My numbers are similar (not exactly the same):

Major Dia: 0.3678
Minor Dia: 0.3239
Thread Depth:  0.2555

I am measuring with thread wires (0.029 dia) and am trying to get a pitch dia 
of between 0.3468 and .3430 (class 2A or better).

-Tom


> On Jun 5, 2017, at 5:30 AM, andy pugh <bodge...@gmail.com> wrote:
> 
> On 5 June 2017 at 02:22, <tom-...@bgp.nu> wrote:
> 
>> Currently I do that by cutting a diameter with the threading tool.  I
>> measure that with a micrometer and I enter the DRO value in the tool touch
>> off for that tool (I have a routine that leaves the tool at the diameter
>> after cutting so this works).  But I am wondering, I don’t have a DIAMETER
>> value in the tool table for the tool.  Should I?  Is a zero (or
>> non-existant) radius value causing Linuxcnc to think the tool is longer
>> than it really is when cutting?
> 
> 
> How do your numbers compare with line 502 of this spreadsheet?
> https://docs.google.com/spreadsheets/d/1m5zkO9-SbQaYWbTPlQXJ2VA73Ys8WgWDrPk_rEukHc0/edit?ts=57064122#gid=0
> 
> (This is a version of the table I complied 20 years or so ago, but modified
> to include the effects of crest and root flattening/rounding)
> 
> The DXF file of the inserts shows a 0.05mm radius, whereas as the web-page
> table shows 0.06mm. In either case the tip is rounded, not flat.
> 
> You might consider drawing the thread in CAD, with the exact profile for
> the thread and grade required, and then fit an exact drawing of the insert
> into it. That might answer the question of how to touch-off and what to.
> 
> It is an interesting puzzle, and I am another who will admit to "creeping
> up" on one-off threads.
> 
> -- 
> atp
> "A motorcycle is a bicycle with a pandemonium attachment and is designed
> for the especial use of mechanical geniuses, daredevils and lunatics."
> — George Fitch, Atlanta Constitution Newspaper, 1916
> ------------------------------------------------------------------------------
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> _______________________________________________
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users


------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Reply via email to