Circular Saw Emergency Stop Embiggener

thingiverse

The NVR "stop" button on my Ryobi circular saw has always been a source of frustration. It's located 300mm below the table and set back quite far, making it difficult to access with ease. The surface area is only about 15 X 10 mm, which doesn't help matters. Using the saw in normal operation was a challenge, as I often needed two or three attempts to successfully hit and depress the button. It required an extended finger to operate, which wasn't ideal. In emergency situations, it would be even more difficult, especially with fingers flying around like crazy. For some time, I've been thinking about designing a better switch. At one point, I purchased a larger aftermarket switch that could fit on the saw. However, it didn't have the necessary connections for the blade braking feature required in the UK market. The original switch works by shorting the motor when released, quickly stopping the spinning blade after power removal. I could have removed the extra wires for this feature, but I liked the rapid stopping it provided and didn't want to alter the saw's body. Instead, I installed the new switch on my router table and continued using the Ryobi's frustrating switch assembly. Today was the day I decided to take action. My design constraints were that I shouldn't have to make any irreversible changes to the saw and that the new switch had to be tough enough for various impacts, from a flat hand to a piece of two by four. Here is the result: The start button can now be easily accessed through the hole on the front or by lifting the "STOP" flap. Most of the time, the flap is the only thing you can hit without thinking about it. The new switch attaches using the original upper mounting hole with a longer bolt and is large enough to withstand abuse. It's also designed not to break in emergency situations. To fit the two parts together, I submerged both pieces in hot water, making them flexible enough for me to gently force the pins on the "STOP" flap over the hinge component where they clip into place. The rounded edges of the hinge legs were a big help with this step. One minor issue: On my saw, the last few millimeters of the flap's travel are obstructed slightly by the shape of the Ryobi body moulding. However, since the switch acts well before that point is reached, it's not really an issue. If I ever remake the flap, I'll simply add a 5 degree taper on the underside to clear the body. Other than that, it's a perfectly fine job. Happy printing!