Loading ...
Sorry, an error occurred while loading the content.

70082Re: [Bulk] RE: [mach1mach2cnc] BackLash.. Finally.!! :)

Expand Messages
  • Paul W. Chamberlain
    Mar 1, 2007
      Actually, the reverse is true.

      Conventional milling (cutting chips away from the material) is used
      for removing bulk material.

      Climb milling (cutting chips towards material, and the cutter forces
      tend to "climb" up on the material) gives a smoother finish.

      On my Taig, I only use climb milling for 0.005" or less material
      removal. Back when I was running FADAL Workcenters, most of the
      programs cutting aluminum were climb milling throughout the run. But
      then, we also had some spot facing inside cast aluminum housings
      using endmills held in 12" extensions... no perceptable chatter.

      I have a compressed air blow gun in my enclosure, and clear the chips
      before the finish pass to reduce re-cutting chips for the best
      finish. I use a mister, so chips stick around. Flood coolant would
      keep the chips clear.

      Paul, Central OR

      *****

      --- In mach1mach2cnc@yahoogroups.com, Dave <dc9@...> wrote:
      >
      > I always thought that climb milling was to be reserved for hogging
      with
      > rough milling cutters and such. And that conventional milling was
      the
      > best approach for a smooth finish. If that is the case, then who
      would
      > really care about backlash compensation when climb milling since
      it's a
      > roughing operation anyway unless the machine had a tremendous
      amount of
      > backlash?
      > Am I wrong about that?
      > Dave
      >
      > Mark Vaughan wrote:
      >
      > > I think about it from my manual mill which has loads of backlash.
      > >
      > > Conventional mill and you take up the slack before you make
      contact.
      > >
      > > Climb mill and I have to tighten the jibs and feed reel slow to
      stop the
      > > cutter sucking the workpiece in with a grunch as it snaps up the
      backlash.
      > >
      > > All this applies to backlash compensation, you won't be able to
      stop the
      > > cutter pulling the workpiece in on climb milling, but it will
      effect where
      > > the cut ends.
      > >
      > > May just be an issue that compensation cannot be used when climb
      milling.
      > >
      > > Dr. Mark Vaughan Ph'D. B.Eng. M0VAU
      > >
      > > Managing Director
      > >
      > > Vaughan Industries Ltd, reg in UK no 2561068
      > >
      > > Water Care Technology Ltd, reg in UK no 4129351
      > >
      > > Addr Unit3, Sydney House, Blackwater, Truro, Cornwall, TR4 8HH,
      UK.
      > > Phone/Fax 44 1872 561288
      > >
      > > _____
      > >
      > > From: mach1mach2cnc@yahoogroups.com
      > > <mailto:mach1mach2cnc%40yahoogroups.com>
      > > [mailto:mach1mach2cnc@yahoogroups.com
      > > <mailto:mach1mach2cnc%40yahoogroups.com>]
      > > On Behalf Of art
      > > Sent: 01 March 2007 20:06
      > > To: mach1mach2cnc@yahoogroups.com <mailto:mach1mach2cnc%
      40yahoogroups.com>
      > > Subject: Re: [Bulk] RE: [mach1mach2cnc] BackLash.. Finally.!! :)
      > >
      > > Hi Mark:
      > >
      > > Hmm, I hadnt really though of any connection to climb milling..
      Ill
      > > keep my
      > > eye on that
      > > and give it some thought. Originally, I had planned on making
      LCam do the
      > > backlash with true movements, but it really complicates arcs, as
      they
      > > become
      > >
      > > parabolas, not a good thing..
      > >
      > > Thanks,
      > > Art
      > > www.artofcnc.ca
      > >
      > > Videos And Support Forums http://www.machsupp
      > > <http://www.machsupport.com <http://www.machsupport.com>>
      > > ort.com
      > > Users Map: http://www.frappr <http://www.frappr.com/machsupport
      > > <http://www.frappr.com/machsupport>>
      > > com/machsupport
      > > ----- Original Message -----
      > > From: Mark Vaughan
      > > To: mach1mach2cnc@ <mailto:mach1mach2cnc%40yahoogroups.com>
      > > yahoogroups.com
      > > Sent: Thursday, March 01, 2007 3:32 PM
      > > Subject: RE: [Bulk] RE: [mach1mach2cnc] BackLash.. Finally.!! :)
      > >
      > > Hi Art
      > >
      > > Just thinking aloud for a minute, and this may not be viable.
      > >
      > > For backlash to work correctly it would depend on whether you are
      > > conventional or climb milling, this would set whether backlash
      > > compensation
      > > is required at the start of a cut, or at the end.
      > >
      > > It's a bit like tool offset compensation and really needs
      commanding
      > > within
      > > the Gcode, as you said this starts to make it complex.
      > >
      > > However you are writing a tool, lazy cam, that might have much of
      the data
      > > available to do this. Either by adjusting the parameters in the
      right
      > > place
      > > to do the compensation itself, or since you set climb or
      conventional
      > > milling, then you could also set a Gcode command to set the
      backlash on in
      > > the right place.
