Removing mashed up a screw from delicate equipment.

srichards

srichards

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I can't get out be screw which is holding a projector bulb in. Screw head is mangled so it doesn't turn and screwdriver spins hopelessly. Normally you'd drill it out but that doesn't seem a sensible option and would likely cause damage.

Any tricks to managing to get enough purchase just to loosen it so it could be none with pliers if needed? Replacement bulb comes with new screws. Tried blue tack and the elastic band trick to no avail.
 
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Is there room to get a small pair of Mole grips on the head?
 
You can buy a bit from Screwfix that is for removing knackered screws.

Here

Hope this helps
 
Nod said:
Is there room to get a small pair of Mole grips on the head?
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Maybe. I've tried needle nosed pliers. I've only got large mole grips.
 
Superglue/solder to the screwhead?
 
Davec223 said:
You can buy a bit from Screwfix that is for removing knackered screws.

Here

Hope this helps
Click to expand...

It's a bit delicate to be drilling into so I didn't want to resort to those ideally.
 
gramps said:
Superglue/solder to the screwhead?
Click to expand...

Yes. I think glueing a screw bit to it might be the only option left now!
 
Sometimes I've had joy with a bigger driver but it required more force downward (so it doesn't creep up out the screw) and a slow twist.

Not sure if cutting the screw with a Dremel is worse than drilling it, but if its a raised head you could cut a slot if you have the means to do so.
 
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Any chance of a picture and an idea as to the size of the screw and head, Suz?
 
Done it! Some brute force and another go with the pliers must have loosened it as I felt it ting so it must have just stuck on.

Bulb changed with only minor blood loss.
 
The trick is to use the correct screwdriver bit for the screw and not to overtighten them! If possible, swap supplied screws for stainless steel ones - they're harder and less likely to have the head damaged.
 
Nod said:
The trick is to use the correct screwdriver bit for the screw and not to overtighten them! If possible, swap supplied screws for stainless steel ones - they're harder and less likely to have the head damaged.
Click to expand...

It wasn't me that changed the bulb previously. I think they re-used the old screws instead of replacing them. The new bulb has new screws and is absolutely fine :thumbs:

I can't over-tighten anything without needing power tools :D
 
:)

Way back when assembly workers used hand tools during assembly, Henry Royce designed a set of spanners whose handles were just long enough to enable the assemblers to get the bolts tight but not long enough for them to overtighten them.

I've lost count of the number of Pozidrive screw heads I've mashed with Philips drivers and vice versa (and brass woodscrews whose heads I've twisted off...) Been a while since I've ripped a thread out of an alloy casting with a stainless screw though.
 
Davec223 said:
You can buy a bit from Screwfix that is for removing knackered screws.

Here

Hope this helps
Click to expand...

I end up having to do this about once a month due to poorly made screws or screws that have even been stripped in the manufacturing process. I work with quite delicate equipment and this kind of tool is by far the most effective way I've found of removing those stubbon screws.

You don't need to drill deep, but just enough to allow the removal tool to bite. Once the tool bites then the screw will in 99% of all instances just unscrew. It can happen that screw head will break. If that happens then that screw was way over-torqued and probably would have never been extractable, so a complete drilling out becomes necessary.
 
I can't remember where I saw them but I did recently see a set of left handed/anticlockwise drill bits for sale. I've seen them used in preperation to using an EeziOut type extractor but the extractor ended up not being needed - the heat from the drilling combined with the direction of rotation drew the (small, sheared off) stud out!
 
Nod said:
I can't remember where I saw them but I did recently see a set of left handed/anticlockwise drill bits for sale. I've seen them used in preperation to using an EeziOut type extractor but the extractor ended up not being needed - the heat from the drilling combined with the direction of rotation drew the (small, sheared off) stud out!
Click to expand...

Yup in theory you should always use them prior to easi outs as obv. any snagging of the bit whilst drilling is likely to tighten it, only adding to the problem. In practice, they're rarely(as in never) available so a correctly sharpened bit at an appropriate speed usually suffices
 
Nod said:
I can't remember where I saw them but I did recently see a set of left handed/anticlockwise drill bits for sale. I've seen them used in preperation to using an EeziOut type extractor but the extractor ended up not being needed - the heat from the drilling combined with the direction of rotation drew the (small, sheared off) stud out!
Click to expand...

My experience of reverse thread extractors is they simply don't, unless the screw is already loose in the thread. If it's in any way tight the extractor just shears off flush making the problem worse.

Where possible I use an impact driver to remove stubborn screws (I appreciate that this may not be an option on the internals of a projector).
 
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