Jigsaw blades tend to blunt very quickly when used on MDF or other composition boards, but the wear only occurs over a very limited part of the blade. If a saw with a total stroke of 20mm is used to cut 12mm board, only 32mm of blade is used. The worn section is 10mm upwards from the sole plate and 22mm downwards, and the remainder of the blade, maybe 80 or 90 mm, is unused and unusable.
There are a couple of ad hoc ways around this. One is to grind off the top inch or so of blade so that it fits deeper into the chuck; this works OK on my old Black and Decker, but is not viable if the chuck requires a particular profile on the blade head. Another is to fix spacers onto the sole plate so that the saw rides higher, and a lower section of blade is thus presented to the workpiece.
The manufacturer could implement this second solution by making the height of the sole plate adjustable.
-- angel, Jan 24 2005

Do you know whether or not the cutting would be as true if the cutting zone of the blade is moved--as the cut zone is moved further from the attach point of the blade?
-- bristolz, Jan 24 2005


The cutting zone would be just about as accurate as long as a roller guide were attached to the sole plate. The present roller couldn't adjust with the sole plate since it usually seconds in the orbital function (mechanically linked to the motor). With a fixed guide on the sole plate you wouldn't be able to use the orbital action. (most jigsaws nowadays that use the quick release T-shank blades have orbital strokes, but you can set them to zero). You'd also have trouble designing a plate mounted guide that aligned with the blade for pivoted cuts. This is all too much trouble. I really like the new saws. Lot quieter, stronger, more accurate. When the blade gets worn, grind the top inch off and mount it in your old Black and Decker.
-- JungFrankenstein, Jan 24 2005


I'm waiting for someone to market a little hand-held water-jet.
-- JungFrankenstein, Jan 25 2005



random, halfbakery