I have a CPAP machine whose dial broke off. Was hoping to 3D print a replacement, but I don't see an obvious way to attach it. I figure finding the specification would help.

Has 3 leads on the bottom, 2 on the top (not visible), and one lead on each side.

There's some marking on the bottom, but I can't make them out.

Anyone know the part?

Switch image with board

Closeup of markings

  • \$\begingroup\$ does the black part in the middle turn? ... the two tabs on the sides are not leads ... they are part of the mounting bracket \$\endgroup\$
    – jsotola
    Commented Oct 17, 2020 at 1:19
  • \$\begingroup\$ @jsotola Yeah I figured they were more for structure. I can't get it to turn, but I also don't have much leverage on it since its circular. I should have gotten a top-down picture. \$\endgroup\$ Commented Oct 17, 2020 at 1:39
  • \$\begingroup\$ Looks like maybe a standard 9mm pot. If you have excellent soldering tools and skills it might be easier to remove it and get a replacement with a shaft. Can ya dig it? \$\endgroup\$ Commented Oct 17, 2020 at 2:03
  • 4
    \$\begingroup\$ please post a picture of the broken off piece \$\endgroup\$
    – jsotola
    Commented Oct 17, 2020 at 2:48
  • \$\begingroup\$ Check the ALPS catalogue. Replacement is probably about $1. \$\endgroup\$
    – user16324
    Commented Oct 17, 2020 at 12:25

1 Answer 1


The broken part resembles the one on the right in this picture.

enter image description here

It appears similar to this rotary encoder switch with a push switch. It's a 5 pin SMD type with three pins for the encoder and two for the push switch.

enter image description here

Quadrature pulses generated by the rotary encoder switch would be used for scrolling through the menu and the push switch for selecting an option, during set-up.


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