GearHeads Corner

General Category => Third Party Software => Topic started by: Mooselake on September 16, 2015, 11:22:56 AM



Title: Gearify
Post by: Mooselake on September 16, 2015, 11:22:56 AM
Gearify is aimed at non-circular gears, and especiall y non-circular planetary gears that I've been casually watching for the last year or so.  It was written by a grad student, no updates on YouTube or his site for 5 or 6 months, so I'm trying to get him to respond and see what it's current status is.  Judging from the tutorial video views it hasn't gotten a lot of attention .

It's got something similar to Gearotic's functiona l gears (including turning a picture into a gear, like make an Art gearhead), plus a tool to automatic ally create non-circular planetari es.  Certainly not in Gearotic's class,  but looks like it could create some fun looking toys.  Something else to make with my new K40 laser engraver/cutter...

Anybody here have any experienc e with it, seen it before, or have any comments on it?

Kirk


Title: Re: Gearify
Post by: ArtF on September 17, 2015, 12:05:20 PM
Hi Kirk:

  Looks like great software for decorativ e gears. Its gears do not roll though, near as I can tell they rub.
 So dont use them for loads at all,they are subtracti ons of a shape during a rotation, so they dont really follow a pitchline, as a result, they would have a speed wobble equal to the number of teeth per rev. and a wear pattern due to the mesh rub. Or at least thats what I saw last I looked. But as I say, for decorativ e gears, definitel y a nice package.

Art


Title: Re: Gearify
Post by: Nate on September 18, 2015, 07:58:22 AM
  Looks like great software for decorativ e gears. Its gears do not roll though, near as I can tell they rub. ...

Do you mean that they act by surface friction rather than normal forces on the faces?  (I think we all know that gears have to slip against each other a little bit to work properly.)  It does look like these gears 'roll' more than they mesh, but I'm not sophistic ated enough to tell by looking.


Title: Re: Gearify
Post by: ArtF on September 18, 2015, 11:02:43 AM
Nate:

 The theory of gearing relies on the pitchpoin t being the tangent to the pitch circle at all times. Youll notice in an involute set the teeth always
contact only on the tangent to the pitchcurv e, this means the ratio of the two gears remains a constant at the radius of one vs the radius of the
other. To have this true, you need involute teeth.

  Watch those gears as they "mesh" and youll see the contact point moves from the outside of a tooth to the root of the tooth
during the rotation. Since the motion ratio at any point in time is the instantan eous ratio of the two radii , that radii
is changing by the distance of the top of tooth to the bottom. This causes a harmonic motion equal in frequency to the #teeth times the
speed of the gear. Thats what causes noisy gears. If youve heard silent transmiss ions when their new, iits because the pitchline contact
tangents are perfect, as they wear they can get noisier as the contact point starts to wobble about the perfect pitch radius.  The greater the distance
delta from pitch circle the greater the harmonic vibration, and the greater the wear. A worn out gear wears out much faster than one
that isnt worn..Its an accelerat ing effect.
    Those round teeth on a gearify gear have a harmonic equal to the full tooth depth from my look at them. They "seem" to mesh well,
but unless you have an involute profile of one sort or another, you cannot or should not bear a load.. 

  My non-circulars are based on similar mechanics, I too use subtracti on for them, but you have to subtract a virtual hobb, you cant just
subtract from the mating gear. And if you do that then the arc length of the pitchline comes into effect and things get a lot more
complex.  Though as I said they are pretty and at the low price of the software, probably a bargain for that type of design.  :) )

Art


   Just my reading of the theory though..


Title: Re: Gearify
Post by: ArtF on September 18, 2015, 11:04:32 AM
Nate:

 >>I think we all know that gears have to slip against each other a little bit to work properly.

   Actually,  this statement is the key, gears should roll, not slip, slip is friction, frictions kills and is noisy.. could saved myself
a paragraph and some mental math.. lol

Art


Title: Re: Gearify
Post by: Nate on September 18, 2015, 02:22:02 PM
>>I think we all know that gears have to slip against each other a little bit to work properly.

   Actually,  this statement is the key, gears should roll, not slip, slip is friction, frictions kills and is noisy.. could saved myself
a paragraph and some mental math.. lol

Involute gears have to flex or slip a little at the contact point.  Consider for example a simple case of 1:1 circular gears in some frame.  The only place where the gears are locally moving with the same velocity is where the pitch circles meet.  At any other point on the pressure line, the idealized contact surfaces of the gears will be moving at different velocitie s.  (If gears really worked better when they rolled against each other without slipping, then we wouldn't lubcricat e them, right?)

The rollers that gearify produces, on the other hand, may well be able to roll against other without slipping, and the reason that they may be unsuitabl e for transferr ing torque is that their mechanism relies on friction, rather than on pressure between the contact surfaces.


Title: Re: Gearify
Post by: Mooselake on September 19, 2015, 06:53:47 AM
I finally heard from the developer, who says he's got some updates in the works. 

The 60,000+ pound pile of 8 foot logs in my yard is going to be eating up some free time as it's being prepared for the 4 letter white stuff season, but trying the gearify trial is still high on my list.

Kirk




Title: Re: Gearify
Post by: ArtF on September 19, 2015, 07:54:57 AM
Nate>

 >>Involute gears have to flex or slip a little at the contact point.

 No. They dont. Let me put it this way, two round gears in a closed frame with perfect involutes and no wear, have no slip, no rub and
the only friction is rolling friction. Slipping is not part of the design. Since the contact point is always in tangent to the pitch circle, it rolls
on its mating surface at all points. Now DO they slip, you bet, we live in an imperfect world.

   Seriously though,I think its a mistake to think two involute gears slip by design..I dont believe they do.. at all or at any point in
the tooth. The whole point in most gear design is to eliminate most if not all slippage, rolling is the way they work. Gearify gears cannot
roll, if they did, their teeth would be involutes . One measure of slipage is the amount differenc e from involuted shape a tooth is. Thats a
quick measure, the more different from involute the shape, the more slipping there is. This is a generalit y, but math is math..   

>>the rollers that gearify produces, on the other hand, may well be able to roll against other without slipping

   Respectfu lly, I disagree. . :) , the math says no... ( While Im often wrong, the math never is...)


