Coaching Notes for 3D Newbies
If you’re willing to invest about $300, you can become involved in the emergent technology called 3D printing.
The purpose of this document is to share some “personal experiences” as noted by a 71-year old guy getting into the hobby. Things that may not be apparent to people over 50 who have never been out on the bleeding edge of tech.
Basic 2D Printing
When you strike a key on your computer, what happens?
Quite likely, a small C library call (maybe scanf) will be looking for key presses. As you depress the key, a letter is “chosen” and it is displayed on your screen. Screens (and paper) have two directional orientations to make them “addressable.”
These are spelled out in X (side-to-side) and Y (back and forth – to you or from you when the surface is horizontal) calls.
When your “letters” are sent out to a regular (like inkjet printer) the print head:
- Moves to an X location
- Moves to a Y location
- And a “squirt” of ink takes place.
Because the 2D printer is quite precise, it can make very fine ‘squirts’ of ink. In order to conserve computer resources, the common letters are handled as (on Microsoft) products as TruType Fonts – which is where the file_last_name ‘.TTF’ comes from.
Many ‘Squirts Later’
In 3D printing an additional axis called Z is added. This moves the print head up and down.
Instead of a single-shot like a 2D printer – which squirts once – a color of ink (or a mix for colors), in 3D printing, the head spews continuously. That is, the print head deposits a thin “layer of hot plastic” at the X. Y, and Z coordinates specified.
By “going over the same place” – and layering on more material – over many passes of the print head an object may be printed.
There are many ways to manipulate material in this X, Y, Z “build space.”
In the printer being shown in this first Build Companion, we will be using a small (SainSmart) Creality Ender 3 design. I picked one up on sale from Amazon Woot! For $169 earlier this year.
All of the Creality Ender 3 designs are similar, but there can be differences. Such as:
- While most have “heated beds” the material of the bed can vary. A slightly roughed carborundum glass bed is good (and very level). On the other hand, a plastic (with embedded glass fiber) is much cheaper.
- The “print head” can vary. The type of print heads have evolved, including the more recent “Mark 8” or “Mark 10” print heads. The one we’re building, though, is an earlier model.
- Degree of assembly can vary, as well. This unit was only about 50% assembled. There was a bed assembly with cables attached. But there were also a fair number of small parts.
Now, let’s look at the micro and macro scales of where 3D printing is headed:
Printing Concrete and Steak
Starting with the “big stuff first.”
Maybe you’ve seen workmen putting in concrete? Concrete is placed in position and when it cures, it “sets up” and – if the surface it’s poured on is still workable – layers of concrete can be built up.
In fact, there are already several companies making 3D concrete buildings using just this approach. Concrete is layered onto a building site and the result can be a huge building. One is called Vulcan 3D and they make concrete printed homes (see video). In 2020 along came COBOD with printing of a 2-story house. Sky’s the limit? Yes.
It’s a good beginning video to watch because the small 3D printer you’re about to build uses similar print-ciples!
Except, instead of squirting concrete, the print head in your machine heats up filament of plastic (1.75 mm), melts it – and then squirts it out a nozzle. When properly positioned over a previous layer, build-up of a layer takes place.
Steaking 3D Printing
If you now imagine a hybrid between that concrete printer (printing something a little larger than ultra-thin plastic) and a color inkjet (mixing colors to get a desired PANTONE, CMYK, or RGB), we now have the basic idea of “protein printers” such as reported on in this article six years ago.
About the only things to be ironed-out are a standard set of “flavors” that can be printed to reliably make various “flavors” of protein. Mark Ure’s words on this: Whoever can issue a CMYK equivalent for printable proteins (to generate reliable taste) will be THE company with the (Soylent Green) type future to own.
Curing speeds and temps of printed proteins may well determine texture (or ‘tooth’ to the gourmet types).
Ah…I can hear it now: “Joe, print a rib steak, 30% infill and make it 100 mm by 30 mils, would yah? Hit some Johnny’s Dock seasoning salt on it, too…”
All served in a PPE equipped bubble-booth…
OK, let’s get back on task…no more head-tripping.
Basic Printer Capabilities
Essentially, you can print almost anything imaginable that will fit inside the Ender 3 printable space: 220 mm (wide) by 220 mm (deep) by 250 mm (tall). That’s 8.7 inches square and 9.8 inches tall. 734 cubic inchs. That’s like being able to print a container for just over 3-gallons of milk.
