Well i didnt expect it to continue to go so smoothly......got all the bolts out easy enough on 3 of the rubbers and then booom!!!,....one of them gets mushed....& subsequent meddling means it is well and truely focced.
The engine will be coming out but whats the best plan of action?...i have a basic cordless power drill and im guessing i need a decent easy out set plus a punch maybe although how much the punch applies to an allen bolt im not sure.
So i know I've not to choose a drill bit too big that ends up obliterating the bolt itself.......do i need a left hand drill bit so as not to further tighten the bolt & if so can i just buy maybe 2 sizes of left handed drill bits on the cheap or most conveniently ie homebase or jewsons or can anyone recommend a decent kit complete with all i need?
Lets be honest i wont be regularly doing this but I'm staying positive and seeing it as a learning process and in future i might have have an idea what to do on any projects or even help someone else out.
They are really tight...heat of the engine etc so i need something that wont in turn snap off and then ill just be throwing the engine in the skip as i cant be focced trying to learn how to drill out an easy out with diamond tipped machinery....just to get a few quid.
Any help appreciated as always.
Cheers
Nog.
Easiest way to go fast........don't buy a blue bike
Plan A: take to engineers/ bike shop & get them to do it~ shouldn't be too expensive & then THEY are responsible if all goes pear shaped.
Plan B:
Should be able to do yourself with power drill.
A few tips~1) use quality cobalt stub drills, they'll be hard enough to tackle the bolt no sweat & as stub drills are shorter than standard, easier to hold square to workpiece by hand (& less likely to snap)
Cheap drill bits are a waste of money for drilling steel.
2) centrepunch very carefully, the closer you get that punch to the center of the bolt the more likely you are to pull the job off without damaging the cylinder heads thread.
Start with an 1/8"/3mm drill, then work up through sizes.
I think they're M6 bolts, tapping drill size for m6 is 5mm, don't go bigger than this or you'll cut into threads~ whats left of the bolt should be removable with some prying with a small screwdriver or similar.
3) if you do cut into threads a little, can usually be cleaned up good enough to go with an m6 tap.
4) If you do fluff the drilling up, you could still get it helicoiled so it's defo not scrap!
5) alternatively drill a 3-4mm hole in bolt remains & use screw extractor~ i've had mixed results with these, so prefer just drilling out.....bear in mind if you snap the screw extractor off in bolt you're in deep doggy dos as they are (or should be) hardened steel.I did manage this once :o
Good luck if you DIY, just take it slow & methodically.
(05-07-14, 09:29 PM)69oldskool link Wrote: Plan A: take to engineers/ bike shop & get them to do it~ shouldn't be too expensive & then THEY are responsible if all goes pear shaped.
Plan B:
Should be able to do yourself with power drill.
A few tips~1) use quality cobalt stub drills, they'll be hard enough to tackle the bolt no sweat & as stub drills are shorter than standard, easier to hold square to workpiece by hand (& less likely to snap)
Cheap drill bits are a waste of money for drilling steel.
2) centrepunch very carefully, the closer you get that punch to the center of the bolt the more likely you are to pull the job off without damaging the cylinder heads thread.
Start with an 1/8"/3mm drill, then work up through sizes.
I think they're M6 bolts, tapping drill size for m6 is 5mm, don't go bigger than this or you'll cut into threads~ whats left of the bolt should be removable with some prying with a small screwdriver or similar.
3) if you do cut into threads a little, can usually be cleaned up good enough to go with an m6 tap.
4) If you do fluff the drilling up, you could still get it helicoiled so it's defo not scrap!
5) alternatively drill a 3-4mm hole in bolt remains & use screw extractor~ i've had mixed results with these, so prefer just drilling out.....bear in mind if you snap the screw extractor off in bolt you're in deep doggy dos as they are (or should be) hardened steel.I did manage this once :o
Good luck if you DIY, just take it slow & methodically.
Cheers geezer this is the type of experience based info im after.....i am a bit worried that a screw extractor might not cut it due to the heat...although the others came out without too much effort it was the initial snap that took the effort......however the screw extractor is more my level of precision.......you say cobalt stub drills but do they need to be a left handed screw??
Easiest way to go fast........don't buy a blue bike
You could try filing a notch in the head of the bolt and then turn it out with a screwdriver. Or if that doesn't work and the bolt isn't seized it's just got a damaged head you can sometimes get away with just drilling the head off it to release the pressure and then file a notch in it and turn it out with a screwdriver
I am an on site engineer in hydraulics and occassionaly come across this issue. The best way out I have found is to get a torx bit that is a little larger than the hex, use a hammer to seat it securely. , the torx bit cuts its own profile into the cap screw and the combination of the tapping and the better fitting bit helps get it out. Never failed me yet. Even tried it on m16 cap screws just a larger scale.
What ever you do do not use an easy out, they break to easily and make the job much more difficult when they do break.
As I said on the other post and as 69oldskool said the first option is to drive a T30 or T40 torx into it can be done with the engine in the frame, but will be easier with the engine out. The hammering effect will help break the bond also.
Most definitely the Left hand drill bit is the way to go. The standard drill bit will tighten the bolt more if it "gives" when drilling.
You could also have tried hammering a normal socket onto the outside of the allen key bolt. I have done that a few times when the torx method has not worked, just another option if it happens again.
If you worried about falling off your bike, you'd never get on.
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