Lost but Never Forgotten

Posting some art I’m generating from mechanical drawings of my old projects.  This is a subject that will come up again soon, I promise. ;)


[More to come!]

Week 40, 2015 – Ideate, Iterate, Create!

Sorry, again with the ‘pictures on the way’, I have to clear off the workbench so I can take pictures of a bunch of stuff…so no pictures in this post yet.

Yes, I know the first weekly of the month is usually the acquisitions update…but most of my purchases won’t arrive until next week, so…
┐( シ)┌

I’ve been busy with a couple projects this weekend, related to some of the stuff I bought– the few bits that are here already, namely some audio rigging for my podcasting/video setup –and I figure this is a good time to cover this bit of process.

As someone who has spent the majority of his adult life ‘almost making things’– always failing for one reason or another –it is not lost on me just how absolutely mind-blowing it is that I now have a literal god damned magic box that just substantiates my ideas from thin air.  (Or more accurately, from the 1s and 0s of the designs on my computer, and spools of plastic filament.)

Anyway, where was I?  Oh yeah. So, I got this cheap little microphone boom, and I got a new mic cable.  First things first, I needed a way to attach the cable cleanly to the boom and manage it.  Calls for some little cable clips, methinks.


btw, I thought ‘ideate’ was a ridiculous portmanteau I came up with, but apparently it’s an actual for-reals word that only sounds ridiculous and made-up. Go figure.

I figured I’d better keep it simple; no point getting flummoxed at this stage of the process by trying to outsmart myself design-wise… So just a simple double-clip. A square clip to attach to the boom’s square tube frame, and a circular clip for the cable.  Out came one of my trusty digital calipers, and soon I had the measurements; the frame tubing was nominally .410″ square, and the XLR mic cable was a little under .250″ in diameter.  So those are the numbers I worked with.

Three minutes later, I had the simple design ready to print.  Dropped it into Simplify3D, warmed up the printer, and 5 minutes later, I had the part.  Fit like a charm! It was slightly loose though, and that brings us to…


One of the wonders of 3D printing is pretty easily summed up in the name of the process/industry it has given rise to; Rapid Prototyping.  Not only does it allow you to near-instantaneously go from idea to reality, but to quickly and inexpensively go through countless design iterations, working out flaws, testing refinements, and so on.  I mean, it costs me $0.11 worth of plastic to print eight of these clips, so printing one, trying it, tweaking some things, and printing another hardly costs me anything, except time…and at 5 minutes a pop, that’s not a huge concern when I can be working on plenty of other things (Or relaxing!) while the printer does its work.  So, anyway… The clip was a little loose on the frame, so I made the dimensions a little smaller.  That still didn’t seem to do it, so I tried again, but now it was too small, and still loose…there was something missing. So I took the first one, and squeeze the legs together– bending them a little –and when I stuck it on, it stayed put. Aha!

So this time, I set the dimension back to what it was, but I designed a 5° inward bend on the legs. (I had also, in an earlier iteration, merged the outlines of the circle and square completely, to make the cable lie flatter on the boom…the original design only had them overlap 50%.)


Knowing this design was as perfect as it was going to get, I printed eight of them.  About 30 minutes and 1.8 meters of filament later, I had them, and they were great!  They still don’t stay put on the frame perfectly– not like on the cable, but the cable has a really ‘grabby’ rubber surface –but they’re no longer loose enough to slide around under their own weight.  Maybe I should try dual-extrusion printing them with a NinjaFlex inner wall to grip the metal tubing.  (I still haven’t received my Teflon tubing yet, so I haven’t reassembled the left extruder…)

MADE COOL THING – Filament Spool Holder

Well, here it is.  This is what I consider to be my first ‘real’ part.  I mean, sure, I designed that webcam mount and a few other things, but they were all crude early attempts.
Simple Smooth Spool Holder

I decided that a spool holder was going to be absolutely essential.  Besides just making it a pain in the ass to change, having the spools mounted to the back of the printer caused a lot of feeding friction– though I never had a jam, I did have a particularly brittle transparent ABS filament snap off at the extruder a couple times because it took too much force to feed it –and most importantly it makes it impossible to put the printer on my 14-inch deep wire shelving.  I wanted to be able to mount the spools above the machine, make them as fast and easy as possible to swap, and make it feed as smoothly as possible. To take care of that last point, I knew that whatever I did, it was going to need to involve bearings of some kind.

Mechanical drawings.

Mechanical drawings.

At first, I thought about other designs I’d seen, like a horizontal post that the spool hangs on,
with a single straight race loaded with like quarter-inch ball bearings, which the spool rests on…  But mounting that would be problematical, and there’s no guarantee that the balls would roll smoothly.  It also wasn’t necessarily universal.  In the end, I settled on a very simple and elegant concept; just have each rim of the spool rest on a pair of skate bearings spaced apart by a printed frame.

Assembly diagram.

Assembly diagram.


The end result was some beautiful work, with some additional cutouts to lighten it up and reduce material usage and print time. (I later found out that the reduction in print time was negligible, depending on the print settings, because of the additional time spent printing perimeters.)

And it printed just as good as it looked…which is something I could definitely get used to.

The printed parts.

The printed parts.


I put them to use immediately, moving the printer to the shelves, and setting up the filament spools above it.

The spool holders in action.

The spool holders in action.

I need to design and print some little clips that attach to the spool holders, and then to the wires of the shelf… I purposely avoided integrating a shelf attachment method to allow for flexibility in their use.  In future design iterations, it might be useful to include some manner of guide tube near the front or something, so I can just plonk the spool down on the holder, feed the filament into the tube, and have it come out where I want under the holder.  Because currently, I have to stick the filament through the shelf first, before I set the spool down, so that the filament is coming down from the center of the spool…this is less than ideal.  I think it’d also be cool to print them in Taulman Bridge filament, so the finished parts would be nigh-indestructible!

UPDATE! 2015-08-30 Posted to Thingiverse!

Thingiverse and MakerBot are running a contest, #FilamentChallenge, with first prize being ten spools of either MakerBot ABS or PLA.  The challenge is to design a spool holder, so I submitted this design. You can find it on Thingiverse here! It’s my first submission to Thingiverse, but it won’t be my last.

And by the way, you can see that nearly six months later, the spool holders are still working perfectly.

Still in service, six months later.

The spool holders are still serving me well, six months on.

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