Adventures in 3D printing – my first prints

As mentioned, I got a 3D printer – a Printrbot Simple Metal. In fact, I got one, returned it because it was defective and got a 2nd one. That one was damaged during shipping so I opted to repair that one myself. It costs $10 and took just a few minutes.

So, I finally got to a point where I’m ready to print my first print!

WP_20150413_22_07_41_Pro

About is a 1” x 1” rectangle with 15% fill.

It’s all about the first layer:
When the 3D printer prints, it needs to lay down the first layer (obviously), and then the layers are built on top of that. The problem I had was that the plastic was coming out, but it wasn’t sticking to the bed. As you might imagine, this turned into a glob of melted plastic, pretty quickly!

The internet says to not print directly on the bed, because the objects are difficult to get up. Instead, it’s recommended everywhere to use 3M painters tape:

image

You cover the print bed with 3 x 2” strips. Then, the first layer is supposed to stick. Well, it took my quite a bit of plastic to continue reading that you MUST then wipe the painters tape with isopropyl alcohol to get any residue off. Once I did that, the first layer stuck!

Dealing with the filament feed:
As the 3D printer is going, it has a gear with teeth that pulls the filament into the melter. Next, I was starting with a fresh 2.2lb spool. That might not seem like a lot, but with a little motor pulling, it eventually failed. From the previous owner, I have this spool holder – which is better than nothing, but it didn’t solve the problem (note: this is how good the quality CAN be, this was literally printed by my printer by the previous owner):

WP_20150412_10_45_49_Pro

it fits on top of the those two supports:

WP_20150412_10_50_02_Pro

So, at some point during the print, EITHER the motor couldn’t pull more filament, or the puller gear worked it’s way loose. I say either because I got through another print, but eventually that gear did stop turning and I needed to re-tighten it. So, that print was like 97% done, but failed because no more filament came out! So it stopped… just like, almost done:

WP_20150414_20_38_49_Pro

To fix this, I re-tightened the gear that pulls the filament and I put on a 1.1lb spool which is only like half-full. At that point, I got a “good” print. This is the fan shroud you can add to the Printrbot Simple Metal which directs the air a little better:

WP_20150414_22_03_55_Pro

Above, I tried also printing a spacer, but I think I messed something up in Cura, but the shroud worked:

WP_20150414_22_08_01_Pro

It’s tough to capture a good picture of these because it’s shiny plastic. In real life though, this feels relatively smooth (you can feel the tiny bumps) – but it looks MUCH worse than it feels. Here is the inside, which too, feels relatively smooth but looks horrible because of how the light hits it:

WP_20150414_22_28_45_Pro

Back to the spool issue, this is where things get VERY cool! People come up with designs for things and publish them, for free. For example, if you search for “spool” on Thingiverse, you get almost 5,000 results!

https://www.thingiverse.com/search?q=spool

So, you can start from those ideas, re-work them or just print them straight from the site!

OctoPi for the win!
For example, I have an “OctoPi” set up with my 3D printer. This is such a fantastic, and well-executed idea for the Raspberry Pi!

This is a standard Raspberry Pi, which has a built-in web server. This means that instead of having to physically have your 3D printer next to your computer – connected via USB. You could put the 3D printer in a different place, and access a “control panel” of sorts via the Raspberry Pi over WiFi (or Ethernet)!

image

You can load file, have complete control over the printer, send it “g codes”, etc. One of the really cool things it can do is capture a time-lapse video of each print! If you buy a cheap camera for the PI ($22 on Amazon) and hook it up, it just sort of works!

Here is the time-lapse for that fan shroud, above:

You might notice the video is a little wonky. The time-lapse is in the first few seconds, then the rest of the video is nothing. That is one my list to investigate.

Meanwhile though, I have this camera propped up. It would be nice to have it permanently mounted – and to even have an LED light come on to consistently light the print bed. Well, if you go back to Thingiverse, there are a zillion of those out there. I’m planning to try to print this one tomorrow:

https://www.thingiverse.com/thing:714375

This holds the Pi up at the bed level, then gives a place to mount the camera. We’ll see how that goes.

Getting better prints:
At this point, I can now consistently print things and have them come out. The quality though, is not great. It turns out there are a few key things that one can tweak:

  • The temperature – I’ve tried a a few different approaches from 180 Celsius to 210 Celsius (which is what I used for above). However, I used PLA plastic above, and you’re not supposed to go that high because you get sloppy/mushy prints (like above). However, 180 simply didn’t work – so I need to find the perfect temperature for PLA. After reading, 190-200 is considered ideal – so I need to dial that in.
  • The z-offset – again, a great print starts from the very first layer. If that is messed up, you’ll have little strings of plastic which will mess up layers further above. So, I think I need to dial that in a little more.
  • The fan shroud – that should help too, immediately cool the plastic, which prevents oozing. I’ll install the one I printed, tomorrow.
  • A heated bed – you “need” a heated bed for ABS, but it can be useful for PLA filament too. The idea is that the bed is simply “warm”, so that the cooling process takes a little longer. If the piece cools down too fast, it will warp.

The good thing too is there is a LOT written up on 3D printing. So, you can pretty easily find answers to problems. For example, Printrbot has this useful page on troubleshooting bad prints.

Next steps…
OK, so after a lot of effort, I feel like I have a decent handle on creating things to print, troubleshooting the printer, and actually creating prints! So from here, there are few things I want to work on:

  • Print a case for the OctoPi and camera so that they consistently create time-lapse videos.
  • Ideally add an LED or two, hook them to the GPIO ports of the Pi and have them light up the bed for the time-lapse too.
  • Dial in the temperature and z-axis to get higher quality prints which are more precise, and less stringy.
  • Print a new filament spool holder so that the feed gear can easily pull from the spool. Need to find a good design on Thingiverse, then print it!

Do you have a 3D printer? Have any advice for me? If so, PLEASE let me know – I feel like a pioneer, as I don’t know anyone else who has a 3D printer!

Posted in 3D Printing, Computers and Internet, General, Infrastructure, Linux, Raspberry Pi, Uncategorized

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Archives
Categories

Enter your email address to follow this blog and receive notifications of new posts by email.

Join 5 other followers

%d bloggers like this: