3D printing to the rescue
2012-02-25 21 Comments
I bought a new bicycle, recently. My first with drop-bars. The additional brake-levers ease my mind, but make it more difficult to attach any more stuff. So I went looking for a well-reviewd, certified (German Straßenverkehrszulassung) headlight with a clamp that would fit into the space right next to the stem.
The Busch & Müller Ixon Pure seemed to fit the bill. It comes with a too small clamp, but a larger one can be bought separately. Only after doing so, I realized the the lamp is put on in the opposite direction for this oversize clamp! This means the business end has to be in front of the bar, where I do not have enough space thanks to the cable connection-thingys of the brake levers.
What a great opportunity to see how far the Free Software parametric solid modeling application FreeCAD has come! The 0.12 release didn’t cut it, but with a checkout a while later, I managed to model what I call the sled, with the relevant part put on in reverse. There were a few issues I had to work around, but except for some fillets I had to do without, I suceeded. Not production ready (not that anoyne claimed that), but very promising. Kudos to the developers!
After having a quick look at the mesh in Blender, I went to shapeways.com. They claim their strong & flexible material can be used for living hinges and springs, and as far as it is required in my case, it works fine.
The quality of the surface and the corners is not great, but aside of the those ridges on the lever, overall precision seems to be excellent, as far as I can tell with such a small part. It fits very tightly, but so does the original.
The original sled has a metal inlet for the screw thread. I simply modeled a tunnel with the smaller diameter of the screw. Required some force to screw it in but seems to fit well now; only time will tell if this is a durable connection.
It took 10 days from order to shipment, $ 12.05 for the part and $ 11.31 for shipping, resulting in € 17.73. Edit: The model available for printing or download.
From a pure filling a need point of view, this was a bit expensive in time and money, but I just had to try it and enjoyed the process. On to a future with free/open modeling tools, model libraries and affordable 3d printing! 🙂
Thorwil's 
That is truly ground-breaking. There is a whole industry based around cyclists and annoyingly incompatible parts.
3D-printing could really shake up the status-quo. Thanks for pioneering this.
suidine
p.s. Do you mind if I submit this post to bikehacks.com? I think it would really go down well with those readers 🙂
Thanks! Not at all, submit wherever it seem appropriate.
Really smart thinking, dude! 🙂
Very impressed. I watched some 3d printing at work over in Fablabs in Manchester in the UK and was jealous for all the bits I ‘could’ change on my bike.
Will have to hunt out the software.
Thanks for sharing
Really nice! What file format did you use when submitting the drawing to Shapeways?
From this page: http://www.shapeways.com/tutorials/supported-applications and this page: http://www.shapeways.com/support/design_upload_and_3dprint , it looks like it was STL format…. is that right?
Maybe add a link to the object in shapeways gallery, if it’s there? And how did you make the model – did you just measure it with a ruler and then try to make the closest reproduction in free-cad? Certainly a walkthrough of the exact software steps used (I’ve never used cad software before, but would love to see an explanation), and formats, and so forth, could be a great follow on post. I think lots of people would be interested in making simple 3d objects, if only they knew how, and could bo so fairly inexpensively.
Yes, STL. I just made the model available at http://www.shapeways.com/model/474691/.
I took dimensions with a sliding caliper, which I would say is a must-have tool for a task like this. At least as long as you can’t use a 3D scanner ;).
I would consider creating a walkthrough, but that’s a lot of work I do not want to invest now, as I had to use some workarounds which I hope will become unnecessary soon. Also, there is no released, much less packaged version of FreeCAD that can do it.
[…] Thorsten Wilms wanted to attach a headlight to his new bike. He bought a Busch & Müller Ixon Pure bike headlight with two clamp delivered but both were not fit for his bike, one was too small, another was oversize, and when he put it on he found […]
Thanks for your great example! Your piece is just what 3D printing needs now: practical and graphical examples of what you can obtain with it.
I’m a novice using freecad. I love parametric interface, but some of the complex elements of your piece are out of my reach. Do you mind to publish the file in native freecad format?
Besides, keeping in mind that tutorials of freecad are in a early stage, I really would appreciate any advice about how you generate the most complex parts of your piece.
Thanks in advance,
Juan
You’re welcome. Here’s the file: http://dl.dropbox.com/u/485382/ixon_sled_07.fcstd
The sketch for the cylindrical part makes it extend into the body above it. This is a workaround, as otherwise FreeCAD refused to extrude that shape and treat both as one. Only later I saw that I could have modeled them as separate bodies to then apply a union.
The lever is the most complex part, but not hard to model as one sideway extrusion and a cut from above (as with a cookie cutter, but for the part you take away, not the part you keep).
Thank you very much. I am very interested in freecad as a main tool for 3D printing, and your example is very inspiring and graphical. However, I haven’t been able to understand how did you produce several elements:
How did you cut Pad top from the main piece?
Where do the three fillets come from? what is their origin?
Do you know any tutorial that explores sketching and 2D drawing apart from basic official one? It is not enough explanatory in order to produce pieces such as yours
I find freecad as a tool with a huge potential for popular 3D designing for 3D printing. Indeed, parametrical interface is very comfortable for designing exact pieces and elements without messing with the mouse. However, lack of proper tutorials doesn’t permit the fulfilling of this potential
Thanks very much in advance
Juan
Pad top is separate from the main piece, because I added its sketch to the ZY plane, not to a face of the existing geometry. Also there is no overlap with existing geometry. This behavior of FreeCAD broke my expectations, even though I don’t recall how Solidworks handles it.
You can toggle visibility of the construction steps with Space key (including the final mesh).
My intention was to use fillets on all edges, because real objects can’t have perfect hard edges. If you do use a technique and material that gets close to the ideal, you end up with edges that might become painful …
It looks like this 3D printing does a reasonable job of smoothing the edges, but can’t realize a difference between 0 and 0.1 mm radius (should have known, that’s so tiny).
I only looked very briefly at the existing tutorials, as my training with Solidworks, even after a long break, allowed me to pick up FreeCAD easily enough.
Awesome 🙂
You may drop your 3d files (and a short description) at http://www.thingiverse.com (3d community for open source models) to find a larger audience.
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Absolutely fantastic! Good work, inspirational stuff.
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Great post. How was the service from Shapeways?
Thanks. Shapeway’s documentation, upload form and preview are pretty good. Production/shipment happened within the estimate, I mean to recall. Packaging was fine. There simply was no need for communication outside of the automated ordering process, thus no test of their service in the wider sense 😉