"Closed source" parametric models

Short summary of idea: what if there were a service where the full model was kept private, but customized versions could be requested/automatically generated.

Thingiverse allows customizable models but it requires the openscad source be fully public. And plus, thingiverse sucks.

There have been times I want to share a parametric model but I dont want to post the source because I’m embarassed that the code is ugly, or it imports models from other projects that I dont want to share. I can also envision a scenario where a watermark is added to a model to prevent the most blatant ripoffs, but if all the source code is published, it defeats the purpose. I dont have any models with watermarks but if I did, I dont know how I could share parametric versions.

If I were building such a service I might use AWS Lambda to do the rendering of model to stl files. Last time I wrote server side code it was php but I would probably teach myself node.js, which seems to be the modern way of doing things.

What I dont know how to do is to handle other CAD packages. I haven’t really looked into it but I’d expect it to be a challenge unless there exists a simple free model-to-stl renderer.

I’m mostly just thinking out loud. This probably would have been one of those ideas that I keep to myself and goes nowhere, except with Tom’s parametric “OPCNC” it indirectly becomes more relevant.

I’d be interested to hear what other people think. I don’t know if there is really a need for private-source parametric model generation, or if there is a niche where it is important, even if it is a small market.

Why bother Tom is doing it for us.

I guess I need to clarify, separate of the non-commercial issue, I am not protecting my files. I really don’t care.

1-I honestly just see zero way to support random 5" diameter builds and the issues that come with all the things that come along with it. I am not just trying to sell units, I am trying to help people enjoy using it. CAD is a skill that is awesome to have in the CNC world, learning how to make a part is more the point to me than someone making it for you?

2-At 1" diameter the plastic is by far the weakest point. We have every size below that. Lots of builds on thingiverse smaller. One is being taught as a full engineering class at Washington state.

3-I had no idea metric hardware was that big of a deal, Changing nut traps would take me a few minutes, but supporting it would take us all a lot of work. Think of how many times you have seen “what is the difference between the 6/32 and 4mm tool mount?” Now multiply that by a lot more parts, cap heads, off sized hardware, square vs hex. I built a machine that works with all hardware, some are just not as easy, specificity is not a design trait I care to cater to. I am working things into the newer parts. I guess people think I made it US specific, Nope, I made it fit the largest hardware. The holes fit the larger 4mm and 8mm bolts, the small nuts stops fit the larger 6/32, and the larger 8mm nut stops…and anything smaller.

4-Open models mean easy removal of my marks, this gets into the non-commercial part and I will not touch that here.

5-I can tell you right now, even my models 8-9 revisions in are not fully parametric. You have style elements and collisions to worry about. Can it be done, sure, was it ever worth it to me…no. I change a model and spend hours making the little things work.

6-No supports, easy to print. Hard to make parametric, again not impossible.

7-To reiterate #1. I didn’t really care early on I gave all sorts of people my files. All they did was make things worse for me, combining parts, screwing up the build volume, making things fit specific hardware, not clearly labeling it, calling it better or revised, improved when most didn’t even work. Who got the emails…me. Look at the build vids he did and look how many people said it was stupid not to combine the lock and bottom corner…that was the first “improved” part I remember. They are printed in a different orientation to be strong.

So that is most of my rant.

I would love to be convinced otherwise, No non-commercial debates at this time please. I could save all my parts as a parasolid and upload them in minutes.


I agree that the chaos is bad for everyone, and I am unsure if this helps, but I think its a possibility. In the early reprap world everything was chaos and almost all the printers were shit. I am wondering if Tom’s design will create a similar scenario.

A customizer would have to allow constraints, or even a drop-down list of options. Switching metaphors I’m thinking like options on a car. The private model is not to keep secrets as much as it is to define what is a supported configuration vs. after-market you’re on your own.

Still, your point is a good one about beginners not even understanding the options, whether its the tool mount or even the tube size. Looking back these questions seem obvious but the customization for a new person will make it much more difficult and the odds of success are decreased.

Thanks for your explanation, I need to think about this some more to fully internalize the perspective.

I really don’t know if that would be best or not. I do know it is easiest for me to iterate and improve, but iteration with more eyes could really accelerate things. That is why just releasing customizable parts doesn’t seem like the best reason to be releasing parts that would add to the chaos. Like you are saying some guidelines/limits make things easier.

Limiting people’s options is the only way to reduce customer service duties without throwing more bodies at the problem.

Simplicity is key, especially when you help both people who buy stuff directly from you and the people who spend months sourcing the lowest price on aliexpress.


I have a bearing bracket that just barely fits from 23.5mm to 25.4mm. So a singular part set is what I was working on but am not getting enough time at CAD right now. Before that was a set of sleeves, so one set of parts and some size specific sleeves. So many ideas and not enough time to try them all.

All in the interest to get past the build issues. The hard part of CNC shouldn’t be building it, it should be cleaning up the mess you make with it!

Doing it server side could get expensive. You woukd have to do openscad or freecad. So then who would design the parts using those tools and want them closed but customizable? Pretty slim number of users. It would probably be super fun to make though.