Tips for these type of mounting holes

Other Hardware General Electronics
1

So I'm not sure if this is a common occurrence in pcbs or maybe in very small scale pcbs, or if ones I'm showing are just more budget level of design.

Can anybody help me with feedback on my two possible ways provided in terms of it being a extreme No-No that I'm not aware of because of a beginner state.

Also if anyone can explain why it would be a No-No or if it actually is fine to do, as well as any other suggestions on being able to secure these types of through holes without resorting to an absolute permanent adjustment such as glueing the entire board or some other permanent method.

This is a picture is showing the mounting holes that have metal inserts that are unthreaded

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This one looks to have 4 mounting holes, but tge inner 2 are clearly merged with an other component.

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The two bolts in the picture beside the boards I am able to very carefully line up and slowly turn it in and it creates a snug tight fit and I'm able to carefully unscrew it and there seems to be a slight formation of the threads allowing me to put it back in a little bit more smoothly.

Is it okay to do this with the metal through hole mounting spots? If I was to use isopropylene and a air duster to gently blow away any metal flakes that may have come off?

An alternative to doing it this way is my idea of this:

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Taking a breadboard that's meant for actual soldering and then cutting out a little chunk on the edge such as where I marked so that I can solder this junk to the pins on the component with having a little hole drilled out in the mark spot prior to the soldering that is providing ample room for washers and bolt heads.
Then on the other side I could take these male breadboard jumper pins and cut the wire off a quarter of an inch or so away and then solder it to the pin on the bottom and crazy glue the three jumper bodies together to replace the perfectly aligned three horizontal pins that can go into a breadboard or controller directly.
I don't consider this to be an extreme permanent method as I've used solderwick on much more complex Corrections so I feel at a beginner level this is an easy method of being able to return to default if needed.

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Mounting holes like this that are not manufactured with an included metal insert and are like the previous or even worse leaving you absolutely no clearance for a washer or head.
Without resulting to a 3D printed custom enclosure what could I do to make use of this Mounting hole that will allow me to use it with a better supporting method then just having a nipple that will not hold it in place if it tips upside down.
This hole is on an UNO R3 compatible clone model that I picked up for ease of mind allow me to not shortout the proper boards that cost quite a bit more which came as the controller in some of the kits.

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And finally some of the modules like this only have a single hole somewhere that is quite large and gives off the feeling it is a functional aspect of the board and not meant for shoving a bolt through, is that correct or is this actually a mounting hole?

I know 3D printing an enclosure designed for this specific component is probably what most people are going to generally recommend, but I just don't have access to a 3D printer to make something for this scale because of minimum print costs required and the amount of time it would take to 3D model the enclosure of such a case when I have at least 28 different little boards like this that all have similar holes for diameter but zero consistency in the spacing and Alignment between the various holes and location from the edges.

Any other suggestions on mounting this type of very small scale piece please try to keep a concept that you can undo without damaging the board at a beginner level, as I'm trying to make these pieces still work on a breadboard but also conveniently able to fasten on to some kind of a rail or Surface.

Thank you very much for your time to read this.

2

I'm using nylon screws, bolts, washer with stand-off

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Adafruit sells those for example

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3

You don't want to mess with the metal inside a through hole. It often serves as an electrical connection between front and back board layer.

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4

But this still does not address the requirement that I show a few examples of using a washer/head that secures the PCB from both sides of the hole being the issue as this will to some degree cause the bolt to want to not go through the hole at the proper orientation when tightened because there is a interference that the lip of the fastener is being interfered with.

So I am seeking approaches that I do not have to be careful of or roll the dice on when I am squishing/nudging some of the solder or edge of component.

I thought I had mentioned that I was seeking a either confirmation that my two proposed methods are fine. Or other approaches that will not cause the actual nearby elements from being at risk from the most convenient approach of believing that squishing the solder or side of a component with the overlapping fastener head is a thing you just don't have to be concerned on

5

So the last picture I showed where it only has a single hole that is easily within the ability to use some kind of fastener and washer without interfering nearby stuff, if this actually is a mounting hole or if it's a needed opening in the PCB to make the circuit work?

6

Get a 3D printer, and print whatever bracketry and mounts you need.

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Assortment boxes of spacers have lots of pieces you don't need, driving the per unit cost of the few you do use, thru the roof.

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3D printing solves a host of mounting issues:

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Note the insulating red fiber washers under the screw heads.

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7

The most common approach is to use threaded standoffs and screws/nuts.

