Empathy List Archives

E

Entropic

Fri, Jan 30, 2015 4:25 PM

gearModule.scad http://forum.openscad.org/file/n11323/gearModule.scad
I've just written this code that creates a gear based on different
parameters. I just posted it here to see if anyone has any suggestions for
improvements or extra details I can add. Also I thought that someone might
benefit from this if they aren't able to make a gear themselves.

Basically, what do you think? How can this be improved? And enjoy!

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View this message in context: http://forum.openscad.org/Gear-Making-Code-tp11323.html
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gearModule.scad <http://forum.openscad.org/file/n11323/gearModule.scad> I've just written this code that creates a gear based on different parameters. I just posted it here to see if anyone has any suggestions for improvements or extra details I can add. Also I thought that someone might benefit from this if they aren't able to make a gear themselves. Basically, what do you think? How can this be improved? And enjoy! -- View this message in context: http://forum.openscad.org/Gear-Making-Code-tp11323.html Sent from the OpenSCAD mailing list archive at Nabble.com.

CL

Chow Loong Jin

Fri, Jan 30, 2015 4:46 PM

On Fri, Jan 30, 2015 at 09:25:55AM -0700, Entropic wrote:

gearModule.scad http://forum.openscad.org/file/n11323/gearModule.scad
I've just written this code that creates a gear based on different
parameters. I just posted it here to see if anyone has any suggestions for
improvements or extra details I can add. Also I thought that someone might
benefit from this if they aren't able to make a gear themselves.

Basically, what do you think? How can this be improved? And enjoy!

Teeth need to be involutes (think of trapezoids warped along the circle that
forms the circular pitch of the gear).

And have a look at https://github.com/openscad/MCAD/blob/dev/gears/involute_gears.scad.

--
Kind regards,
Loong Jin

On Fri, Jan 30, 2015 at 09:25:55AM -0700, Entropic wrote: > gearModule.scad <http://forum.openscad.org/file/n11323/gearModule.scad> > I've just written this code that creates a gear based on different > parameters. I just posted it here to see if anyone has any suggestions for > improvements or extra details I can add. Also I thought that someone might > benefit from this if they aren't able to make a gear themselves. > > Basically, what do you think? How can this be improved? And enjoy! Teeth need to be involutes (think of trapezoids warped along the circle that forms the circular pitch of the gear). And have a look at https://github.com/openscad/MCAD/blob/dev/gears/involute_gears.scad. -- Kind regards, Loong Jin

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Entropic

Sat, Jan 31, 2015 8:19 PM

Wouldn't it work well enough if it wasn't involute?

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Wouldn't it work well enough if it wasn't involute? -- View this message in context: http://forum.openscad.org/Gear-Making-Code-tp11323p11360.html Sent from the OpenSCAD mailing list archive at Nabble.com.

P

pff

Sat, Jan 31, 2015 10:02 PM

Well that depends what your usage will be.

(1) For the virtual world, a non-involute shape will work fine.

(2) For the physical world, it can be no doubt maked to 'work', at least for a
little while, especially if it is carrying virtually no load and the spacings
can be iterated until they mesh and one has little concern for noise or life
time of the gears.

(3) For the physical world with a real load, maybe not so much :-)

Nice description at wikipedia:

http://en.wikipedia.org/wiki/Involute_gear

Phil(f) in WI

On 1/31/2015 2:19 PM, Entropic wrote:

Wouldn't it work well enough if it wasn't involute?

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Well that depends what your usage will be. (1) For the virtual world, a non-involute shape will work fine. (2) For the physical world, it can be no doubt maked to 'work', at least for a little while, especially if it is carrying virtually no load and the spacings can be iterated until they mesh and one has little concern for noise or life time of the gears. (3) For the physical world with a real load, maybe not so much :-) Nice description at wikipedia: http://en.wikipedia.org/wiki/Involute_gear Phil(f) in WI On 1/31/2015 2:19 PM, Entropic wrote: > Wouldn't it work well enough if it wasn't involute? > > > > -- > View this message in context: http://forum.openscad.org/Gear-Making-Code-tp11323p11360.html > Sent from the OpenSCAD mailing list archive at Nabble.com. > > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org >

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Entropic

Sun, Feb 1, 2015 1:33 PM

Thanks. I'll just give it go on my schools 3D printer and see what happens.
What the worst that can happen. Besides the filament isn't too expensive
anyway.

