OK heres a nice problem !
I have a heap of stakes for use on an anvil with a 1 1/8" (one and one
eighth inch) square hole but my anvil is just a tad smaller - probably a
Short of grinding down all the stake shanks, any suggestions how to enlarge
the hardie hole. The anvil is obviously rather hard, and turns a file. I've
tried carbide burrs but am getting nowhere.
If I could mount it on my edm machine I could cut it out easily but it's
rather a large lump of steel
Bromley, Kent, UK
Clearly you aren't thinking laterally. Why not mount your EDM machine
on the anvil? ;-)
Actially, not an entirely frivolous suggestion - might well be
possible to lash up an EDM sinker that you could bolt onto the anvil,
and plugging the bottom of the hole would give you a nice little
resevoir for the electrolyte.
Just a thought...
Do you think it would work with an extension socket like the ones for
Morse tapers? This would not require any machining of the anvil at all.
The working height would be somewhat higher and a close fit to the
rectangular hole in the anvil is a must not to compromise the stability.
Now that you have the advantage of an edm machine producing the square
tapered hole for the stakes in the extension should pose no problem. It
is also possible to make the extension in two parts bolted together
making it possible to mill the square holes.
Andrew Maws> OK heres a nice problem !
You could always put it near your EDM machine and put an extension arm
sticking out of the front to mount the electrode on (remember to earth the
anvil to the machine table). This type of trick is often used for sparking
the end of shafts, etc that won't go in the tank.
The other thought is that there is no reason that stakes have to go into an
anvil, you could make up an alternative mounting for them (but it is nice to
have something "solid" under them).
Normally it should not be a close fit between the hardy hole and the
shanks of the stakes. If it is the stakes run the risk of getting stuck
which they should not. Have a close look at your anvil and I bet the
hardy hole is not tapered only the shanks of the stakes are. Forget all
I said about a tapered square hole in the extension socket in my earlier
post. It should be straight.
If the stakes get stuck you have to give them a whack with the help of a
piece of round bar trough the other end of the hole. This is one reason
why the hardy hole always runs right trough the anvil.
Use a threaded hole in the square shank on the extension socket and keep
it firmly in place with a drawbar right through the hardy hole and you
will not be able to move it even with a sledge hammer. This square shank
does not have to be tapered but should have a close fit to the square
hole in the anvil. It does not have to be long just enough to keep it in
place sideways. The draw bar will make it sit firmly on top of the
anvil. Let the threaded hole go right through the extension socket.
Make the draw bar out of a tube so that you could get at the stake if it
should get stuck.
Just an idea how to solve your problem. Two stupid ideas can sometimes
be combined to a less stupid one you know ;=).
Andrew Maws> Ulf, I like the concept, but I think it would be too wobbly to be