"tnik" wrote in message
...
On 11/16/2011 9:57 AM, wrote:
On Tue, 15 Nov 2011 17:16:48 -0800, "PrecisionmachinisT"
wrote:
wrote in message
...
I posted a while back that I might be buying a Fadal mill and running
it from a phase converter. Well, I'm buying it. I'll write the check
tomorrow. It's a model VMC-15 and has rigid tapping so I guess I'll
need that parameter changing info. Also, just what is the advantage of
rigid tapping over tapping heads?
Thanks,
Eric
The main advantage of having rigid tapping is that it allows you to use
standard drilling collets and chucks instead of having to buy a bunch of
additional specialty tooling that is only useful for tapping.
So all the compression/tension tap holders and collets I'm also buying
are not neded? I can just hold the taps in ER collets for example?
Eric
You can and we have before, especially when we didn't have a tap holder in
stock. But we have found out that it's much safer to use a rigid tap
holder. Least if its in a tap holder, you KNOW the tap isn't going to
spin. Plus we have a bunch of tap holders anyway for the machines we have
that don't have rigid tapping.
Well, if a tap is going to spin, it almost always will spin on entry and on
reversal it will come back out of the part just fine and so whether or not
it breaks off instead of backing out is largely dependant on how far it can
be shoved upwards before bottoming out in the collet, and I would much
rather have the tap spin and ruin a collet than to have it break off and
**** up an expensive part but even then it's still kind of a crap shoot.
That said, even though there is rigid tapping on two out of our three
Fadals, I don't use it simply because most of our workload repeats...which
means that I would have to either edit at the machine, produce a duplicate
program for pretty every freakin job that involves tapping, or maintain a
list of jobs that can't run across the machine that lacks the function ( and
try to schedule production accordingly ) all of which IMO would
unnecessarily complicate things.