David Wilkinson wrote:

> Yes it's your intersection with a cylinder to make them truly cylindrical on the
> outside that does it.  I tried differencing the teeth with a cylinder in my
> macro and the time taken goes up dramatically -. 6m.24s. as against 17s. !
> Probably the fastest way would to do this would to add some more points to the
> tooth prism.
> >
> >i don't use diametrical pitch because it's an imperial base messurement, i use
> >metric when ever i can... i'll add it to the next version.  mdl = 1/PD   (= mm of
> >pitch diameter per tooth)   :)
> >
> yes, as you say, continental europe always use module because it relates to the
> metric system and probably many British firms do so nowadays.  I don't know
> about the USA, they have been pretty reluctant to change to the metric system,
> but it's many years since I was involved directly in mechanical engineering.
>

> You will notice I made my gear macro with the centre of one of the teeth lining
> up with the y-axis and also make available the angular pitch outside the macro
> so that it is easy for a user to arrange for them to be correctly meshed.
>
> As you say there are a lot of bells and whistles that can be added, I tried to
> keep it as simple as possible for non-engineers who just want to model some
> gears that are realistic.  Things like the pressure angle and accuracy are very
> easy to alter in the macro.  If you want to go for extreme realism, then perhaps
> you should  consider adding radii to the root of the involute, tip relief to the
> top of the tooth - and even the positive correction of both gears (this is how
> engineers avoid the working surface of the tooth going below the root circle).

positive correction is in it already... took me forever to get the function to do
that...
I'm just adding root radii and tip releaf right now, it was the next thing to do
before

i go to other gear types :)

> >
> >This one is called polar_gear 'cause it is my middle step before making the bevel
> >gear one. polar coordinates are easier to convert into bevel gears...
> >
> All the best with your efforts.  I look forward to seeing your results.
> David
> dav### [at] hamiltonitecom
> http://www.hamiltonite.com/

will have more very very soon... oh, i just moved the intersection into a bounding and
it sped up amazingly... i bet when i go to the new method i'm going to use, it'll make
it even faster :)

oh... my next version is for megapov only, i think... well... no, i'll make that
settable...

well... have fun all :)
       the Loial Raven

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