So You Want to Buy a 3D Printer? - Part 2

In our last adventure I was dealing with a clog, after having taken apart the print head to replace the fan and try to figure out why it wasn't printing as it should.

I left it with the clog and me looking at taking more advanced measures.

I did continue.

The first thing I did was take a piece of piano wire, heat it up, and jam it down the filament path to try to gather up any filament boogers. This is kind of like a cold pull except that it will gather up a different kind of debris. Larger pieces will stick to the wire and be pulled out since it's smaller than the diameter of the tube. I got out some gunk so that looked promising.

Another run of cleaning filament dashed those hopes.

I did a couple more passes of piano wire - cleaning filament before deciding there wasn't anything that was going to get pulled out.

It was back to cold pulls, hoping that the adventure with piano wire had at least moved around whatever was clogging the nozzle.

Two cold pulls later and it was still not working. I was on the verge of taking it apart so I could get to the nozzle more directly.

Now when I do a cold pull I like to make sure I know what's going on. Typically you heat it up to 265, run the filament (or push it down) until it comes out the nozzle, then cool to around 180-190 and pull it back out. I tend to set the temperature for the cool down rather than try to catch it at the right time. I set it to 190 and it works.

This wasn't working.

The next time I set it to 185 when I was going to pull it back out. And I found a chunk of something in the end of the cleaning filament. This is good. This is what you want. Cleaning filament is undyed nylon so it's kind of a translucent cream and you can tell if it gathers up anything in the process.

THIS time the cleaning filament ran nice and clean. It was the thick, smooth extrusion that I needed.

The moral of the story here? That sometimes you have to just keep at it and you'll get it working again. A clog can always be fixed, even if that fix is putting on a new nozzle. This time I could use the standard methods (with the extra kick of piano wire) to clean it out and continue.

Why piano wire? Because it's hardened wire and can stand up to heating and abuse. This stuff is really tough. You need special nippers because it will chip regular ones. It's serious stuff and very handy if you're going to be using it for various things. But if not then I recommend skipping it because while the wire isn't expensive at the hobby store the nippers are.

Let's go onto another thing that happens - twisted filament.

Almost all the time if your filament gets twisted it's user error. You can never let the end of the filament go unsecured. If you do there's every chance it's going to slip under a winding and then you get twisted filament. That will bind up at some point and do something as simple as break or as nasty as pull the filament roll around and screw up your alignment.

There are rare times when you get twists on the roll and they aren't user error. I've had it happen. I've seen the pictures of it from other brands. We honestly don't know how it happens at the factory since it should never be able to happen but it does.

Untwisting filament is kind of an exercise in patience. You can't just unroll it to the twist, untangle it, and roll it back up. That darn twist will keep sliding behind what you're unrolling. There's plenty of instructions on how to do it but I'll simplify here.

Keeping a grip on the end of the filament you back roll it to loosen up the windings. You keep doing that until you've got a nice amount of filament loose, hopefully with your tangle in there somewhere, then slide the whole mess over the side of the spool. It is a mess at this point. And I have yet to do it where there aren't windings on the spool that didn't get pulled off so I need to repeat a couple of times until it's just one piece being unwound. It's not pretty.

Then there's the fun of winding it back onto the spool. Filament is wound while it's still hot and it keeps the curve of the spool. And it's springy. So it's all over the place as you're trying to figure out how to get through the twists and hopefully deal with the tangle. I know most filament is cheap enough that I could cut off the part I've pulled off the spool and I have done that when it kinks or just gets too frustrating. But I like a challenge. Sometimes.

Ok. Clog is cleared! Filament twist gone! Ready to print, right?

Nope. The broken filament in the print head means it won't let me load new filament.

This one worked with the easy fix. Heat it up to cleaning temps, let the filament ooze out and soften, run some cleaning filament until the old stuff is gone. Then lower the temperature and load the new filament.

Except it didn't seem to want to load.

