HTD Pulley Generator SolidWorks

As written in the title I made a generator based on Timing Pulley Design Tutorial. Except using equations I used the design table.

While I was designing, I couldn’t find a way to modify global variables across configurations. I used the design table to solve this problem. In fact, global variables can be modified across configurations. Thanks, @ClayTownR for the suggestion, you can see his solution down below.

Specs for pulleys (for now) :
Teeth: 16-18-20-22-…-86
Width for the belt: 15mm
ID: 1/2 hex shaft
Pitch: 5mm
Material: HDPE (Thanks to @benjierex for the suggestion. You can check their thread about HDPE machining here )
Step 1: You can download the generator from here. Extract the file

Step 2: Now you need to add this to your toolbox. Open SolidWorks and then right-click to your toolbox.

After that click configure. You will see the toolbox configuration window.

Select a folder or create one in the toolbox. Next, right-click and add a file. Then add the part which you have downloaded in the first step.

I looked at the article in javelin tech for adding parts to the toolbox. If you want to add your custom part, it will be helpful.
You are ready to go :smile:

Note: It is my first time doing a generator and I didn’t manufacture pulleys in this generator. I made this generator because it is so time-consuming to search on the internet for pulley or draw a pulley every time you need it.
I hope this generator will be helpful. I am open to feedback and suggestion. Let me know if I made mistakes.



That looks really nice. How do you plan on manufacturing this though? If you’re gonna use CNC or laser you can’t really have flanges on both sides of the pulley.
What we did this year with our milled pulleys is we had a flange on one side and 3D printed the second one for the other side, the way you have it right now it can only be made with 3D printing (so, not Delrin).


Acually, I didn’t plan :slight_smile: . My team didn’t have resources last year (2020). However I think if there will be 2021 season, we can try it . Which production type and material do you suggest ?

In fact, you can modify a global variable across configurations. In particular, this can be done with a design table. Create a column for “$VALUE@[your variable here]@EQUATIONS” and you can enter in any value you want. I’ve used this before for making configurable tools, such as gears. It helps as you can use this to use the intelligence of SW equations, controlling things like suppression states, in a much more wieldy way than using design tables exclusively.


Depends on what you have available, if you want to make it out of Delrin or metal you’d have to use some CNC cutting machine (mill, laser, waterjet etc.) in which case you could 3D print the flanges separately. If you don’t have access to anything like that you could just 3D print the whole pulley. This also works fine for most applications, it just takes more time to make this way but it is cheaper and easier, especially since almost all teams have 3D printers. Either option would save you a lot of money compared to COTS pulleys so i’d recommend looking into it.


It’s not unheard of at all to use either press-fit flanges, or bolt together pulley halves, or even just not having flanges at all. A lot of the Vex pulleys for example have press-on flanges.


I added your solution to my post . Thanks

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I will change the material for this version to HDPE I saw on the internet that it can be 3d printed. I will make another version as halves (as @CIM suggested). I know this question isn’t for this thread. Which bolts did you use when you were manufacturing this pulleys? When I was trying to make as halves in 16 teeth pulley distance between PD and ID is small so I can’t fit bolts. ( bolt fits but it contacts with shaft) How can solve that?

That was our first attempt at milling pulleys and we used M3 bolts to connect the halves (we also switched to flat head from what is in the picture for aesthetics mostly). We milled all our pulleys out of 20mm HDPE sheets, and specifically in the indexer we needed very wide pulleys which is why we initially connected two halves to form 40mm pulleys, but in all other parts of the robot we just cut the whole pulley, 3D printed the second flange and constrained them together with spacers. This way you don’t need bolts at all. Seeing as you want to 3D print pulleys though you could just print them with both flanges all in one piece

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I want to have many alternatives. If something goes wrong about 3d printing, I will switch it to the milling method. By the way, I updated to HDPE. Thanks for suggestion

I made the second version.Here is the link. This time I made halves. I add holes for M3 16mm DIN7984 bolt and PT nut style 1 DIN EN ISO7040.

I got inspired by Andymark Toughbox nut holes. Will the holes create problems in the future ? What do you guys think?
andymark toughbox example

They shouldn’t cause problems but they’re going to be very annoying to machine if you’re using a router/mill and not 3D printing. The whole point is that the pulley halves are machined in one setup each. Adding counterbores means you’ll need to flip and re-zero each pulley half to machine from the other side. Not impossible but probably not worth it. If you really don’t want the bolt head and nut sticking out the sides, you can use a countersunk (flat head) bolt and countersink the holes by hand, then make the hole diameter smaller on the second pulley half and tap into it instead of using a nut.


At this point, I’d probably just make a press-fit ring and matching boss for one side of the pulley. Less hardware to worry about, fewer ops, etc. Maybe you can even find a COTS oversized washer you can design around.

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I need one of these for Inventor, the included belt generators are far from ideal. :confused:

I made one a while ago, if you want to make it an iPart generator it’s not that much work.


Does this work in older versions of Inventor or only 2021?

Only 2021, but if you need I could make a 2020 version fairly easily. Any earlier and I would have to reinstall that version.

I’m running 2018 in order to maintain compatibility with the schools licenses.

On a separate note, I really wish Autodesk would improve backwards compatibility, it’s annoying to have to have the same version on every device. >_>

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This looks super useful! Thanks for sharing.

It’d be pretty awesome to see an OnShape version of this too :nerd_face:


My sarcasm sense is tingling, but just in case: