Helicals are go !!

[ArtF]

Dan:

  During the clearance ( the first few moves, the tip touches as it clears the tooth "hole", after that
only the side of the tool touches as it shaves the material on the tangents of the involute. Mine have
all come out quite clean, the shaving leaves no real toolmarks . The tip is the only thing that in my mind could
leave a toolmark, and my tip never really touches after the cleance passes.

  It IS important the the blank be the right diameter so the zeroed bit is the right height..b ut even then my is
clean if Im off, but the teeth are the wrong width...

  I find a segmentat ion of 8 is fine ( John also found that 8 was fine at his end ), but I never did one in metal,
so it may be worthwhil e asking John if he had to clean his up at all, I never had to in wood..

Art

 

[Dan]

Thanks Art. I will try to figure why the tool tip touches the tooth while shaving here. Please let know if you have any further thughts for the possible reason.

Dan

[ArtF]

Dan:

   How bad is it? Does it destroy the actual tooth? If the A axis is backwards in rotation you get very bad gouging, remarkabl y you get what kinda looks like a gear though..

  If you can, send me a pic, it may give me a better idea.

Art

[John S]

Dan, Can you post details of the gear you used mod teeth etc ?
You say you are using a 4mm end mill? must be a big gear ? 3mm cutter only just fits a 2 Mod gear and they are quite chunky.

There might be a problem in that a couple I did last show had noticable marks on them, never gave it a thought but the two sample ones I did were fine.
The two sample ones would have been done with an earlier version, show ones with one of the latest.
Did anything get changes Art in later releases ? You may be able to match the sample version by date posted in this thread with what version of GM was current at the time?

OTOH the marks on the show ones could be backlash in slides or rotary table as these machine do plenty of work but get neglected between shows. Most show days and that is either a 4 day or 6 day show they run non stop from 10:00am unti 5:00 pm.

John S.

[ArtF]

John:

  One thing Im very meticulou s on is to not touch Gcode routines that work. The 4th axis routines I am VERY carefull about simply because they are
so hard to test. They have their own code classes , one for helical, one for bevels, and they havent changed since your helical tests to the best of
my recollect ion. They dont even use the solid models just in case I should change something there, the helicals and spur gear 4th axis actually use only
the internal parameter s of the gear ( PA, Module, root diameter etc.. ) to keep them separated . I do this so I dont have a "Doh" moment because I hate
setting up my 4th axis to do the testing.

Art