Re: Form tapping blind holes, what coolant?

On Mon, 7 Jan 2008 16:25:04 -0500, "Tom Accuosti"
<taccuostiMY@xxxxxxxxxxxxxxxxxx> wrote:

Matt Stawicki wrote:
On Mon, 07 Jan 2008 15:20:06 -0500, Randy <rbraun333@xxxxxxxxx> wrote:

On Mon, 07 Jan 2008 08:56:33 -0800, brewertr@xxxxxxx wrote:

On Mon, 7 Jan 2008 11:26:12 -0500, "Tom Accuosti"
<taccuostiMY@xxxxxxxxxxxxxxxxxx> wrote:

Randy wrote:
I will be tapping a bunch of 4-40 blind holes in 6061 alum, would
like to just keep using my flood coolant, even though I know a
bunch of guys here hate "toilet water". Ran a few test samples
and manually applied lube. I was afraid of the coolant trapped
under the tap and hydraulicing it. What works? go slow so the
coolant can get out, or just abandon the flood and manually blow
out the holes and add lube?

You can get form taps that have three or four pronounced "lobes".
Alternately, some will have an oil groove cut along one side.
Either one should work just fine in Aluminium with water. We tap
bling holes in our lathes all the time that way.

Tom

Ditto what everyone else said so far and assuming rigid taping, run
the RPM near machine maximum for your rigid tapping cycle.

Tom

This is one of those things I'm still getting used to, the spindle
speeds in CNC work, Hell the old manual mill topped out at 2850. My
VMC will do 8000 for 20 min and 6000 continuous.

I had programmed 1000 PRM and 25 IPM, but I chickened out and ran it
at 400 RPM and 10 IPM.

IPM??
Why would you use a per minute feed on a tap?
I would think you'd be better off using IPR.

'cos he's using a mill, Matt. Those guys don't know how to think properly
about feed rates, remember?


Yeah, I remember. I also remember how back asswards it seems:-)
They keep talking about chip load, and how it needs to be constant,
but yet they program in IPM and intentionally mess with chip load
every time there's a variation in RPM! Plus, to calculate chip load
they HAVE to calculate the feed per revolution anyway! Why on earth do
you have to convert it to IPM?? You want .0005" per tooth chip load on
a 4-flute cutter - .0005" x 4 = .002" per revolution. Done deal. No
matter what rpm you run, you got a .0005 chip load. Even if the
spindle bogs down on a heavy cut, ya got a .0005 chip load, and no
chance of over loading your cutter.

Has to be a hassle. I've never done it, but from what I've read in
this group, to do a pocket in a part, it seems that with the same
cutter you constantly have to change feeds. Ramp in at one feed, move
over at another, slow down for the corner, speed up for side 2, slow
down for the next corner, Etc, etc, and then clean out the center at
yet another feed.

Now, lets change the rpm cause I'm smoking the cutter. How many feeds
are you going to have to change??? Let's hear it for IPR! Who cares
what you do with the RPM, you still have your constant chip load. Make
perfect sense to me:-)

The only reason I EVER program in IPM is when milling or cross
drilling on my Swiss. Don't have a choice. I HAVE to feed in IPM
because the main spindle is stopped.

Found out about IPM the first time I had to mill on a Swiss. "How do
you do that?" Just take your IPR x RPM. "That's simple enough, Cool!"
Then I heard about chip load. "Oh, OK. How do I do that?"
Well, first ya gotta find your IPR!!!!!!

DUH!

Do you guys turn around and go up the stairs ass first? :-)

Matt
.

Relevant Pages

  • Re: Form tapping blind holes, what coolant?
    ... RPM, but wanted to keep the chip load the same as it was, I would have ... Using IPR, if I make an RPM change, I don't have to do anything else. ... My feeds stay exactly the same as they were. ... 4-flute cutter, is .002" Per Revolution of said cutter, i.e. the ...
    (alt.machines.cnc)
  • Re: What is the best speeds and feeds reference?
    ... I want to write a calculator to figure out the best speeds and feeds ... Cutter diameter does not factor into "feed per tooth" a.k.a. chip load, ... into surface feet per minute for determining RPM. ... determines how fast your axis feed can be to maintain a given chip load. ...
    (rec.crafts.metalworking)
  • Re: What is the best speeds and feeds reference?
    ... I want to write a calculator to figure out the best speeds and feeds ... Cutter diameter does not factor into "feed per tooth" a.k.a. chip load, ... into surface feet per minute for determining RPM. ... determines how fast your axis feed can be to maintain a given chip load. ...
    (rec.crafts.metalworking)
  • Re: Speeds/feeds among diff. machines
    ... On a KMB1 Hurco, the fastest these can be milled with a 2 flute carbide em, with one pass at 1/4", is 2.4 ipm at 2400 rpm. ... Coolant is dribble-style. ... In another thread, it was pointed out that faster slotting might be achieved with very fast feeds at, say, a doc of .030. ...
    (alt.machines.cnc)
  • Re: Form tapping blind holes, what coolant?
    ... They keep talking about chip load, and how it needs to be constant, ... matter what rpm you run, you got a .0005 chip load. ... cutter you constantly have to change feeds. ...
    (alt.machines.cnc)