Shelly Clamp 120A Din Rail Mount

There were two motivations for creating this model. One of them was a need to make my switchboard cabinet look nicer and the second one was just fun learning onShape, finding ways of efficient modeling.

The first was pretty challenging because of available space constraints. Also, I had to model the clamp first.

Obviously, I was trying to find something suitable and ready to use first, but in the end, I borrow some ideas from random projects creating my take from scratch.

The mount is made of a vertically oriented 71mm x 120mm plate, with the ability to hang and lock it onto 35mm top-hat DIN rail. The width equals the size of 4 DIN modules. 120mm is the boundary chosen for my use case (see photos).

Each Shelly clamp is fixed to the mount with pair of holders. The connection is made with the use of threaded inserts and bolts.

The plate has holes for threaded inserts making possible different positioning of clamps. Unused holes in corners might be used for mounting a cable organizer.

Note the whole project is tight on space. Especially its total height (incl clamps) exceeds one of DIN height dimensions by a few mm. In my case, it does not matter - the switchboard cabinet cover just has enough tolerance. A blindfold for the cover holes has to be modified a bit to click.

Also, there is limited space on the backside of the plate between inserts cover and the rail. It’s good to practice with a spare DIN rail prior to mounting it in the box.

Parts to print:

  1. plate x1 - printed on its front face
  2. locks x2 - printed on its front face - might require tiny fixes with a file (overhangs)
  3. holders x6 - printed as they stand - likely will require fixing the overhang square window to allow fitting all parts together
  4. organizer x1 (optional) - printed upside-down

Parts I used to compile:

  1. threaded inserts M3 x 5.5mm - 7x - insert slowly to not break covers on the bottom.
  2. bolts M3 x 6mm - 6x. The flat head is advised due to the model. I’ve used DIN7984/A2, a low-profile flat bottom head for an Allen wrench
  3. bolt M3 x 16mm. The flat head is advised due to the model but I’ve used a countersunk head successfully

Print notes:

  • Printed it on Prusa Mini standard 0.4mm nozzle, 0.20mm QUALITY preset
  • Fire retardant FRJet filament (from Filament-PM company).
  • Modeled with 0.2mm of clearance parts.

Links
Prusa Printables
Thingiverse
The holder model in onShape
120A Clamp model in Onshape

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