Involute Gear

UPDATE: drawings are finally here: 4.0 - 2D drawings + new pricing

Hi All,

New to the forums, been using Shapr3D for about 2 weeks now, I’m both impressed and unimpressed at the same time, maybe I’ve been spoiled in my career using large CAD packages like NX, Catia, Solidworks etc.

My background is in gear design, so of course the first thing I wanted to try was to draw a gear! Well it wasn’t exactly as straightforward as I hoped, but it is possible to true a involute gear profile in Shapr3D (You will need to know some background in gear calculation to drive a spline feature in an involute profile, happy to give a tutorial here if it helps).

Some handy features I hope they bring into the software is to make more line feature properties available to drive other geometry. For instances, making a straight line equal in length to that of a reference arc length etc. Oh and some proper array functions jeez!

But it is definitely a fun experience never the less!


Awesome stuff! Would love to hear more about your experience. Especially about what you’ve missed, and how we could make Shapr3D better for you.

A tutorial would be amazing :slight_smile:


Thanks for the response Istvan.

Mostly my experience was very positive and I understand your companies software is still developing and adding features. For me, I’d really like to see Shapr3D as an all in one portable CAD package. Something I could take with me to a client, quickly mock up a design with them and then take that back to the office and create technical drawings from etc.

Just from my few hours mucking around, I’d like to see

  • More sketch properties and features,

Take solidworks for example, you are able to do some really clever stuff with sketches, make lines lengths equal to circle diameters or arc lengths, snap to mid points, make points equal distance on spline pathes etc. I know that is more on the “parametric” side of things, something Shapr3D isn’t meant to be, but the right balance between parametric and direct modelling i think is really powerful.

  • Technical Drawings
  • Array Tools

Having to copy 21 teeth of a gear by increasing copy sizes was a pain, some simple array tools like circular pattern, linear pattern would be super productive

  • Input calculator

Being able to input dimensions via a simple on screen calculator so you can do multiplication/division is such a simple yet great productivity tool

  • Seperate sketches even if they are on the same plane
    This is just a personal grief. I hate cluttered sketches, so normally seperate them for clarity, even if they are on the same plane, something Shapr3D doesn’t let me do!

  • Sheet Metal functions

This is a big wish, but i see a lot of potential for using this for sheet metal parts, but not being about too fold designs flat for laser cutting means its not really feasible without inputting the design into a third party CAD package with a sheet metal engine, like Solidworks, to fold it flat for you.

I think some of these have been brought before and are probably on your teams list somewhere.

Thanks for listening!
Cheers, Patrick


Great stuff, super helpful feedback. Most of these things are on our roadmap for the next 6-12 months, except sheet metal. Sheet metal is something we are considering, but it’s not in the planning phase yet.


Gear tutorials YES PLEASE! :clap:

1 Like

Hey Oregonerd,

I’ll try and post something here specifically for Shapr3D over the next week, i have a Masters Thesis due in the meantime… :frowning:

You will need to know how to calculate, base, pitch, addendum and root circles as well as tip or tooth thickness, there are some calculators online for free you can look at, but it is handy to know how to calculate it by hand so worth spending a few moments reading up on it

once you know that, the CAD side in Shapr3D doesn’t take too long to setup, and then you have a template you can copy to draw other gears.

Cheers Patrick


Great with an gear expert in here for input:)

One workaround is to use a online gear generator, import to Shapr3d as dfx and extrude it.
I´ve also used mcmaster-car.


Yes that is quite a common way of doing it even with CAD systems that are more capable. But I’m a stubborn fool who likes to keep it all inside 1 software haha. It is handy if the design is fluid and still changing as it saves you re-importing geometry all the time


Interested in making gears for 3D printing, How does “base, pitch, addendum and root circles as well as tip or tooth thickness” change by material?

These features are basically linked to the module of the tooth, among a handful of other things, not the material, higher module, bigger teeth and vice-versa. The variables at play are many so I won’t dribble on too much, but it is not as simply as, plastic gear = this module tooth etc. But from my experience in 3D printing, due to the surface roughness I would think a larger tooth size would be better than a smaller one, as any accuracy problems with 3D printing won’t be as sensitive to a larger tooth profile since the deviation won’t be as much. Basically I would try and make the gear teeth as large as possible, with out causing a problem know as “under-cutting”, where you start to weaken the gear. Gear designers do all kinds of tricks to avoid that, with methods such as profile shifting etc. But that is a book in itself haha :smile:

That’s awesome news. We belive in You !

UPDATE: drawings are finally here: 4.0 - 2D drawings + new pricing

Just came across this. Would definitely love to see some better support for gear design. I have used Shapr3D a TON for 3D printing, and it’s really bothering me to have to go learn another program to do my own gears. I know you can use a generator and import, but Shapr3D is so brilliant to work with, I’d love to be able to do it all in here. It is impossible to create a double helical / herringbone gear in here.

1 Like

While we are dealing with involute curves I do not find a parametric function driven drawing object.

It is extremely useful in involute design as you have the cog sweep over an angle while you have a function driven by the angle describe x and y coordinates.

Involute parametric curve example

Xt = r * (cos(t) + t * sin(t))
Yt = r * (sin(t) - t * cos(t))

And set the range of t like t1 = 0, t2 = pi/4

And while we talk about parametric if all dimensions had identities they could be used in a formula/equation editor to do some computing and add marvelous constraints.

A parameter driven curve should have endpoints and be able to take part in tangent, coincident, perpendicular etc constraints.

And for threads I would need some innovative 3D spiral objects that can drive a drawing plane (aligned and twisted in various ways) to produce solids or cuts.

Generally 3D paths would solve a lot of design challenges and cause enough trouble for Shapr3D developers for the rest of their careers of course.

As the design becomes more advanced it becomes easier to have it all fall apart if you start deleting major objects in the history list. Same with everything you design even in the real world. If you remove the house the windows will have nowhere to attach.