My 7″ grinder, that I bought so long ago I can’t remember when, had the trigger switch fail on it yesterday. What I learned is, that the design of the trigger switch has changed, and no matter where I go on the internet, the switch I need no longer exists.

So now I have to buy a new *!#$%&@# grinder.

Not that anyone is probably over concerned what I need a grinder for, but I’m attempting to build a winch to haul my shell sacks off the bottom of the river, up into the boat. The design is based on the capstan I used many years ago as a deckhand on a towboat. I picked up a cheapie 3hp engine, bought a capstan drum off of EBay, and also got a shaft adapter made, to make a 5/8″ shaft on the engine accomodate a 1″ bore on the capstan drum.

I’ve already custom built the base, to bolt on to the front deck of my boat. The boom arm is almost done, I still have to mount a pulley I made from a hand truck wheel rim, to the outer end of the boom, and install the motor, with its new capstan drum, at the boom riser.

For anyone wondering, what the bejeezus is a capstan? A capstan is made with a cylindrical drum, tapered at both ends. This taper allows a rope to feed onto the capstan without fouling. With the drum powered by a motor, you wind a rope around the drum which will generate a pulling force. The relationship between the capstan and the rope is interesting. The more winds of rope you wrap around the drum, the harder it pulls, but how hard it pulls also relies on the person manning the capstan, you have to supply some pull yourself to make the rope cinch up on the capstan, for the rope to gain enough traction to pull.

In a sense it’s a clutched rope pulling device, that uses the pressure of the operator to act as the clutch. With some winds on the capstan, but no pull from the operator, the capstan will turn, but not effectively engage in its work. The number of winds around the capstan will dictate how hard it pulls, when the operator engages a pulling force on their end.

I still do not know if this will work. I will know when it’s time to test it, and prove, or disprove, the concept. I tried this once already, but I went with 12V DC instead of an IC engine. My first attempt to lift my weight belt harness of 45 lb went like this. The rope pulled tight, started to lift, and promptly blew an 80 amp fuse. Thus ending the experiment and demanding another attack angle.

I’m hard headed enough to make it work, one way or another.

Success is often measured in your failures. Which makes me a pretty successful guy 😉

P.S. I’m fairly sure the reason the fuse popped is, I did not have a strong enough electric motor. After researching electric motors, price/weight (last thing you want in a boat is dead weight,) I found that the IC engine weighs about the same as a powerful electric motor, and it actually costs less. So, here we go.

I’m bound to learn something else before this is done…