New support for inductive switches for PRIMO

Hi,

I have designed a new support for using inductive switches with the MPCNC PRIMO. The support was designed with the following requirements:

  • The inductive switches will be used instead of the end stoppers (in future)
  • … but mostly these switches will be used for auto-squaring (I am building a new controller unit that supports auto-squaring)
  • I wanted to design a support/mount that can be used for start/end so that every truck needs only 1 switch (although the controller unit has 16 inputs). But I did not want to have too much switches installed.

Here is Version 1.0 of the Inductive Switch Support including a couple of parts. The mount is designed for 12mm inductive switches. In my case I am using NPN NO (normally open): LJ12 A3-4-Z/BX - 6V - 36V DC.

In addition to the printed parts I have used “rivet nuts” to get high quality threads within the parts - really a cool way to do, I can only recommend!


The rivet nuts will be implemented in the parts using a soldering iron. Heating it up you can melt-in the nut :sunglasses: and you will get a nice and strong connection with the thread and the 3D-part. In my parts I am using M5 rivet nuts.

Here a small “modell” to demonstrate how it should work at the end. The ALU-rail will be mounted between the “legs” (in my case the ALU-Profil-Frame 30x30) of the PRIMO.

How the parts will be implemented in the PRIMO construction?
This is the way/idea how it should be working:


The mount for the switch will be attached in the middle of the truck in a way that the switch will be placed under the truck. On a 15x15mm Aluminium “rail” a mount and a sliding carriage (adjustable in height and moving direction of the truck) will be installed with the possibility to use a screw (metal) for the inductive signal. On the Alu-rail you can install 2 mounts/sliding carriages for start/end signal using only 1 inductive switch per truck.

  • sliding carriage has 1 nut for the “signal screw” and a slot to fix it at the rail mount (adjustable)
  • rail mount has 2 nuts, 1 to fix the sliding carriage, 1 (bottom) to fix the mount with the Alu rail
  • for my Alu-Profil Frame I have also created some holder to fix the Alu-rail at the 30x30 Frame at the ends

And so it looks in real life:



The parts are designed in a way that they are usable for both pipes (X-direction and Y-direction) even if the y-axis is mounted “over” the x-axis. The slider is long enough to support it.


The inductive switch mount can also be adjusted at the truck so it can be moved round about 1 cm back and forward. With a screw it can be fixed at the truck so that the switch doesn’t move during usage.

In this way it will be possible using a start and end signal (the Alu-rail is placed between the legs of the PRIMO)

Now I need to finish my controller unit and … :stuck_out_tongue_winking_eye: :stuck_out_tongue_winking_eye: :stuck_out_tongue_winking_eye:

In my opinion quite nice stuff! What do you think?

Ciao
DJ

PS: I have also designed a holder to attach the Alu-rail with a “normal” 25mm pipes for a standard MPCNC PRIMO.

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That’s a lot of work there, but very clean! What is the advantage over the endstops?

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From my point of view:

  • no mechanical switch
  • only 1 switch for start and end
  • more robust than these micro switches (mounted at the trucks)
  • in this way better to adjust

but of course more complex (with mount, slider, rail etc.) to implement.

I didn’t quite understand the min/max from the same switch that’s pretty cool.
And I HAVE had two switches fail on me. One, I apparently cooked while soldering, my bad, lol.
Again, nice work!

I have added a mount for the z-axis so that currently with:

  • 3 inductive switches you can control all your axis (1 for X-, 1 for Y- and 1 for Z-axis) for start- and end-stoppers. It also supports e.g. Homing in EstlCam to get stable references
  • 5 inductive switches (1 for every truck which means: 2 for X-, 2 for Y- and 1 at the core for Z-axis) you can realize the stoppers (start and end) but also autosquaring x- and y-axis :crazy_face: