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3D Printed Shim

Shim

I needed a few shims to make something fit just right and I grabbed a piece of 3mm acrylic that was sitting on my desk, figuring I could easily cut it in the shop, but 3mm was just too thick. I could have tried to sand it down to the proper thickness, but at this point I would have had to cut three shims to the proper size, and get them all down to the correct thickness. (I didn’t want to use wood, as something would be sliding against the shim, and wood wasn’t the best choice.)

OpenSCAD

I took some measurements with digital calipers, launched OpenSCAD, typed in the dimensions, and had a 3D object ready to be 3D printed in just a few minutes. While I did have to wait for the 3D printer to heat up, and print the pieces, I could easily do other work while I was waiting for the prints. I didn’t spend time cutting and sanding things to get them the exact size.

Sometimes 3D printing is the right answer, and sometimes 3D printing doesn’t have to be revolutionary or solve big problems, sometimes it can solve the (little) problem you have, quickly and easily, and that’s enough.

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Mac OS X & Windows

Mac OS X & Windows

It’s been a long time since I had to use Windows servers, probably ten years and six operating system versions. Back then I dealt with Windows shares not as an admin, but a normal user. I ended up writing utilities in bash or Perl that would delete .DS_Store files and “dot underscore” files being written to Windows shares by Mac OS X. Now that I am again dealing with Windows shares (again, not as an admin) I thought I should dust off my old scripts (one of which is dated 2002.)

But it seems the world has changed in the last ten years, and now I can deal with “dot underbar” (the proper name) using dot_clean, which is built into Mac OS X. I’ll also be using dot_clean on DOS formatted thumb drives and SD cards that are going into other operating systems.

There’s still those pesky .DS_Store files, which I do not want littering any of the Windows shares at work. It seems you can prevent .DS_Store file creation on network volumes by using the following command:

defaults write com.apple.desktopservices DSDontWriteNetworkStores true

That should make for neater volumes and file shares when I move things around… Now if only I could deal with the other annoying Windows server stuff. Often I cannot rename or delete a file or folder on a Windows share. Sometimes I’ll try it from a Windows machine instead of from Mac OS X, and occasionally it will work, but often I’m only able to move all the files out of a folder and then can’t delete a folder. If I can rename an empty folder, I end up renaming it “delete me” but I still cannot delete them. Does everyone have these sort of Windows issues? (Again, I am not an admin, just a normal user.)

Sometimes I really miss of the Mac OS X-based servers I used to run. (Well, every time I have to use a Windows server, actually.)

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Screen Printing Demo

ground tracking station

I did a screen printing demo class at Milwaukee Makerspace, so that other members can make use of the awesome equipment we have available…

I grabbed this fine piece of art titled ground tracking station from OpenClipArt a while back, and figured it would come in handy…

Krambo Industries

After a number of edits to make it “cut-friendly” and adding my own text, I used the Silhouette Cameo to cut some vinyl to use for the mask…

Vinyl prep

Since we’re going to stick the vinyl on the back side of the screen, make sure to reverse your image before you cut it! (You can do it right in the Silhouette software.)

screen back side

The vinyl gets attached to the back of the screen. I don’t have a photo of the transfer paper, but yes, I needed to use transfer paper. Getting the vinyl to stick to the screen can be tricky! Go slow, very slow, and make sure it transfers ok. It may not stick very good (yet) but it will work.

Once the vinyl it in place, tape it good on at all four sides, and then add more tape. (It’s clear packing tape, hard to see in the photo.)

screen front side

Flip the screen over, and press down on the screen, so it will stick to the vinyl better. Add more tape. Really, preparing screens involves a lot of tape. (The white thing on the screen is just the backing of the vinyl, which I used to save a bit of tape… It’s taped in place. Yes, more tape!)

Printed shirt

It was the first time screen printing for everyone who attended. Usually at least one or two people have had some experience (usually in high school) but this time no one had done it before. Here’s the shirt Asim printed. It turned out good!

Printed shirt

While I only talked about printing light ink on dark shirts, Andrea brought a black shirt, which we printed with dark red ink. She said she wanted to do a bleach treatment on the shirt, which should lighten up the fabric but not the ink. Hopefully I can get a photo of that when it’s done.

Sample print

I did a print on paper as well so I could add it to the “Wall of Stuff” at the Makerspace.

After I cleaned everything up I had a member ask when I’d be doing another demo/class. As usual, I don’t know the answer yet! Usually when enough people ask about it I do it. So, yeah, I’ll do it again, at some point.

(Here’s a blog post about a previous printing that I did.)

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Because, 3D Printer…

Because when you’ve got a 3D printer… You might as well print things…

3D Printing

3D Printing

3D Printing

3D Printing

3D Printing

3D Printing

3D Printing

3D Printing

3D Printing

3D Printing

Also… OpenSCAD.

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In Advance of Troubleshooting

Teensy

I’m working on a new exhibit that will be using an Arduino (actually, a Teensy++ 2.0) to talk to an application running on a PC via serial data. The Teensy will be sending one byte to control the application’s behavior. This is an upgrade from an older version where the Teensy just sent keystrokes to the application. The nice thing about sending keystrokes is that it was very easy for anyone to troubleshoot because they could just open Notepad and press some buttons to see if they were sending any output. The bad part was that if a normally closed switch was open, it would just stream characters to the computer, which could make things hard to troubleshoot for some people.

ATMTester

To deal with the troubleshooting issue (which will eventually come up, as it always does) and make it easy for non-technical people to view a serial data stream, I wrote a simple application in Processing that reads the byte and displays the value, along with the status of each physical control of the exhibit.

ATMTester

The exhibit should always have the Teensy plugged into COM3 on the PC, but again, once something leaves the shop we never know what strange things might happen. When the application starts up it will present a dialog showing the COM ports, and asking you to select the correct one. If you select the wrong one it will just display nothing. This should be enough to help troubleshoot things via phone or email.

The trickiest part was the code to choose the COM port. (I know, we don’t call them “COM ports” on Mac OS X, and yes, the application works fine on Mac OS X, that’s another thing I love about Processing.) The code for choosing the COM port came from this forum thread How to let the user select COM (serial) port within a sketch?.

I did have to install Java to get the application to run, but it looks and functions like any other Windows application. Here’s hoping this all works and never has to be used, but is there just in case…