Larger printers have more print volume. Our Creality 10, for example is 300 mm by 300 mm and prints 400 mm tall. That about 9 1/2-gallons in size.
You will (with practice) be able to master a number of printable plastics. You’d want to use a food-safe plastic for the milk container: PETG is ideal.
The usual starting point is PLA. This is a low melting point, but quite serviceable plastic.
From there, you can move into harder materials (like ABS – a kind of styrene) but you may wish to vent print fumes of styrene outside because the smell isn’t all that good.
As mentioned, PETG is great for making items that will be around (or in contact with) food. While things – like low-temperature gaskets and toys can be printed with Thermal-Plastic Urethane (TPU).
What are the critical workflows?
We’re HUGE on workflows. It’s our holy grail of Life. To get things done, just figure out the recipe. If necessary, adapt and adopt. As long as you keep up with the “recipe” [workflow] you’ll have a high chance of success.
1. Find or Create a design
Recommended designs for the Ender 3 include a wide range of clever accessories you can print yourself. Imagine – a tool that can print its own upgrades. Why, how cool is that? Seriously: You can download fan covers, arms to direct filament, reel holders to place the 2.2 pound rolls of filament where you want them.
Oh, and none of the filaments seem to come on the same center diameter rolls (which is dumb!).
In addition to printer enhancements, if you have created a design of your own, you will simply export it as an .STL file. That’s short for “stereolithography.”
2. “Slice the Design”
(For your specific printer.)
3D Printers do not print .STL files directly. There are simply too many adjustments and variables between printers. One printer may work best with a 0.4 mm print thickness, but in other applications perhaps 0.3 mm print layers work best.
And it doesn’t stop there. Almost EVERY one of the 1.75 mm filaments you can select from will have its own, unique, “best settings.” These include bed temperature, print head temp. Feed rate of material. And many of these can be “declared” in the slicing program. Obviously, 0.2 mm layering will be finer, slower, and take twice as many machine passes in order to “squirt out” a piece compared with an 0.4 mm print.
3. Adjust printer in advance
Bed Leveling is Critical!
If we had to highlight a few of the “most common” errors in 3D printing, the major ones would include print “bed leveling” and a lack of patience.
Let’s take patience first: Prints will be a joy to behold when done. But a large print can take 10 hours or more. So, don’t begrudge the project the extra few minutes so the bed is thoroughly warmed up. If your printer says “Wait 4 minutes”? Add at least 50% to that. Six minutes.
When the bed leveling process says “repeat 4 times” before beginning your first print? Go six. The effort on the front end to get things as close to perfect as you can totally pays off with superior prints.
With the print bed as level as you can make it, go to Menu>Prepare>Preheat PLA. Make sure the first drop-down (preheat PLA) is selected with a tap. Because you don’t want to heat just the bed or just the nozzle. Watch your temps come up on the main screen.
Insert your micro SD card into the card slot on the left front of the printer.
4. Load “Sliced File” – Run Print
Make sure you have glue sticks of hairspray to coat the GLASS bed evenly.
If you have a bed that is flat glass, a good coating of hair spray or glue stick is needed. However, the print be material that is very lightly textured (which is what this printer is) then no glue or spray is needed.
If you are using hair spray on a glass bed, give it time to thoroughly dry. 3 coats is a good start. Just remember that the hairspray will result in a “build up” so another two (or more) tweaks of bed leveling will be required.
Load and begin the print.
Select “Print from TF Card.” If you don’t see your file (puppydog.gcode or something like that) then use the “refresh option.” This will become apparent when you’re printing off one card and loading up another card with more prints. Manually file refresh to see the changed card.
5. Cool, Remove
Just like our discussion about patience heating (heat propagates and an evenly heated bed is a wonderful thing!) the same is true when a print is done. Unless the building is on fire, relax, admire your work, and make notes on what you would like to change in successive prints. Go for a walk. When the temperatures are normalized, carefully remove from the build surface.
More on this when we get into details, details…
6. Finishing Operations
This is where an X-acto knife is a great tool. The prints that come on “platforms” may need to be cut away. This waste is called “flash” and it’s a holdover from injection molded styrene modelmaking of 60-years ago…
If you want to apply some smoothing, we recommend fine (220 grit) sandpaper. A print needing rougher than 220 grit? You might consider reprinting with different temperatures and print speeds!
