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

[timnexxial]

While taking out my max2 axles to fit the bearing cages that come with the track kit, the last one (rear left), surprised me with the tip of my reasonable quality allen key snapping off in the grubscrew that keeps the sprocket located on the axle.
Has anyone had success with this kind of challenge?

A strong magnet hasnt worked with a little scratching and rattling, and naturally it has sheared with a small mountain peak sticking up out of the grubscrew so drilling will be interesting Im sure. Grinding through that little gap looks like fun too so Im wondering how hard it is to shear one of these grubscrews and fix it once I get the damn axle out coz I cant see how that will happen with the grubscrew holding that sprocket in place.

I would really appreciate any suggestions.

[vader8x8]

If you can use a dremel with a small burr bit, you could possible grind enough of a "flat" onto the broken piece to make a center punch on it for drilling. I'm assuming it's not sticking out of the threads enough to use a dremel cut off wheel to cut a slot in it to use a flat scew driver to back it out. Maybe a small flat sharp chisel, tap it with a steel hammer until it bites and use a wrench on the hex shaped shaft of the chisel to turn it out?

[thebuggyman1]

Is the setscrew sticking above the sprocket tube at all? If it is you can put a nut over it and weld inside the nut, remove the setscrew and toss it.

Just remember to flood the inside of your tub with water or use wet rags to keep the weld splatter from creating holes.

[timnexxial]

Thank you both, there's nothing above the the sprocket tube to work with unfortunately so the dremel before drilling would be the way forward at this stage and maybe an easy-out after that, havent tried it on things without a thread before, would need to stop before the thread caused too much expansion but still get enough bite for a straight pull? Drilling and then trying to collapse whats left of the hex bit at 5/32 size sounds pretty tricky with steel this hard but at least it wont spin! What kind of drill alloy would do this happily if there's no other suggestions? Oh and for next time what is a good way to soften up threadlocker before trying to take these things out in future coz I was following the manual and have the antiseize and threadlock blue?

[Eldon]

I had the same thing happen to me.I heated the set screw with the allen wrench stub in it.The difference in the metals let the screw expand more than the allen stub thereby loosening the stub so it actually would move in the screw.I was able to pry the stub up enough,with the point of a very small jack knife to grab with pliers and pull out but even something with a wee bit of adhesive or JB weld etc would grab enough to pull it out once it sets.I suspect though like me you freaked!! It will come out.I heated mine with a large soldering gun to eliminate fear of fires put the tip right on the edge of the screw and hold for a minute or so.

[plott hound]

can you grind a slot in it with a dremmel?next to welding a nut on it this is second best.

[timnexxial]

There's only a little spike above the top of the grubscrew so not too good for adhesion and the grubscrew is recessed in the sprocket tube so grinding will be pretty tricky too.

The heating sounds good, is there a glue that you could recommend and what is JB weld?

Thanks guys, cheers Tim

[plott hound]

man,i just remembered a similar experience with a bigger grub screw.broke the tip off my cheapo torx bit while torking a bolt.took a center punch and hammer to the broken peice,damn chunk shattered and came right out.

[Eldon]

If you have a little tiny spike then when heated and a little penetrating fluid for lube I bet it will come out with tweezers,easily.JB weld is a brand name of two tubes of a metallic like compound when mixed hardens but that probably in second thought would cause more trouble than it cures. Just try the heat sounds like an exact replay of what I had. Next set screw just heat it a bit before trying to melt the thread locker compound.

[timnexxial]

Will give the heat and grab a shot but the little spike is really little and if I cant grab a seventh of a 5/32" will dremel it flat and try centre punching...here's hoping and thanks for your help

[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.