Learn from millions of experts
In this tutorial I am going to show how to design involute gears from scratch without using fancy mathematics or built-in functionality. I use SolidWorks but you should be able to use just about any CAD program.
The model from this tutorial is found here:
Involute Gear Design from ScratchAnswered with a tutorial: https://grabcad.com/tutorials/tutorial-how-to-model-involute-gears-in-solidworks-and-show-design-intent
Thank you very much Steen. That was the most helpful tutorial I've watched on gear design for CAD users. I appreciate the effort and time you've put into it.
Greetings from Argentina
Hi. At step16 i get a massage ''The syntax o equation is incorrect''. Can you help solve this please?
Great tutorial.
There is just one thing I don't understand. In step 18 the following is unclear:
"You can also draw a point offset the initial value (13) along the base circle to get the lowermost point on the involute."
Could anybody explain this more clearly, preferably with a screenshot? Any help is greatly appreciated.
Hi Stephen - I thought you were on a fishing trip with your buddies and a case of beer, but you're still active on GrabCAD? Have fun :-)
Very good tutorial. I'm not a Solidworks user but still found it very interesting. Thanks!
Thanks Sebastian. Glad you liked it. I was happy to finally get it uploaded - that took more effort than writing the tutorial :-)
Tutorial very good friend, but I think I have another way faster and efficient, I'll only assembly
Nice, Please kindly add if you have more details about Addendum modification coefficient if the given is the base tangent lenght of 3 teeth
Really appreciate the effort put in to making this tutorial,only recently started using Solidworks so looking for as much input as possible.Thanks Steen great tutorial!
Hallo Steen,
Thanks for the tutorial ferry nice.
Greads from Holland.
Ben
Hi Daniel,
Another good question. Sorry for not having spotted it until now. I had to dig deep to come up with the explanation. The value is obviously correct, since the gears that you design with the method mesh perfectly. If you had used a different value, the cogs would be too thin or too thick.
The explanation is that in order to mesh perfectly, the gap between two teeth need to be identical to the width of a tooth: Think of gear racks that can be considered gears with infinite radius. When two identical gear racks are held against each other all teeth will contact at the same time (in theory anyway). So the angle between two teeth are double the angle between the contact points on the pitch circle and the centerline for a tooth is exactly in the middle because of symmetry, which is half of the angle between the contact points or a quarter of the angle of a cog. Q.E.D.
Hope this makes sense?
Thanks for your reply Steen! It makes perfect sense. We were learning about gears in school and essentially this was a homework assignment so thanks for clearing that up and for the tutorial.
Mr. Winther I touch solidwork for very first time. After your step by step tutorial I create my gear and move it. My shape of tooth is just according 1/4 of tooth angle and became. Your explanation is excellent. Thank you very much.
I am fishing. Grabcad on my ipad is not liking my comment. You did a great job on this tutorial.
how did you calculate the winding spiral I have always been trying to figure out how that is done
Oh, of course. Well that thing is that you don't need to calculate anything - it's all done through geometric design as per the instructions.
Really great Tutorial Steen. Thanks for taking the time to put it together.
You're welcome Dave. Glad you liked it and thanks for your comment :-)
How to mesh three gears?Can we do it using Move component>Physical Dynamics. I tried but failed.
The gear mates should work for any number of gears any sizes as long as you use the pich circle for your identities. Show your original sketch then pick the pitch circles of any two gears to mate them. I have an assembly with three gears mounted on a plate each gear a different size and each concentrically mated to a hole in the plate. each set of holes is spaced to the radii of the pitch circles of two gears added together I have a 2" gear and a hole mounted 1.5" below that for a 1" gear and another hole drilled 3.5" below that for a 6" gear. All are mated to the plate and holes then I set the teeth together and use the gear mates.
You must align the teeth BEFORE picking the pitch circles.
Hi guys, Steen greet tutorial, if you go into mechanical mates in the mates, (below the list of standard mates) there is a gear mate, use that and just click on the ID of Steen's gears and it will give them a 1:1 ratio as they are the same diameter
Good question! I have just tried by adding an extra gear to the assembly. It does work - but not very well. You need to move the sensitivity slider (I moved it close to max-setting) and the gears will move albeit not very smoothly.
Cheers,
Steen
How did you define that the centerline of the gear cog in step 22 is offset one quarter of the angle for a cog?
Excellent... But in the end if you add a constraint of gear it spins better
It is a detailed tutorial but I'm finding that the model it produces is not robust enough to change the size later. The geometry fails and SW reinstates the previous values. I'm going to start again from the beginning creating each step as a separate sketch, and if I can get it to behave more parametrically I will then maybe set up some variables to change in the part properties. It is a pity there isnt a built-in gear tool in SW as this is taking too much time to create a basic part.
The attached shows how to model a helical involute gear in SolidWorks.
In real manufacturing modeling requires special software because gears are often not pure involute: involute has modifications and the root surface is complex. There is special software to calculate these gear tooth surfaces offered by spiralbevel.comAttachments
Model_ZI_worm_in_SolidWorks.pdf, 748 KB
Download
The attached shows how to model a helical involute gear in SolidWorks.
In real manufacturing modeling requires special software because gears are often not pure involute: involute has modifications and the root surface is complex. There is special software to calculate these gear tooth surfaces offered by spiralbevel.com/ http://www.findkishoes.com/