Brian Lough

3D Printing Revisited

Time to get back on the 3d printed horse

I have owned a 3D printer for over 2 years and I really haven't made full use of it. To be honest I've never really gave it a good go. 3D printing is a skill that needs to be learnt like any other and at the same time that I was learning how to use my printer was when I was starting to get into Arduinos, and if you are familar with my stuff you'll know which hobby won out!

Even with that said, I think 3d printing is almost like magic. The accuracy of even cheap kits is amazing, I find looking at a 3d printer mesmerizing, it's so easy to lose a few minutes just watching it do it's thing.

The printer is a Geeetech Aluminum i3 Kit that I got fron Banggood I believe. It was incredibly difficult to put together! Modern kits seem to be a lot easier.

So as mentioned I have used it on and off since I had it, the most notable projects I have used it for would probably be:

Immersion Bot
A device for switching my water heater on and off using Telegram.

Immersion Bot

Zelda Chest
A chest, from Zelda. Ah no, it had lights and sound it was actually pretty cool

But I really haven't made full use of having a printer. In total I doubt I have even used 1KG of filament.... but all that's the past, this is about the future!

My wife's printer that she won should be arriving this week and rather than let the original printer be set out the pasture or stripped for it's parts I decided to try fix it up and get it printing well, either to use it myself or to potentially sell on if I don't have the space for both.

Physical Issues

My printer is still working, but it currently has the following physical issues:

  • Fan on the extruder has a cracked fan blade
  • One of the Z axis rods makes a loud noise when moving, and appears to me to not be straight (noticible when spinning)
  • A nozzle that has never been replaced (I assume they should be replaced every now and again!)

Fan is an easy fix, I bought a new one for $1.50 from Aliexpress* (Mine is the 4010 12V version)

Z Axis rod is a little more work, but I bought a 1M of M8 threaded zinc plated steel rod and a pack of M8 nuts (100 of them!) off a website in Ireland for €2 and €3 plus €6 shipping (that still hasnt shipped after nearly a week, so I need to chase that up!).

Nozzle, not even sure if this is an issue but they are 31c from Aliexpress* so I bought a few of them too, couldn't hurt.

Printing Quality

After setting up my printer again for the first time since adding a new desk to my office, I created a design for an upcoming project in thinkercad and loaded up the STL into Cura.

The the first issue I into was no fillament was coming out! I knew it wasn't a blockage or anything mechanically wrong as I could feed filament through by instructing the extrusion motor to move. I eventually found the issue, for some reason Cura was now using a fillament diameter of 2.85, despite me never using that before! Once I changed that we had some progress.

photo_2018-07-25_22-12-52

I was having some serious issues with my first layer, which not only resulted in a weak first layer but also some adhesion issues. My bed was too far from the nozzle, so I adjusted that to where I could just about slide a piece of paper underneath. This was the results after:

photo_2018-07-25_22-12-58

I may have gone too far but it at least it was working much better!

I was also having some serious stringing issues, that for some reason I don't have a photo of! I used this video by Maker Muse to figure out what I needed to change.

I ended up basically increasing the retraction up, it was at 5.5mm, I jumped it to 10... which was a mistake as the extruder got clogged. After clearing that up I went for a much more sensible 6.5mm and that helped hugely from where I started out.

The next issue I had was I had some very weak layers. You can see in the photo below but the first few layers of the column are really poor.

photo_2018-07-25_22-13-13

And the column wall got thinner at the top, although it printed, it had major underextrusion in parts.

I went to a channel I've been subscribed to since I pretty much got the printer for inspiration on what I could improve, Jimmy Shaw's tidbits. Jimmy had the same printer as me (not sure if he still does) and shared some great tips about it. During this video he gave good details on the settings that he used, and the print I think speaks for itself in terms of it working out for him!

So I basically copied his settings, which I'm happy to share if anyone cares! (I'm not at that computer right now to take a screen shot or export the settings).

I did the thing you should never do when trouble shooting, I changed two things! I also increased the size of the model as well in an effort to make it less fragile.

photo_2018-07-25_22-13-07

These turned much better. There is a fair amount of Z wobble (which I'm hoping Jimmy's anti wobble brackets might help with) and also there is a small bit of stringing but overall huge imrpovments to what I was getting before!

So I would call this a succesful first effort at getting back on the saddle. Now I just need to remember to stay on this time!

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