Making a gear knob - how to insert a button?

[I_wanna_Shed]

Hi,

A colleague at work is trading me some Huon Pine in return for a turned gear knob for his car (its a Smart car, which he has converted to 100% electric drive by himself).

I've attached a very simple overview of the gear knob (outside diameter is between 30-40mm). The tricky bit is that there is a micro switch on one side of the metal shaft, so we need a button to be able to press this micro switch.

My thinking has come to drilling a hole through the side of the gear knob to align with the switch, but how do I make up some sort of spring loaded contraption which also stops the button (made from turned down timber?) from popping straight out?

I'll measure the switch travel tomorrow, but it looks to be about 3 or 4mm.

EDIT: the button just needs to push in momentarily and then return back out, it is not like a light switch where it has remain on/in.

426296

Thanks for all of your help!!

Nathan.

[BobL]

What about something like this?

426301

I was going to suggest making the pieces yourself but given you are not going to have a whole lot of room, maybe take a closer look as some pen kits and you might be able to adapt the click end and spring from a kit.

[MandJ]

Just a random thought in case side fitting throws up a problem, since he modified the vehicle, I'm assuming that he fitted that switch, so just putting it out there but, if a button (press insert) operated from the top of the knob is easier then he might be able to change the position of the switch in the shaft to allow for that.

[Skew ChiDAMN!!]

How fiddly d'you wanna get?

Something like this should work...

426315

...with a steel pin inserted vertically in the knob as a retainer, passing through a slot in the button. A spring can be added in the slot in the button, pressing against the steel pin. Installation of such a spring would be fiddly, but there are quite a few ways to accomplish this.

After everything's assembled a small timber plug can be inserted to conceal the end of the steel pin. (Also, if the pin's a loose fit, this plug would help to prevent it from dropping out. ;) )

[dubrosa22]

Can the button be tapered so it cannot fall out?