- Ultimately, this design creates more anxiety than it's worth.
- The company that sells the CHUG no longer sells the files to print it at home.
Background on the CLUG
A while back, a couple of enterprising designers from Vancouver ran a Kickstarter campaign that ultimately raised $80,000+ to manufacture CLUG; a tiny wall-mounted clip meant to act as a bicycle rack, of sorts. I missed out on the campaign, but one really cool aspect to the Kickstarter was that backers ($9 tier, I believe) would be granted the digital .stl files that would allow them to use their own 3D printers and print the CLUG themselves at home! How cool!
Unfortunately, after the initial release of the digital file to the early backers, the CLUGsters flaked. Once the CLUG had been (exceedingly) funded, the designers decided they wouldn’t make their digital files available for purchase. Instead, they claimed that they were “hard at work getting the 3D Files ready for sale“. To the best of my knowledge, it’s been an entire year and there’s absolutely no indication, at this point, that they intend to sell these files. Joseph Larson realized this nearly 6 months ahead of me, and took matters into his own hands with a blog post titled “How I stole the Clug and why I don’t feel bad about it“.
Reverse Engineering
Feeling inspired by Joe’s assertiveness, I decided to do a little reverse-engineering of my own. I started out by researching the product. I found as many pictures and videos of the CLUG as I could. Humorously, my best resource ended up being on the CLUG website itself! Although they’d decided not to sell their digital files, they left their 3D printing instructions on their website! Furthermore, they actually included (full scale) screenshots of the individual components being prepared to print. Because I’m familiar with the software, I could tell they used Makerbot Desktop.
Not only were the screenshots tremendous feature references, they also allowed me to scale my design appropriately. One helpful aspect of the Makerbot Desktop software is that the grid it uses to represent the 3D printer’s print-bed is rendered at 1 cm per side. Knowing this, I was able to calculate both components’ footprints (42mm x 38mm on the larger piece), as well as their wall thicknesses (2 mm).
This next screenshot tells me that the software is set to slice the model at a layer height of 0.30 mm. The screenshot after that shows me that there are 101 layers total!
SolidWorks Modeling
Without boring you through the step-by-step details of the CAD work, I created both components as independent solid bodies in the same part file so that I could build them up parametrically. Taking advantage of symmetry, I started with the outside shell and treated it like sheetmetal.
I then mirrored the piece, added in some structural support, and included the holes that attach the bracket to the wall.
Next, I attacked the second component. I added several reference planes and geometrical points that would facilitate me creating the two lofts shown below.
After doing some feature mirroring, I hid the first component. Then, I added more material along the midline of the piece to give it structural strength.
Lastly, I added the features that would allow the inner component to “clip” to the outer piece.
The only thing left to do was to actually print the models!
Wait, no. I lied. The last thing to do was mount the reverse-engineered CLUG on the wall and attach my bike!
Conclusion
My original intent with this project was to release the stl’s out into the world. However, after using my modified CLUG for around two weeks, I’ve decided to table that thought. My bike hasn’t actually fallen yet, but my version of the CLUG doesn’t have as much clamping force as I’d like. I’m nervous that, at any moment, my bike could come crashing down. I’ve considered going back and revisiting what I have, but at the end of the day, I’ve decided that I’m just not a fan of this design. It’s discreet, sure, but the easy pop-in/pop-out concept just isn’t worth what it costs me in anxiety.
I think I’ll probably come up with my own 3D-printable wall-mounted bike rack in the very near future, so stay tuned!
Update (4/17/17): Perhaps against my better judgement, I’ve decided to go ahead and share the Clug’s reverse engineered STLs here on agcross.com. No plans to throw them on Thingiverse for the time being. It should be emphasized that, if you choose to download, print, and use these, you are doing so at your own risk. I am not at all responsible for any damage incurred to person or property following the use of these STLs. I should also be explicitly clear that I don’t trust this open clamping design whatsoever. That being said, if you fail to heed these warnings, let me know how it turns out!
