Case screws

[LinuxJedi]

Hi,

My Atom did not come with the two screws to hold the top and bottom parts together. Anyone know what they should be in terms of length and thread?

[baz4096]

4.11 x 39mm according to this post: viewtopic.php?p=317054#p317054

However the Atom Reference Manual states two short and two long screw, so perhaps measure how deep each hole is and select your screw length accordingly.

[LinuxJedi]

4.11 x 39mm according to this post: viewtopic.php?p=317054#p317054

However the Atom Reference Manual states two short and two long screw, so perhaps measure how deep each hole is and select your screw length accordingly.

Ah, many thanks, I couldn't find that thread when searching.

It should say four short and two long (it does in the technical reference manual anyway). The four short are to hold the motherboard top shell, the two long hold the two halves together, those are the two missing. I probably could have figured out an appropriate length, but as with that other post, mine were never fitted, so I didn't know the intended thread.

[baz4096]

It should say four short and two long (it does in the technical reference manual anyway).

Sorry, it was late when I posted, I should have double checked my wording… hopefully it was of some use.

[LinuxJedi]

Sorry, it was late when I posted, I should have double checked my wording… hopefully it was of some use.

No worries, definitely helpful. It does appear to be between somewhere M4 and M5 in thread width, and I think somewhere between 2.5cm and 5cm in length. I'll pop to a DIY shop later to see what I can find.

Thanks again!

[baz4096]

I think 11 gauge is around 3mm. Worth buying a few around 3-5mm and gently testing smallest first before committing. Hopefully someone who has an Atom can give a more definitive answer before you go out

[LinuxJedi]

For those playing along at home, these are what I found worked perfectly. Although the countersunk head isn't ideal (the hole is wide enough that it doesn't matter) the width and length is perfect. I also tried 4.2mm threads (imperial size 8 ) and they wouldn't grip.

[1024MAK]

IIRC, they are what is commonly called “pan head self tapping” and are sized as “No.X gauge) where X is a serial number (typically No.4, No.6, No.8 and No.10 are relatively common).

In general, they are available from various suppliers in various different lengths.

Mark

[LinuxJedi]

IIRC, they are what is commonly called “pan head self tapping” and are sized as “No.X gauge) where X is a serial number (typically No.4, No.6, No.8 and No.10 are relatively common).

In general, they are available from various suppliers in various different lengths.

Mark

Correct, they are. The gauge is imperial measurement, many manufacturers today align to the nearest metric width instead, even when they use the old gauge on packaging. This sits somewhere between an 8 and a 10 on the imperial system (sometimes you can get No.9, the ones I used would be a 9 in the old system).

[baz4096]

IIRC, they are what is commonly called “pan head self tapping” and are sized as “No.X gauge) where X is a serial number (typically No.4, No.6, No.8 and No.10 are relatively common).

In general, they are available from various suppliers in various different lengths.

Mark

Correct, they are. The gauge is imperial measurement, many manufacturers today align to the nearest metric width instead, even when they use the old gauge on packaging. This sits somewhere between an 8 and a 10 on the imperial system (sometimes you can get No.9, the ones I used would be a 9 in the old system).

That was my initial mistake. I read “4.11x39mm” as four lots of No. 11 of 39mm.

“4.11mm” x “39mm” would make a lot more sense, especially if an original screw was measured with callipers.
4.2mm would be no.8 and 4.8mm would be no.10. 4.5mm seems good.

Did the existing thread in the hole match with the new screw?

[LinuxJedi]

That was my initial mistake. I read “4.11x39mm” as four lots of No. 11 of 39mm.

“4.11mm” x “39mm” would make a lot more sense, especially if an original screw was measured with callipers.
4.2mm would be no.8 and 4.8mm would be no.10. 4.5mm seems good.

Did the existing thread in the hole match with the new screw?

No problem, I didn't quite parse it correctly the first time either

There is no existing thread, it appears this machine was originally a kit one that was never screwed together.

[baz4096]

Ahh and it didn’t crack the moulding? That’s good. Oddly, even if though I don’t own an Atom, I find myself needing a pair of Atom case screws (as of an hour or so ago), so suddenly this thread has more relevance! Thanks for the feedback! Did you get yours up and running by the way?

[LinuxJedi]

Ahh and it didn’t crack the moulding? That’s good. Oddly, even if though I don’t own an Atom, I find myself needing a pair of Atom case screws (as of an hour or so ago), so suddenly this thread has more relevance! Thanks for the feedback! Did you get yours up and running by the way?

Nope, didn't crack the moulding at all, I was very careful to test, and that is why I didn't want to go all the way to a 5mm thread, as it looked too wide for me (and 4-4.2mm wouldn't bite). 5mm might be fine, but I didn't want to take the risk. If you need any, I have the rest of this bag of screws left over

Yes, mine is all up and running. For the most part, it was all working great out of the box, apart from a dead capacitor on the PoR circuit.

Thanks to hoglet for the Noise Killer and RGBtoHDMI boards and to CoolNovelties who designed a new Atom cassette cable based on the specs I gave (which they now sell). I documented the process here: https://linuxjedi.co.uk/tag/atom/

I still need to go through / backup all the tapes that came with it, and there are a few extra ROMs that came with it too that I want to check out.

[1024MAK]

This link takes you to a useful document (screw technical data sheet) that details screw dimensions and threads.

Mark

[baz4096]

Found some pan head stainless steel No.8 1 1/2” pozidrive that fit the existing threaded holes on my loaned Atom perfectly.