We’re not too keen on files. While they will do great at removing material for the first pass, files tend to “load up” with plastic residue quickly.
Setting Up Your Workspace
How much room?
One printer or many? Many people will only need or want a simple Ender 3 type machine. Others, with more grandiose visions (like us!) plan to evolve mixed content Kits. These may include a printer circuit board and a 3D print file, for example. (Can you imagine printing and assembling a complete high-performance metal detector??? OMG what fun, huh?)
For us, the basic finished workspace will be an Ender 3, a Creality 10 V2, and when we get to it, a Creality 10 MAX when we need larger build volume.
Because we also plan electronics as part of our kits, we will also have a couple of small (3018-type) CNC machines for router printing circuit boards.
Be careful with colocation issues: 3D printers work best in pristine air. They are adding material. CNC machines toss off dust and debris as part of their subtractive process. At a minimum, a panel between them, or put them in a different area completely.
Walk-by or seated? Sounds silly, but think about it a bit. Do you want your printer(s) working while you’re trying to think about something? The movement out of the corner of your eye can be distracting.
Heating and Cooling
Machines are very much like people. Ideal print temps 75-80 degrees. About “laying on the beach with a cold one on a warm day” is about right. We’ll get into the humidity talk when we get into printing as this build rolls along.
I’ve run some prints with ambient air temps down around 53F. To get a good print, I used a slightly hotter extruder nozzle temp (210) than the regular PLA default (200). At higher ambients, you would expect to use a slightly cooler nozzle temp.
Key thing is you want the ambient (room) temps to be consistent at least for the time you’re running the print. Bed heat stability needs for even prints is obvious. Aluminum beds (with a stick-on build mat) also shrink when cooled and expand when warm. If you’ve got a cold room to print in, consider buying a small 250 to 300-watt space heater. Maybe come up with a modest enclosure for your printer(s). Don’t aim the heater at anything, or at the printer. You want to give air lots of “mixing space” in order to provide a thermally stabilized setting.
Outside venting is best if you’re printing any of the low temp styrenes. (ABS). A very small fan and dryer vent hose is more than adequate.
Cheap Enclosure Ideas
There are a bunch of “cheapies” on Amazon for under $100. I can’t bring myself to buy one, however. So what are some neat ways to build a great enclosure?
Chair mats are available for about $30 each and are an inexpensive way to building a see-through enclosure. Far cheaper than buying high-end Lexan (polycarbonate) sheet. Just make sure to get the mats built for hardwood floors. The kind with the “carpet grabbing knobs” is a beast to work with and usually not very transparent.
I figure on a frame made of 1-inch aluminum angle stock maybe 1/16th inch thick. eBay for that.
Greenhouse plastic is our low-cost pick for our side, backs, and tops. These are very efficient with a thin layer on each side with an air-gap center; clear plastic ribs as spacers. Not as pretty as a door made of clear mats will be when we get to it (and using open pin removable hinges). But in our unheated, though lightly air-conditioned shop, it will give us the best heat management at the lowest price during cool months.
Lighting should not be overlooked. While an LED light bar on top of the printer gantry sounds great you’ll want to print offset brackets. Because some light is shaded by the print head. We find a 2-watt LED flashlight gives us more flexibility. Cheap. On-hand.
Where to Build Your Print Space?
Shop bench is a fine place. Since at our bench we have (almost) every tool on earth at hand. You won’t need too many, or any at all.
Modest tool kits are fine.
- Most machines come with a couple of Allen wrenches for assembly. But you can never have too many.
- Have calibers handy – Use for getting right size bolts with no guesswork.
- Example: 5mm 8 vs. 5 mm 10 screw.
Nice to have’s:
- Glue sticks
- Hair spray for glass bed (Aquanet is fine.)
- Removal tools, small metal putty knife
- Clean workspace
- Is the printer’s “home” ready?
- Got a dry cleaning bag (or even a garbage bag) to keep dust and dirty off your masterpiece?
- Is the assembly bench clean? Run a vacuum over it.
- Assorted tools
- Most come with basics
The “usual” include Allen wrenches But for $12 bucks on Amazon, consider something like this:
Or, from your own tool kit:
- Flush cut diagonal cutters
- Needle nose pliers
- Assorted tie-wraps (4, 6, or 8”)
- Glue sticks and/or hairspray
- Two or more rolls of PLA.
