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SketchUp to STL Plugin with No Dialogs

Tuesday, June 14th, 2011

When designing parts for the Makerbot my tool of choice is Google SketchUp. I’m able to do this easily (and for free) due to the work of Nathan Bromham and Konrad Shroeder. Their skp_to_dxf plugin quickly exports my model into stl format, which can then be read by ReplicatorG.

One minor annoyance though. Every time I run the plugin I need to specify “Millimeters” and “STL”. I’ve been revising a lot of models lately; trying things out then checking the resulting tool path in skeinforge. Somewhere around the 20th time specifying the SAME THING, I decided to go into the plug-in code and just hard-set my options.

The result is my variant of the plugin, which I’ve labeled skp_to_Custom. I did almost nothing. I commented out the dialog code and instead included a section at the beginning of the code where you can hard-set your options. That’s it. But MAN has it saved me some aggravation.

Download

Tags: Makerbot
Posted in Projects | 6 Comments »

Laser-Cut Business Cards

Saturday, June 4th, 2011

I’ve really been saturating the blog with ear-bud wrap posts lately. This should be the last one for a while. I decided to order some laser-cut copies of the earbud-wrap business card. They were a bit expensive, but I’ve been wanting to laser-cut something for some time. I went with 2-color acrylic, and I think they turned out really well.

Tags: earbud holder
Posted in Mechanical | 4 Comments »

Earbud-Wrap Business Card

Sunday, May 15th, 2011

I made one last (for now) modification to my Credit Card Earbud Holder. The wrap now ends with an over-pass that really locks everything in place. As before, it’s insanely easy to remove the wrap.

The other thing I realized is that, if laser cut from thin plastic, this would make a really neat business card. I don’t really feel like paying for a laser-cut version at the moment, so I just printed out a shipping label to illustrate. If you DO feel like laser cutting this bad boy, I’ve uploaded the plans to Thingiverse. (The plans will also help you if you just want to make one out of an old card)

UPDATE: I got some of these laser cut. They look amazing.

Tags: earbud holder
Posted in Mechanical | 2 Comments »

My Take on the Credit Card Earbud Holder

Thursday, May 12th, 2011

Yesterday on Lifehacker they posted a forehead-smack idea. Take a credit card, cut it up a bit. You’re left with a free, light, earbud holder. I’ve got a bunch of old cards lying around, so I made one.

I Didn’t like it. My design grievances:

You wrap in the short direction, which means more wrapping to get the job done
Having the earbuds stored on either side means you need to put in each bud individually
It takes just as long to unwrap as it does to wrap

It needed some work to compete with my current method. The beauty of using cards is that they’re easy to work with and plentiful (in my house at least.) It only took about an hour (7-10 iterations) to settle on a winner. Meet my new earbud holder:

The earbud slots are wide and next to eachother, so you can get the buds in quickly with one motion
You wrap the long way, so you’re done in half the time
The way the plug is clipped ensures that the wrap stays put, but…
Because the wrap isn’t in channels, it slides right off once the plug is detached. WAY faster.

UPDATE: I went through a few more iterations and came up with an improved design.

Tags: earbud holder
Posted in Mechanical | No Comments »

Google is Keeping the Offset Header

Wednesday, May 11th, 2011

I have a one-track mind whenever I see a new Arduino variant. My eyes drift to one spot to see if the offset is still there. Naturally I did the same thing when I saw that Google is releasing its own Arduino-type thing

Lo and behold, there’s the telltale gap. I’ll need to look at any schematics they wind up open-sourcing, but I’m fairly certain: Sparkfun will be selling these for a while longer.

Tags: Arduino, Offset Header
Posted in Mechanical, Projects | 1 Comment »

Arduino Uno Keeps Header Offset

Monday, September 27th, 2010

The newest version of the arduino was announced last week. At first glance it seemed as though they got rid of the offset header spacing, but a closer look at the spec showed that it is still 0.16 inches. It would have been a bold move to change that spacing; there are a lot of 0.16-spaced shields out there. Looks like Sparkfun will be selling offset headers for some time to come.

This changes everything

Friday, August 13th, 2010

A lot of my projects involve 120VAC, switching relatively slowly. Most people use mechanical relays in that situation, but I don’t like them; I try to avoid moving parts whenever possible. Up to this point, I’ve always used solid state relays. They work really well, but they’re expensive. What this means is that I’ve needed to move my same 2 SSRs from project to project, which is kind of a pain.

Well no more! Enter the humble Triac. They’re tiny, cheap, and in my slow switching applications the circuitry isn’t too complicated. That being said, it’s still the most complicated circuit I’ve ever attempted.

I figured a good first application would be a switched outlet. It’s fairly simple, and it’s something that I could use in prototyping later on.

And there you have it. A neat little package with two independently controlled power plugs. The best part is the cost. The whole thing cost less then $10! With SSRs it would have been ~$80, and I don’t know if they even would have fit in the box.

