Removing a start drive screw from a disc in a caddy

[Dave R]

Some time ago I bought a used Proliant to act as a file server.

When it arrived it still had one disc in.

I discovered why on further investigation - one of the 4 start head screws which held the disc into the caddy had been rounded off.

My problem now is how to remove this without destroying either the caddy or the disc.

I can't get at the internal end of the screw without taking a circuit board off the disc.

I do have a spare caddy (if I can find it) but I would like mto get the disc out if possible.

Any ideas welcome.

Cheers

Dave R

[Oh, and this is a new install of a 2016 version of Pan because reasons.]

[Fredxx]

You don't mean Philips or Pozidrive?

The usual way is a Dremel with a thin cutting disc to create a screwdriver slot. A small (thin) diamond wheel would be the best way.

[Joe]

I've used a tool like this which worked very well. Unfortunately it was Japanese and at the time, not available here. It needs to be of good quality to work well, and of course there's no way to judge that on the Net..

[alan_m]

It depends on how rounded off.

File the tip off a cross head screwdriver bit so it sits further out on the shoulders of the cross on the head of the screw.

Place the screwdriver in the rounded of head and give the end of the screwdriver a gentle tap with a hammer. This can often slightly free up a tight screw before using any other method of removal.

Use the correct size screwdriver but place a flat piece of rubber band between the screwdriver and the rounded off head of the screw.

[Joe]

Also try to tighten the screw for a moment before turning the other way.

[Davey]

I got a set of those from 7dayshop some time ago. The one I tried worked well.

[Paul]

Screw extractor ? It has a drill bit on one end, and a reverse tap on the other end (tightens counter clockwise).

The vibration will not be good for the disk drive, particularly.

You can try the reverse tap, without using the drill bit end first, but it might not be able to get a purchase on the metal.

The instructions say to not go too quickly, when using the tap. So it has a chance to thread itself in.

Paul

[John Rumm]

I would try a a anti-clockwise cutting drill bit about the size of the screw shaft. It will either catch on the head and unscrew it, or drill through the head and separate it from the shaft - both will free the drive from the caddy, and should not subject the drive to too much vibration.

You may then be able to remove the remaining bit of thread with pliers, or just cut it off flush and rely on the remaining fixing points alone.

[alan_m]

I would favour an ordinary drill bit slightly larger in diameter than the screw shaft and drill far enough so the head of the screw separates. The only thing to watch out for is the metal swarf and brush down with a dry soft brush and a wash down of the pcb with IPA before proceeding to use your newly freed disk.

[Thomas Prufer]

Increases friction between screwdriver and screw. That's all it does, and it does that very well. Belongs in every bag of tricks! (Also used in aviation under the name "Viscogrip"... yeah, expensive.)

Thomas Prufer

[Theo]

For getting a stripped screw out of an iPhone, somebody recently recommended superglue and baking soda. You make a paste and then glue a screwdriver bit into it, leave it to set and then screwdriver it out. The mixture can then be softened using acetone.

I've not tried this myself.

Theo

[wasbit]

If this is a pan head screw as opposed to countersunk, & you have access, a pair of water pump/gland nut pliers can often get enough grip to get the screw moving.

[Jeff Layman]

Is the thread end of the screw in metal or plastic? If plastic, it might help to put the caddy into a plastic bag and then put that in the freezer to get the screw to contract slightly. It might then be easier to turn. If it's in metal there's no point in trying a freezer as there will be little if any difference in contraction between the metals.

[Andy Burns]

The last time I had given up getting a mangled screw out, and had decided sod-it, lets just drill it out, the drilling immediately spun the screw out, can't remember whether I'd left the drill in reverse

[Joe]

With this size of screw and drill, it doesn't take long to drill it by hand. Obviously it helps if it is a brass screw rather then the increasingly common stainless steel type.

[David]

Thanks.

At £25 it would be cheaper to replace the caddy. :-(

Cheers

Dave R

[Rob Morley]

Sometimes you can reshape a stripped screw head by peining it with a small hammer or flat punch sufficient to get a driver to grip. Otherwise cut a slot in the screw with a small abrasive wheel - if the screwdriver breaks the head, remove the side that didn't break using a punch or further application of the abrasive wheel. Or you might prefer to remove the head with a drill - use a bit the same size as the screw (3 mm?) - use high speed and feed it gently or it is likely to snag, might break. Sometimes a left handed drill will snag and remove the screw - I have a set but rarely use them. With the head removed you can extract the remains of the screw with vice grips or good pliers; failing that the drive will be fine with only three screws in it.

[David]

Thanks.

Now to measure the size of the screw head.

Being a small computer screw this could mean that the extractor is too large.

Do I need a very small left hand thread drill bit?

Cheers

Dave R

[David]

I think they are Torx. Yep - just looked at the bits and they are Torx - thought there might be more splines but it is just very fine.

Size 5 {units} which is the smallest in my Draper toolbox of fancy screwdriver bits.

Callipers say 1.6 mm external so quite a small screw.

Cheers

Dave R

[David]

Yes, that is very similar.

PC is a Proliant Server Gen 8.

Cheers

Dave R