Art


Title: Re: Gearify
Post by: ArtF on September 19, 2015, 08:59:28 AM
Nate:

(Im not arguing the point here, but I do think a discussio n on this is valuable to people watching who may want to understan d more on this topic,
It is after all defined as "The fundament al law of Gearing" , and as it is the basis of all gearing, I think it bears a discussio n, and in such things
I do not pretend to expertise, Im simply explainin g what I have learned from experienc e in the math, so where Im wrong, please let me know..
(I hate carrying wrong informati on. :) )

 First, a quote from the involute gear wiki and repeated in another form by Faydor Litvin ( My god of noncircul ar gearing who is reponsibl e
for getting me intereste d in noncirclu ar gearing.. ...)

"Where the line of action crosses the line between the two centres it is called the Pitch Point of the gears, where there is no sliding contact".

  Any gear which does not maintain a line of action, is by definitio n a gear that slides. Involutio n though , as you are thinking intuitive ly, is
not the only shape a gear tooth can have, BUT, its the only shape that allows for each gear to share the shape. Youll notice in epicycloi dic
gears the pinion has a differing shape from the wheel. Same with cage gears and such. The shape of the mating gear to any gear is really
defined in the shape of the wheel's tooth by the cycloidic math of the motion of the originati ng shape. Involutio n gives each the same shape
and has the benefit of no slippage at any point in their contact. Any shape other than involute should never be run fast, it will wear quickly
as no other shape Im aware of has no slippage.

   Now, as to the instantan eous speed ratio, in involutes as you watch the contact point rise from bottom of tooth to top, youd be
forgiven for thinking this is causing an instaneou s shift in speed, .. but it doesnt. This is because the contact point is moving out from center
at the exact same curve as the pitch curve. At any point the ratio is identical . So long as the contact point on any tooth is tangent
to the point where the two pitch circles meet, the ratio is exactly the same ratio between the two circles. It never varies at all. In good gears,
this makes them silent and very smooth. In a polished gear you'd need no more lubricati on than a trains wheel, and it would be as quiet.
Measuring vibration s caused by speed variances is a good way to measure how worn a gear is.

   In any other case, the more off tangent you are, the more the ratio varies. So in round teeth, ( watch then carefully in slow
motion) the contact point basically moves around all the curves. So is starts at the root and the contact rises to the top and then back
to the bottom of the next tooth. Note the tangent at each point. they point wildly from straight out( at tip to bottom contact) and then
to straight up when the two teeth meet in the middle. This violates "The fundament al law of gearing" and the line of action varies from
0 to 90 degrees on each tooth. This causes the speed to vary by the ratio differenc es involved,the deeper the tooth , the more the vibration
in speed. This vibration has to happen, the math demands it, and as you rotate such a gear youd feel it vibrate, the deeper the tooth , the
higher the amplitude of vibration and frictiona l wear. Now as a disclaime r I can say I have never made such a gear, perhaps when youve made
 a set you can let us know if Im right or wrong, Im simply picturing the numbers not the reality.

  Ive been asked about this topic for over  a year now and haven't wanted to comment, I havent wanted someone think Im picking on
a competito r with some technical ity, Im really not. I like what the software does, I think its decorativ e and looks nice and at its price
point is a very good value. Its a clever subtracti on method and Ive not added it to Gearotic (for those that have asked) because its done,
the solution exists at a good fair price point, and Id rather spend my time researchi ng and programmi ng things that haven't been done
or aren't offered at a fair price.

   So, thats my take on it, correct me if you feel Im wrong, but let us all know how the gears work, might get a copy myself. :)

Art

 


Title: Re: Gearify
Post by: JustinO on September 19, 2015, 09:59:41 AM
Hi Art,

My understan ding is that for gears that obey the fundament al law of gearing, the pitch point is the only point where there is pure rolling; it is the only place where the two gears are going the same direction at the same velocity. Litvin's explanati on of centrodes helped make this clear to me.

Gearify looks like an interesti ng little narrow utility. If I were intereste d in gears with "round, square, or triangle teeth" I might buy it.

Thanks Art,
--Justin


Title: Re: Gearify
Post by: Mooselake on September 19, 2015, 11:01:36 AM
Don't forget about Mike's eccentric planetary gear calculato r, "Astronome r", which is my main interest.

Been enjoying this discussio n; nearly mentioned in the OP that they obviously weren't involute teeth and not suitable for any kind of load, but y'all have that one covered.  All I want to do is make cool looking gadgets that don't really do anything useful - kind of like me these days.

I should contact Mike again and see if he wants to chip in here.

Kirk


Title: Re: Gearify
Post by: ArtF on September 19, 2015, 03:29:14 PM
>>My understan ding is that for gears that obey the fundament al law of gearing, the pitch point is the only point where there is pure rolling;

 "The angular velocity ratio between two gears of a gearset must remain constant throughou t the mesh".

  This is the fundament al law of gearing engraved in stone. :)

  Give this a moment of thought experimen t. If an involute tooth slipped on its contact point at any point in its travel , this law by logical inference
must be disobeyed . The speed at the time of slipage has just varied. It must at all times be a constant or the math simply falls apart. This is why
it is soo difficult to involute tooth a noncircul ar gear, you MUST maintain the pressure angle and tangent to the pitchpoin t, or you violate the law.
  As yet, I havent seen any men in black approachi ng so I suspect Im on the right side of the law.

Truths:

  1) Good Gears dont slip, they roll, on every point of contact.
  2) Taxes never really go down,
  3) You die.

-- you know, prove me wrong and Ill really feel the idiot. :) lol

Art


Title: Re: Gearify
Post by: JustinO on September 19, 2015, 04:13:12 PM
Not my responsib ility.


Title: Re: Gearify
Post by: Nate on September 19, 2015, 05:08:46 PM
I think that we agree about what's going on but have different a different understan ding of what the words mean.

Lets suppose we have a pair of circular involute gears, asin(1/2) degree pressure angle (because it makes the math convenien t) both with a pitch radius of 10.  One gear centered at (0,10) rotating countercl ockwise at 60 rpm, and one centered at (0,-10) and rotating clockwise at 60 rpm.

