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openscad / MCAD

OpenSCAD Parametric CAD Library (LGPL 2.1)
http://reprap.org/wiki/MCAD
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Gears not producing involute gears #67

Open trayracing opened 7 years ago

trayracing commented 7 years ago

MCAD/gear.scad is not producing involute gears as claimed - the teeth look very boxy. image

For comparison: gears.scad quotes a cartertools web page on gear construction. That page works through an example that corresponds to gear(number_of_teeth=20, diametral_pitch=16, pressure_angle=14.5, clearance=0.009860625); That cartertools gets this: image which looks a credible tooth profile, when compared to wikipedia

I tried this in 2015.3 and 2016.09.18 (git a5e4def) on windows 10, using both F5 and F6 and both appear to have the problem. I have not dug around to figure out if it's gears.scad or openscad at fault.

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bond4u commented 7 years ago

use MCAD/involute_gears.scad

trayracing commented 7 years ago

Thanks.That would be a great addition to the top of MCAD/gears.scad:      "//Non-involute gears. For involute gears, use MCAD/involute_gears.scad".As gears.scad currently reads, it's misleading. The first line after the copyright notice is:      "//test_involute_curve();" Then it references an article on involute gear design. From: bond4u notifications@github.com To: openscad/openscad openscad@noreply.github.com Cc: trayracing daqray@yahoo.com; Author author@noreply.github.com Sent: Wednesday, March 22, 2017 5:48 AM Subject: Re: [openscad/openscad] Gears not producing involute gears (#1955)

use MCAD/involute_gears.scad— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub, or mute the thread.

kintel commented 7 years ago

This should be moved to an MCAD issue (https://github.com/openscad/MCAD/issues)

hyperair commented 4 years ago

Hmm, gears.scad hardly looks useful in light of involute_gears.scad, especially when the documentation states that it should generate involute gears. Might be good to simply drop this module altogether.