Jogwheels are nothing more than rotary encoders.
The only tricky party to the jogwheels is mounting them.You have to mount them to the underside of the top panel otherwise the lip/nut interferes when you try to spin them.
I found the best way to mount the jogwheels is by soldering the encoder to a mini PCB, then using the mounting holes on the PCB to secure the PCB/encoder to the top panel (see images). I cut out the hole in the top panel to be almost exactly the same diameter (6mm) as the shaft of the encoder. The cutout on the platter is a 'D' shape to match that of the encoder. Clearly, you could do a better job mounting these by using a standoff.
Use felt feet on the underside of the platter to reduce friction. MK1
used a similar design for the wooden jog wheels. They worked a bit better. The weight and the grip (added by the polyurethane) made them easier to spin, almost effortless.
If you want the most superior and responsive platter you have a number of options.
- Build the recommended noise filter and install it on the underside of the proto-board.
- Use more expensive mechanical encoders.
- Upgrade to a super fancy optical encoder
I feel the recommended Bourns encoders paired with the noise filters give extremely good response, but I am no scratch DJ!