The pressure line is at 30 degrees so let's say that two teeth are meshing, momentari ly, at the point  (2 , 1)

Now, the distance from the center of rotation of the top gear to the contact point is sqrt(4 + 91) and the distance from the center of rotation on the bottom gear is sqrt(4 + 121) so, at the point of contact the bottom gear is moving faster than point of contact on the top gear.  They're moving at different speeds at the point of contact so they can't be rolling against each other.

Discounti ng the effect of imperfect ions, gears behave like idealized rollers that do not slip so the angular velocity ratio of the gears as a whole will stay constant, but the action of the gears - in other words the meshing of the teeth - has to have some slippage to work, even with idealized gears.

As Justin correctly notes, the only point where ideal gears can actually roll against each other is the pitch point.

Quote
...If an involute tooth slipped on its contact point at any point in its travel , this law by logical inference
must be disobeyed ...

The idealized sliding is parallel (i.e. tangent) to the instantan eous contact surface, while mechanica l action of the gears is perpendic ular (i.e. normal) to that surface so the sliding doesn't influence the rate of rotation per se.


Title: Re: Gearify
Post by: ArtF on September 19, 2015, 07:43:59 PM
Nate"

 Well said. I agree. And in the case of the gears we're discussin g Im suspiciou s of the line of action, I dont believe there is one. More of a constant
rotation. But as I said, Id like to hear of the experienc e in building a set..

Art
 


Title: Re: Gearify
Post by: Nate on September 20, 2015, 12:56:12 AM
Well said. I agree. And in the case of the gears we're discussin g Im suspiciou s of the line of action, I dont believe there is one. More of a constant
rotation. But as I said, I'd like to hear of the experienc e in building a set..

I'd be curious to see how well it produces circular 'gears' too.


Title: Re: Gearify
Post by: ArtF on September 20, 2015, 06:09:45 AM
Nate:

   You know, I like to sleep on it in things like this, because although things have a habit of looking simple,
Ive found underlyin g complexit ies in most algorithm s of this sort. Your math is much better than mine, I think its
obvious from your responses to questions such as this. I appreciat e that expertise being around. 

    Justin was right of course in his statement that they must slide, mine is a confusion with sliding that
causes a angular change and sliding that doesnt. I had discounte d sliding that doesnt.  As you pointed
out well, sliding in the tangental direction has no effect on the rotationa l velocity where sliding in other
vectors necessita tes it.
   Personall y, I have trouble thinking of it as sliding at that point as it implies more than than
its reality. Since the contact point is touched only instantan eously and the next contact point is moving
in its own rotation coordinat e system to meet the next contact point at its admittedl y different speed, the result
is a roll along an involuted trajector y curve where each point meets perfectly at its own relative speed with the next
contact being the proper distance and offset away. It isnt something I think of as a slide, but it IS sliding.

   I find when I start to compete multiple coordinat e frames of referance I get confused easily as to context
in those frames. Consider any single point and they meet perfectly in time and space throughou t the
curve, and for this I picture no sliding. A result of knowing that temporall y each point meets perfectly
with the next one in space when designing the contact curve. The curves are though, of different lengths.
 Enough to hurt my head. :)

   So I had to look into some other assumptio ns to ensure I have it right. The involute is the best shape to my
mind as it keeps the line of action as pure as possible, but what about circular teeth? From a freshen-up look
this morning at my reference s, it appears round teeth are fine, but with the proviso the contact point is kept to the
 pitch circle point or as close as possible, something which can be done by using the proper generatin g curve.
 
   In essense, the method gearify uses, is a valid one, since it is rolling a gear around another its doing a virtual hob,
Im unsure if the generatio n profile changes to match the contact point, but its a valid a way as any other in terms of
the generatio n, and if the contact point is relativel y stable, then Id say a load is fine. I do think though for a round
tooth gear to work, the generatin g profile would change from gear pair to pair in order to match that requireme nt.

  In any event, thx for the explanati on, I like to have my confusion s in math or terminolo gy fixed as I go. :)


Art


 



 Thx for the update of my internal model
on how that works.



     
 
 
   


Title: Re: Gearify
Post by: Nate on September 20, 2015, 12:45:07 PM
If I understan d the videos correctly, then gearify may produce gears for transferr ing load, but it will do so by accident more than design.

A better example for non-involute gears is the imaginary gear feature in gearotic, or cycloidal gears tha were historica lly used in clocks.  The 'virtual hob' in gearify seems considera bly less sophistic ated than what would be necessary to produce one of those.


Title: Re: Gearify
Post by: ArtF on September 20, 2015, 01:44:05 PM
Nate:

 Perhaps, I find noncirclu ars a bitch to subtract, but its possible it works as well as any other I suppose.
   I know when I began subtracti on as a build method it really had a habbit of showing flaws in my thinking,
but round teeth may be better at it. I have sent the author an invite to join us, I was pleased he contacted me,
he may be able to tell us more about the way it works. They look nice in any event. :)

>>A better example for non-involute gears is the imaginary gear feature in gearotic

  Actually, those were an attempt to produce a floating pressure angle involute. . Im amazed how popular they were,
I guess I may have to add them back in.. maybe Ill put them in the new wizards program.. let people script some
changes to them.

Art


Art


Title: Re: Gearify
Post by: John T on September 21, 2015, 08:33:04 PM
Hi Art
I am not qualified to weigh in mathemati cally,  all I know is that my involutes don't slide if I get the center distance right. This is based on observati ons of my clocks running for years, If the center distance is off all bets are off.

John


Title: Re: Gearify
Post by: ArtF on September 21, 2015, 09:01:17 PM
Hi John:

  Its really a matter of definitio n and context .. normally, if a wheel rolling on another slips, the speed of the two wheels must differ
for a moment, but in the case of the teeth in a gear, they can slide and not affect rotation as its a slide thats in a direction al
vector that is the same as the motion..t he slide allows the rotation. That having been said, its not very observabl e. More math
than visable reality. This slip happens while two curves roll off each other in their own motion paths...

  Ive read more treatises on tooth profile than I care to admit, but in the end, though everyone has a wizbang new profile every couple
years, they always come back to the involute it seems. Its just the best compromis e you can  make for the job of gearing. I laughed the other
night in fact when I came on Gearotics Knuckle Gears. I thought I invented them, they were made years ago by someone, tested and found
to be wanting in strength. ( But their pretty.. )..