Triac Box from br3ttb on Vimeo.

There’s one issue I’m going to need to keep an eye on. Apparently, if a Triac overheats, it tends to fail into the on position. There’s nothing here that detects if this is about to happen, so I’ll have to keep an eye on it for a while to be sure there’s adequate cooling

Update: There is NOT adequate cooling. I did a real test just now. 1500W toaster oven on high. after a minute I started smelling perfboard. Everything was disconnected before any damage was done, but some design revisions are in order before I try to switch high loads again.

Tags: Triac
Posted in Electronic | 3 Comments »

DIY Safety Razor Handle

Saturday, March 6th, 2010

It’s terrifying.Â I’m still in shock that it actually works, but it totally does. One dollar of materials and two or three hours of work, and I now have a safety razor of my very own.

Why? Why would you do something like this?

Basically, I’m cheap and I like making things for myself. I’d been toying with the idea off-and-on since reading a Lifehacker post on safety razors. It all came together for me this past week.

Eureka!

I was looking at an image from an old razor patent when inspiration struck. Based on the known razor width and some trigonometry, I was able to determine that the two main radii were 0.53″ and 0.66″. It turns out that these are almost identical to 3/4″ and 1″ sch40 pvc, which is available everywhere.

Construction

Sorry. No mid-build pictures on this project. I never thought it would work. This was supposed to be a study of sorts, just seeing how things might work in further iterations. Instead it worked, and I’m stuck trying to give the gist of it…

Cut a piece of 3/4″ pvc slightly bigger than the desired top piece.
Wrap sandpaper around some 1″ pvc and sand down the botton edge of the 3/4″.
Cut a section of 1″ pvc for the bottom piece.
Make holes in the top and bottom pieces.
Run a bead of jbweld down the center of the top piece.Â as it hardens shape it into a ridge.
After the jb hardens, sand such that it just fits the blade’s slot.
Remove material from the bottom piece to make room for the jb ridge.
In theory, you’re done!Â In reality there’s some fine-tuning to do.Â It took me about an hour of trial-and-error sanding until I was happy with the final shape of the top piece.

I’m going to shave with this for awhile, and when I make the next one I’ll try to be more diligent about documentation.

Tags: DIY Safety Razor
Posted in Mechanical, Projects | 10 Comments »

OpenSCAD: A Love Story

Friday, November 27th, 2009

Ok, maybe that’s a bit strong, but I’d definitely say we’re dating. I heard about OpenSCAD from the Make Blog, and with a belly fully of thanksgiving turkey I tried it out. I agree with the Make post and the referenced Thingiverse post : In the right hands, designing the right parts, this is a game changer. I played around with it for maybe 3 hours, and was able to generate this:

Insane. I’ve been toying with the idea of making a grist mill using burr plates. The main hurdle for me was visualizing all the different angles and how they would interact. I tried drawing one in SketchUp, but after many hours, I threw in the towel. Before OpenSCAD came along I was trying to build the mental momentum to draw the plate in Processing! Seriously. I was going to use their 3D libraries and a TON of math so I could play with a parametrized model.

Speaking of coding, I should also mention that the code to generate the model is TINY. I’ve spread it out and commented it here, but in rough-and-dirty form, the code is less than 10 lines. 10 LINES! I’m free to edit any of the parameters, re-render, and a new model pops right up. Great stuff.

So I’d say there’s a new tool in the tool-box. It’s by no means the only one I’ll use, but certain modeling tasks just got a heck of a lot easier.

Tags: burr_plate, OpenSCAD
Posted in Projects | No Comments »

REALLY deconstructing a Doodle Pro

Wednesday, November 25th, 2009

I didn’t really “deconstruct” the doodle pro in the last post. I split the housing apart with a screwdriver, and I didn’t even show pictures! What a gyp. For those of you that are interested in a little more, here you go:

I pulled apart the drawing panel. It looks like it’s made up of two sheets of plastic. One is embossed with a honeycomb, and the other is then fused over-top. I really had to yank to get these apart, so I’m guessing they used some heat to melt them together.

Inside there’s metal shavings and a PUTRID smelling liquid. You know how cherry, watermelon, orange, etc flavors don’t taste like the real thing? Imagine if the same people were asked to make something that smells like feet. That’s the best analogy I can think of: synthetic feet smell.

Oh man, if you could…

Now the million dollar question… could someone DIY one of these? Maybe using a clear plastic mesh and two thin sheets of the same plastic? I think the hardest part would be dealing with the liquid. It needs to be viscous enough to hold the shavings in place, it needs to be opaque, and the plastic layers need to be fused closed with the liquid in place.

If you could make one in the 3′ x 4′ range, the payoff would be huge. Even if you don’t do what I’m thinking with it, it would still make a kick-ass whiteboard replacement.

Tags: Magna_Doodle
Posted in Mechanical | No Comments »

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