OpenSCAD is a game changer for 3d printing

[mouser]

This is a post about a (free) program called OpenSCAD:



I recently bought a 3d printer.  Mostly just because they've gotten good enough and cheap enough that I woudn't feel too bad if it mostly sat on a shelf.

I've been having quite a bit more fun with it than I expected, mostly because of the amazing site thingiverse.com where people have uploaded thousands of printable things you can just download and print (it's not *quite* that easy yet, there's plenty of tinkering and troubleshooting still required with today's cheap 3d printers).

Mostly I've been printing things to bling out my board games.

But this past week a couple of people teamed up on the DonationCoder forum to help make a model of our site mascot (Cody the Bird), and a customizable base for him to sit on.  You can follow along with that thread here: https://www.donation...ic=45256.0;topicseen

A photo:


I've tried experimenting with doing 3d design using tools like Blender, and my brain completely shuts down, which is a shame because it would be fun to be able to DESIGN models not just print models that others have made.

Which brings me to the reason I'm posting, OpenSCAD.

OpenSCAD has been a revelation for me.  It's basically a CAD (computer aided drafting) programming language and development environment, which makes it easy for a programmer to design and model 3d objects for printing, using algorithms/code.

It's a joy to use -- you can write programs to create 3d objects and instantly preview and study them and then save them for printing.  And most of the models on thingiverse that are customizable are made with OpenSCAD, which is a great way of getting started.

My mind is swimming with the idea of creating both useful and precise objects, but also useless and mathematically interesting objects...

Here is a video talking about OpenSCAD:

[ayryq]

I knew you'd like it I had the same experience after trying more organic programs (blender) and more supposedly-precise ones (sketchup). Neither category was compatible with my brain. But OpenSCAD just makes sense! Lately I've been printing parts for my father-in-law's recumbent bicycle. He needed a part with a radius to match that pipe and a hole just right there, and in about 10 minutes I had a design done. While there are certainly applications for which it is unsuited (c.f. my attempt at modelling Cody), for anything which is basically geometric, or for anything which requires precise dimensions, the use of a language rather than a gui is a huge asset.

Edit to add: I won at the 3d-printing game when I used OpenSCAD to model, and then successfully printed, a new heel-tip for one of my wife's high-heel shoes. Other models I've made which might be useful to others include a model-rocket launch-rod cap, and a little platform to mount a circuit board to a rod.

Eric

[mouser]

Many thanks for helping me get into it, aryq 

[mouser]

Today I used my 3d printer for something useful.

I have an (old and expensive to repair) automatic trash can opener, and in a fit of anger I slammed down the lid and heard something break..  Opening it up revealed a plastic gear has snapped in half in the gearbox mechanism that opens and closes the lid.
I tried epxoying it and supergluing it, and both fixes lasted less than a day.  I then tried to figure out how I might order a replacement part.  No luck.

I finally decided to try to use my 3d printer and print a replacement.  I used OpenSCAD, which is magic, and an awesome library for it called involute_gears.

After a few experiments to get the fit exactly right, it seems to be working great.  This is definitely the future of repairs.

[mouser]

My 3d printed replacement gear failed yesterday, after a few weeks.

I thought maybe the teeth had broken, but opening it up it was clear what happened -- the D bore in the center had deformed into a circle and so the gear was slipping.

This gear undergoes some pretty strong forces against it and PLA is not made for such stuff.

I've reprinted it, making it as thick as I dare, and then "baked" it in oven for an hour, which people have documented can strengthen prints.

I'll see how long it holds up..

[Nod5]

Brainstorm: Any chance you can reinforce the print? Maybe a flat round metal washer with a centre hole a bit smaller than the D shaped hole. Use a metal file to enlarge the hole to exactly match the D hole. Then edit the CAD to embed the washer in the middle of the gear print.

[mouser]

something like that could work.. another option would be to find a small flat metal piece, and modify the 3d gear print to have an indentation where i could lay it in to be the bottom of the D bore -- since thats the place thats getting worn down.

With the new gear I also printed it a bit smaller/tighter fit so I had to hammer on the piece to the spoke -- and then baked it with it on the metal spoke, hopefully shrinking it even further to fit the D shape spoke.  I'm hoping that will help.

I have had to do 4 corrective solders of the very thin motor wires from taking this whole thing apart so many times.. At some point I am going to have to give up the battle but it's a bit like avoiding covid-19 at this point -- I feel like it's a game and to give up would be to admit defeat...

[wraith808]

something like that could work.. another option would be to find a small flat metal piece, and modify the 3d gear print to have an indentation where i could lay it in to be the bottom of the D bore -- since thats the place thats getting worn down.

-mouser (June 16, 2020, 02:25 PM)

That was the approach that I was thinking of.

[Target]

change the design of the gear such that instead of printing the 'D' shape it has a keyway instead.  That way you can insert/replace a piece of square (?) wire or rod to form the flat in the centre (FWIW keystock comes in standard sizes and should be readily available)

[mouser]

Here's a video talking about a similar thing: