Release Jul 28 - 2018 - Helical error
Posted: Sun Jul 29, 2018 1:27 am
Hi All:
Gearotic was updated yesterday in its development version due to a fix
being applied for a helical error in 4th axis milling.
My thanks to George M, who found teeth thin on a DP16 helical. I found that a tangental helical angle correction was not being applied to the tool. A tool in helical should be considered to be larger by the sine of the helical angle during planning and it wasnt.
George was instrumental in finding this and very patient as I went over the math carefully
to find the issue.
Smaller helical angles and cuts where the tool size was much smaller than the teeth
would not show this clearly, but on a DP16 gear it was quite obvious and caused
cutoff with large roots. This has been corrected and the tool simulation in gearotic has changed so the tool is a round cylinder which makes it much easier to see any cutoff on the profile. If youve had helical problems in the past this fix may explain the problem.
If viewed from above in the sim, one can now see down to the bottom of the inside of
the tool cylinder. I find now the top view to really show well how helicals are cut.
This isnt yet complete as Im still crunching numbers to verify some of the math
involved in tangency calculations. The development version now contains these corrections
for helical gear 4th axis op's. The sim now shows a much tighter conformance to the vitual
gear. Testing continues. These changes affect only helical operations in 4th axis milling.
The maximum tool size displayed has also been shrunk by the sine of the helical angle
to show a proper maximum size tool possible without gouging.
Ive been working on a few things in the background, which may take a few more weeks
of a couple months to see if they work, hope your summer is going well.
Thx
Art
Gearotic was updated yesterday in its development version due to a fix
being applied for a helical error in 4th axis milling.
My thanks to George M, who found teeth thin on a DP16 helical. I found that a tangental helical angle correction was not being applied to the tool. A tool in helical should be considered to be larger by the sine of the helical angle during planning and it wasnt.
George was instrumental in finding this and very patient as I went over the math carefully
to find the issue.
Smaller helical angles and cuts where the tool size was much smaller than the teeth
would not show this clearly, but on a DP16 gear it was quite obvious and caused
cutoff with large roots. This has been corrected and the tool simulation in gearotic has changed so the tool is a round cylinder which makes it much easier to see any cutoff on the profile. If youve had helical problems in the past this fix may explain the problem.
If viewed from above in the sim, one can now see down to the bottom of the inside of
the tool cylinder. I find now the top view to really show well how helicals are cut.
This isnt yet complete as Im still crunching numbers to verify some of the math
involved in tangency calculations. The development version now contains these corrections
for helical gear 4th axis op's. The sim now shows a much tighter conformance to the vitual
gear. Testing continues. These changes affect only helical operations in 4th axis milling.
The maximum tool size displayed has also been shrunk by the sine of the helical angle
to show a proper maximum size tool possible without gouging.
Ive been working on a few things in the background, which may take a few more weeks
of a couple months to see if they work, hope your summer is going well.
Thx
Art