   I actually have gearify now, I've been in contact with Michael , its creator and we've swapped programs. (Developer s courtesy :) )
Its quite well written and for those inclined to that type of gear Id heartily recommend it. He's been very cleaver in how he lets you design
the two gears.

Art
 
 


Title: Re: Gearify
Post by: Nate on September 22, 2015, 03:20:47 PM
I am not qualified to weigh in mathemati cally,  all I know is that my involutes don't slide if I get the center distance right. This is based on observati ons of my clocks running for years, If the center distance is off all bets are off.

Here's a really nice animation:

https://www.youtube.com/watch?v=14yMFdgWM-A

It's a rack and involute pinion, but we can think of the rack as being a really big gear - so big that we don't notice the curvature .

It should be obvious that the teeth on the rack don't move up and down at all, and that the teeth on the pinion move downward (and sideways), just to the side for a moment at the bottom, and then back up (and sideways).

That means that the contact point on the rack is never moving up and down, and the contact point on the pinion almost always is.   How can that happen if they aren't sliding against each other?



Title: Re: Gearify
Post by: ArtF on September 22, 2015, 08:00:47 PM
Very valid point, can actually be seen easier in Gearotic if you slow down the rotation on the circ gear tab, ( better resolutio n that way..)

Art


Title: Re: Gearify
Post by: jmurphycnc on September 23, 2015, 09:56:04 AM
I have purchased the "gearify" software, and it is certainly fun to "play" with. Since I was a metal machinist for many years, I didn't really think this was going to produce "Technical ly" accurate informati on for practical use, but it has provided some enjoyment (toys for the granddad and the grand-kids).

My only drawback is that the dxf output from Gearify is not compatibl e with my Aspire software, so I have to do the "save and convert" or "Save as" in another program before it becomes importabl e.

For the money, I'd say it fair value.

John


Title: Re: Gearify
Post by: ArtF on September 23, 2015, 11:03:17 AM
John:

  Yes, DXF out put can be a bear to match up with everythin g else, its a very nonstanda rd standard. . :) . At Gearifies price
point I think its a bargain.

Art


Title: Re: Gearify
Post by: Mooselake on September 23, 2015, 01:08:36 PM
Based on one attempt Gearify may not import DXFs from Gearotic.   I created a 4 sided gear in Gearotic, saved it as a DXF without toothing (which may be the problem.. .), then tried to import it into the Gearify demo.  No luck, while it didn't report an error nothing imported.

In the non-existent world of unlimited time, I was wondering if Gearotic could add a way to have optional plugins, and Mike could modify Gearify and offer it as a Gearotic plugin.  It'd probably take an Art clone or two before that'd happen, not to mention Mike deciding it'd help pay those school loans.

Nice to see that there's other interest in Gearify, and that Art and Mike are looking at each other's product.

I didn't see any equivalen t to plating/boxing in Gearify, and haven't gotten far enough in the tutorial (giant log pile in the yard...) to learn anything about gear carriers (or whatever the correct term is) to make working devices.  How did you handle it, John?

Kirk


Title: Re: Gearify
Post by: ArtF on September 23, 2015, 01:43:19 PM
Kirk:

  The new scripting system  is coming along quite well, its starting to look impressiv e, and it will be my initial attempt to try to hook more things together.
Once its complete, Im hopeing it will offer a way to allow extra objects to be added to gearotics total, or to
massage various data that Gearotic or any other program puts out. As I've said before I hope to allow DXF imports ,but havent needed
them till now. ( Though spokes and indicator s and such are all just dxf's so Gearotic has been able to load DXF's for some time..
  While Auggie will not be the final way to do this, its scripter will be involved I suspect as well as the ability I need to come up
with to attach hardware. Im hopeing to have a Visual Studio project thats open source to hook to Auggie and another to add objects
to Gearotic. AllObject s in Gearotic are encapsula ted in a single class called a "3dObject Class", it hold all informati on needed to make
and simulate any object in Gearotic, so I really hope to get to the spot where I can allow others to define an object, so that it
imports to Gearotics database for machining , planning, or putting in a box.  We'll see how this year goes.. :) , I have several requests
and small bugs to get of the way from this past summer. Ill put more informati on on a post in the release topic , it time I posted a note to
new users as to what to expect this year.

Thx
Art


Art


 
Art

     


Title: Re: Gearify
Post by: Mooselake on September 23, 2015, 01:59:58 PM
Ill put more informati on on a post in the release topic , it time I posted a note to
new users as to what to expect this year.
The unexpected things are always the best part of every Gearotic developme nt season :)

Kirk


Title: Re: Gearify
Post by: Gearify on September 23, 2015, 04:14:04 PM
Hello All!

This is Michael Valle, and I am the creator of Gearify. I have been enjoying this discussio n and I wanted to add some comments.

I want to begin by saying that I appreciat e ArtF's perspecti ve of Gearify and Gearotic being complimen tary rather than rivals/competitors. I think his analysis of Gearify's current limitatio ns are accurate.


My initial objective when creating Gearify for my father's project, was to help him produce an internal eliptical gear mechanism with teeth that would neither slip, nor grind to  a halt. I had a strong math and programmi ng backgroun d, but at the time, no knowledge of the formal theory of gearing. I walked into a coffee shop with a pad of paper and played with a bunch of different ial equations . I walked out with a solution on paper, not only for elliptica l gears but for any reasonabl e shape. My solution, however, only described smooth, toothless gears. Producing the shape of the teeth puzzled me until I was on Winter break from college, and I devised the subtracti on method and produced the very first version of Gearify.

I didn't realize at the time but what I had essential ly done was created a piece software that:

1. Violates the fundament al law of gearing.
2. Gives you all the goodies you are entitled to if you are willing to violate that law.

Fewer constrain ts = More degrees of freedom. That's the philosoph y behind Gearify.

An excerpt from Gearify's user manual:

"The creation of gears for industria l applicati ons is
a highly developed engineeri ng science. Gearify is only partially based on this science, and
instead relies on an original approach using Different ial Equations, Numerical Methods, and
Computati onal Geometry in order to allow more freedom of design."


