removing a stripped screw
 

Im struggling to remove a stripped screw on the bottom on my SX3.
The screw is completely rounded off and no way any driver will work.
The screw is very countersunk into the chassis, so dremelling will require a very fine and small blade, and im not sure where to purchase
Any ideas?

One other way to do it is to get a fine centre punch and small hammer and tap it out. Make a punch mark near the outside of the head and then gently tap it anticlockwise with the punch at an angle.

Not that easy and you might need someone to help you hold the chassis

Depending on the original hole size, get either a T8 or T9 (Torx) driver. You can either put some pressure on the driver or gently tap it in the nackered hole. The torx will hopefully bite into the srew head and you will be able to remove it. I have had success with this method over the years, and not just on toy cars

The original screw is a 1.5mm hex i think. But its not going to me more like a 2mm , could you link me to a driver thats suitable?
Cheers
Chris

Techniques I have used many times (eBay cars) is ...
An imperial driver such as 1/16 will sometimes fit a knackered metric hole
Torx driver 9 or 10 I think?
Cutting a slot in the screw and removing with flat head, will leave 2 small marks in chassis but at least car can be repaired
Have you checked that you cannot remove all surrounding screws and twist the part it is threaded into, ie bulkhead screw
There is an old tale about using solder to go hard in the screw and using that to remove but I have never tried it.
You may need to heat up screw if it is heavily thread locked
Twisting the affixed part is easiest of all choices if possible.

I tend to drill off the head of the screw.

If you know the screw is an M3 try a 5mm drill bit, if an M4 try a 6mm drill bit etc.. Go nice and slowly and you will get to the point where there isn't enough material left to hold the joint tight and the head will fall of with a gentle wiggle.

The stub that is left is likely to be undone with a pair of pliars or small mole wrench.

If the stud feels tight and is into a metal part use a good soldering iron to put some heat into the joint as this will break down any (sensible) threadlock used and make it much easier to get out.

You can also buy screw extactors which have a reverse spiral thread at one end and conical milling cutter at the other end.
You use the milling cutter end in your power drill to form a particular shaped cone in the rounded head of the screw. Flip the extactor over and run the drill backwards with some solid downwards pressure and it will cut into the new cone form and wind the screw out!!

These aren't cheap but compared to the price of a new chassis they make a god investment.

+1 on drilling the head off, a lot safer and cleaner and the existing mauled hex makes a good pilot for the drill

I always carry a set of small drills in pitbox that fit in the dremel chuck just in case.

You can use a worn down slim cutting disc with a dremel to avoid marking the chassis either side but it depends whether you can get easy access as you want to be 90 degrees to screw really to make a strong slot for screwdriver.

I've done the dremel method a few times, using a fine/thin sandstone cutoff disc (a number of which are included with any dremel) - and then I later repair the two small knotches/grooves I've cut into the plate with JBWeld or similar metal-repairing type of epoxy. Works like a charm.

Cheers guys, lots of good methods.
Tryed a few things so far

1. Dremelling a notch to try a flathead screwdriver out ( couldnt get the notch deep enough) was making the screw worse.

2. Tryed to flatten 2 sides of the screw and using a gripper, loosen the screw.
( couldnt get a good enough grip on it)

At this point, the screw is completely mashed,
Problem with all this is, i dont really have the equipment or the technical skills to get the screw off.

Are you going to Worksop ?

I use the slot method ( not that there's anything wrong with drilling but to me that's the last option ) never failed yet. Thread lock is a nightmare on small fixings. I use the tiniest dab of the tamiya blue stuff but only where absolutely necessary !

You need to make the cutting disc quite small to avoid slotting the chassis too much.

I wont be at Worksop unfortunatly.
The the screw is attached to the motor mount, which comes away from the chassis, so no risk damaging that. Just cant get the slot cut well enough to get a screw driver to turn it

If the screw is in the motor mount why don't you do what I said and remove the rest of the motor mount screws and unscrew/ twist the actual mount not the screw?

+1 on the torx,you might not be able to save this one,but remenber nxt time,also if you have a soldering iron,use it to melt the thread lock by holding it on the screw head,then quickly undo it,

HTH

Torx method worked great for me. T9 torx for a m3 2mm hex screw.

Next try putting a slot in it and use a flat blade. I tried drilling one once and it just ran further in.

This pretty much although you won't find an extractor that works for such small screws (that I've ever seen). And my smallest "Grab-it" bit will not work on a 3mm screw.

Drill the head off and be done with it, one HSS bit will tolerate drilling heads off around 5 x Ti 3mm screws before you need to replace it. Alu can be drilled out endlessly with a HSS bit.

I'd adjust down 1mm from Roger's advice, if you have a 3mm screw, drill the head with a 4mm bit, not 5mm (IMHO).

I use the smallest Pro-Grabit after touching the head of an M3 with a 5mm drill bit (standard 118° end form)

http://www.machinemart.co.uk/shop/pr...C-screw+extrac

Drill the head off the screw, Use about 4.5mm bit (The size of the Countersink)
then the motor mount should just come out. Obviously you will have the thread in the motor plate. You may be able to remove the rest of the screw with some pliers or mole grips

if all fails, Grab some Hydrochloric Acid about 36% (HCL)
Drop the alloy in the acid, The alloy will not be effected by acid, but the steel screw will dissolve.

Thats the best way to avid damage to your chassis or the alloy part. But it will take some time.

Or if your not too bothered about a few marks on the chassis, dremmel a slot into the screw and use a flat head.

Just drill the head off.
as Roger said.
Then you can take the mount off with the stud and use some pliers.

once its out, if it's the 2 that lock the motor mount into position, there button heads, these can be swapped for cap heads with a thin washer, and taking a tiny bit off the hight of the head, much less chance of them stripping then