- Don’t suppose you have 0.4 mm nozzle picks already, do you?
Buy desiccant packs on Amazon. When you’re done with a roll of filament and there’s always lots left, seal it up with a desiccant pack or the filament will degrade quickly! Being crazy, we’ve ordered a special filament dehumidifier which you can find for about $75.00. Useful here since we have high humidity in the summertime.
Two or three calibration print files should be acquired. Your printer may come with an SD card already in the machine. Look here for test print materials.
Handful of downloaded free designs you want to print
Thermometer with humidity indicator will offer extremely good guidance when comes time to twiddle and tweak.
Masking tape your table edge during assembly. I can’t tell you have many times I’ve gotten sick of moving furniture to find a missing nut or lockwasher. A piece of masking tape on the vertical surface of your bench edge, sticking up a quarter inch, will usually keep all dropped parts from falling into The Abyss.
Computer Coaching setup
Pause for this note on spacebar for stopping Youtube videos: When you have your laptop playing, Youtube videos start and stop with the spacebar. Sure, you can rewind, but pay attention to a step, tap the space bar, do the step. Then tap the space bar for the next step. If your “head’s in the game” you won’t do much – if any – rewinding.
We are using two coaches: 3D Canada video here.
Preprint Final Inspection
Once you have the printer assembled and ready to roll, there are several things to do before you attempt to run a print.
First: Run the up-down stepper motors to their extreme up and down positions several times.
While you are doing this, keep an eye on the extruder feed stepper motor. If the cables are not secured right, the stepper motor cable “E” can be pulled out. If this happens during a print, you’ve just lost a print.
Second: Ure’s “Secret Sauce” for bed leveling.
The first pass at bed leveling is done “by the book.” That is, you go to the menu and select:
[From Main Menu]: Prepare (tap to select) then scroll down to ”Disable steppers.”
This is spelled out in basic assembly videos. When you adjust the bed height, you want just a “bit of grab” to a standard piece of 18 or 20-pound printer paper when slid under the extruder nozzle.
The second part (and this is my own “secret sauce”) is to engage the stepper motors and then hit “AutoHome” on the menu. This will move the build plat to the front (toward you). The extruder will go over all the way to the left. Then it will come to rest over the left front corner of the print bed.
Before the Secret Sauce, I recommend taking off the left front clip (that holds on the heated bed mat). The reason is when you hit “AutoHome” the clip can interfere with the extruder movement. You don’t need that. With this in mind, now you perform…
Secondary Printer Adjustment
NOW you go into [from Main Menu] Prepare> (tap) > Move Axis
You will be moving both the X and Y axis. I have four “standard leveling spots” I use – nothing special but they are as follows:
- 20, 20 (left front of bed)
- 200, 20 (right front of bed)
- 200, 200 (right rear of bed)
- 20, 200 (left rear of bed)
The reason for this “extra leveling series” (using the steppers) is it struck me after a few prints that there may be a difference between the manual positioning of the extruder and the “actual position” when driven by the steppers. This seems to give better results. Experimentation, though, is key.
The First Print
I have to say there was some disappointment in the SainSmart Ender 3 because when I got everything set up (before running print #1) having done a ton of research, the supplied filament was not enough to actually run the sample file (puppydog.gcode) that came with the unit.
As a result, I ended up with a “headless dog” print that has approximately zero value. Except as a story-writing prop…to explain how “in-filling” is used to reduce the amount of plastic required for a print…
What to Print?
Don’t bother trying to run anything other than a few examples of the demo print file that came with your printer. Reason? More than anything, these files are pretty solid and will help you build confidence.
The Biggest Pain is Filament
We have found several problems related to the filaments sold (pretty much everywhere).
The first is that the center holes come in a variety of sizes.
Obviously, there’s only some semblance of organization and the 73 mm range -while common – isn’t a real standard. I have one roll that is 83 mm and others can be as small as 52 mm.
Compounding your frustration? The mounting and holder for Ender 3 filament has a 31 mm diameter, but there’s no way to get the 34 mm ridge off the outer end. It’s one of those “Wild West” of design areas.
Some filament is not “nicely” wound on spools. In other words, when cold (as the shop gets overnight) the filament tends to stick to layers under itself. This can cause filament feet tensions to be all over the place. In a worst case, it can ruin a print.
