Creating Non circular gears

[Anonymous]

Hello, I am attempting to create a non-circular planetary gear in Inventor. I have the gear shapes made, however, I cannot get the teeth on the gears to work. I have tried to use a rectangular pattern on the 3D tooth using the path of the gear, but the teeth do not follow the path correctly and some fail to even connect to the gear.

Is there an easier way, or, for that matter, a way at all, to create non-circular gears with correct teeth. I have seen programs like gearify that can do it, but I don't want to learn a new program or how to transfer that to our 3D printer.

Attached are the files I am working with, along with a picture. One of the files is missing due to the apparent inability to send more than three files. Thanks in advance.

[JDMather]

Your Sketch1 is a bit of a mess - I would start by fully constraining Sketch1.

Can you ask your instructor to join this discussion.

Note that there are a bunch of issues (i in circle) indicated in your browser.

Once you get Sketch1 fixed - I can show how to fix the rest of the part.

[Anonymous]

Yeah I know the sketch is a mess, but I went through and constrained it all.

This is my instructor's account, by the way, so he is seeing all of this. Feel free to ask him anything.

I have to go to my next class; my instructor will try to keep up. If not, I'll be back in this class at 8:00 a.m. on Friday. 

[JDMather]

---

@Anonymous wrote:

....I have to go to my next class;.... 

---

Yeah, I have to get to my next class too.

Just keep checking back here.

Tip: Equal Constraint (=) will save you a lot of work.

[JDMather]

---

@Anonymous wrote:

Yeah I know the sketch is a mess, but I went through and constrained it all..... 

---

When you know that something is a mess - start over.

That is what I did.

I moved your sketch dimensions into groups.

Note that whenever you find yourself repeating dimensions - you are probably working too hard.  Get lazy and do it right the first time.

Use the KISS (Keep Inventor Sketches Simple) principle.

Step 1 - Turn on the visibility of the Origin Center Point - AND USE IT!

Start over and create your Sketch1 as shown.  (Are you working from some sort of reference material - your dimensions do not make logical sense to me?)

[GeorgK]

Is there an iLogic or VBA Code to create the gears?

DESIGNING OF NON-CIRCULAR GEARS

http://prozamet.pl/art_2008_3_08.pdf

Thank you

Georg

[JDMather]

Before even attempting to use code - it is critically important to learn the foundation basics of sketching.  If the sketching isn't understood - the geometry isn't understood.  You might as well purchase off the shelf from manufacturer who has studied the geometry.

[JDMather · Accepted solution]

Turn on your sound.

[Anonymous]

Thank you for all your help. The fact that you actually manage, as shown in the first part of your video, to create the gear how I want it gives me hope that this project is not in vain.

I've attached the fixed file. I also attached what I am trying to model. I do not have the physical part, so my measurements have been based of that picture. Unfortunately, I cannot get the actual measurements as this is a single person's work and he/she doesn't want to reveal it, since they are trying to sell the project that is seen in the picture.

[JDMather]

Create Sketch2 as shown.

(Project Geometry the vertical construction line from Sketch1.)

The tooth must penetrate some distance down into the gear as the curve changes from convex to concave.

And the fillet cannot be part of the sketch for the same reason - it has a continuously variable tangent to the main curve.

You can change the dimensions if this is not what you really want.

Attach your revised Sketch2 file here for the next step (you can go ahead and Extrude this one tooth).

[Anonymous]

Ahh OK, I think I see what my problem was now. So, if I use that new Sketch 2 where the tooth penetrates into the gear, I should then be able to do the rectangular pattern on that and then I'll have to manually fillet each tooth, but they should be in the right position. Correct? I don't currently have access to the project or the software, I'll have to finish it when I'm back in class.

[JDMather]

---

@Anonymous wrote:

... then I'll have to manually fillet each tooth, ....

---

Select the All Fillets option and Inventor will find all of the appropriate edges (60) in one simple shot.

[Anonymous]

Ok thanks, I appreciate your help. That should be enough to do this project. Would I then be able to take this same idea and apply it to the other two gears of this model: the outside ring one and the innermost one, as long as there would be no other hitches I can not recognize.

I'll keep you updated when I work on this again, but for now, I believe you have solved my problem. Cheers, and thanks again.

[JDMather]

---

@Anonymous wrote:

..... That should be enough to do this project....,

I believe you have solved my problem. ....

---

Oh, I might have misled you a bit and left out some critical information.

I will be impressed if you figure out the "Rectangular" Pattern without another question or two.  

[Anonymous]

Just wanted to update you on my progress. I have finished making the gear. We are in the process of printing it. We do have two classes, so I'm limited in my print time, and we are having a few hitches with the 3D printer that we haven't worked out yet, but I'll post a picture of the finished project, whenever that happens.

[GeorgK]

Hello @Anonymous,

is it possible to get the gears? They look fantastic.

Thank you.

Georg

[invapprentice]

Hi JD

Might be the silliest question you ever heard.

How did you group that dimensions?

Thanks in advance.

invapprentice

[JDMather]

Edit sketch.
Click and drag.