Internal Hardware for dual concentric knobs

[birdyguy]

Hello fellow builders,

Happy New Year to all. As winter has set in, I have resumed my NGX build. I've just completed making molds and casting knobs for overhead, mip and pedestal. I have spent countless hours googling for the hardware that sits in the internals of the dual concentric knobs and have yet to find a source. This hardware attaches each knob to the shaft independent of the other. Does anyone have or know of a source for this type of hardware?

All the Best

[John_B]

for dual concentric rotary encoders I literally drilled through the shaft of a rotary and out the bottom..them enlarged the hole a bit.
(ok you lose the push switch on that rotary)
I then use 1mm brass rod through the hole to control the back rotary..I use a perspex "adapter" which pushes into a short piece of plastic tube which in turn pushes over the shaft of the back rotary giving a flexible coupling... Drill out through the outer knob so the brass slides through I then use a piece of shaft from a rotary switch or encoder push and glue this onto the piece of brass sticking out and push the "inner" knob on

If you need a diagram I can probably knock something up

John

[birdyguy]

Thanks for your reply John. Sounds kind of complicated and not sure I have a steady enough hand to drill down through the shaft. I may just end up drilling a hole through the knobs and set screw them to the the shaft but would be really nice to find a hardware source for the inners.

[John_B]

Google "dual concentric rotary encoders" there's a few out there but a bit expensive like £17 or $39 ish

[channex511]

Hi.
This is what I do. It's pretty much what John B is describing I think.
The aluminum box section is from a spirit level bought from a pound shop.
The encoders are the really cheap ones from eBay.
Each unit costs around £3 each.

Thanks
Paul

photo 1.jpg

[Efe Cem Elci]

http://nonolight.free.fr/air_cockpit..._Nonolight.pdf

Hope this helps...

[birdyguy]

Hello fellow builders,

Thanks very much for your inputs, some of your solutions to dual encoders are very good, however I think I didn't make it clear the question that I was asking.

I'm enclosing a picture of the dual encoder knobs and their hardware.

It's the little bits that secure the knobs to the encoder shafts. that I am trying to find.

[Efe Cem Elci]

Ah... the set screws...

like shown here in black?

[John_B]

Hi Ed

The ones you are showing are "collet" type fixing. I have never seen the actual business bit sold separately !

I personally use the set screw fixing like Efe Cem Elci is showing. I have a friend that makes all Boeing knobs at a fraction of the price of the commercial items, including Concentric knobs. Here is a pic of one of the pairs he made for me for my EFIS (he does grey too) The panel itself I made though you cant really see it.

George concentric.jpg

If you are inerested I can ask him to for prices (I made panels for him in exchange )

John

[John_B]

Sorry ED
I have just re-read the original post

can you not simply dill a small hole from the outside to the central bore and screw in an allen keyed grub screw? (this what the guy that makes mine does). They grip quite nicely into the resin without having to tap a thread

John