Alright, so I'm planning to get some custom wood handles and knobs made for my Europiccola (planning to go with recycled skateboards, should be neat), and I'm thinking about the steam knob. Would live insight or warnings from anyone who has done similar!

On the mechanical side:

• It's a 2008 model, so the knob is secured with a roller pin, not a grub screw, good.
• My current idea is to tap the existing hole in the rod - sounds like folks have had success with an M4 tap.
• On the new wooden knob, instead of drilling straight through side to side like the OEM knob, only drill through the backside (probably slightly undersized).
• Counterbore the backside hole.
• Use a socket head M4 to pass through the knob, and thread directly into the rod.
• Should be plenty secure to hold the knob, and with the screw countersunk, should be fairly clean from the rear, and not at all visible from the front.

On the knob design, I'm planning to go with a lever (I have a few Campagnolo levers in mind that I'm deciding between), mounted into a wooden base. Have not got around to figuring out either the wooden base shape or mounting mechanism for the lever (since each lever would need a different method).

Also also, thinking about the shape of the boiler cap, lever handle, portafilter handle, tamper handle.... and maybe some other accents. Once I get further along with that, maybe I'll rename the thread or spin that off elsewhere.

Anyway, does my steam knob fitment make sense? I can do up a little schematic as well if needed.

I have used the screws to set into the shaft existing hole and stops the rotation of the knob. I have not drilled a new hole into the steam knob, into the rod may give more strength, i have also done set screws from both sides.

Quick and dirty mockup! Will have an actual woodworker make the final version.

Cassette for the boiler top knob?

Would give good grip, but maaaaaybe a little tough on the hands I am trying to figure out what boiler cap shape I want though - getting a full wood knob/lever set done.

I did see someone with Oury grips for portafilter and lever handles the other day (not what I'm after, though).

If you're doing the shifter, then maybe a front hub shape.

Oh, that would be a lot of fun. I could see a rear high-flange or sheriff star hub for the boiler cap too... Unfortunately I think that's all getting into a realm of tools/resources I won't have access to.