Hello Guest it is April 23, 2021, 03:13:35 AM

Author Topic: Mach 3 turn constant sfm?  (Read 29875 times)

0 Members and 1 Guest are viewing this topic.

Re: Mach 3 turn constant sfm?
« Reply #30 on: December 10, 2010, 07:11:45 AM »
 :D
 :D
 ;D
This was found in a cave written in ancient Hebrew on some old papyrus.
It has been translated. (most likely copied from the original stone tablets)
(rpm = sfm × 3.82 ÷ cutting diameter)
There was a Spread Sheet along with the Dead Sea scrolls but it was in an unsupported version.
Could make up a new one though. :)
« Last Edit: December 10, 2010, 08:24:25 AM by Overloaded »

Offline budman68

*
  • *
  •  2,354 2,354
    • View Profile
Re: Mach 3 turn constant sfm?
« Reply #31 on: December 10, 2010, 01:12:05 PM »
Dave,

Quote
got an "English" version?

yes I do, I will post it up tonight. Only problem is I think its white on pink  ;D

Graham


That's quite alright, beggers can't be choosers.   :)

Thanks,
dave
----------------------------------------------------------------------
Just because I'm a Global Moderator, don't assume that I know anything !

Dave->    ;)

Offline Graham Waterworth

*
  • *
  •  2,307 2,307
  • Yorkshire Dales, England
    • View Profile
Re: Mach 3 turn constant sfm?
« Reply #32 on: December 10, 2010, 03:36:36 PM »
Just for Dave

A table of the old fashioned way of working  ;D

Graham
« Last Edit: December 10, 2010, 03:39:34 PM by Graham Waterworth »
Without engineers the world stops

Offline budman68

*
  • *
  •  2,354 2,354
    • View Profile
Re: Mach 3 turn constant sfm?
« Reply #33 on: December 10, 2010, 03:41:14 PM »
Thank you sir -  8)

Thanks,
Dave
----------------------------------------------------------------------
Just because I'm a Global Moderator, don't assume that I know anything !

Dave->    ;)

Offline DaOne

*
  •  236 236
    • View Profile
Re: Mach 3 turn constant sfm?
« Reply #34 on: December 10, 2010, 04:16:59 PM »
a bit more math that may help some people...


IN -- MM Conversion...

MM = inch x 25.4
IN = mm / 25.4



SFM -- RPM Conversion...

SFM = ( RPM x DIA ) / 3.82
RPM = ( SFM x 3.82 ) / DIA



IPR - IPM Conversion...

IPM = ( # of teeth in the cutter x IPR ) x RPM
IPR = ( IPM / RPM ) / # of teeth in the cutter



Drill Point Length Calculation...

Depth = ( DIA / 2 ) / TAN ( ANGLE / 2 )



Thread Depth Calculation...

External Thread Depth = .61343 x ( 1 / # of threads per inch)
Internal Thread Depth = .54127 x ( 1 / # of threads per inch)
External Thread Depth ( SHARP V) = .86603 x ( 1 / # of threads per inch)  MODIFIED POST: ADDED SHARP V 12/10/10 RICH

Cutter Comp Shift Calculation...

   Compensation for an Angle...
      
      Z Shift Amount at the End Point = TNR x ( 1 - TAN (ANGLE / 2))
      X Shift Amount at the Start Point = ( TAN (ANGLE) x Z (above)) x 2

   Compensation for a Radius...

      Z Shift Amount at the End Point = TNR + Part Radius
      X Shift Amount at the Start Point = 2 x (TNR + Part Radius)
« Last Edit: December 10, 2010, 04:27:47 PM by RICH »

Offline Dan13

*
  •  1,208 1,208
    • View Profile
    • DY Engineering
Re: Mach 3 turn constant sfm?
« Reply #35 on: December 13, 2010, 05:50:54 AM »
Yes that seems to be a good likeness ;D

Ok quick test, first thing was add a blended feed DRO to the screenset

MDI
G96S200
M48S1000
M3

Start at X10
G1X200F0.5

FPR starts at 0.5 and as spindle slows gets as high as 1.3
Blended starts at 490 and remains constant
Next

Start X200
G1X10F.5

FPR Starts at 0.5 and as spindle speeds up it goes as low as 0.16
Blended starts and maintains 155

In other words its well screwed up and would be good to know if others get the same results with the same inputs with SS and PP.

Hood

Hood,

Just did a quick test. Seeing similar behaviour here as well. Mach3 always maintains same mm/min feed and adjusts the mm/rev accordingly. The mm/min feedrate at which it moves corresponds to the mm/rev feedrate at the beginning of the move. This is with a Smooth Stepper.

Dan

Offline Hood

*
  •  25,838 25,838
  • Carnoustie, Scotland
    • View Profile
Re: Mach 3 turn constant sfm?
« Reply #36 on: December 13, 2010, 05:54:59 AM »
Thanks Dan, maybe someone that uses the PP can test to see if its the same, that way I will know who to moan at ;D

Hood
Re: Mach 3 turn constant sfm?
« Reply #37 on: December 13, 2010, 06:29:34 AM »
I did tests as described in my previous posts and mm/rev is adjusted so mm/min is kept constant.  I do not use smoothstepper and the behaviour is the same as described by the guys with smoothstepper so nothing to do with it.  Can anyone suggest a way of getting around this without having to wait for Mach to be fixed ??????????? Some Brains programming or something?

Jorge

Offline Hood

*
  •  25,838 25,838
  • Carnoustie, Scotland
    • View Profile
Re: Mach 3 turn constant sfm?
« Reply #38 on: December 13, 2010, 07:04:21 AM »
Ah sorry, missed your post :(

Dont think really there is another way but I am not up on macros/plugins etc so maybe someone else who is can help, might be possible with formulas but again not got any experience of them. 
I will be sure to let Brian know its screwed ;)

Hood

Offline Graham Waterworth

*
  • *
  •  2,307 2,307
  • Yorkshire Dales, England
    • View Profile
Re: Mach 3 turn constant sfm?
« Reply #39 on: December 13, 2010, 07:11:01 AM »
It is possible but not practical to do, the problem is you would have to split every move into small segments and recalculate the speed and feed, this would be a nightmare to do even on a simple part.  I am sure the surface finish would suffer and the delays cause major jerkiness.

Best wait and see if Brian can fix it.

Graham
Without engineers the world stops