Oh noes! My (production) Arduboy lost a screw!

I just noticed that at some point today my Arduboy lost one of the ridiculously tiny screws that hold on the back cover.

Can someone (@bateske?) let me know the exact size/spec of this screw so I can find a replacement?


Sorry to hear : (

I had to search around for a bit, but pulling it out, it’s smaller than the gauge I have, but it’s a mm or less. I think you could match it up if you went into a hardware/electronics store. And then UNF threads is where I would look first.

Use at your own discretion :arrow_heading_down:

Yes, that’s a good idea. I have some Loctite thread lock that will definitely be applied to the other screws and this screw’s replacement, once I figure out the size.

The screw is so tiny, the challenge would be in not making a mess. Maybe dab on the tiniest bit of the low strength stuff (Loctite 222) with a toothpick?


You’d want to use loctite sparingly. We will ship you out some send me a message we can get them out to you! Let me get the exact specs of the screw and post it a little later.

I’ve got the Loctite, no need to send me any. I was thinking the same thing as @ekem, apply a tiny bit with a toothpick to avoid over-application.

I think he meant he would send you a screw : ) If you do try out the loctite, let us know how it works out, I’m curious if the purple can be kept from showing through the bottom of the nuts or not.

Hey, I never heard anything about the screw specs. My Arduboy is still missing a screw… @bateske?

hehe < 1mm and UNF. Honestly, I’d just go to a hardware store and see which fits. But @bateske could make this easy and post the specs.

When I need to find a size, I just head to the nut section and start trying to screw in the screw to nuts. Pick a non-safety nut, and if its the right size, it will thread right in. No force should be needed.

But seriously bateske, whast the official shank size and thread pitch : P

Yeah, I’d do that but my local hardware store has tiny stuff like this in individual sealed bags where you can’t really test them.

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Well I guess this thread is about screw terminology and identification for the time being.

I believe it’s an M2.5x2 countersunk head…

I’m not actually a huge fan of it, I wanted to find a panhead but supposedly they couldn’t be sourced? Or maybe it came above the surface.

Chances are arduboy will become a snap fit with a plastic back at some point, how does this make people feel? Keep in mind that would really help it be cheaper!


@bateske are you still offering replacement screws? Mine has lost 2, while sitting in a pocket! My local hardware store doesn’t seem to stock this size. I think I’ll definitely try some LocTite…

Putting a button/pan head in will really help, so will putting in a single start washer, or lock washer. One of the problems with a countersunk head on a flat surface is you don’t as much contact between the screw head and the surface face, so you dont have much friction there, and the screw will counter rotate when subjected to vibration. So just a simple panhead will be a big improvement.

Perhaps the factory could use thread lock when installing the screws?..

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Mmmm that’s something I think might be looked at, but that’s a pretty intense process to control, and would increase cost for either the person to apply the dope or build the tooling to do it. It also may not be needed if different screws get sourced.

From a maintenance and tinkerer’s perspective, I enjoy screws. They are the way to assemble panels or housing that gets opened more than once.

Most snap fits are plastic locks that require a tool or force to separate. There are two things that I always find true about plastic connections or snap-fits in general in disassembling or assembly 1) I will gouge the housing and leave a mark with the tool I’m using 2) I will break 1 or more pieces of plastic, or bend something so it’s no longer a spring.

Then out comes the drill, tap and screws.

@tastewar we can get some replacement screws for sure. They really shouldn’t be coming out but it seems like there was one worker in the factory who wasn’t tightening them down all the way?

Using liquid loctite in the factory is a real no-no. Assembly factories hate using glue or any liquid substances because they get all over things.

It might be possible to purchase the screws with the loctite already on them, I’ll look at that but it’s likely too late to do this for the kickstarter versions.

Thanks, @bateske! I agree that they shouldn’t be coming out; I can only speak from my personal experience, which is that they sometimes do :wink: . To be clear, I had not removed any screws myself, so they were in whatever state they came in from the factory. And I’ll gladly pay for the screws and/or postage, just haven’t found that size here.

How should I go about “ordering” them?

Private message me with your address information, I’ll have them sent out very soon!