Bottle Top/cap Knob

This is a cheap and easy to make knob, using just an ordinary plastic soft drink bottle top, a bolt, a nut and two washers.

It is especially suitable for projects where a bolt needs to be turned to adjust something.

I'm actually surprised that a similar instructable has not yet been published, as it seems such an obvious idea. My sincerest apologies if it has indeed previously been published and I missed it.

The picture shows all the parts necessary. Actually bigger washers would be better for a tighter grip on the bottle top.

Just drill a hole in the centre of the bottle top the size of the bolt you're going to use.

The first picture shows the order in which the parts fit together. Then just tighten the nut very tightly. A lock nut is preferable, and you can of course also add glue to help avoid slippage. I usually use an ordinary nut, and lock it by damaging the bolt's thread beforehand with a metal punch (second picture).

The first picture shows the finished knob. You can of course also use different size tops (second picture) for the appropriate torque/control you need.