snapped drill bit help

[macafee2]

Not a good morning. I have snapped a 5mm drill bit in a 4.5mm hole, the hole for the bolt that holds the rear nearside bracket on the trailing arm for the brake hydraulic pipe.

Now is not a good time to need to change a trailing arm.

There is no part of the drill bit to grip, what drill bit can I try, to drill out a snapped drill bit.

macafee2

[marinabrian]

Hmm, a drill bit to drill out a snapped drill bit.....you'll be lucky

Can you not simply drill a fresh hole adjacent to the original, tap that and screw the bracket in a slightly different place Ian?

Brian

[steveo]

Hi
You can't really drill the old bit out, high speed steel drills are hard.
If the 4.5 mm hole is a clear hole can you get a 3 or 4mm punch in and try and knock it out from the reverse side of the hole.
This Is obviously not an option if its a blind hole
Regards
Steve

[macafee2]

It is a blind hole.

Would it be safe to drill and tap another hole in the trailing arm?
Brian, I was relying on you to just name a drill bit to use

I was wondering if I could "tap" the bit through and out the other side.
Right now I cant even find anywhere that does spark erosion, Google is letting me down.

I was in such good sprits before this happened, now I feel completely drained.

I wonder if an MOT tester would notice the brake pipe flapping in the wind

macafee2

[Blink]

Originally Posted by marinabrian

Can you not simply drill a fresh hole adjacent to the original, tap that and screw the bracket in a slightly different place Ian?

The problem with doing that is the bracket needs to line up with its recess in the arm - and that can only happen if the original screw hole is used.

[marinabrian]

Ian, it is not possible to grip the flutes of the drill bit with a pair of needle nose pliers and wind it out?

I wouldn't imagine drilling another hole will weaken the structure of the cast iron arm substantially if that's the only option you have at your disposal.

Just out of curiosity, why did you unbolt the bracket in the first place? I ask as I've always just slid the brake pipe grommet out of the bracket in the past

[marinabrian]

Originally Posted by Blink

The problem with doing that is the bracket needs to line up with its recess in the arm - and that can only happen if the original screw hole is used.

Not really necessary if you use a rubber lined P clip to replace the original bracket Simon.

There will always be a workaround to make a safe job, something like this......



Brian

[macafee2]

massive update

The bit is out and hole now drilled.
It must have been the very tip that snapped off. The drill snapped into at least 3 parts.

I tried with a puch to "undo" the drill bit and it either shattered or was just the tip but it seemed to come lose and then with a flick of something come out.

Lessen learnt and very very very gingerly tried with another drill bit. It got stuck a couple of times even going slowly but reversing the drill it came free.
My mistake was not to start the drill off slowly first time.

omg I am so relived but totally worn out

macafee2

[Blink]

Originally Posted by marinabrian

Not really necessary if you use a rubber lined P clip to replace the original bracket Simon.

There will always be a workaround to make a safe job, something like this......



Brian

Yes, that would work.

Or an easier (but not as safe or solid) alternative is one of these tied round the trailing arm, assuming they do one with the right diameter for the hose and a fully enclosed loop. It wouldn't need another hole drilling.

[marinabrian]

Originally Posted by macafee2

massive update

The bit is out and hole now drilled.
It must have been the very tip that snapped off. The drill snapped into at least 3 parts.

I tried with a puch to "undo" the drill bit and it either shattered or was just the tip but it seemed to come lose and then with a flick of something come out.

Lessen learnt and very very very gingerly tried with another drill bit. It got stuck a couple of times even going slowly but reversing the drill it came free.
My mistake was not to start the drill off slowly first time.

omg I am so relived but totally worn out

macafee2

Right, deep breath cup of coffee and a biscuit and then pop along and put the lottery on Ian

Good stuff

Brian