HOWEVER! It is my hope that I can eventuall y find or produce a suitable generaliz ation of the involute tooth concept for arbitrary non-circular gears. So far I have the following possible strategie s:


1. Find some credible literatur e with a clear and reasonabl e approach to generaliz e involute teeth to non-ciruclar gears (no luck so far)
2. Devise my own generaliz ation that at LEAST removes vibration (I have some ideas)
3. approxima te the non-circular shape as a series of circular segments and use appropria te involute teeth per segment (meh.. I don't even yet know if this makes sense)
4. Allow the user to upload a "virtual hob" (which Artf mentioned) so that the portion cut away from the subtracio n process can be larger than the tooth itself. This is a big feature on my TODO list. May not solve the issue but may get me closer.

So that's where I'm at with involute teeth. Its definitel y my most requested, and desired feature, but as ArtF mentioned, it is very very hard to involute tooth a non-circular gear.

Let me comment briefly on DXFs since this is a key issue for interoper ability of Gearify and Gearotic. Gearify makes use of the popular NetDXF project https://netdxf.codeplex.com/ (https://netdxf.codeplex.com/) for all of its DXF importing and exporting functions, which is still being developed and maintaine d. They recently included support for Binary DXFs, and are still weeding out bugs in general (I actually contribut ed to the project by writing the Spline elevator). I have yet to update Gearify's NetDXF reference s to the newest version, so when I get a chance to do so, that may fix the compatibi lity issues! Otherwise, be aware that Gearify currently only imports and exports ASCII DXF files. In any case, this will continue to improve as that project is developed . :)

As for future updates, I have an arbitrary non-circular rack and pinion gear interface in the works, as well as an extended "Astronome r" interface . Non-circular planetary gears are of great interest to me, and I have found a solution that allows for more symmetric al and less eccentric designs. the current interface produces a class of gears that are so eccentric they are difficult to build.


Feel free to ask me any questions or offer ideas for how you would like to see Gearify improved, or possible solutions for how to make the gears more suitable for applicati on. :)

Thank you all!

-Michael Valle


Title: Re: Gearify
Post by: Nate on September 23, 2015, 11:10:48 PM
...
HOWEVER! It is my hope that I can eventuall y find or produce a suitable generaliz ation of the involute tooth concept for arbitrary non-circular gears. So far I have the following possible strategie s:


1. Find some credible literatur e with a clear and reasonabl e approach to generaliz e involute teeth to non-ciruclar gears (no luck so far)
2. Devise my own generaliz ation that at LEAST removes vibration (I have some ideas)
3. approxima te the non-circular shape as a series of circular segments and use appropria te involute teeth per segment (meh.. I don't even yet know if this makes sense)
4. Allow the user to upload a "virtual hob" (which Artf mentioned) so that the portion cut away from the subtracio n process can be larger than the tooth itself. This is a big feature on my TODO list. May not solve the issue but may get me closer.

So that's where I'm at with involute teeth. Its definitel y my most requested, and desired feature, but as ArtF mentioned, it is very very hard to involute tooth a non-circular gear.

....

Feel free to ask me any questions or offer ideas for how you would like to see Gearify improved, or possible solutions for how to make the gears more suitable for applicati on.

My impressio n is that gearify produces 'roller' profiles which (in the idealized case) have a continuou s point of contact between the two rollers, rather than one that "jumps around" like the red dots in this youtube video:

https://www.youtube.com/watch?v=14yMFdgWM-A

Is that impressio n correct?

IMO Generaliz ing involutes to no non-circular profiles really isn't that hard. It's basically just like generatin g involute tooth flanks point-by-point.

I worked through the basics earlier this year: http://gearotic.com/ESW/FavIcons/index.php?topic=1313.0

For more advanced topics like how to use profile shifting I can't help you much.

I played with interpola ting the roll line as a series of circular arcs and putting involute teeth on those, but that can have mechanica lly undesirab le propertie s. For example, it won't work properly for non-circular gears with a fixed pivot.


Title: Re: Gearify
Post by: ArtF on September 24, 2015, 06:34:13 AM
Nate:

  :), you guys hurt my head, your math backgroun d is far advanced to mine. I struggle to do such things
as tooth a noncircul ar, and generalis ing it is something Ive spent many attempts at, including generatio n
point by point. While Ive gotten close, the virtual hob seems to be the only solution I can come up with
so far.
       Its a good discussio n, and I agree with its direction, Ive always felt there is a formulaic generaliz ation
of involutio n for any surface. Ive tried and tried to derive it, but its just over my head. When this happens
I just try to keep studying the subject till I understan d. So your comments are helpful for what I can glean.
       
   
Art


Title: Re: Gearify
Post by: Mooselake on September 24, 2015, 07:24:20 AM
Hi, Michael!  Welcome to the Gearotic forum.

Guess it's time to cough up a few bucks and get rid of the wiggling in the Gearotic display :)   They're forecasti ng rain in Moosevill e, so the outside project I got talked into (running antenna wiring in an old firehall) might get cancelled, which will free up the day for dinking around with the laser and Gearify/Gearotic.

I didn't see any provision for shafts, either sizes or locations, in Gearify gears, did I miss them?  Also, does the postmaste r address on your site still work?

Kirk


Title: Re: Gearify
Post by: Nate on September 24, 2015, 10:12:21 AM
Nate:

  :), you guys hurt my head, your math backgroun d is far advanced to mine. I struggle to do such things
as tooth a noncircul ar, and generalis ing it is something Ive spent many attempts at, including generatio n
point by point. While Ive gotten close, the virtual hob seems to be the only solution I can come up with
so far.
...

Since Micheal was asking about it, I've been thinking about the best way to explain it.  So here's an attempt:

I'm going to assume that you can work out how to generate circular involute tooth profiles point-by point starting with the theory of involute gears.  So you know, for example, that there are two contact points on tooth flanks that correspon d to every point on the pitch circle.   If that doesn't make sense then starting with a foundatio n of involute gear theory might be more productiv e.

The non-circular analogue of the pitch circle is called a roll line.  (I tend to call it a pitch line, or pitch profile, and there may be other terms, but I'll call it a roll line here.)  Similarly, let's call the analogue of the pitch point the roll point.

