PCB interlocking right angle designs?

I am trying to create a project where I would like to interlock one PCB into another 90 degrees. I don’t want to use those special right angle connectors or any PTH ones either. Just to make a cutout in one PCB to insert another into. See attached screenshot.

I’m assuming that fabs have limitations on internal cutouts. Such as not being able to make internal sharp corners, yes? If so, what are some clever ways to do this so that the mating PCB can be perfectly positioned without wobble? (assuming tolerance is perfect). Any examples out there?

Why don't you just put fastener through holes and mount the vertical PCB with right-angle metal brackets ?

Brackets are not connectors. "L" brackets are used all the time. You simply need to add fastener feedthrough holes in both PCBs.

It's not rocket science.

Yeah, you generally can’t get right angles on cutouts.

Either use brackets, or make a jig to ensure proper alignment during assembly (before you solder it in place). The tolerances, at least from cheap board houses that hobbyists usually end up using, are not tight enough that you can rely on the board design to ensure that there isn’t wobble (for one thing, the thickness of the board is not constant - when I did this, I found that inserts from one panel were very tight in the same holes where ones from another panel were not). Make sure that you don’t have any traces/copper overlapping with the milling cuts - one board house I work with will just omit any milling cuts that do that, without contacting me. Didn’t find out until they arrived. I suspect others will object to that (though most, I think, would contact the customer about that!)

I just use extruded aluminum:

I'm trying to avoid brackets that they make for these N20 motors because I don't have space and it requires extra fastening hardware. Already explored that option. But are there any examples where people have done it this way before?

shai:
I'm trying to avoid brackets that they make for these N20 motors because I don't have space and it requires extra fastening hardware. Already explored that option. But are there any examples where people have done it this way before?

So you want to support the motor gearbox on a PCB?
What ever you do to connect 2 PCBs at right angles, you are going to have to provide extra gussets.
If its mounted with a motor then you have vibration as well.
How big are the PCBs?
As you only have a CAD drawing, I'd say you haven't ventured into the real world and experimented.
Get your hands dirty and try some of the solutions.
Tom.. :slight_smile:

I think you are thinking that because that's your objective that it is possible, like one has anything to do with the other. (these kind of oversights actually are not uncommon in the real world)

You obviously did not start this post from the normal engineering starting point.
You did not start this post by simply asking the question:

"Is it feasible to mount a gearbox motor 90 degrees to another PCB using cutouts"

Just to make a cutout in one PCB to insert another into. See attached screenshot.

Did you provide any motor load or torque data ?

Is this not relevant ? Is mounting a motor the same as mounting a vertical PCB ?

If so, what are some clever ways to do this so that the mating PCB can be perfectly positioned without wobble? (assuming tolerance is perfect). Any examples out there?

If you laser cut the hole in the pcb before stuffing and epoxy the vertical pcb before mounting the motor,
it might hold, but without any info on the motor it's hard to say.

You can solder a few thick stiff bare wires to both boards, and then bend the wire to 90 degrees. You probably need something like 2.5mm2 (which you can strip out of some electrical cable).

So, lay two boards end to end. Solder the straight wires to each board. Carefully bend to 90 degrees.
For rigidity I would cut a couple of small square pieces of board, and glue them in to help brace the corner.

I've seen the wire thingy done a fair few times in old machines that I have stripped for salvage.

Or make use of pin headers.
Solder some pin headers (female to one board). Solder some bent 90 degree pins to the other board.
Apply super glue to the pins and fit together.
You can buy the headers and bent pins anywhere.

Other than that, start thinking out of the box and come up with an idea or method that works for you with the resources and knowledge you have. Be inventive!

Steve

This entry at stackexchange has an interesting approach using plated through holes and a toothed edge to the
other pcb: pcb - OK to connect boards perpendicularly like this? - Electrical Engineering Stack Exchange

You can use an idea similar to this.

See post #15

Solder double sided PCB to the mother board as I did here.

Nice !

MarkT:
This entry at stackexchange has an interesting approach using plated through holes and a toothed edge to the
other pcb: pcb - OK to connect boards perpendicularly like this? - Electrical Engineering Stack Exchange

Thanks! This is pretty close to what I was looking for! However, I was hoping to not solder as that requires more manual labor. I'm counting pennies here :slight_smile:

See what I came up with. I did a bit of an extra half circle cutout to remove any sharp edges that wouldn't be able to manufacture because routers always leave a bit of a radius. This way the PCBs butt up against each other face to face. I added 0.10 mm tolerance on all sides. This small 1.6mm PCB is sandwiched between two 2mm PCBs using standoffs in between with M1.6 screws. What do you all think?

“I was hoping to not solder as that requires more manual labor.”
“I'm counting pennies here ”
“See what I came up with.”
“What do you all think?”

“I added 0.10 mm tolerance on all sides.”

Haha sounds like you have very little (or no) experience in manufacturing anything.
Spend some time at training yourself how to properly use tools, then you will have an idea on what’s possible.
Read up on torque.

This thread is approaching a big waste of volunteers time.

Thanks! This is pretty close to what I was looking for! However, I was hoping to not solder as that requires more manual labor. I'm counting pennies here :slight_smile:

Maybe if you wait long enough they will invent a machine that will do it all for you!

Steve