Thursday, January 21, 2021

Getting to Know the New Tools

At the end of my postings on rearranging the shop back on the 9th & 10th, I mentioned part of the reason was to make room for a 3D printer in the shop.  As I mentioned then, the starter printer I bought was the Creality Ender 3 V2.  After a problem with UPS, chalk it up to the shipping backlogs people are talking about, the printer arrived on the 16th, originally promised by the 11th.  After spending time getting my engine to run, today seemed like a good day to assemble the printer.  It's mostly done, except for the final stages of setup and a thorough check out. 

Creality photo, but you knew that.

Why did I go down this road?  Like lots of people, I've been intrigued by things I've read about 3D printing, known more broadly as AM - Additive Manufacturing, while the more familiar kind of machining is subtractive manufacturing.  Say I want to make something like the cylinder on my engine, very visible in the video Tuesday.  I start with a piece of metal, in that case a steel bar, and then using various tools and machines, subtract the right amount of metal in the right places until it matches the drawing.  With additive manufacturing, I'd start with nothing and then add material until it was done. 

Printing metal is far beyond what I can do, but as printers have become more common, more and more people are using the 3D printer to create tools to see how they can improve their work.  I was really surprised to see these guys using plastic tools to bend sheet steel 0.134" thick.  This was PLA plastic, the most common kind and not one we think of as being strong.  I've more regularly seen guys printing things that I'd think wouldn't be strong enough, like one guy who printed bevel gears for an engine he was working on and it worked.  I can't believe it's as strong as one cut from metal, but it was definitely strong enough.

A couple of years ago, I did a post on how to make metal things from plastic prints.  At the time, reader Ratus and I had a conversation in the comment section.  He said he was surprised I didn't have a printer already, to which I replied I was a bit surprised, too, but I was considering making one.  At that point, Ratus said something that stuck in a background process in my head, "Build? Ha! ... You can't buy all of the parts for one as cheap as an ender3 'kit'."  That's what put the idea of that particular printer in my mind.

A month ago, I put together an email to him and asked some questions, basically if that was still true and still a good way to go.  Ender has many model printers and I was seeing several newer models.  He was a great help in getting to this point.

The learning curve now is going to be centered on learning to use the Slicer software provided with the printer, at least at first.  The process is very similar to what I've been doing with my CNC machining.  Parts are designed in CAD and then go through the slicer, which is a different kind of CAM (Computer Assisted Manufacturing) program.  When presented with a solid model, all the software knows is the outside shape of the solid.  The CAM program outputs the path of a cutter that takes away (subtracts) everything except the shape.  You tell the slicer how thick the walls need to be and how much fill-in plastic is needed between those walls and it turns those into the slices or layers that the printer makes.  The printer puts down thin lines of heat-softened plastic. 


This shows the density of fill-in as a percentage of space inside a group of cubes. There are virtually catalogs of what the fill could look like instead of little hex-like bubbles: sharks, cats, honeycombs, you name it.  As density of the fill goes up, so does strength, weight and the amount of filament in the print.  It's another learning curve to climb.



6 comments:

  1. There's a huge group of 3D printer guys over at https://www.arrmaforum.com and they make some incredible stuff with them. I was seriously considering getting one, but man, that could really be a time sink!

    I went so far as to install the software so I could at least download and examine some of the parts they've come up with.

    It's so cool to be able to display a part on your PC and be able to flip it around, zoom in and out, rotate, etc, etc.

    Have fun, SiG. It's a whole 'nother hobby!

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  2. I had bought my son an Ender 3 Pro for Christmas a year ago. I had previously bought two 3D printers back around 2013 for about $600 each (a Solidoodle 2 and a Robo 3D) and had a fair amount of succes printing in ABS with them, so I did not have very high expectations for a printer that only cost $220.

    Let me tell you, that little Ender 3 has run circles around my other two printers. This little printer is rock solid rigid, and is far more rigid than my other two printers.

    My son has his Ender 3 Pro dialed in almost perfectly and he raves about the Cura slicer. We did replace the extruder with a metal extruder, and we also installed a new board with the quiet drivers.

    You will learn the wonders of the 20mm calibration cube and of The Benchy.

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  3. We bought an Ender 3 a few months ago, as an "upgrade" from a very used and worn out Replicator 2. We had a bit of a learning curve with it, and I had to twitch the assembly more than I expected, but now that its up and running I like it alot. I am using the free version of Cura for my slicer software instead of the default software, I like the options better, but not everyone agrees, so go with what works for you.

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  4. I have an ender 3 pro and a cr-10s. Both are pretty good printers out of the box, and can be tuned for great performance. I also recommend cura as a slicer, their PLA default profile is a pretty good starting point.
    With costs as low as they are, there's no reason every workshop shouldn't have a 3d printer. Rapid iteration of part design through CAD and 3dp is a huge boost, and having the ability to rapidly design and deploy fixturing, drill guides, router jigs, and other manufacturing aids is so wonderful you'll wonder how you got along without one.

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  5. Got a Ender 3 Pro a few weeks ago. I'm still setting it up. It can be a time sink, but some of the prints I've seen out of the Ender are amazing.

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  6. "As density of the fill goes up, so does strength, weight and the amount of filament in the print."

    Well, not exactly.

    The amount of filament and weight does go up. As does print time, by a lot. Sometimes even doubling or more with each 10% bump.

    But the strength is another matter.

    A higher percentage of infill doesn't equal a stronger part.

    I first saw this talked about in a "3d Printing Nerd" (Joel Telling) video from early 2016.

    "3D Printing: Stop Wasting Plastic on Infill Percentage"
    https://youtu.be/fuGqsZjdPQM

    TLDR
    Less infill, more perimeters/top & bottom layers.

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