So let's say we want to make a set of involute non-circular gears, and let's suppose that we've produced two "nice" roll lines so that they'll roll against each other with fixed centers of rotation and with the point of contact - i.e. the roll point - always on the line between centers.

Then it's relativel y straightf orward to model the rolling action of one roll line against the other.  (For example, that's something that gearify already does.)

Now, to build involute tooth profiles from this action we need to pick some way to determine tooth phase, and a pressure line.  There are natural ways to do both of those:

The pressure line can be effective ly the same as it would be for circular involutes:  It's the line that intersect s the line between centers at the roll point, and is off perpendic ular by the pressure angle.  (There are two of these pressure lines, one for the rising flank, and one for the falling flank that correspon d to the two direction s of the perpendic ular.)

Similarly, the tooth phase is a linear sawtooth function of the arc length of the roll line.

So for every point on the roll line, we have a pressure line and a tooth phase, so we can work out the correspon ding contact points, and this lets us generate the tooth flanks point-by-point.


Title: Re: Gearify
Post by: ArtF on September 24, 2015, 01:21:58 PM
Nate:

 Very well explained, the problem Ive found is in the convexiti es.. that does work for me till the point where convexity causes a problem, been so long I cant say exactly what the problem was.. .. but you know, the one point you mentioned I hadnt tried was using a sawtooth phase on the arc length for flank position,...thats brilliant .. I may have to revisit
that code..

Art


Title: Re: Gearify
Post by: Gearify on September 25, 2015, 10:03:45 AM
Nate,

"Now, to build involute tooth profiles from this action we need to pick some way to determine tooth phase, and a pressure line."

Wow. This is essential ly what I had in mind, only I was of the opinion that "picking" my own pressure line and tooth phase would not constitut e something I could advertise as legitimat e involute teeth, but rather my own personal bastardiz ation of a precisely defined concept.  :D I have not had time to extensive ly review and understan d in-volute tooth theory to know how much is good enough (I am involved in too many projects. .. )

This discussio n is very motivatin g to me! If we can come up with a feasible definitio n I can definitel y implement it in Gearify! :)

Here is my question for you though, Nate. By whatever definitio n you're working with, what is the pressure angle measured from on a non-circular gear? In circular gears, the line tangent to the roll lines at the point of contact is always perpendic ular to the line through the centers of rotation (which gives us some nice propertie s). On non-circular gears (especiall y the more eccentric ones) the tangent line can be quite far from perpendic ular to the line through the center. See the diagram below:

(http://i21.photobucket.com/albums/b299/mikau16/pressure_angle_zps5fpiwed6.png) (http://s21.photobucket.com/user/mikau16/media/pressure_angle_zps5fpiwed6.png.html)

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

Thoughts?



Title: Re: Gearify
Post by: Nate on September 25, 2015, 11:14:18 AM
Here is my question for you though, Nate. By whatever definitio n you're working with, what is the pressure angle measured from on a non-circular gear? In circular gears, the line tangent to the roll lines at the point of contact is always perpendic ular to the line through the centers of rotation (which gives us some nice propertie s). On non-circular gears (especiall y the more eccentric ones) the tangent line can be quite far from perpendic ular to the line through the center.

I don't know what the official definitio n is or even if there is one for non-circular gears.  Art and I discussed the same question in the other thread.   As far as I'm concerned, the preferred usage is the angle off p1-p2.


Quote
If measured from (p1-p2) I feel that there would be severe disortion s where t1-t2 differs significa ntly. But if from t1-t2, the gears may not "push" on eachother properly and the entire benefit of involute teeth is compromis ed.

Thoughts?

Mechanica lly speaking you probably want to measure the angle from p1-p2 and live with the distortio ns.   That's what I was trying to describe, and, mechanica lly, you want the action to be close to that line.  There's a lot of freedom in tooth profiles, so the roll line tangent line can somtimes also work.

In the illustrat ion, if we imagine that we're turning the red gear clockwise as the master and the yellow gear is the slave and the gear flanks are roughly perpendic ular to the t1-t2 line, then it's likely that the gears would just separate.



Title: Re: Gearify
Post by: Nate on September 25, 2015, 11:16:01 AM
Here is my question for you though, Nate. By whatever definitio n you're working with, what is the pressure angle measured from on a non-circular gear? In circular gears, the line tangent to the roll lines at the point of contact is always perpendic ular to the line through the centers of rotation (which gives us some nice propertie s). On non-circular gears (especiall y the more eccentric ones) the tangent line can be quite far from perpendic ular to the line through the center.

I don't know what the official definitio n is or even if there is one for non-circular gears.  Art and I discussed the same question in the other thread.   As far as I'm concerned, the preferred usage is the angle off p1-p2, but I worked this stuff out for myself.  Other people will have other notions.


Quote
If measured from (p1-p2) I feel that there would be severe disortion s where t1-t2 differs significa ntly. But if from t1-t2, the gears may not "push" on eachother properly and the entire benefit of involute teeth is compromis ed.

Thoughts?

Mechanica lly speaking you probably want to measure the angle from p1-p2 and live with the distortio ns.   That's what I was trying to describe, and, mechanica lly, you want the action to be close to that line.  There's a lot of freedom in tooth profiles, so the roll line tangent line can somtimes also work.

In the illustrat ion, if we imagine that we're turning the red gear clockwise as the master and the yellow gear is the slave and the gear flanks are roughly perpendic ular to the t1-t2 line, then it's likely that the gears would just separate.




Title: Re: Gearify
Post by: Gearify on September 25, 2015, 12:10:52 PM
"so the roll line tangent line can somtimes also work."

Sounds like this could potential ly be a user option!  :D

I do wonder how the distortio ns would appear when the roll-tangent line is significa ntly off-normal to the center-to-center line...

Here is another question.

We can define the pressure lines as a series of "snap shots" where the line is chosen to pass through the contact point at a particula r point in time. So there is in a sense a "jump" from one pressure line to the next as the position of the line switches for each tooth, to pass through the varying point of contact of the roll lines. This jump may produce some abrupt changes in stress and pressure that may be undesirab le (am I wrong?).

