On 2008-10-01, Vernon wrote:
On Sep 30, 11:33*pm, "DoN. Nichols" wrote:
[ ... ]
* * * * Simplest thing would be a wood frame around it with window
screening all around it, and some easy way to get inside if you need to
use the front panel controls. *This should keep the chips out, and let
air flow through to cool it.
* * * * If you're going to add a braking resistor (if you decide that
you *need* instant reverse), you want it to mount to metal, not wood, to
avoid fire. *In use those can get fairly hot.
[ ... ]
* * * * * * * * * * * * * * *Once I've determined that both motors run
I will attempt to finesse the thing into something more
sophisticated.
* * * * O.K. *You can probably test the idler motor (perhaps with the
fan removed) by driving it from the VFD.
The consideration being that with the fan in place, it will
probably draw too much for the VFD to run it. But bare, with no load,
it can probably be spun up by a 3 HP VFD with no problems -- especially
if the VFD is set to a long acceleration time.
[ ... ]
Then there's tooling. *I hope to buy some kind of lot assortment on
ebay. *I looked tonight. *A couple of guys are selling it saying
they're retiring. *Of course I still don't know an end mill from a
collet.
* * * * You will learn -- and this approach, while it might not give you
everything you need, will get you started.
[ ... ]
Hey Don,
According to the on-line owner's manual for this and other Hitachi
VFDs, if I understood it correctly, they already have a programmable
instant reverse circuit. That section of the manual went pretty much
over my head. But at least the node is there. Apparently they
recommend you "try it" and if it's not fast enough recommend adding
another resistor.
Right. And the spindle of a mill is not nearly as massive a
thing to accelerate as the spindle of a lathe with a large chuck in
place, so the built-in resistor in the Hitachi should be sufficient,
unless you hang a big boring head on the spindle, and set it for the
highest speed -- probably a bad idea anyway, from the likely imbalance
of a boring head.
Indeed, I did start two threads. One for the mill drill and the other
for the lathe / mill. I myself forget which one I'm in. But the mill
is a KBC brand. It is an old model Grip-16 visible on the
kbctools.com website under "mills". Takes an R8 collet. Oddly, mine
is painted "grizzly green". THe KBC guy stridently denied any
connection between KBC and Grizzly. The new ones, as seen in the KBC
catalog are a different color scheme.
Well ... color schemes are easy to change -- just a different
requested color from the real manufacturers in Taiwan or China. :-) And
yours may have been from before Grizzly started selling metalworking
tools in addition to woodworking tools.
The foot print of the mill is approximately 16" x 24". The narrow
dimension is the width. The Diacro punch press table I have is just a
little wider than the base of the mill. But the mill is a tad longer
front to back than. Nevertheless, both the base of the mill and the
feet of the table are drilled to something like 1/2".
Hmm ... how strong a slab are you mounting it on? Is it thick
enough to accept drilling for anchors? If not, go for the outrigger
legs instead -- which will also make it easier to move things if you
decide to re-arrange the shop's layout.
The point about
the table and work overhanging is a good one and well taken.
The tech support guy for the VFD seller tells me that lots of people
install the drives in the cabinet beneath the mill. I intend to duly
consider this.
IIRC -- the cabinet in your case is an open frame table. But if
you mount a metal plate on the back for the power lines to go through,
and enclose the sides and front in window screening, it should keep the
chips clear, and allow airflow to keep the VFD cool. Obviously, plug or
tape over the holes in the top which have not been used to mount the
mill.
But I am definitely concerned about burs, chips and
dross falling into the innards. Of all the 3 phase albatrosses I have
around the one I'd most like to get going after the mill is a 48"
bandsaw.
A good choice. I wish that I had one of that size.
Following that I have an antique Lincoln 3 phase welder. It
is a DC generator welder spun by a 3 phase motor at the base. Looks
like a fire hydrant on wheels. Probably built in about 1943 or
something like that. I've been unable to discern the horsepower as
yet.
Hmm ... perhaps -- assuming that you don't use the welder near
full power rating -- you might be able to get away with a capacitor
start circuit like the Phase-O-Matic -- or like the auto starting
circuitry on a rotary converter.
If it is that old, the horsepower will probably be smaller than
you would expect for the size.
Can you find current and voltage specs on labels on the outside
of the device?
Good Luck,
DoN.
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