This instructable will show you how to improve an inexpensive scroll saw. This type of scroll saw typically accepts blades with pins, but comes with adapters for pinless blades, which are more commonly used. Specifically, I obtained this scroll saw from harbor freight tools, which I think is a great place for hobby tools.
Although you can purchase knobs, they are typically very expensive. For me, a #10-32 screw costs $0.09 versus a knob which costs $2.80 which I found at a local Ace Hardware store. I will show you how I made my own knobs for less.
Step 1: Original Adapter
For reference, this is the original adapter. To use pinless blades, the blade must be inserted between two adapters and tightened with a hex-wrench. When there is no tension on the blade, it does not stay on the scroll saw body and falls off, since tension holds the adapter to the scroll saw.