GearHeads Corner

Hi,

This may be crazy simple, so sorry if it is. However, despite what number I put into the bevel angle box, the only gears it generates are 90 degree shaft angle. Any idea what is going wrong? Thanks

tim

Hi Tim:

Press regen after changing the shaft angle, just tested here to be sure, works fine.

Thx
Art

Thanks for the quick reply Art. I feel like a moron, but no matter what I do I can never get the angle to change. I feel like I am missing something basic, but I can get pretty much every other feature of the program working. Could you possibly make a simple file and post it with non-90 degree bevels and I will poke around to see if I can replicate it?

I have been doing the following workflow:
Spur Gears>Bevel>Specify tooth and angle>regenerate>Create Pinion (or Wheel)
And then I go to project control and they are always 90 degree gears. For what it's worth, I can get the helical properties to work. I am not really sure what is going on. Thanks again.

tim

Hi Tim:

  Thats very weird....  Here is a project with 2 65 degree shaft angle bevels, and 2 23 degree shaft angle bevels. See what they do for you..

Art

Thanks Art.

That works and I can reproduce them. I was trying to make gears with an angle higher that 90, and it never kicked an error, just kept making them 90. I swear I tried some 60 degree gears, but I guess I didn't.

I am looking to make a wobble gear. Any idea of a good way to do it?

Tim

hmm, wobble eh?  Define that... :)

Art

Nutating is probably more accurate. Something like:
http://www.eurekamagazine.co.uk/design- ... tios/2448/

or

http://scholarworks.wmich.edu/cgi/viewc ... ors_theses

On a completely different note, would it be possible to output 3D data for only a pie slice that encompasses one tooth's worth of each gear? With the bevel and helical gears, the surface count climbs tremendously and solidworks has trouble importing them without exhausting its memory. I am sure this is poor programming in SW, but importing a slice and patterning it would be much faster.

Thanks!

tim

Hi Tim:

  Thx for the treatise on nutating gears. For the life of me I cant figure a why on those. I see how they work,
basically the same as epicyclidal gear reduction, bot seem very similar with the nutatin gear having the disadvantage
of being more complex... Ill keep them in mind for future work.

  I cant as yet put out such a slice, but I will try in near future to put the gear out in a stp type of format so that programs
such as solidworks dont choke. Im very very close to the stage of attempting that. Within a few weeks a new version
of GT will be released as a sanity check aginst hardware out there vs the new code for speed and workability. Then Ill be
experimenting with new output formats for CAD users .

Thx
Art
 

Art,

No problem and thank you for the continued replies. Nutating gears do create a lot more headaches with the shaft angles and such, but there are possibilities for CVTs and other functionality that I need for a project that are more difficult with other types of gearing. It is just a concept at this point. There is a PSU thesis out there somewhere that covers some neat CVT designs for helicopters and it is pretty cool stuff.

Thanks for the update on the exporting. I look forward to the additional capabilities.

Tim