5634
« on: October 06, 2009, 08:43:40 PM »
ART,
Just a few more tests.
I was curious on how things would behave as the spindle speed was increased.
In post # 481 things scaled rather linear at 115 rpm. as shown below.
TPI TRUE PITCH MODIFIED PITCH
10 .1 .1008
20 .050 .0504
40 .025 .0252
So i did some testing at higher spindle speeds. If I go past 600 rpm i would need to change kernal speed
above 25000khz so a little limited ( trying to keep stuff constant).
The threading was for 10 TPI ( .1 pitch ) 40 passes.
RPM PITCH / Inch MODIFIED PITCH USED FOR PERFECT LEAD
(DECREASE)
115 .008 .1008
194 .0055 .10055
402 .0035 .10035
So the pitch decreases also as the RPM increases. I will assume that for smaller threads at the higher rpm
they would proportionately decrease as like the 115 rpm tests for 10, 20, 40 tpi.
Just a note, according to Mr. Smid, a lead error will be intoduced on long threads if you use a Feedrate less than
six figures ( not required for leads divided into 4 or fewer decimal places ).
RPM
--------
I din't try any of the advanced threading plugs in yet. I will confirm my measured spindle rpm's later since a friend will be lending me an accurate time measuring device.
I wonder if the error goes away at 1000 rpm?
RICH