After a very long time of struggling with the blade guard on my Bosch 3915, I bought a new saw. While I was writing the blog mentioning the common problem with the Bosch compound miter saw, I came up with a simple fix and applied it.
The blade guard on my Bosch 3915 compound miter saw sticks. The mechanism to retract the blade guard is a metal slide (actuating cam) that rides on a guide bearing. The glide path along this slide has several ‘steps’ which control the retraction of the guard as the handle is pressed downward toward the work piece. The problem happens when the bearing hits the first ‘step’ on the slide. For a while a forceful press would pass the step, raising the guard and completing the cut.
As the bearing started to fail from the extreme force it suffers from the steep angle of the first step up along the slide, I removed and replaced the bearing to no avail. Next, I removed the slide and put it on my grinder, easing the slope of the first step. I figured if it weren’t so steep it would roll better. That didn’t work.
I cut a piece of steel and screwed it onto the slide, modifying the slope into a perfectly smooth incline. This took five minutes to do and my saw is back to it’s super-smooth action!
BTW: This fix results in the blade guard resting in a “slightly” opened position (see photo) which is infinitely safer than removing or pinning back the guard. I was taught safety first and never pin back my blade guards, not even on a wormdrive while cutting rafter tails.
I am very pleased with the results of this fix. In fact, it is such an improvement I would purchase this Bosch saw new and apply this patch before I would buy a ‘yellow’ brand saw any day.