Once again, the case comes into focus for a temperature stabilized printing area. 75 to 80F is about ideal, though much warmer than my best “thinking human” temp which is down around 67F, or so.
Printing is Not Fast
There are several prints I’ve run that have been in the 6 to 10-hour range. Seems like forever when you’re coming into the pursuit. But, after a while – especially if you place the printer where you will be walking by it all the time – the time fades into background. Besides, if you need finished product faster then buy another printer. They regularly go on sale for under $200. I would expect even the larger formats to be under $350 by January. But that may vary, based on geopolitics next year. China, Taiwan, blah, blah…
There are basic instructions in the manuals (mine was SainSmart, but I assume all have at least basic troubleshooting). Bu there are several things to mention when you take your first couple of prints off the machine.
First item is called “flash.”
The printer will often make a thin “base plate” on which the desired part is then printed.
Two tricks to help you get these off your print bed.
First is to heat the bed up to an ABS temperature (rather than PLA). The PLA having a lower melting point will soften – usually enough – to allow it to be simply pried-off.
The second (though you can’t do this with a glass bed!) is to warm up the bed (really warm) and then – taking off the clips holding the bed in place – remove the bed cover and bend it gently over the edge of your work table. Make certain to betnd it back, though, or you will play hell trying to get good prints off of it.
The second lesson in “flash” is called “bridging problems.”
Here’s an example part for your Ender 3 build it you’re doing the small printer.
Here’s where all the string (melted filament) came from:
Often times, designers will not put in “supports” or dial-back their printing plans in order to allow a solid build. As a result, the first (lower) layer for filament for the outer diameter of the knob will just “hang out there in space.”
As it does so, it will sag.
The first pass will sag a lot, then the successive layers will – over multiple print-head passes – begin to build up. As they do so, the “open bridge” will eventually “fill up.”
The main thing, when you see a print like is not to go immediately to the “Aw shit!” moment. Instead, looking at the bridges, can you simply cut them back good? Second part of the question is “When turned over into the normal [as used] position, will the part look OK and be fully functional?”
In this case, the answer is?
Somewhere between taking a part with what looks like plastic hairs all over it, off the heated bed and closely inspecting it, the purpose of the flush-cutting pliers and the tiny tweezers will become apparent. You’ll use them – and that rough small raspy file, too – to clean up useless plastic and make the part all pretty-like.
Or, if this knob is just for the extruder stepper motor call it good and onto the next column.
The first big one to worry about is the nozzle and bed temperature settings.
If your small part bridges are sagging too much, try dropping the nozzle temp down 5 or 10 degrees. You will want to turn it back up, though. Since when cool, the plastic of the layers does not “grab” as well. The result is layers are weaker and with no ‘flow’ (because its too cool) the look of the project will suffer.
If you can phrase a precise problem to Google, the answers are always available.
If your prints are waaay out of whack, there’s an excellent page to bookmark courtesy of Simplify3D here which has lots of common printing problems along with possible solutions to try.
I won’t even attempt to do this detailed an analysis of failures. But, I will tell you that if you find what looks like your problem, click on the picture of the goober and there are lists of things to try.
I tend to keep by nozzle a bit too close to the bed and it’s a matter of time and practice to work out how firmly the typing paper should move between the bed and the paper to get that ideal first pass.
Oh, and it would be neat if all print sources were perfect too, you understand. Same with filament – everyone of them is different.
We don’t offer technical support, but if you have questions and post it on the https://ultra-make.com website, which I only check in on once a day, I will write up articles and additional comments as seems to move me.
Have fun with this stuff. It’s really a hoot!
Our December Build project is a Creality CR-10 V2. Then in January, the build will be a ham radio project. I’ll be trying to make a Thermoplastic Urethane gasket for the missing (*and available nowhere) waterproof front panel gasket for the Icom M-700 SSB transceiver I picked up to use on 60 meters… Might toss in some antenna insulators for that, too. It will give us a chance to see how hard or easy?) the AutoCAD ThinkerCAD program is for rendering ideas from “between the ears” to rolling off the printer…
Next Sunday on UrbanSurvival, though, the Sunday Making Column does more DYI Screen Door improvements. Fun project but hate the raccoons that have moved it up the DYI list….
Write when you get rich, or make something besides money!