Nate Duxbury's Blog

Make all the things!

Introduction and things so far

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I have been meaning to start a blog to talk about making things for a while now, and finally got around to it now. Whether it be lack of time or procrastination, I kept putting off starting this. Now that I’ve passed the hurdle of starting it, I hope to update it weekly with whatever I worked on that weekend.

Introduction

For those of you who don’t know me, my name is Nate, and I am currently in school for Mechanical Engineering at the Ohio State University. Even more currently, I am co-oping with Hendrickson International in their Controls business unit. I am very interested in mechanical design, and computer controlled machinery.

Now, what this blog is really supposed to be about: making things and ways to make them! Sometime in the last two years I learned about 3D printers and was instantly sold. I was fascinated with the ability to take a digital design and watch it build up a part from nothing. Unfortunately, being a college student, my discretionary funds for things like this were very very low. That was until summer 2013, where I was able to land an engineering internship with Irock Crushers. Working with Irock opened up a lot of opportunities for me. I was able to refine my 3D modeling skills and also find some funding for my first 3D printer.

3D Printing

I had researched a lot of 3D printer designs while I was working at school, and a lot of them involved having already printed parts and a myriad of threaded rods to connect everything. On top of that some of these designs seemed very prone to wobble, which I had read diminished print quality. When I had the opportunity to shop around, I found one that I liked in the Prusa i3 by makerfarm.com. This website offered  a kit that had everything I would need to make a printer. The kit arrived very quickly and I spent all my time after work that week assembling and tweaking.

Assembling the laser cut sections.

Assembling the laser cut sections.

Assembling the components was as simple as following the guide and videos online, which was top notch. Putting things together was easy and reminded me a lot of the Legos I played with as a kid. However, all the electric connections and the controller electronics really stretched my skill set. I had messed around with arduinos in class and had no problem plugging in connectors in a computer, but this was a little more advanced than that. Again, the guides were great, so I managed to get it powered on with an old PC ATX power supply and it was time to start printing!

It lives!

It lives!

The first print was definitely not what I thought it would be. It was supposed to be a 20mm cube, but looked more like a squashed square blob of plastic. My dad asked me why my new machine could only produce something that he could with a hot glue gun. Here I learned my first lesson with computer controlled machines: Calibration! Once I pulled out some calipers and adjusted some values in the software, I was able to get significantly better prints. A lot of my first prints were either calibration objects, small models or machine upgrades.

Results after my first week of printing.

Results after my first week of printing.

At the time of writing, I’ve gone through probably 4 lbs of plastic printing random little things. A lot of the stuff is just little models or toy like objects. I’m still calibrating and figuring out new and better ways to use this machine effectively. One of the upgrades I did added auto-zero sensing capability which drastically improved print repeat ability. But that is a whole different post in its own right.

 

CNC Mill

This summer, I again found myself in a position where I could afford a machine. I already had additive manufacturing, so why not try out a more traditional manufacturing method? To that I end I purchased a mechanical kit for a shapeoko 2 CNC mill. This was very similar to a 3D printer in that it has control of 3 axes and can move in very fine steps. However, being a mill, it starts with a block or sheet of material and cuts out what I design.

First test plot.

First test plot.

I already had a dremel to use as the spindle for the machine, and an arduino micro controller from a previous college course. So with the kit in hand and leveraging my knowledge that I gained from building my 3D printer, I began building the CNC mill. I spent a night tapping the aluminum extrusions and getting all of the frame components set into position. After the first weekend of work, I had run out of time building before I could install a dremel and actually cut something out. So, I zip tied a marker to it and decided to draw something instead.

First movement of the CNC

First movement of the CNC

Again, I found that calibration was an issue. It is very crucial to have the work surface level in relation to the tool to get good results. Luckily, the shapeoko is slotted in many places and allows for adjustment to square everything up. The next weekend I could get home, I moved the mill into our basement workshop and started cutting. The first thing I cut was an ‘N’  into a piece of MDF trim that my dad had laying around.

First real cut into something.

First real cut into something.

What I really wanted to work with was acrylic though. My brother has made some awesome things with a laser cutter and acrylic at his local makerspace. So I set out to replicate a little bit of what he does. My first tests with acrylic were cutting old pieces of plexiglass laying around the shop. I used the wrong bit, the wrong speeds and the wrong material. My machine couldnt handle the forces involved with pushing the wrong bit through the old plastic too fast. I had some minor luck with an engraving bit and some refined speeds, but I still couldnt cut things out, only scrape the surface. Also, old plexiglass is a huge pain to deal with. The paper backing that is supposed to easily peel away when youre done cutting? Good luck. It takes a huge effort to de-paper the plastic and even longer to get the adhesive off.

Trials of different speeds to find the right one.

Trials of different speeds to find the right one.

 

This first post is really only a short introduction of what I work with on the weekends. Hope you found it interesting! My next post should have some more stuff about what I’ve actually made with my printer and CNC.

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