 1/2 HP at 125 & 250 Volts.
Mounting the switch on a scrap piece of plywood cut to fit the tensioning arm of my bandsaw, along with two H-F rare earth magnets on the other side, as shown in the photos, I opened & wired one of the lamp’s power wires through the switch.
The mounting of the switch as shown allows tripping when the upper wheel mounting assembly rises up when tensioned, and with the assembly held in place by the magnets thus making it adjustable for different blade tensions / mounting heights. In this case though, adjustment for a 1/4” blade at a lower setting works for the 1/2” blades as well, due to the flex in the switch arm and roller.
I leave the lamp plugged in at all times, with the lamp base switch always on, so the lamp only powers on when the saw is under tension, is used as a work lamp, and can only go off when the tension is relieved. Now when I turn out the shop lights, if these is a glow at the saw, tension release is needed.
My only problem now, what to do with the other 9 switches. Got to work on this, any suggestions?
-- "I am a firm believer in the people. If given the truth, they can be depended upon to meet any national crisis. The point is to bring them the real facts." - Abraham Lincoln