5541
General Mach Discussion / Re: Problems threading on the lathe
« on: October 22, 2009, 05:51:13 PM »
ART,
Now this is good news!
Tests all done with Ver.028 - OCT22-1 as shown below:
20 passes @.0002" / pass
Spindle Speed Averaging / Constant Velocity / Debounce Interval=600
Index Debounce=10 Z=60 IPM @ 6 accel / X =80 IPM @ 8 accel
RPM PITCH LEAD ERROR AT LENGTH ( +=INCREASE -=DECREASE)
0.5" 1" 1.7" REMARKS
---- ----- ----- ------ ------ -------------------------
116 .1 N.A. -0.0008 -0.0008
402 .1 N.A. -0.0007 -0.0011
116 .5 +0.0000 /.0014" +.0.0005 / 0.0014 Just measured at two different places abt 180 degrees apart AT 1/2" and 1" lengths.
Attached are the data reports for each.
From a practical point,if actual threading was done and you could hold the diameter and cutting was good, then based on the lead errors above,you would produce a Class 3A thread.
There was a little of the "oscilating" seen but I think what i was realy seeing was backlash. The Z has 0.0008" and the X has 0.0003".
One of the things that come to mind is the acceleration and deceleration.
What i saw was the "oscilating" starting to occur at about 2 threads short of the end of the thread and after 10 thread cycles. Could be wrong. As long as your in these kinds of tolerances who cares!
SO need to have additional testing to see if the above holds true over time.
RICH
Now this is good news!
Tests all done with Ver.028 - OCT22-1 as shown below:
20 passes @.0002" / pass
Spindle Speed Averaging / Constant Velocity / Debounce Interval=600
Index Debounce=10 Z=60 IPM @ 6 accel / X =80 IPM @ 8 accel
RPM PITCH LEAD ERROR AT LENGTH ( +=INCREASE -=DECREASE)
0.5" 1" 1.7" REMARKS
---- ----- ----- ------ ------ -------------------------
116 .1 N.A. -0.0008 -0.0008
402 .1 N.A. -0.0007 -0.0011
116 .5 +0.0000 /.0014" +.0.0005 / 0.0014 Just measured at two different places abt 180 degrees apart AT 1/2" and 1" lengths.
Attached are the data reports for each.
From a practical point,if actual threading was done and you could hold the diameter and cutting was good, then based on the lead errors above,you would produce a Class 3A thread.
There was a little of the "oscilating" seen but I think what i was realy seeing was backlash. The Z has 0.0008" and the X has 0.0003".
One of the things that come to mind is the acceleration and deceleration.
What i saw was the "oscilating" starting to occur at about 2 threads short of the end of the thread and after 10 thread cycles. Could be wrong. As long as your in these kinds of tolerances who cares!
SO need to have additional testing to see if the above holds true over time.
RICH