Problems drawing connected arcs

[DickB]

JLT, that's awesome! I'm busy right now, but will definitely look at this later. I've made a few changes to your scripts, and have wanted to dig in more to see if I could make some more extensive modifications. I'd really like the ability to produce involute gear sets.

Dick

[JLT]

Dick,

Oddly enough, when I first put together the radial vector generator, I began with involute profiles till I did some research and realized that cycloidal profiles were typical for clock works. I'll dig up the involute profile work that I had done before (which I seem to recall was much simpler than the cycloidal!) and pass it along this weekend...

R, Jon

[DickB]

Cool! I have projects in mind other than clocks, and the involute profile seems more appropriate. I know a few other forum members were looking for gear design tools as well for different gadgets.

[oscarl48]

And here I go getting back sucked in on trying to learn how build clocks again.

I typically don't have such problems learning stuff but for whatever reason clock design and gearing seems to be my current nemesis. All these designs and ideas are very inspirational though.

A sincere big thanks for bringing it back up. I do have a growing pile of gears just sitting in a corner.

[DickB]

The wabble gearing simplifies clock design. You need only one 12:1 wabble set for minutes to hours and one 60:1 set of seconds to minutes.

[JLT]

Dick,

I've uploaded the latest Radial Vector Generator v1.5a at the original post http://forum.carvewright.com/showthr...ctor-Generator , as I realized that the Wabble script I provided earlier wouldn't work with the older version. The new zip file contains both the Wabble Gear and the Involute Gear profiles. I haven't actually cut either the Wabble or Involute Gears, so you might be off roading a bit when you first go to use these profiles. Also, in playing around with the Involute Gear generator, I noticed that large gears didn't generate well with the normal pressure angles of 20+ deg, so I incorporated a check in the Involute script to ensure that the base diameter (where the involute profile begins) is larger than the dedendum circle, and if not, throw out a new recommended pressure angle... The discussion on the involute gear profile might eventually warrant another thread...

R, Jon

[DickB]

Thanks! I only got a chance to take a quick look - I wish I didn't have other projects in the queue right now! This will definitely be a big help.

FYI, there are cases where one would want to adjust the percentage of arc on the wabble gears to less than 180 degrees - does this make sense?

[JLT]

FYI, there are cases where one would want to adjust the percentage of arc on the wabble gears to less than 180 degrees - does this make sense?

Yes, makes perfect sense... easy enough to incorporate as another parameter, presuming the profile is always an arc, and not a sinusoidal wave... Although off the top of my head, I can think of a few ways to incorporate the parameter...

1) As the range of the arc, from 0 - 180 degrees, with 0 of course being a flat line, and 180 being the full arc.

2) As the height to the "tooth tip" away from the pitch diameter. Of course, this would be bounded by 0 and whatever height represents the radius of the width of the tooth.

3) As a percentage from 0% to 100%, basically being translated to an arc from 0 to 180.

Not sure what my inclination is, as I haven't dabbled in wabble gears, but suspect #3 is most intuitive to interpret the outcome...

[DickB]

You and me both - I'm just starting in wabble gears. Haven't cut one yet, but will do so soon.

[JLT]

Dick,

Uploaded the next iteration of the Wabble script, including it in a re-upload of the v1.5a zip file at the original post http://forum.carvewright.com/showthr...ctor-Generator.

In addition to the parameter to control the height of the tooth arc, I also incorporated the generation of the Ring Gear with an additional parameter to permit adjustment to the Ring Gear diameter to provide some clearance between the Wabble and Ring gear teeth as they pass each other. My intuition tells me there's more math to the profiles than simple arcs (kinda like the rolling action of the involute and cycloidal profiles), but I could be wrong...

R, Jon