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RepRap Report #4

RepRap

Calling this RepRap Report #4 is probably not even close to a proper title, but I’m going to use it anyway to cover the latest changes to my old MakerGear RepRap Prusa Mendel, which is a Prusa Mendel (iteration 2) I started building in 2011 and finally finished in 2012. It worked well for a few years, and around 2015 I seemed to have a lot of issues making it work reliably.

I eventually got a cheap clone E3D hotend so I could switch over to 1.75mm filament, and it didn’t work well so I eventually got a real E3D hotend and then it seemed as though I just could not print ABS. It never seemed to be able to maintain a proper temperature. I gave up on it when I got a Maker Select Plus and put the RepRap to the side…

I figured that since there was a problem getting up to heat for ABS, maybe I could try PLA, since it uses a lower temperature than ABS. I grabbed a file I recently printed on the Maker Select Plus and gave it a go.

RepRap

In the photo above you’ll see the MSP print on the left, and the RepRap print on the right. The print on the right is a bit smaller in diameter, and it’s not round… it’s oblong. We’ve also lost the hole in the center, but that’s pretty much always been the case. The MSP print is probably at 0.15 or 0.2 layer height, and the RepRap print is probably 0.3 or 0.35 layer height.

RepRap

The bottom also looks pretty bad on the RepRap print. Those round holes are looking pretty oblong and a bit uneven overall.

reprapre-02

And here’s where we really see an issue. The MSP print is 9mm tall, while the RepRap print is just over 6mm tall. We’ve lost nearly 3mm in the z axis. Not great! I figured I should try a second print to see what I’d get…

RepRap

I got this… Wow. It’s, uh… terrible. Now, I did not use a cooling fan while printing this. I always printed ABS with the RepRap, so I didn’t even have a cooling fan installed. I may try some tests with ABS again, or I’ll add a cooling fan if I try PLA again.

I’m not convinced the RepRap will ever be a good printer. I mean, five years ago, it was decent, and I made a lot of things with it, and they were good enough. I’ve thought about upgrading it into a Prusa i3 since I could reuse most of the parts, and would just need a new frame, which I could probably just laser cut. That might be a good option, but I’m also half convinced that if I take the whole thing apart I’ll never get around to putting it back together!

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Apple Wait…

Apple Wait...

At Maker Faire Milwaukee in 2015 I presented a piece titled Apple Watch, and at least one person enjoyed it enough to make me think about creating another piece utilizing the same concept, so for Maker Faire Milwaukee 2016 I presented Apple Wait….

Apple Wait...

Apple Wait… (like Apple Watch) consisted of a Raspberry Pi Model B connected to an Apple Monochrome Monitor from 1988. Instead of just attaching the Raspberry Pi to the monitor with some gaff tape, I added in one more reference to technology, an iPhone box.

Apple Wait...

It seems the box for an iPhone is just the right size to house a Raspberry Pi Model B. Interesting enough, the iPhone 4S and the Raspberry Pi Model B were released about the same time frame. They are very different devices, with different goals, aimed at different audiences. Why not merge the two together? Technology is interesting!

Apple Wait...

For Apple Wait… I took a busy indicator cursor from the olden days of computing on Apple devices and brought it into the modern day, but made it 8-bit and low-rez, because retro is in. If you’re interested in learning more about old things, check out Where did the loading spinner originate?, The Design of Spinning Indicators, Spinning pinwheel, History of the Mac Spinning Wait Cursor, and just for a laugh, The Marble of Doom.

Apple Wait...

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Hakko Soldering Iron Fix

Hakko Soldering Iron Fix

Once upon a time at the museum we found an old Hakko FX-888D soldering iron for Sam to use. He tried to solder things, but it did not work. I tried soldering things with my Hakko FX-888D soldering iron and it worked great! I looked at his iron and declared it “not working properly” and then we stopped using that one.

This week I tried using my Hakko FX-888D soldering iron and it just did not work. I ‘raised’ the temperature and it still didn’t work. Meanwhile, Becky soldered about a dozen buttons with her iron while I was still trying to do one. The solder would melt but not stick. Weird, and then I discovered that I probably managed to “adjust” the temperature instead of “change” the temperature. Yeah, confusing, right?

This is (sort of) explained in the Hakko FX-888D soldering iron manual, very poorly, but start on page 5 and see if it makes sense. If not, watch this video.

If you don’t want to watch the video, here’s the procedure for resetting the Hakko FX-888D soldering iron to the factory defaults, which totally fixed my problem of it not getting hot enough to make good solder joints.

  1. With unit turned off press both UP and ENTER buttons
  2. Turn the unit on while continuing to press both UP and ENTER buttons
  3. The display will flash the letter “A”
  4. Release both the UP and the ENTER buttons
  5. Press the UP button
  6. The display will show the letter “U”
  7. Press the ENTER button
  8. Your iron is now reset!

I’m posting this here because future me will probably screw it up again, and then I’ll read this post and know how to fix it. Also, if Becky ever screws it up, she can look here too!

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CAD Things…

Stand

I recently had to design a simple cabinet to serve as a stand for a mill/lathe. I thought about pulling out some rulers and triangles (yes, I used to actually do drafting with pencils and paper) but instead I decided to try using OpenSCAD.

Stand

I used specific colors in my design, of course when you actually render a thing in OpenSCAD the color goes away, but you can export the different views just fine without rendering. Here are the various view of the thing. Oh, since OpenSCAD is a “unit-less” thing which mostly outputs in millimeters (at least for STL files) I just assumed the units were inches.

Stand

I used the OpenSCAD “scale” feature to scale up the thing by 25.4 times in each direction, which means my 1 millimeter became 1 inch.

Stand

But in a real drawing you plan to hand to someone you need dimensions for things. While there’s been some experimentation in adding them, there just doesn’t seem to be an easy way to show dimensions of things in OpenSCAD. I resorted to printing out paper and marking it up… with a pencil.

Stand

I probably need to learn how to use FreeCAD for this sort of thing. I’m sure I can easily add dimensions with it. One of the really interesting things about FreeCAD is that it has an OpenSCAD Module. You can import a CSG file which you’ve exported from OpenSCAD, and you can just open .scad files as well.

Much more to explore here… stay tuned!

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Adjustable Rectangular Mount

Adjustable Rectangular Mount v1

I finally got around to creating a parametric version of the 3D printed mount I’ve been using for the past few years. Typically I’d just open a previously designed thing in OpenSCAD, make some adjustments, and export an STL to print. Eventually I realized that I should just create a bunch of variables so I can easily just make minor adjustments each time and not have to do a bunch of find & replace operations.

The result is Adjustable Rectangular Mount v1 which you can find on Thingiverse and Youmagine.

It’s a work in progress, and it still needs some tweaking, but I figured it was worth releasing to the world. (Hey, make it better if you can!) It doesn’t work for all sizes and configurations, but for most of my needs, it’s good enough.

Adjustable Rectangular Mount v1

I should probably do more research on how to improve things by reading through other OpenSCAD code, but as mentioned, you’ve gotta start somewhere. I’ll probably be using this one quite a bit in the future, and I’ll update it as I can.

This mount specifically expects that you can use screws (or bolts) to mount it to a surface you can screw into or drill through. I also often add some double-sided foam tape to the inside of the mount and stick it directly to the object being mounted.