On Tue, 21 Nov 2017 12:54:35 -0700, "Bob La Londe"
wrote:

I've decided I need some sizes of tool holders for the Hurco KMB1, that just
do not seem to exist. I've looked at various options and employ several of
them, but what I really need is solid one piece tool holders in those sizes.
In order to make things a little quicker for setup and tool changes most of
them will get extended nose for holding the tools so that small tools with
have a similar over all length to larger tools. Among them of course is a
handle full of 3/16 and 1/8 with an extended nose. Maybe upto 3/8. To this
end I've picked up some "micro" carbide boring bars. Those I have on hand
have a 3/16 shaft with a flat to orient the cutting tip.

Anyway, my plan is do everything except back drill the clearance hole in one
setup on the modestly ok import 14x40 lathe. The locking color will get
machined separately and expanded with heat to be slipped on later. After
measuring several commercially made tool holders that part really isn't all
that critical. The taper is what accounts for all of the accuracy of the
tool.

My query is about the little baby boring bars. The best way to set them up
and mount them. I don't have any boring bar holders that small. I almost
said "of course," but I've learned when it comes to machining if somebody
can think of it somebody has probably already made one. For my larger
boring bars I have actual boring bar holders that fit the QCTP on the bigger
lathe. Now I do have some tool holders for my QCTP that have a groove in
the bottom for a boring bar. I keep a 3/8 boring bar in one all the time.
Its pretty handy. I am just wondering if the little tiny 3/16 shank (.120
minimum hole size) micro bars will hold well in that or if they would just
get lost. I'll have to cut pretty light since I'll be boring medium hard
steel, and I'll be creeping up on a dimensions with a minus pin gage, but I
want to get as rigid as possible with such a small tool.

My first thought was that I might have to make a holder for the little
boring bars that will fit in the QCTP holder. I'll be drilling and boring
modestly deep for that size tool.







Greetings Bob,
Holding those small bars in the v grooved will be fine. And the
setscrews will locate on the flat to boot. You may run out of height
adjustment though. This means you might need to put a little spacer on
the tool post for the knurled height adjustment nut to bear against. I
do this with no problems.
Eric