Solutions for a sheered screw

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danielj
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Solutions for a sheered screw

Post by danielj » Sat Feb 10, 2018 6:20 pm

Argh. I thought this was undoing, turns out the threadlock had turned to concrete...

It's the earth post - and it's non-standard thread :( . Any ideas? Ideally don't want to be making more holes in things...
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Lardo Boffin
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Re: Solutions for a sheered screw

Post by Lardo Boffin » Sat Feb 10, 2018 6:31 pm

I think you apply heat to loosen threadlock? Maybe a soldering iron would do?

Once loose you may be able to remove with pliers?
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danielj
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Re: Solutions for a sheered screw

Post by danielj » Sat Feb 10, 2018 6:44 pm

That's slightly irrelevant now as the screw has sheered off... :D It wasn't apparent that the screw had sheered as it appeared the nut was turning fairly happily... Basically need a solution for properly joining the earth to the PSU casing. :?

d.

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sydney
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Re: Solutions for a sheered screw

Post by sydney » Sat Feb 10, 2018 6:45 pm

Could you not just drill it out and replace it with a small nut and bolt?

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danielj
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Re: Solutions for a sheered screw

Post by danielj » Sat Feb 10, 2018 6:53 pm

I'd rather not as it'll ruin the painting on the back of the PSU :?

d.

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1024MAK
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Re: Solutions for a sheered screw

Post by 1024MAK » Sat Feb 10, 2018 6:54 pm

Drill it out.
Countersink the outside.
Fit a suitable machine screw with star washer, then nut.
Fill in the head of the machine screw with filler.
Paint over it :wink:

Mark
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1024MAK
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Re: Solutions for a sheered screw

Post by 1024MAK » Sat Feb 10, 2018 6:56 pm

Or, replace or extend the Earth wire, and attach it at the other end of the case...

Mark
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sydney
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Re: Solutions for a sheered screw

Post by sydney » Sat Feb 10, 2018 7:11 pm

Could you remove the post somehow and screw in a slightly larger bolt, cut off the 'head' then screw the nut on? Probably not! :lol:

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danielj
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Re: Solutions for a sheered screw

Post by danielj » Sat Feb 10, 2018 7:22 pm

I'm wondering if I can just unfill the old head, unscrew it and do as Mark said. I can't work out what size screw it was - it seems to be 4.4mm diameter... That doesn't seem to correlate to anything?

d.

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Re: Solutions for a sheered screw

Post by johnkenyon » Sat Feb 10, 2018 7:51 pm

danielj wrote:I'm wondering if I can just unfill the old head, unscrew it and do as Mark said. I can't work out what size screw it was - it seems to be 4.4mm diameter... That doesn't seem to correlate to anything?

d.
Possibly a BA thread/screw?

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danielj
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Re: Solutions for a sheered screw

Post by danielj » Sat Feb 10, 2018 8:15 pm

I missmeasured - it was 3.3.

My plan is this - I've found an M3 tap, SO:
cut the rest of that one off, drill 2.5mm hole in from left on the flange there, countersink, tap with M3, put M3 machine screw in, screw everything to that, breath.

Sound reasonable?

d.

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martinw
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Re: Solutions for a sheered screw

Post by martinw » Mon Feb 12, 2018 12:07 pm

Possibly a 4-40, used to use them a lot when I worked in the States.

https://www.mouser.co.uk/Electromechani ... ?P=1z0z2i2

Martin

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