Gearify

[ArtF]

>>As far as I can tell, base circles are great when you want to generate the gears on paper using physical tools like string

  lol, your probably right, but I tend to figure these things out with trigonometric analysis, my background is not such that I can
create the equations necessary to bypass the information things like the base circle give me. One of the papers Ive used in the
past for involution theory on a noncircular gear was based on doing exactly that, they included a formula for the base curve of the ellipse
as it relates to the tangents of the ellipse,( it really isnt a shrunken ellipse, the profile actually crosses over with curvature)
from there they suggested an involution based on  point by point changes in that base curve.
  I did attempt their suggested procedure , but found it was really no more efficient that what I was doing codewise, so moved on to
virtual hobbing..

Art

[Nate]

... my background is not such that I can create the equations necessary to bypass the information things like the base circle give me. ...

I've been musing on this, and am unsatisfied with the explanation that I gave earlier:  it's not practical, doesn't address things like planetary gears and racks, and doesn't provide insight into how I'm thinking about things.

What language(s) are you guys coding in?

[ArtF]

Nate:

>>What language(s) are you guys coding in?

  C++ here.
 
    I know what you mean, language is a problem. Something like a base circle not being considered isnt really
accurate to me if we consider an oscculating circle.. which is really an analogue for the actual base circle. Circle though becomes
poor terminology as its neither a circle nor neccesarily inside the ellipse.  I guess I consider the term  "the tangental 
series of points defined by the objects pressure angle calculations" ... but its easier for me to consider that a base circle. :)
  Either  way you try to describe a solution, I suspect its more an algorithmic discussion as Im sure its solvable, Im just not willing
to do 30,000 lines of code to do so. When I get far enough away from an elegant solution, I wait till I have one. Hobbing
works well as it takes the trochoidals into account in the more extreme noncirculars.
  That having been said, I welcome the discussion on a better and more elegant method, I do like it when the numbers line up.,
and your ideas sound like they have a lot going for them..

Art

[Nate]

...

If measured from (p1-p2) I feel that there would be severe disortions where t1-t2 differs significantly. But if from t1-t2, the gears may not "push" on eachother properly and the entire benefit of involute teeth is compromised.

Thoughts?

It looks like I misremembered, and you want to use the tangent line for gears that are that eccentric.

[ArtF]

>>It looks like I misremembered, and you want to use the tangent line for gears that are that eccentric .

  So is that a drawing of using tangent lines of the shapes themselves? Or pressure angle calculated
tangent points, or osculated circle tangents?


( Ill be away starting tomorrow for 12 days. Ill catch up then. :) )

Art

[Mooselake]

Enjoy your vacation!  Try not to think about gears :)

Kirk

[Nate]

>>It looks like I misremembered, and you want to use the tangent line for gears that are that eccentric .

  So is that a drawing of using tangent lines of the shapes themselves? Or pressure angle calculated
tangent points, or osculated circle tangents?

...

The pressure line is off the tangent line by the pressure angle.  I.e. rotating the analogue of the t1-t2 line by the pressure angle.

Enjoy the vacation.

[ArtF]

Nate:

>>The pressure line is off the tangent line by the pressure angle.  I.e. rotating the analogue of the t1-t2 line by the pressure angle.

  Yes, I agree. What Ive been referring to as the base circles, are those tangent points set at the same distance from pitch point ( cos of the elliptical radius) as the base circle normally is, so  I still refer to them as a base circle points as they are an analog of the same thing in a circular gear. I think for the most point were speaking the same thing, in different languages. Originally, I used to use that (cos()*R) at pressure angle to determine each of the  base points for any point in the rotation, then calculate the involution from that point. Now all that was ,to my mind ,necessary to pick a start point for the involution to occur, but
as you stated it, calculating a running contact point up that line sounds better and easier, with no need to
figure the involution angles involved.. maybe..

  >>Enjoy your vacation!  Try not to think about gears

  I will and Ill try. But Ill fail. lol  Thx
Art

[Gearify]

Hello!

Some of you may be interested to know that Gearify is developing a new tool for the generation of involute teeth on arbitrary pitch curves.

Teaser video can be seen here:
https://youtu.be/8aOFbEwis1w

I made an in depth mathematical analysis to understand how the constraints and degrees of freedom change at each point along the curve and made some intriguing discoveries.

Feel free to leave questions or feedback. The tool is not released to the public yet, but if anyone has a significant and immediate need for such a tool, we can discuss.

-Gearify

[ArtF]

Looks good. Looks very similar as to how Gearotic does it, a digital subtraction where the involute evolves from the instantaneous rate of change during its construction? I find it works well until pressure angle drops too much , then the gears fall apart in real life running while they simulate fine. Backlash tends to be an issue
depending on contruction and elliptial coefficient. They look good though, generation seems smooth.

Art

[Mooselake]

Glad to see new development with Gearify!

Kirk

[Gearify]

Looks good. Looks very similar as to how Gearotic does it, a digital subtraction where the involute evolves from the instantaneous rate of change during its construction?

Right now, these curves are generated without any subtraction at all, just solving differential equations numerically in 2 dimensions. This produces "pure" involute curves that are exactly correct at every point. The only problem is that since these curves evolve, they may interfere with each other as they engage or disengage, so my last task is to find an appropriate solution to minimally clip, truncate or sheer off areas to prevent the teeth from jamming - that final piece may be done via a subtraction algorithm, but we'll see.

-Michael

[Mooselake]

I just emailed Michael Valle wondering if he was still around, and he replied that he's "hard at work developing the next version and expect to announce some very exciting new features that are planned for it in the coming months."

Kirk

[ArtF]

Thanks Kirk:

Good to know. Its a nice program. I expect I'm several months away
from the next incarnation as well. Im finding the physics a bit harder to properly
simulate in 3d versus the Auggie simulator in 2d. ITs a great learning experience though.

Art

[Gearify]

Hello, all!

As was mentioned above I am indeed hard at work on the next version of Gearify. I just released a 20ish minute video/talk on the status of the upcoming product.

https://www.youtube.com/watch?v=rnZDdAplqp4

Hope you all will check it out!

-Michael