I have a Jet 1236 lathe. Like many lathes, it has a master power switch in an awkward and unsafe location. If you have a problem, the switch is on the opposite side of the “kill zone” from the normal operating position. It is dangerous to access (you literally have to put your face down by the action area) and too far away and to awkward to operate for safety or quick reaction. A quick-action safety switch on the right-hand (tail stock) side of the lathe is highly desirable. There are many ways to do this. Here is the method I chose.
Note: The Jet 1236 turning speeds are manually adjusted, incrementally, with a lever. This is not a Variable Speed lathe. I do not know if this suggestion would work safely with a VS lathe with its electronic control package. Do not implement this suggestion without first consulting with the manufacturer to make sure that interrupting the power at the power line will not damage your lathe. Additionally, this is a 115VAC system. I would not recommend it for a 220VAC lathe.
I have implemented a safety switch for a total price of around $10 and an hour of work. See image. I purchased a simple, non-regulated power strip at a hardware store, glued a couple of 0.5” rare-earth magnets on to the side (available from many catalogs), and glued a slim metal rod (flat end, bent) to the on/off switch. I covered the end of the rod with a black plastic sleeve – red would be better. I mount this switch on the back side of the lathe somewhere on the tail-stock end. It is set up so that “off” is a push away from the body, toward the back. (You can whack it with the back of your hand holding the hand tool you are using.) Just plug the lathe into the power strip and plug the power strip into your power source. I put masking tape over the unused plug holes to keep dust and shavings out. Depending on what you are doing, you can move the strip to an appropriate location. The magnets hold it on firmly, but it is easy to move when desired. [Close observation of the photo will show it glued to the side of the lathe at that time. It is not good to have it stuck (literally) in one location. There is no one optimum location. Use the magnets.]
I sometimes use this switch instead of the main power switch because it is so handy, but that is dangerous. It might be possible to accidentally turn on the lathe unexpectedly. I strongly recommend that if you use the safety switch as an “off” for convenience, that you also then turn off the main power switch for safety.
I find that some power strips have a very weak switch, and the weight of the rod makes it very sensitive. You can adjust this with the length of the rod and it’s vertical angle. I have not had any problem with unexpected stoppage. Because this is a safety switch for accidents, it is better that it be on the sensitive side rather than hard to push. Another note: if you hit it hard, as you might during an exciting time, it could bounce back on. Plan ahead for this and practice an emergency to get a feeling for how your individual installation behaves and what hand motion you need to use to ensure that it stays off.
For an alternative auxiliary electrical switch for the Jet 1236, click this Wood Central forum link.
I have found this to be an extremely useful and user-friendly addition to my lathe. It is very handy if you are doing hollowing and need to turn the lathe on and off frequently from the tail-stock side. I highly recommend it to anyone who has an appropriate lathe that would benefit from its application.