How would others design a housing for something?

[m_c]

I've got a PCB designed for connecting a touch probe/tool setter in my little CNC mill, and it's not really something I've done before.

This what the final assembly should roughly look like -


I'll call the front, the side that the jacks will mount through.
Ideally I want the PCB to be held by the front jack threads/nuts, with the rear sat on a couple supports at the corners, with possibly a latch in the centre, just to provide a little bit more security.
My plan is roughly -
Draw the front face with a flat front panel, with a slot/recess for the front PCB edge to locate in.
Add the holes for mounting the jacks.
Create the bottom, with the rear supports.
Then create the remaining three sides, followed by deciding how I'm going to handle the top (there'll also be three 3mm LEDs, but I've not added a 3D model for them yet)

I'm just wondering how others would create such a part, that involves being quite tightly modelled around a pre-existing part.

 

[julianf]

I'd buy one of those little diecast boxes and get my drill on it.

But I don't have a 3d printer, so I realize other people would do it all in house.

 

[8ob]

@sako243 is into this witchcraft.

Bob

 

[sako243]

I wouldn't bother with a 3d printed housing if it's just a generic box. Buy one that'll fit it, quite often the manufacturer will have 3d files for you to put things in.

You can then cut holes through the sides and use those for generating 1:1 drawings as drill templates for the various sides.

If you're bolting the front on then I'd just shove a couple of M3 holes in the back corners and use some wee standoffs to hold them down. Can do the same at the front if you so wish. Far simpler than faffing with clips.

When I'm down in the office tomorrow I'll grab a snapshot of one such PCB and the case I'm mounting it into.

 

[m_c]

This is where I'm at


I'll probably thicken up the front for a bit extra strength, and I'll need to make it longer to allow enough room to get screws in the corners, while still being able to get the PCB in to position.

In hindsight, I should have just designed it around a suitable enclosure, but where's the fun in that?

 

[Misterg]

If that's to scale (I assume it is! ), I really don't think you'd need anything other than the two jack sockets to support that PCB adequately. If you think the back of the PCB still needs support, add a couple of pillars on the base that you can fit screws into and provide appropriate holes in the PCB.

I went metal with mine, but your electrics look neater (my probe doesn't have an LED, so there's one on the box):

 

[m_c]

I have somewhat over complicated this PCB.

It has two connection probes.
It accepts 24V, and will switch 24V, but only sends 5V to the probes.
It also has a jumper selectable circuit, that will send a signal if a probe is plugged in (so it can be used as an interlock to avoid the spindle being switched on with a probe inserted).

 

[Kram]

If your designing the pcb I would add some screw mounting holes and fix it with standoffs onto alu sheet which can then be mounted any way you like without any mechanical stress on the pcb. if the pcb is fully supported by the jacks then at some point the solder joints might recieve stress and fail, depending how well the rest fits together.

The sheet can have securing tabs off each side. It may be that a 5 sided lid can screw onto the tabs to complete a box.. or a pair of 3 sided halfs, much like a computer power supply is often made.

Look at how commercial products are enclosed, its usually done for cheapness and reliability.


Does the enclosure need to be sealed if its any where near cnc/coolant?

 

[Screwdriver]

I've got a PCB designed for connecting a touch probe/tool setter in my little CNC mill, and it's not really something I've done before.

This what the final assembly should roughly look like -
View attachment 428947

I'll call the front, the side that the jacks will mount through.
Ideally I want the PCB to be held by the front jack threads/nuts, with the rear sat on a couple supports at the corners, with possibly a latch in the centre, just to provide a little bit more security.
My plan is roughly -
Draw the front face with a flat front panel, with a slot/recess for the front PCB edge to locate in.
Add the holes for mounting the jacks.
Create the bottom, with the rear supports.
Then create the remaining three sides, followed by deciding how I'm going to handle the top (there'll also be three 3mm LEDs, but I've not added a 3D model for them yet)

I'm just wondering how others would create such a part, that involves being quite tightly modelled around a pre-existing part.

First thing I would do is decide exactly where I want to put it.

Then I'd stick up a photo of that location and ask what sort of case could be created to suit.

 

[Wedg1e]

I put together a Raspberry Pi-based microcontroller for an industrial x-ray system (though it could be used for other things of course)... started off by 3D modelling the Pi and the accessory modules plugged into it and then created the box around it - the boards slide in and screw-on end plates keep everything in place:

The green terminals are connections to a digital inputs card and a relay output card. I then realised it need an Arduino board to read an analogue input that the Pi couldn't handle, so created a piggy-back frame to support that as well:

I even modelled (roughly) the 5V fan to make sure the duct size, mounting boss locations etc. were right. Got to love 3D CAD

 

[Agroshield]

This is where I'm at...

I hope this is not inappropriate, but have you confirmed that the board will enter the box? If it needed to be removed from the drawing as shown, it has to lift up a little at the back and then slide backwards so the threaded bosses are clear of the holes.

If the holes are circular and tight around the bosses, it will not tilt - but that is the beauty of a 3DP - you can make the holes elliptical (taller vertically than horizontally) so it will tilt, but still be tight in the horizontal direction.

You also have to consider the board's overall length when tilted to a slight angle - that will be slightly bigger than its overall length when horizontal.

The slot at the front of the case is perhaps unnecessary. If the board projects more than the face of the boss, just thicken the inside of the front wall locally around the boss (same effect as putting a thin washer on the boss before you poke it through the hole).

Fillet all your internal corners as they are stress risers.

 

[m_c]

I hope this is not inappropriate, but have you confirmed that the board will enter the box? If it needed to be removed from the drawing as shown, it has to lift up a little at the back and then slide backwards so the threaded bosses are clear of the holes.

I realised that when I added the rear side. Good thing about 3D modelling, is I just measured the distances involved, and added an extra mm clearance