Any ideas for removing a snapped hex key tip in a sprocket retaining grubscrew?

[timnexxial]

Couldn't move it so onto the drilling.

Hex key doesn't seem to want to be centre punched or drilled does it.
Apart from the little shard I was trying to grab the sheared tip doesn't protrude from the grubscrew which is recessed into the sprocket tube about 2mm.
I have ground with the dremel so there is an even dish in the top of the hex key tip and can't get good adhesion with glue or magnet to pull it out.

I would love to drill out the 5/32" of high tensile steel currently loitering in the grubscrew, what drill alloy does this effectively?

[whipper-ag]

[wfo]

thats what i was going to say

[rdr]

bout the onily thing going to touch that is a carbied masory bit sharping up on a silcon carbied wheel /. robbie

[timnexxial]

Thanks all, have just got a goodie bag from the tool shop, tungsten carbide dremel burrs (didnt think one would do it), set of masonary bitz to sharpen up and I been told to push hard, and some superouts.
When I get a hole I'll try the quikouts first before superouts then total destuction, that left rear sprocket position certainly cramps my style.

[timnexxial]

It's bloody hard drilling, (excuse the Australian vernacular)
Does annealing make the metal easier to drill, Whipper?
And what's a good speed to drill with the sharpened masonary bit, Robbie? s'pose I can't use the hammer setting (bugga!)

[whipper-ag]

[liflod]

I've been told that taking a large piece of angle iron and a BFH, drive the sprocket with the BFH via tha angle iron. It will snap the set screw and allow the sprocket to slide off the axle.

I've used a diamond burr on a dremel to remove the broken set screw on my Max IV.

I've also drilled and tapped all of my sprockets to 3/8 so that I can use a larger set screw with a 3/16 allen head on them. The 3/16 allen is less likely to break and the larger diameter is less likely to freeze in the hole.

[timnexxial]

Sage advice gentlemen.

I was just kidding on the hammer setting, although the angle and BFH will make me feel better as a last resort and upsizing was definitely on my mind.

Will anneal and carbide drill today, cheers Tim

[rdr]

Sage advice gentlemen.



Will anneal and carbide drill today, cheers Tim

yes let it cool as whipper said then drill it our wit pleanty of oil . robbie