One could, however, define a MOVING pressure line.  Such a pressure line would always be intersect ing the point of contact between the roll lines, and the point of contact would linearly travel along this "floating" pressure line.

This is similar to how a Cubic Bezier curve is generated . Imagine the green line below is our "floating" pressure line. The orientati on of the line is defined by either of the two "pressure angle" notions we defined (this is constant if measured from (p2-p1) as described earlier, and continuou s if measured from (t2-t1)), and the position of the line would be continuou sly defined by the point of contact on the roll lines...

What do you guys think?  
(https://upload.wikimedia.org/wikipedia/commons/thumb/3/3d/B%C3%A9zier_2_big.gif/240px-B%C3%A9zier_2_big.gif)


Title: Re: Gearify
Post by: ArtF on September 25, 2015, 01:54:22 PM
I think youll find the pressure angle is measured not from the pitch circle, but from the base circle, so if we shrink the ellipse by the base circle amount,
then compute a tangent between the two offset base ellipses, that would be the pressure angle Id use ( and do currently) in computing the involutes .

 I think Nates idea is a really good one. Ill probably play with it in the coming months to see if it improves on hobbing, but I have read papers
on the hobbing being superiour simply because it deals with degenerat e solutions to Nates idea. Its like the tips of the teeth on high K areas
of the curve, the hob finds it naturally, the involute equations start to produce some nasty overlap that needs to be dealt with.. at least thats
what Ive experienc ed so far.

Art



Title: Re: Gearify
Post by: ArtF on September 25, 2015, 01:58:39 PM
Michael:

 As an example, in your drawing, Id imagine the proper line of action is if you moved T1 to a 1/4 inch inside the red on a line from
c1 to p1, and then places t2 at a line crossing pitchpoin t to a point 1/4" inside the yellow... that woudl be the proper line for that gear.

Art


Title: Re: Gearify
Post by: Nate on September 25, 2015, 02:43:04 PM
...
 I think Nates idea is a really good one. Ill probably play with it in the coming months to see if it improves on hobbing, but I have read papers
on the hobbing being superiour simply because it deals with degenerat e solutions to Nates idea. Its like the tips of the teeth on high K areas
of the curve, the hob finds it naturally, the involute equations start to produce some nasty overlap that needs to be dealt with.. at least thats
what Ive experienc ed so far.
...

Right, the hob is good for finding clearance s, but if the profiles are degenerat e, then 'virtual hobbing' will produce bad gears.  (I.e. gears that lose mesh or with rotationa l ratios that are inconsist ent with the roll lines.)


Title: Re: Gearify
Post by: Nate on September 25, 2015, 03:03:36 PM
...
We can define the pressure lines as a series of "snap shots" where the line is chosen to pass through the contact point at a particula r point in time. So there is in a sense a "jump" from one pressure line to the next as the position of the line switches for each tooth, to pass through the varying point of contact of the roll lines. This jump may produce some abrupt changes in stress and pressure that may be undesirab le (am I wrong?).

One could, however, define a MOVING pressure line.  Such a pressure line would always be intersect ing the point of contact between the roll lines, and the point of contact would linearly travel along this "floating" pressure line.
...

The pressure line is stationar y in the reference frame of the pitch point. In any reference frame where the pitch point is moving the pressure line will be moving as well.

In this video the pressure line is the red line, and the red dots are points of contact.  Can you explain what time in the cycle the "jump" you're concerned about occurs?

https://www.youtube.com/watch?v=14yMFdgWM-A


Title: Re: Gearify
Post by: Gearify on September 25, 2015, 03:16:48 PM
Let's say that P(t) is the point of contact between the roll lines at time t. The line of action (as you defined it) passes through P(t), and is oriented based on the pressure angle.

Suppose the pitch point begins contact at time t0 and moves smoothly along the line of action until the next tooth is engaged at time t1. Now a new line of action is engaged and will pass through point P(t1).

For a circular gear, P(t0) = P(t1). for a non-circular gear, they are most likely not equal.

So imagine in the video you posted, imagine that the height of the red line would instantan eously jump to a different vertical height every time a new tooth engaged.


Title: Re: Gearify
Post by: Nate on September 25, 2015, 03:48:28 PM
...
So imagine in the video you posted, imagine that the height of the red line would instantan eously jump to a different vertical height every time a new tooth engaged.

The pitch point is moving continuou sly along a continuou s path.  There's also a continuou s rotation.  What does your math education tell you about the compositi on of continuou s things?  Also, does continuou s motion 'instantan eously jump'?

The "dots" do jump back to the start of the line of action - that's the sawtooth phase I described - but the motion of the line of action as a whole is going to be continuou s in any setting where the motion of the gears is continuou s.

...

BTW:  If we imagine that the gear in the video is rolling along a stationar y rack, then the only way that P(t0) = P(t1) is if t0=t1.  You're not thinking in terms of the reference frame of the pitch point.


Title: Re: Gearify
Post by: Gearify on September 25, 2015, 04:31:16 PM
I think I'm not communica ting what I am trying to say properly. I do understan d compositi on of continuou s functions is continuou s. I think we're talking about two different things but I'm not sure where our disconnec t is yet.

(http://i21.photobucket.com/albums/b299/mikau16/line_of_action_zpsu1nbissm.png) (http://s21.photobucket.com/user/mikau16/media/line_of_action_zpsu1nbissm.png.html)

In the above diagram, the circular gear has a line of action who's position (I'm talking about the entire line segment's position) remains constant relative to (let's call it) the observer. But the non-circular gear has a line of action that is at a different horizonta l location. So, either the horizonta l position (relative to the observer) of the line of action would need to jump to new horizonta l position after each tooth engagemen t, OR, the location of the line of action is allowed to vary continuou sly over a single tooth (in which case the "dots", which are interpola ting across a moving line, would actually follow a continuou s curve).

Do what I' m saying make more sense now?



Title: Re: Gearify
Post by: Nate on September 25, 2015, 05:12:03 PM
...
In the above diagram, the circular gear has a line of action who's position (I'm talking about the entire line segment's position) remains constant relative to (let's call it) the observer. But the non-circular gear has a line of action that is at a different horizonta l location. So, either the horizonta l position (relative to the observer) of the line of action would need to jump to new horizonta l position after each tooth engagemen t, OR, the location of the line of action is allowed to vary continuou sly over a single tooth (in which case the "dots", which are interpola ting across a moving line, would actually follow a continuou s curve).
...