Being patient fixed that one. The load process built into the firmware has it doing a ram (fast load) for a bit then slower as it builds the pressure on the nozzle. The motor wasn't moving filament on the ram. But it was moving on the slower one. So I kept saying the filament wasn't loaded (it wasn't) so the process would continue to push out at the slow speed. Eventually the leftover cleaning filament came out (that could have been part of the issue) and the new filament was in this neat little spiral before extruding clean.

While the spiral looks cool it's not cool. It means there's .. a clog. This time just letting the filament run cleaned it up and I've got the printer going again.

So there's a whole bunch of little annoyances that happen with far more frequency than any of us like. There's far worse ones but clogged filament is pretty much an expected thing no matter how clean you try to keep your nozzle.

I'll detail the next problem when it happens. Because one will happen.

So You Want to Buy a 3D Printer?

Really? You think you're ready to jump into the wild and wonderful world of 3D printing?

This is where the GM asks "Are you sure?"

Because here's what I've been dealing with on one of my printers. They're the same brand, same version, same pretty much everything. I say 'pretty much' because there are some differences.

A little while ago I had one of the print head fans die on me. No big deal. I had a replacement on hand. Take the old one off, unwrap the cable harness, swap the cables, put the new fan on. It's not that difficult. However...

The fan model I got was the one recommended at the time. If you're interested it's a Noctua. And it even comes with a handy adapter pack! Of course none of the adapters fit my printer. No matter. I have a soldering iron. Clip, solder, heatshrink tube. I'm ready to go!

Fan goes on fine and tests fine.

Then I start getting clogging on various filaments at various times. The same filaments work fine on the other printer. I was annoyed and frustrated. There was a clog serious enough I had to take the print head apart and drill out some of the filament. More on that spool later.

I put it all back together and it's still being inconsistent. Which means I'm down a printer.

I wonder what the previous owner did to this and if the heat transfer isn't quite right. Clogging can be caused by that. So I take the hot end apart AGAIN and put fresh thermal paste on one piece, carefully putting it all back together.

Then it hits me. There had been posts about the Noctua fans but I couldn't remember them. A little searching in one of the Facebook groups and asking the guys in the moderator chat tells me that the Noctua fan doesn't push enough air, causing things like clogs. Sigh.

Luckily I had bought new fans for the pending upgrade, including one as a spare. This isn't quite as involved since it's a fan swap (again). Off with the Noctua, on with the Sunon. At least this one is a pretty black instead of the weird tan and flesh color of the other one.

Since I had the print head disassembled I have to calibrate it again. The full deal, not just the minor one. This includes setting the nozzle height from the base bed manually (you literally use a flashlight to see the space between the nozzle and the print bed) then adjusting the induction probe to a certain height. Only then can you run the software to calibrate. Three tries later (changing NOTHING, btw) I get it to pass calibration. But I'm not done yet..

It still needs to be fine tuned to the print bed. In our world that's called a Live Z since you can adjust the height of the first layer while it's printing. Live. On the Z axis. Pretty cool, right?

Ok. Fine. I have a little file to do this. I load up the printer and the new fan is spinning away. Yay. But the print is coming out in these little dots. Sigh. Nozzle clog. Unload the filament and get out the cleaning filament. That's just nylon, really, but it prints hotter so up the temperature and load the cleaning filament.

This is the point where it would hesitate then start extruding a nice thick line of cleaning filament. Nope. Not this time. There's more of a clog. So a cold pull it is. Set the temperature to where the filament will be solid then wait. Once it's cooled down pull the filament back out, hopefully capturing any stray bits that were hanging around.

Why didn't any of this show up when I had it in pieces? I didn't do a cold pull because I honestly didn't think I had a clog of this nature. They're not that common. The new fan doesn't do squat when there's a solid piece of something physically blocking the 0.40mm opening of the nozzle.

The first cold pull showed a chunk of the last filament I tried to print was hanging around in there. So back up goes the temperature and another cleaning filament load. Nope. Still clogged. Time for a second cold pull so down goes the temperature. The cleaning filament isn't showing anything obvious but it's also not the pretty point I want showing a clear nozzle.