      > >
      > > The other method I suppose is just recommend conventional milling
      if
      > > compensation is switched on.
      > >
      > > Just a thought anyhow.
      > >
      > > Regs Mark
      > >
      > > Dr. Mark Vaughan Ph'D. B.Eng. M0VAU
      > >
      > > Managing Director
      > >
      > > Vaughan Industries Ltd, reg in UK no 2561068
      > >
      > > Water Care Technology Ltd, reg in UK no 4129351
      > >
      > > Addr Unit3, Sydney House, Blackwater, Truro, Cornwall, TR4 8HH,
      UK.
      > > Phone/Fax 44 1872 561288
      > >
      > > _____
      > >
      > > From: mach1mach2cnc@ <mailto:mach1mach2cnc%40yahoogroups.com>
      > > yahoogroups.com [mailto:mach1mach2cnc@
      > > <mailto:mach1mach2cnc%40yahoogroups.com> yahoogroups.com]
      > > On Behalf Of art
      > > Sent: 01 March 2007 13:14
      > > To: mach1mach2cnc@ <mailto:mach1mach2cnc%40yahoogroups.com>
      > > yahoogroups.com
      > > Subject: Re: [Bulk] RE: [mach1mach2cnc] BackLash.. Finally.!! :)
      > >
      > > Mark:
      > >
      > > Too true. My problem was one of what people expect. Backlash is
      one of the
      > > hardest things to do right. Its taken me 3 years to get to that
      spot
      > > in the
      > > driver.
      > > Its important to me to keep it in the driver, I dont want comp in
      the
      > > application, too much complexity.. The old backlash caused great
      problems
      > > for some, and some expect seamless operation with backlash..
      THisis
      > > about as
      > > close as I can get...so far anyway..
      > >
      > > Thanks,
      > > Art
      > > www.artofcnc.ca
      > >
      > > Videos And Support Forums http://www.machsupp <http://www.machsupp
      > > <http://www.machsupport.com <http://www.machsupport.com>> ort.com>
      > > ort.com
      > > Users Map: http://www.frappr <http://www.frappr
      > > <http://www.frappr.com/machsupport
      > > <http://www.frappr.com/machsupport>> com/machsupport>
      > > com/machsupport
      > > ----- Original Message -----
      > > From: Mark Vaughan
      > > To: mach1mach2cnc@ <mailto:mach1mach2cnc%40yahoogroups.com>
      > > yahoogroups.com
      > > Sent: Thursday, March 01, 2007 5:17 AM
      > > Subject: RE: [Bulk] RE: [mach1mach2cnc] BackLash.. Finally.!! :)
      > >
      > > The trouble with all this backlash compensation is backlash is
      play in
      > > your
      > > system.
      > >
      > > Whether compensation is, or is not required depends on the
      direction of
      > > cutting force, whether you are climb or conventional milling.
      > >
      > > Fine on a lathe where load is normally in the same direction.
      > >
      > > Because mach offers backlash compensation many diy users will
      think
      > > it's OK
      > > to build a machine with half an inch of backlash and mach will
      take
      > > care of
      > > it.
      > >
      > > We need to all be very careful what we understand can and cannot
      be done
      > > with Art's backlash system.
      > >
      > > There is no substitute here for tight screws. (No pun intended).
      > >
      > > Dr. Mark Vaughan Ph'D. B.Eng. M0VAU
      > >
      > > Managing Director
      > >
      > > Vaughan Industries Ltd, reg in UK no 2561068
      > >
      > > Water Care Technology Ltd, reg in UK no 4129351
      > >
      > > Addr Unit3, Sydney House, Blackwater, Truro, Cornwall, TR4 8HH,
      UK.
      > > Phone/Fax 44 1872 561288
      > >
      > > _____
      > >
      > > From: mach1mach2cnc@ <mailto:mach1mach2cnc%40yahoogroups.com>
      > > yahoogroups.com [mailto:mach1mach2cnc@
      > > <mailto:mach1mach2cnc%40yahoogroups.com> yahoogroups.com]
      > > On Behalf Of Rich Crook
      > > Sent: 01 March 2007 08:08
      > > To: mach1mach2cnc@ <mailto:mach1mach2cnc%40yahoogroups.com>
      > > yahoogroups.com
      > > Subject: Re: [Bulk] RE: [mach1mach2cnc] BackLash.. Finally.!! :)
      > >
      > > Umm... I think you've got that backwards.
      > > 0.0001 mm is *one tenth* of a micron! A micron is a thousandth of
      a
      > > mm, or .00003937" (just shy of 4 ten thousandths).
      > > I'm pretty sure he meant .0001"
      > >
      > > = Rich =
      > >
      > > >Art,
      > > >Holy shit, 0.0001mm is about 4 microns! Did you have to pawn
      your
      > > first and
      > > >second born for your glass scales? Are you sure you don't mean
      0.0001"?
      > > >
      > > >Andrey
      > >
      > > >Hi Andy:
      > > >
      > > >According to my glass scales, the backlash is exact to .0001mm
      on my
      > > >system.
      > > >Thats about as exact as my system can handle...
      > > >
      > > >Thanks,
      > > >Art
      > > >www.artofcnc.ca
      > >
      > > [Non-text portions of this message have been removed]
      > >
      > > [Non-text portions of this message have been removed]
      > >
      > > [Non-text portions of this message have been removed]
      > >
      > > [Non-text portions of this message have been removed]
      > >
      > > [Non-text portions of this message have been removed]
      > >
      > >
      >
    • Show all 13 messages in this topic