Forum: Virtual Classroom - Sources Of STL Models

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Sources Of STL Models

There are some STL design files published in Virtual Classroom.
They are hardwired to specific diameters of supporting rod, elevation pole, antenna axe and screws.

Did you make this stl's with OpenSCAD scripts? If so, it would be a good idea to publish scripts itself. Then everybody may alter the diameters to whatever he or she wants. Plus, publishing in places like may add some more followers.Yuriy 11th Mar 2016
Thank you Yuriy.

We are of course, familiar with Thingiverse. It's a wonderful resource. We'll discuss internally whether we want to post the drawings there as well.

Concerning the files themselves, these particular part were done in Google Sketchup. Since we were very familiar with the software, drawing and modifying them during prototyping was very quick and efficient. I will investigate exporting them as other file formats. I know I can produce DXF or SolidWorks files.

I will also try to look into OpenSCAD. Although we are trying to maintain a bit of standardization, an automated script to change pipe or screw diameters sounds like a very nice function for the community to have.

Thank yo for the ongoing comments and feedback!


Wade 11th Mar 2016
Well, if you like the parametric drawings approach, I may "port" (or "reverse-engineer") your current models into OpenSCAD scripts. Sketchup then will be a good rapid-prototyping tool. I doubt there is tool for exporting to OpenSCAD, and even if there is one, it will be something like...well...something like auto-generated HTML.

Another interesting possibility with OpenSCAD: you can publish your models on GitHub (or any other version control system). It's becomes possible to merge developing efforts, just the same way as in programming area.
Yuriy 12th Mar 2016
Hi Yuriy

I'd like to encourage experimentation with all sort of ways to share the design of ThumbPointer, so feel free to reverse engineer and/or port the design. A couple of things to note:

1. We intend to change the gearing so that it is difficult to backdrive it, so that part of the design will change pretty soon.

2. From a ThumbNet perspective, we're not too concerned about external version control. All of the "official" ThumbNet stations will receive parts from us, and of course our own parts will be under our own version control. Incidentally, there will be minimum order quantities for these parts, so we will inevitably have some spare (as we occasionally do with the ThumbNet dongles), and will consider either donating these to individuals or selling them at low cost.

Shaun 12th Mar 2016
Greetings, Shaun!

Frankly, I do not understand your answer. I expected something like "it's worth doing it" or "it doesn't worth to do it". Instead I got something like (correct me if I'm wrong) "we don't mind, but we are not planning to use it, even if you'll do it".

MAJOR reason for OpenSCAD is parametric approach. You may say "I have supporting pipe of this diameter and screws of that diameter" and got STLs just for you. It's not directly compatible with industrial manufacturing, though you may use more smart and agile approach, having ordered "constant" parts in bulk and "variable parts" in most common sizes, for example. I don't know your logistics, so you should consider it yourself. I know that MakerBot was able to do it...somehow.

MINOR reason is version control. I'm using VCS even with my own projects, when I'm the only developer. Sometimes (and often) it's quite useful. As far as I understand, Google ScetchUp sketches are not traceable really. You cannot combine some different solutions, for example.

Except of this, I expecting that people will want to experiment with alternative designs very much, replacing separate parts to their own. You will face the situation when after several months after releasing your first design into the wild, you will got a number of better solutions from community, but you'll need to combine it to next-generation design (have you tracked the history of RepRap?). It will be much easier to make such a offspring with OpenSCAD, and it will be much easier to combine numbered offsprings back into single construction with OpenSCAD.

Best wishes Yuriy 12th Mar 2016
As always, you make some great points Yuriy.

I think you and Shaun are really saying the same thing. We highly encourage everyone to experiment with all aspects of ThumbSat and ThumbNet in particular, and we will take all of those ideas that are fed back to us and make a better product for the entire community. We don't want to be a closed shop and try to control anything. We're interested in STEM education and outreach to all students, experimenters and hobbyists.

At some level, we have to have some standardization within ThumbNet, simply so we can write reasonable procedures for students to follow. That is the only area where we will have a concern with "version control". But that only means that the "Official" ThumbNet design will lag a bit behind the "current" design. We can look at it as Beta testing and Alpha releases. :-)

We would be absolutely thrilled for your help in porting the drawings to OpenSCAD. I downloaded the software yesterday when you mentioned it, but as you know, time is always short and I haven't had a chance to even open it yet. There will be a learning curve for me, so if you are already familiar with the software and can find the time to work on it, that would be very much appreciated.

If you need different files from what are on the website, do not hesitate to write me at wade-at-thumbsat-dot-com.

Thank you!


Wade 12th Mar 2016
Hi Yuriy

Wade summed this up pretty well, but as the situation is not quite as simple as it might seem, I should add some clarification.

We want ThumbNet stations to play an important, serious and worthwhile part in ThumbSat missions. For safety reasons, it is highly desirable to know where ThumbSats are in orbit at any point in time. We've designed the tail and vane so that we should be able to track them using radar, but the best way is to download orbital data that the ThumbSat has calculated for itself, using its onboard GPS.

Grabbing this orbital data from ThumbSats is much more important than grabbing the science data, because the orbital data concerns the safety of other satellites and spacecraft. We will of course use large ground stations to grab this data, but the long term aim is to be able to rely on ThumbNet. This means that each ThumbNet station becomes a very important part of the mission, and so ThumbNet Inc has a responsibility to ensure that the stations are working as well as they can, and this means bringing them under the usual configuration control of space missions. The best way to do this is to keep all configuration control in-house, and this means that all 250 planned ground stations (including yours, if you would like to participate) will use parts provided by us, built to a particular revision. All parts will be provided for free to participating stations.

So that's one aspect.

Another aspect is that we have spent a lot of time developing and playing with this tracking station, and we felt that it may be of interest or use to other experimenters, so we are simply giving away the design for free. No strings attached, no expectations, no promises.

The final aspect is that we hope (but can't predict) that experimenters will play with the design and come up with improvements and ideas. I don't want to force or control this, but we would be absolutely delighted if someone with your sort of initiative and drive were to take this on as a project, and to create a means to continue to evolve the design. We would support anyone who takes on this challenge by providing designs, components etc. Any major improvements that come out of this sort of activity would be fed into the formal ThumbNet programme. We will analyse the design (using SolidWorks, the package that was used to create the ThumbPointer design in the first place), create prototypes, test them, place them under formal configuration control, have new components manufactured and then released to all 250 ground stations.

Yuriy, thanks for your time and thought on this, much appreciated!

Shaun 13th Mar 2016