Back up goes the temperature for another cold pull. This time I'll manually feed the cleaning filament until I can see it coming out the nozzle then drop the temperature to pull it back out. A lot of this time is spent waiting for the nozzle temperature to get to where I want it.

While I'm waiting I'll remind you of the temperatures. The printers are in metric so the temperatures are in Celsius. My normal printing temperature is 220C (428F). The cleaning filament works best at 265C (509F). The 'drop' is to 180C (365F). It's easy to forget just how hot these run until you do the math or do something stupid like grab plastic that came right out of the nozzle.

Third run with the cleaning filament. Back up goes the temperature. I'm going to let the print head feed it this time and see what happens. And it's still clogged. Back down goes the temperature. This one also shows as inconclusive. I'm not seeing anything in there but I'm also not seeing the right shape to the end of the filament.

I'm done for the night. I can only do so much before it gets too frustrating to continue. Other people may have more patience but after a long day at work and then putting the printer back together I can only do so much troubleshooting.

Tomorrow I'll work more on figuring out what's going on with the filament not feeding and make a new post about what's going on.

The other printer is chugging along nicely, printing Star Wars: Legion terrain for someone.

What does this have to do with a desire to buy a 3D printer? I'm detailing this to give you an idea of some of the things you WILL have to do at some point. These things are great, until you have to break out the tools to figure out what's not working right. If you're not a patient person and you don't like to tinker with things then you're not going to enjoy your printer.

More Printing! Always More Printing...

I really need to work on the rest of the game stuff but it's so easy to focus on the 3D printers when I've been sitting next to them while I work from home for a while.

These are my printers. They're affectionately known as The 3D Printer and The Other 3D Printer. Or 1 and 2 if I'm using the print servers. They were printing a request for a friend at the time I took the picture. They're not complicated and they don't take long so I wanted to get them finished and to him in a reasonable amount of time. And I'm using up filament in some less-than-useful colors.

When I get a new roll of filament (new being defined as 'new color for a brand') I always do a test print and label it so I know what it looks like. When you start getting multiple colors it makes it much easier to find the color I want. And I can compare them to see which one best suits the project if I'm not painting it.

For the test print I use a low polygon cat. It's scaled down to be 50mm tall and prints in less than an hour. It shows flat surfaces, some curves, and the angles. I then put a label underneath with brand/color/line (if there's more than one line by the brand). I don't put down the plastic type unless it's different than the one I use almost exclusively. That's a waste of space.

You can see where color starts to matter by the two purple cats. They're not as close as the two white cats but they're still ones I can pick up and consider rather than digging out the rolls and not knowing exactly how they'll look when printed. What's on the spool isn't always what is in the finished product when it comes to finish.

I have a small army of these on my windowsill now. I belong to a monthly subscription for 3D printing. I get at least two kilos of filament either in a theme or random. I also get some 3D printing related things and promotional items from the vendor. Overall it's not a bad deal and it's slightly less than buying two rolls individually. This is something for me to think about. The next box is going to help my thinking.

I was doing a LOT of printing to make the dungeon for my game. The convention is next month so I had to push myself. Having one printer down while waiting for a replacement part wasn't helping. But I did get everything printed and a bunch of decor to break up the grey.

That's currently the pile on my desk. I haven't put them away yet nor have I broken out those little tabs in the connection slots. While the printers can technically bridge that gap easily (bridge means just what you think, crossing an empty space while pushing out plastic) if they don't or there's some other issue it's going to be tough to clean up so the clips work. It's better all around to have them there. Even if it means breaking them out. I also want to run a sanding block lightly over the floors and tops of the walls. When the print head lifts it leaves a little point of plastic. Those suckers are sharp. A quick sanding gets rid of the 'ow' factor.

I won't have time to paint it before the convention. I have a lot of other things to do for the game (that hopefully I will be running) but I really want to paint it. I will paint it. After the convention.