got a big problem here

[15mgtar]

I have a problem removing a rolled pin inside my 16mm axis I tried to drill out the 5mm pin using 3mm hss but the drill bit broke inside the hole about 8mm deep then I use my center bit try to drill it out then again the center bit broke on top of the 3mm bit, I tried drilling with 4.5mm carbide which just last only a couple of seconds before it snaps!. So any solution getting it out? the hole is 5mm in diameter but it got rolled pin and inside there got several broken hss bits.

[jalessi]

Find someone that has one of these>

http://www.joemars.com.tw/cutedm_tr100.htm

[15mgtar]

EDM hard to find here. I got a plasma cutter though but gonna ruin everything.

[rowbare]

At this point you don't have much to lose. Maybe get a few cheap diamond burrs (<$1 each) and see if they will do the job.

[diecutter]

If the other side is accessible, carefully locate and drill a small hole on that side and use a drift to drive out all the broken tools. As an alternative, you may be able to relocate the hole for the roll pin if the other components allow.

[HuFlungDung]

First option, as Diecutter posted above. One way to find the 'other end' accurately, if you have some of the hole available above the broken parts, is put a 5mm pin in the vise under your spindle, and center the pin relative to the spindle. Now raise the spindle and turn your part over and slip it over the 5mm pin. If you get a decent amount of engagement, enough to locate the part accurately, you should be able to drill from the top side in this position and come out in the hole. Drill undersize in case the drill wanders a little. Be gentle and estimate the distance accurately, and don't ram the damn drill into the end of the roll pin from the back side. Use a punch to drive out the broken pieces of drill, then look through and see how the alignment is. If it is good, then drill the back side out to full 5mm, stop at the end of the roll pin and drive it out the front with a punch.

If that is not possible, that is a pretty good sized pin. I would set the part up in a rigid setup in a mill, and use a ball end mill to peck-drill the broken parts out. A gentle start with a short ball mill will help center the tool on top of rough, uneven surfaces. Don't expect to make chips, all you make is dust, and you drill only a few thousandths and then retract and blow the dust out with a gentle air blast (while you wear safety goggles). Patience will help you deal with this.

If you have access to an experienced welder, there are welding rods available that you can use to weld down inside of a hole with. UTP65 is the rod, perhaps you can find someone who can cross that over, as most welding rod suppliers have an equivalent competitive product that behaves the same way. This rod will strike easily and makes a flux puddle that surrounds the puddle. Since you only have about 1 or 2 seconds of weld time per spot, this flux will surround the little bead that you deposit and keep it from adhering to the walls of the hole. Keep doing this until you've built up a little tower of weld above the hole. Then weld a bolt onto the top of this and pull the dowel pin with a nut, washer and spacer.

[15mgtar]

Thanks for the support guys, anyway I ended up having 2 holes crossing each other LoL.