So you THINK you want a 3d Printer...

An introductory essay about one of my current hobbies

I’ve been into 3d printing since 2020, and currently own 9 units, in various states of operational.

Most of my stuff comes off either my Bambu P1S or Elegaoo Saturn II 8k, but I keep the others handy for when I might need them.

I see a lot of folks talking about getting into the hobby and not really knowing where to start. That prompted me writing this.

If there is any interest, I can add additional essays that get into more detail.

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So you THINK you want a 3d Printer

3D PRINTING – 001

By: Jesse Barrett

#3dPrinting

You poor, doomed fool…

Err, did I say that out loud?

Anywho, so you've been thinking about a 3d printer, and you have questions. This post is to go over the very basics.

WHAT IS 3D PRINTING?

3d printing is the generic term of any of several kinds of additive manufacturing. This means that material is added to the object being created to then become said object. This is the opposite of subtractive manufacturing (like CnC) where you start with a block of material and then carve away everything that isn't the piece you are creating.

The most common forms of in home 3d printing are known colloquially as Resin and FDM.

FDM stands for Fused Deposition Modeling and is what most people first think of when you mention 3d printing.

FDM IN A NUTSHELL

An FDM printer is at its most basic a hot glue gun at the end of a robot.

There are several common form factors:

Cartesian

EX: the Ender 3 and it's army of clones.

It has dedicated motion in each of the three axes (giving it the name), including the bed moving front to back. This is why they are sometimes called bedslingers.

Cartesian printers are easy to understand, but the mass of the components they are moving place limitations on their speed and efficiency.

CoreXY

EX: Ender 5, Bambu, Voron

Similar to the Cartesians (and still technically one of them), CoreXY printers limit the bed motion to up and down. This results in a much more stable printing environment and therefore higher possible levels of quality. It also means that the heaviest component doesn't move much, and therefore the lighter two can be moved faster, increasing the possible speed.

CoreXY units are the most common in more professional use and provide a reliable compromise between speed and performance, partaking liberally of both.

Deltas

EX: Most FL Sun Printers

Delta printers look like something out of a mid-range SF show and have been used in several. They are built around a roughly cylindrical frame with three supports to which arms attach and then are attached to the print head in the center. The bed is in a fixed position at the bottom, eliminating one of the motion factors that Cartesians and CoreXY have. Instead, the three arms move up and down their supports offsetting the print head in all three dimensions. In operation they remind me of a mechanical spider spinning a web, and they can be hypnotic to watch.

Delta style 3d printers are fastest of the common forms. They are moving the least mass and each element of motion is equal. In units like the new V400 that have been heavily tuned for it, this can result in unbelievable speeds that still produce reliable prints. They aren't as inherently accurate as CoreXY, but they can still turn out some spectacular results.

Due to the basic design, they frequently aren't recommended for beginners, as it can sometimes be hard to wrap your head around what one is doing to cause THAT?!? The newer gen FL Sun printers are generally reliable enough to offset this.

There are a few other designs out there, including but not limited to the handheld and completely freeform '3d pen', but we'll worry about those another time, if there is interest.

All of them use a plastic filament (1.75mm for most home units) fed through a heated print head and squirted onto the build plate and then onto itself in an increasing number of layers to build up the object being printed.

There are some limitations to this design. For example, you can't print in the air, so with certain very narrow limits there has to be a solid connection between any bit and the build plate. If the design doesn't offer this, supports must be added. There are several styles and schools of thought on how they look / work, but it all boils down to 'can't print in thin air, so build a scaffold of some kind'. These obviously have to be removed once the print is done. A number of designers get VERY creative with models that don't need supports, and you eventually get better at minimizing them, but they rarely go away.

The basic design also limits the maximum possible resolution. They are good for a lot of things but small, high detail items like gaming miniatures are effectively out of their range.

Those are handled by the Resin printers.

Resin Printers; The Secret of the Ooze

Resin printers work on the same basic idea (cutting a model into ultra-thin layers and then laying them down one at a time) but implementing it very differently.

A UV light is shown through an LCD screen that selectively blocks some of the light. Where it does shine a photoreactive goo goes from thick liquid to mostly solid. Rip off of thin layer of plastic and then reposition a minute fraction of a mm later and repeat. Typical resolution is in the 2-8k pixel range and 0.05 mm layers. Needless to say, this can produce items of remarkable levels of detail.

The tradeoffs are in the amount of post processing required.

The photoresin is a sensitizing irritant that can cause chemical burns, and a variety of unpleasant reactions depending on the degree of sensitivity. Many people also find the smell objectionable unless exceptionally well vented. It can also penetrate latex gloves, so plan on stocking up on nitrile.

Furthermore, cleaning takes isopropyl alcohol or similar in most formulations. There are other solvents that will work, but IPA is the easy one. Some varieties of resin can use water, but even then it must be handled carefully and not just run down the drain (vat, and recirculating pump at recommended minimum).

Once a print has been 'washed' it is more or less safe to handle. You can now remove the often extensive lattice of supports and do any assembly that complex designs may require before you do the final cure.

When the prints come off the printer, they are only MOSTLY cured. Think a strong ceramic greenware. You have to do a final cure either in a curing box with specific output UV lights, or outside in strong sunlight.

Only then are things done and you are ready to prime and paint.

Plan on reacting ALL spills and such with IPA, as well as setting all of your trash and scrap bits in a bucket in the sun for a while before actually throwing it away. Liquid resin is a hazmat material, but if reacted chemically or via UV it becomes mostly harmless. You will also have to do the same with the IPA once it gets saturated with resin.

Imagine working with thin Bleach Jello and you will be close.

Resins are also more expensive than FDM filaments, to the tune of double or triple in normal circumstances. Most minis don't use much by volume, but with the new generations of larger printers available you can easily use most of a bottle of resin on one larger project.

In return for this, you will have access to a host of minis and figures ranging from free to a number of premium subscriptions that put anything available in your LGS to shame. Additionally, there are a number of interesting industrial resins available that can have some truly unusual uses (3d printed ceramics, anyone?)

So, the first question you have to answer before you get into 3d prints is, "What is your excuse?"

The rule of thumb is: Resin for minis, and FDM for terrain and 'stuff'.

They are both capable of some amazing results, but because they are so very different there is very little overlap in what they do well.

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I haven’t updated it in a while, but my YouTube channel is mostly 3d printing timelapses.