Thursday, October 31, 2013

Wearables project: Rapid prototyping

Fresh print with support material still attached.

Support material removed and tentative white foam rubber padding added.

I can see right away that many tweaks to this design will be necessary.  The front part of the form looks okay, and is similar to what I had in mind.

But the back side of the form is bulky, awkward, and slightly uncomfortable.  Francois agrees.

Compared to original paper model. 

I may have to start over, but considering this process only took a few hours, I'm happy to learn from mistakes and have another go at it.  This is the beauty of rapid prototyping!

Wednesday, October 30, 2013

Wearables project: First cad model

I began this model by drawing a flattened form based on my paper template.  I drew this in Assembly mode in Solidworks, each folded segment a separate part then mated together.  This would allow me to "fold" the virtual model much like paper.

To get an idea, here's what the model would look like once I begin folding it.

I can also refer to the physical paper model while I position the virtual one.

From the virtual paper model, I extract a coherent surface.

And add fillets to the folds to begin smoothing the form.

I create an offset surface from the first one to add thickness to the model.  This is an offset of 1/10th of an inch.

And a lofted surface operation closes the form.  I can now add details and begin to integrate other components.

But before I get into that, I'll be doing test prints so I can test the fit, look and feel of this form.  Here's the model loaded into the Up! printer software.  The print will take about 7 hours.

For fun, here's a mock-up of what this gadget may some day look like.

Tuesday, October 29, 2013

Wearables project: Paper models

Working on paper models to aid me later on when I begin drawing this thing in CAD.  

The great thing about starting with a 2-dimensional form is that I can begin the CAD model by pretty much directly tracing the pattern from this high-res scan.

Sharp angles will allow me to accurately measure geometry and ease the digitization process. Things may get curvy later on...

Z-Axis Tape for solderless circuits

Just stumbled across this product from Sparkfun:  Z-axis tape!!

This is a double-sided conductive tape that will only conduct electricity vertically!  In other words, it will not connect traces next to one another on the x or y axis, only on the z axis.  This could be a dream solution if you want to do some solder-less circuit building with surface-mount components.  I'm excited to try this product and will be ordering some right away.

A demo of the product by Sparkfun (begins around 1:05):

Grab some for yourself here.

Sunday, October 27, 2013

Wearables project: First parts have arrived.

 Bluetooth transmitter and receiver modules arrived in the mail.  Ordered from amazon here and here.  I'll be hacking these for a new project where I'll need to send audio wirelessly between devices roughly 6 inches apart.

Walter keeps watch while I plug in the modules to charge.

First test run of the equipment.  With the press of a button they are able to sync and send audio over a relatively large range.  This guy cut out around 50 meters, with furniture and walls between. 

I'm satisfied, and will now see what's inside.

I started with the transmitter module.  Opened by sliding a large sharp blade along the seam between covers.  I should post a video on my strategies for popping stuff like this open... it can take some finesse.

I found these items inside:  x1 stereo audio cable with stereo 1/8th inch mini jack, x1 3.7v Li-ion battery pack, x1 bluetooth/audio circuit board.


 Without the battery this guy is pretty teensy.

And should fit this project quite nicely.  Next I'll dissect the receiver.  I'm expecting a similar-sized pcb inside.

Tuesday, October 22, 2013

Derby nerd

For the next two "modules," I flipped the model in the Up! printer software, which yielded slightly better results.

Here are the three modules with all of their hardware: salvaged 608 bearings, 1/4-20 bolts with weld nuts to act as sleeves to better fit the bearings, 5/16 nuts to add extra weight, and 6-32 bolts to serve as joints to connect each module together.

I created "links" for joining the modules together using aluminum armature wire, bent to shape with needle nose pliers.  I was originally planning on printing these, but thought they'd be a bit too brittle in the end.

Here's my nerdy derby car, assembled and ready to race.  Usually with a gravity driven racer you'd want to minimize surface contact... but with the extreme curves in the nerdy derby track it seemed like half the battle was staying on the track.

Detail shot of the armature wire linkage.

Decided to name this guy "Derby Nerd" in honor of the event.

I'll be sure to post some pictures of the derby and Milwaukee Makerfest in the coming days.

Monday, October 14, 2013

Mke Makerfest: Nerdy Derby

This coming Saturday, the Milwaukee Makerspace is hosting the 2013 Milwaukee MakerFest.  As part of this, they are holding another Nerdy Derby, open to the public for entries.  I thought it would be fun to build and enter a car this year.

 I grabbed the specs of the standard nerdy derby track  (my good friend Frankie is actually building the track for this year's event and pointed me toward the blueprints).

Having detailed specs, I thought it would be fun to build a car that's completely specific to the track.  A rough sketch of my initial idea... inspired by toy trains / roller coasters from the future...

First I modeled the wheel - this is actually a casing that will fit around a 608 bearing.  I just salvaged a bunch from some old roller blades and have been looking to put them to use.

Dirby track section modeled, Wheels mocked up.

Front view sketch.

Revolved and lofted extrusions...

Fillets ftw.

Added a central bearing holder, designed so the bearing can snap into place.


The design is looking okay so far... time to make a prototype!
Decided this would be best fit for my UP! printer.

Pieces fresh off the printer, still warm.

Holes tapped.

Bearings and hardware added.

Print came out a bit rough.  I'll rotate the next batch on the bed to hopefully get a better finish on the top of this.  But otherwise, I'm happy with this design.  Let's see how many "modules" I can finish for Saturday!