It's the latter - the pitch radius can vary continuou sly over a single tooth.


Title: Re: Gearify
Post by: ArtF on September 26, 2015, 09:02:04 AM
>>the location of the line of action is allowed to vary continuou sly over a single tooth (i

I think thats true since the tangents to the base circle vary from point to point the line of action is variable over time and over the run of each tooth.

   I tried an appraoch I recall where you calculate the base circle, then unwind the involutes point by point from that base circle..

(. problem had something to do with actually computing a base circle in convex areas.. requires looking to the inside curvature, not the outside.. Negative curvature s caused me trouble as involutio n switches polarity so to speak.... Hard to explain till youve coded it I think, or its just my weaker math skills, ). Perhaps, Michael your comment on the sudden shift is related to that thought, there is a point at which the involute shifts direction as K changes polarity. That could by considere d a sudden shift...c onceptual ly..thoug h its really a reversal with decelerat ion and accelerat ion into the new direction of curvature .


Art


Title: Re: Gearify
Post by: Nate on September 26, 2015, 09:20:41 AM
... problem had something to do with actually computing a base circle in convex areas...

When you have a negative curvature, then the center of the osculatin g circle is on the other side of the roll line, and when the curvature is zero, the circle is degenerat e.

I have to say, my eyes crossed a little when I read "... shrink the ellipse by the base circle amount ..." earlier.

As far as I can tell, base circles are great when you want to generate the gears on paper using physical tools like string and pencils, but really only confusing when we have the analytic power of modern computers available .

P.S.  Is the "WiredMind s eMetrics" in the preview supposed to be there?


Title: Re: Gearify
Post by: Nate on September 26, 2015, 09:22:06 AM
... problem had something to do with actually computing a base circle in convex areas...

When you have a negative curvature, then the center of the osculatin g circle is on the other side of the roll line, and when the curvature is zero, the circle is degenerat e.

I have to say, my eyes crossed a little when I read "... shrink the ellipse by the base circle amount ..." earlier.

As far as I can tell, base circles are great when you want to generate the gears on paper using physical tools like string and pencils, but really only confusing when we have the analytic power of modern computers available .  Though if they work, by all means, keep using them.

P.S.  Is the "WiredMind s eMetrics" in the preview supposed to be there?


Title: Re: Gearify
Post by: ArtF on September 26, 2015, 12:21:35 PM
>>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 trigonome tric analysis, my backgroun d is not such that I can
create the equations necessary to bypass the informati on things like the base circle give me. One of the papers Ive used in the
past for involutio n theory on a noncircul ar 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 involutio n 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


Title: Re: Gearify
Post by: Nate on September 30, 2015, 09:18:54 AM
Quote
... my backgroun d is not such that I can create the equations necessary to bypass the informati on things like the base circle give me. ...

I've been musing on this, and am unsatisfi ed with the explanati on 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?


Title: Re: Gearify
Post by: ArtF on September 30, 2015, 10:14:59 AM
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 considere d isnt really
accurate to me if we consider an oscculati ng circle.. which is really an analogue for the actual base circle. Circle though becomes
poor terminolo gy as its neither a circle nor neccesari ly inside the ellipse.  I guess I consider the term  "the tangental 
series of points defined by the objects pressure angle calculati ons" ... but its easier for me to consider that a base circle. :)
  Either  way you try to describe a solution, I suspect its more an algorithm ic discussio n 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 trochoida ls into account in the more extreme noncircul ars.
  That having been said, I welcome the discussio n 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

 


Title: Re: Gearify
Post by: Nate on September 30, 2015, 05:26:14 PM
...

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

Thoughts?

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

(http://www.pedantic.org/~nate/imgs/stargears.png)


Title: Re: Gearify
Post by: ArtF on September 30, 2015, 08:46:13 PM
>>It looks like I misrememb ered, 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 themselve s? Or pressure angle calculate d
tangent points, or osculated circle tangents?


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

Art


Title: Re: Gearify
Post by: Mooselake on September 30, 2015, 10:19:48 PM
Enjoy your vacation!  Try not to think about gears :)

Kirk


Title: Re: Gearify
Post by: Nate on September 30, 2015, 11:56:22 PM
>>It looks like I misrememb ered, 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 themselve s? Or pressure angle calculate d
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.


Title: Re: Gearify
Post by: ArtF on October 01, 2015, 06:36:11 AM
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 elliptica l 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 . Originall y, 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 involutio n from that point. Now all that was ,to my mind ,necessary to pick a start point for the involutio n to occur, but
as you stated it, calculati ng a running contact point up that line sounds better and easier, with no need to
figure the involutio n angles involved. . maybe..

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

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


Title: Re: Gearify
Post by: Gearify on October 30, 2018, 10:11:16 AM
Hello!

Some of you may be intereste d to know that Gearify is developin g a new tool for the generatio n of involute teeth on arbitrary pitch curves.

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

I made an in depth mathemati cal analysis to understan d how the constrain ts and degrees of freedom change at each point along the curve and made some intriguin g discoveri es.

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

-Gearify


Title: Re: Gearify
Post by: ArtF on October 30, 2018, 02:23:47 PM
Looks good. Looks very similar as to how Gearotic does it, a digital subtracti on where the involute evolves from the instantan eous rate of change during its construct ion? 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 contructi on and elliptial coefficie nt. They look good though, generatio n seems smooth.

Art
 


Title: Re: Gearify
Post by: Mooselake on October 31, 2018, 01:28:26 PM
Glad to see new developme nt with Gearify!

Kirk


Title: Re: Gearify
Post by: Gearify on November 01, 2018, 12:30:11 PM
Looks good. Looks very similar as to how Gearotic does it, a digital subtracti on where the involute evolves from the instantan eous rate of change during its construct ion?

Right now, these curves are generated without any subtracti on at all, just solving different ial equations numerical ly in 2 dimension s. 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 appropria te solution to minimally clip, truncate or sheer off areas to prevent the teeth from jamming - that final piece may be done via a subtracti on algorithm, but we'll see.

-Michael