Not Happy. Trashed New Mold

[milrifle]

Seeing as how the sprue plate screw on a Lee mold will never stay tight, I decided to drill and tap my latest two for a set screw. First one went off without a hitch. The second one? Well, I broke the tap off in the hole. Flush with the surface, of course, so there's nothing much to grip to get it back out. I can sometimes get a pair of needle nose on there, but it's not going to turn. I tried heating it up, but no luck. I just ordered another one. I'm glad it was only a $18 mold, but then again, if it were a NOE, it'd have a $%#@ set screw in it already!

[fast ronnie]

depending on what size tap, it could be set up in a milling machine and cut out with a carbide spade drill. I've drilled out a lot of broken taps over the years that way. If the mold is only $18 it wouldn't be worth paying somebody else to do it, but if you have a mill--- any questions, pm me.

[5Shot]

If it's big enough you can try smacking the end with a hard center punch. This will bust it up into pieces you can tap out on the side of the bench.

[country gent]

If you have one of the carbide tipped electric pencils ( the ones used to mark tools and parts by hand) That vibrate the point into the material and the tap isnt to deep. Pad a vise and use it working slowly and carfully. The vibrations may break up the tap and or loosen it for you. I have also used a high speed die grinder with a fine carbide ball nosed burr to cut the center out of the broken tap. Otherwise all you can try and do is heat it and anneal the tap so it can be drilled out. I have removed broken taps at work and depending on how it broken, they can normally be removed with a little work and patience. If above the surface or close a fine point on a flute tapping with a small hammer in the direction to remove it may walk it out. A carbide spade drill may do it Ive had better results with a centercutting carbide end mill though, A 80,000-100,000 rpm die grinder and small ball nosed burr walks right thru them also. The pick and hammer will work at times. If all you have is a drill press clamp it tight in a solid true vise bolted to the table with part in location and use the spade drill or end mill.

[longbow]

I was quite surprised to find that after I broke a tap off in a Chevy 327 block that my Dremel with a carbide bit cut it right out. I would not have believed it if I hadn't done it. Now in that cast I was dealing with either 1/4" or 5/16" so some wigle room. A small tap like #10-24 might no tbe so easy but worth a try if you have a Dremel.

Longbow

[tomme boy]

Get a left handed drill bit.

[dtknowles]

Can't you just start a new hole coming at it from the other side of the corner?

Tim

[rmatchell]

If it's big enough you can try smacking the end with a hard center punch. This will bust it up into pieces you can tap out on the side of the bench.



This has saved me many times

[Blanco]

If this is a Lee mold just move the sprue plate screw hole to the opposite corner? It might be worth the effort ?

[semtav]

get a dremel cutoff disc and make a screwdriver slot in it.

[leadman]

There is a broken tap removal tool but I am sure it would cost many times what a new Lee mold does. Used to have access to them when I worked for Cummins and went to a factory that made front end loaders.

I recently had to drill and tap for 2 set screws and retap the bolt hole to 1/4-20 in my latest Lee mold to get the sprue plate bolt to stay in place. The aluminum seemed especially soft and grabby so used Tap Magic on the drills and taps. I wonder if Lee changed the spec for the raw aluminum they use?

[cold1]

The broken tap removal tools are available at Brownells.

[milrifle]

It was a 6-32, so pretty small. I considered drilling and tapping the opposite corner, and I may still do that, but I already ordered a new mold. The tap is extending into the sprue plate screw hole, so just drilling and tapping a new hole from the other direction is not an option unless I can get the broken tap out. I may do some more work to it, but like I say. I have another on order, so I'm not too worried about it. It just ticked me off.

[mozeppa]

If it's big enough you can try smacking the end with a hard center punch. This will bust it up into pieces you can tap out on the side of the bench.

if its a aluminum mold...he'll just booger it up more.

[SSGOldfart]

I'll give you $10.00 for it as it is even with the broke'n tap

[Blanco]

I have made a cobbled together EDM before using a carbon electrode pulled from a AA battery and a 12 v garden tractor battery, along with some wire and clips.
use the electrode to erode the tap.
I use it for permanently marking my tools.

[Cd662]

I agree that it might not be worth the effort for a 20 dollar mold, but it could be fun to try to get it out. :)

[Cmm_3940]

Can you just leave the broken tap there, and drill/tap a new hole in the adjacent side of the same corner? I just have 6-cav Lee molds, I assume for $18 you have a 2-cav, so I'm not sure how much room you have to work with...

[cheese1566]

Can you wedge in a woman's bobby pin into the flutes of the tap? If you can, sometimes it will give you something to grab with a pliers.

[Enyaw]

Carbid taps will bust up with a good punch but high speed steel just peens and gets tighter. The force it takes to bust up a tap would mess up the mould more I bet.

Diamond burrs and a dremel may grind it out enough to relieve the tension so it screws out. May take more than one or two diamond burrs though.

Carbid drills may work if you flatten the top of the tap and start a hole centered.

Cobalt drills or bottom cut end mills used on a drill press or milling machine may work to get the tap out...if you stay on the tap and not wander into the aluminum.

Always go easy on a tap and back it up a lot and take it out and clean the metal out of the hole and off the tap too.

You may use a cut off wheel and a dremel to slit the side down to the broken tap and separate the slit a little to take the tension off the broken tap to get it out. Then tap the mould by the hole with a lil hammer or squeeze it in a vise to tighten the diameter of the sprue plate hole and see if the sprue plate screw stays put in the tighter hole. If not just make a new screw hole and start over.

Take a thin piece of shim stock made of brass (.001-.003 in.thick) and set it in the screw hole along the side of the hole then put the screw back in. That may help keep the sprue plate screw tight in a new or used mould by Lee.

[Artful]

+1


Can you wedge in a woman's bobby pin into the flutes of the tap? If you can, sometimes it will give you something to grab with a pliers.

or just some straight pins in the flutes

[gwpercle]

Not being mechanically adept at drilling and tapping aluminum, I read about using a small tuft of 0000 steel wool in the sprue plate screw hole to keep it from loosening, I realy didn't think it would work. Too easy....but guess what, two different moulds and several casting sessions and the screws have not loosened! It works and doesn't require a drill, tap or skill to install.
Gary

[MtGun44]

+1 on dremel cutoff wheel to slot it for screwdriver.

Bill