8

I do my prototypes either on PWB (Printed Wire Board) or plywood painted white (White looks nice). I have an assortment of small machine screws such as #2,#4 etc and also similar in sheet metal such as 2/56, 4/40 etc. I normally get them in pan head with never a problem mounting the Arduino modules. I use stainless steel as it is not expensive when purchased from bolt depot.com. Quality has never been an issue with them it is always first quality. Shipping is not normally free but reasonable.

On PWB I mount with machine screws and standoff's. I then remove the components, tap the holes and place ss screws in them. I then place brass nuts on the back side threaded onto the screws and solder in place. It makes a very solid prototype. Again I paint it white just before assembly.

Sorry I forget to mention when soldering I use SS screws so they can be removed as solder does not stick to them. I can double nut if I want, but never have.

9

As I expected and actually Express the request for this method to just be disregarded as a viable comment, yet again doesn't really offer any ideas or methods I requested help on as the two solutions provided so far are direct cases of me saying in my original post that I do not want to squish the actual circuitry between the washers and I have also don't have convenient or economical access to a 3D printer.

Edit, sorry gils, your message shows ahead of this one but was not there when i started typing this.

10

So when tapping the way you do is this not a conflicting method to the above comment on how the reduction of the through hole shaft may affect current traveling from one side of the board to the other?

11

For what standoffs and mounts cost, its economical to buy a sub $300 unit.
I'm a retired manufacturing engineer, I've researched your Q. This IS the best solution I've found. Else you're mounting with double stick tape, hot melt glue, or caulk.
Also, you can print meltable mounting posts so no washers, etc. are needed.

12

But do they come in Barbie Land colors?

13

Sure even glow in the dark, Oppenheimer style.

14

Cool!

15

Yeah, unfortunately not... but there's a huge potential market there...

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16

Not sure what you mean by a sub $300 unit?
Many of the mounting holes in the parts can be adequately used with a very small washer and Bolt it's basically these specific holes that tend to have a either crappy design on or Manufacturing inconsistency creating the lack of clearance ensuring a faultless use.

And one of the reasons I had mentioned 3D printing is really not desirable for me is because this file they estimate at $450 to print once at more than one of my cities walk in print shops.

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The total length and width of that entire collage of parts does not exceed 17 in by 17 in, so I really don't understand why getting this printed off to hold a fraction of my parts costs over four times more than all the parts themselves.

But since no one's yet responded on if my concept on soldering the additional mounting plate idea is fairly harmless, as well as the whole confusion about the last picture being a single larger hole that looks more like a shell the Iron Man Arc Reactor would be in as is this actually a mounting hole or not.

It seems like I'm going to have to either roll the dice and just see what happens or result in Crazy gluing the edge of the PCB to a piece of wood or double-sided taping it down, because I am seeking these more of a low to no risk Solutions that cost nearly nothing out of typical things you would buy from your Home Depot for less than the cost of a burger.
As I do not really have funds left to even order the missing Shields and Wireless type modules and other components I may have such as power supply that is just made for adreno as Plug and Play.

So that's I'm just trying to address some issues where out of all the various range of a starter kit of great quality to a bag of generic sensors from AliExpress that just showed up in a sandwich bag I am trying to store / use these in a way that does not guarantee me causing them to pop right out of the gate that's aside from a couple of make the light blink or see a temperature on a breadboard the only experience I have is unpacking the stuff from the shipping box

17

I think you missed the point of @J-M-L’ s suggestion to use the plastic nuts/standoffs. They would not create any chance of short circuits as they are non conductive. There is no need to “tap” the circuit board mounting holes as there is a nut on the other side from the threaded standoffs.

18

That's the problem. The arduino hardware ecosystem seems to be based on making things as cheaply as possible so most manufacturers cut corners whereever they can and an easy way is to make the boards as small as possible and this often makes them difficult to mount.

No mounting holes is bad enough. Mounting holes that are unusable because there is interference due to a nearby component is just insulting!

Sometimes you can drill out the holes for a larger screw, but you have to be careful that the design wasn't using that through-hole as a connector. Or that the hole isn't connected to + and that your screw will ground it to a metal case.

I have a stock of very small screws and even then I run into this problem. You can buy standoffs that will grip the board from the edges, but again, the board makers put components too close to the edge for that.

The best general purpose solution is double-sided adhesive tape.

19

If you want to use a metal screw in a hole that is too large you can use these plastic sleeves to insulate the circuit from the screw:

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They are available at places like McMaster-Carr McMaster.com

20

Yes, it is a mounting hole. The idea is that you would attach it at the perimeter of a robot chassis. The board looks much too big for a single hole, It might rotate in place.

I would say, a lot of modules seem to have mounting holes as an afterthought.

You could make your own modules using ECAD and have boards made, with any mounting arrangement you want.

Frankly, the circuits on many of those modules are less than ideal, could use updates as well...

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