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View this message in context: http://forum.openscad.org/Gear-Making-Code-tp11323p11369.html
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Thanks. I'll just give it go on my schools 3D printer and see what happens. What the worst that can happen. Besides the filament isn't too expensive anyway. -- View this message in context: http://forum.openscad.org/Gear-Making-Code-tp11323p11369.html Sent from the OpenSCAD mailing list archive at Nabble.com.

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PolyVinalDistillate

Sun, Feb 1, 2015 3:22 PM

If you try a bit of code like this at the end of your file to instantiate 2
gears:

rotate($t*360) //First gear rotation
gear(numberOfTeeth,widthOfTeeth,heightOfTeeth,thicknessOfGear,radiusOfHoleForShaft,sidesOfShaft);

translate([48, 0, 0]) //Second gear X offset for first (48 units is a guess)
rotate(360/40-$t*360, [0, 0, 1]) //Second gear rotation + 1/2 tooth offset
gear(numberOfTeeth,widthOfTeeth,heightOfTeeth,thicknessOfGear,radiusOfHoleForShaft,sidesOfShaft);

you can view it in animate mode ($t can be made to represent the frame time,
causing gears to rotate). Looking at the meshing point in the animation, I
suspect your gears may jam at a 48 unit separation.

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View this message in context: http://forum.openscad.org/Gear-Making-Code-tp11323p11370.html
Sent from the OpenSCAD mailing list archive at Nabble.com.

If you try a bit of code like this at the end of your file to instantiate 2 gears: rotate($t*360) //First gear rotation gear(numberOfTeeth,widthOfTeeth,heightOfTeeth,thicknessOfGear,radiusOfHoleForShaft,sidesOfShaft); translate([48, 0, 0]) //Second gear X offset for first (48 units is a guess) rotate(360/40-$t*360, [0, 0, 1]) //Second gear rotation + 1/2 tooth offset gear(numberOfTeeth,widthOfTeeth,heightOfTeeth,thicknessOfGear,radiusOfHoleForShaft,sidesOfShaft); you can view it in animate mode ($t can be made to represent the frame time, causing gears to rotate). Looking at the meshing point in the animation, I suspect your gears may jam at a 48 unit separation. -- View this message in context: http://forum.openscad.org/Gear-Making-Code-tp11323p11370.html Sent from the OpenSCAD mailing list archive at Nabble.com.

CL

Chow Loong Jin

Mon, Feb 2, 2015 3:26 AM

On Sun, Feb 01, 2015 at 06:33:11AM -0700, Entropic wrote:

Thanks. I'll just give it go on my schools 3D printer and see what happens.
What the worst that can happen. Besides the filament isn't too expensive
anyway.

Sure, if your aim is to learn why non-involute gears aren't good. But if you
want to make usable gears with minimal effort, why not just use MCAD's gear
generator? The involute teeth are all generated nicely already, and all you need
to do is play with the arguments.

--
Kind regards,
Loong Jin

On Sun, Feb 01, 2015 at 06:33:11AM -0700, Entropic wrote: > Thanks. I'll just give it go on my schools 3D printer and see what happens. > What the worst that can happen. Besides the filament isn't too expensive > anyway. Sure, if your aim is to learn why non-involute gears aren't good. But if you want to make usable gears with minimal effort, why not just use MCAD's gear generator? The involute teeth are all generated nicely already, and all you need to do is play with the arguments. -- Kind regards, Loong Jin

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Gear Making Code