The Dimensional Print Studio has joined the ranks of multi-color three-dimensional printing. This is with the FDM (Fused Deposition Modeling) process using plastic extruded filament. The printer obtained, a GeeeTech A20M (the “M” is for multicolor) printer.
The A20M uses two filaments and combines the feeds into a single nozzle. This permits blending (sort of) of the two filaments. The colors don’t mix and when fed to the nozzle together, come out the 0.04MM tip side by side in proportion to the feed. Like stripe toothpaste in a tube. 30/70, 50/50, 70/30 it will show in the print.
Much two-color printing is done with a nozzle for each color. No blending is possible. Using a single nozzle, requires a purge area to pump out the old color before printing (100%) with the new color. A “purge pillar” is built up layer by layer alongside the intended print for purging. This pillar is “wasted” and thrown away and is a concern for some stingy printer owners.
Two color printing can take up to twice as long as single color printing. So, two color printing is not popular for many folks. Especially if they have an extreme obsession or phobia about “wasting” material changing colors.
Waste is a product of all forms of crafting and manufacturing. Does a woodcarver obsess over the 50% waste of material in the form of shavings and chips when carving a figure? Did Michael Angelo obsess over the “wasted marble” when carving David? I think NOT!
Not sorry about the rant above. I’ve just heard about wasting material too many times in 3D printing…
The rewards of having color options are quite enjoyable. For me it has moved my printing further in the realm of an art form, without the need for priming and painting. Or printing multiple pieces to assemble. That will go on, but it is fun to design and see it produced in a single print.
Here are some examples of my first prints. Surely there will be much more to come.
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| This is my first print in two color. It is my own design created in Fusion 360. | The A20M came with a mouse pad!. The rectangle is the purge piliar required to clear color from the single nozzle. |
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| This is a key fob I printed with different color loaded. | The W5EHS is my amateur (ham) radio call sign |
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| This is a process of blending two colors into a single nozzle printer. | Because the colors don't truely mix, the pink rises higher on the right side and the green is lower on the left. |
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| Quilting square coaster I designed in single color has been updated for 2 color printing. | Same pattern, just switch colors when slicing. |
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| Here is a blended color FDM owl nect to a DLP resin printed owl. | Another blended color print. This time red to grey |
The stock build plate on my Wanhao D7 Duplicator is a flat aluminum plate. It has worked well except fo a couple of exceptions.
First is it is very dificult to clean as the resin overflows the top of the plate and floods into bracket area where there are four screw heads and for some reason, several narrow slots that trap the resin. I have been able to clean the area with a bath of IPA and a one inch paint brush, scrubbinng into that small area.
Second, the print surface is highly polished and sometimes prints fail to stick. I solved that issue by using a flat, fine whetstone and while under running water, polishing off the shine to a flat mat finish with a bit of "tooth" for the curing resing to grab. This was an excelelnt modification.
Third, the bracket and plate are PAINTED and the black paint was starting to degrade from the resin and IPA exposure.
The new EPAX3D build plate is a cast aluminum with a sloping top to assist the resin draining off the upper surface. It is also cast aluminum with what should be a very "grippy" build surface. Definately not polished. It also has NO painted metal surfaces. Priced at $65 postage included.
My workshop here in Texas is currently at 100+ degrees. Too hot to run the printer or work out there, so it will be a week or so before I can test this new build plate.
The brackets look very similar but are not exactly the same. I had to do some bending and tweaking but I was able to get them working together without any additional parts. The fit has to be loose enough so the leveling can be done without damage to the video screen. The plates are also slightly different in all dimensions but no problem fiting the vat on the D7.
The new plate will displace slightly more resin on the down stroke, so I will have to pay attention to fill levels in the vat. Not an issue, just a caution.
The pictures will show the rest of the story. As usual, click on a picture to enlarge it.
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| EPAX plate on the left Wanhao D7 plate on the right. | Note the taper makes the EPAX bracket plate narrower. Note slots against plate on D7 bracket. |
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| Bending both plates I was able to make a decent adjustable connection. | The new EPAX plate on the D7 DLP resin printer. |
I have had some time to think about several blog articles I recently read about desktop 3D printing. They were about the time and effort (and money) we and the machine manufacturers invest for the results obtained at the hobbyist class machine cost level.
Example, an original project promoted for hobbyist. REPRAP. A desktop machine that can build itself. Really? No… a few plastic pieces of dubious quality, Yes. It helped kick start the hobby interest. It is not the best printer design.
Two products, one made with hobby level desktop 3D printing and the other with professional injection molded parts. I know what I would purchase. A friend and I both looked at recently designed (large) kit DIY printed parts 3D machine. The non-printed components (~$700) were an excellent choice. The self-printed (plastic) parts could make the complete printer a very bad investment.
The elephant in the room is 3D desktop printing as a hobbyist uses it, cannot deliver equivalent consistent output of conventional subtractive manufacturing, injection molding, or profession additive manufacturing. We may pretend it does. I can produce a facsimile of these items. Professional quality production 3D printers are not small desktop sized machines.
I ventured into resin (DLP) 3D printed, Lost Wax Casting models. I used a Wanhoa D7 Replicator. (lead picture) I had some success. But overall, factors beyond the actual printing proved wax is still the most consistent and cost effective method for a hobbyist doing lost wax casting. Making jewelry on a hobbyist 3D printing machine is possible but not practical.
Prototype modeling is a desktop machine's strong suit. Scale model, low volume, specialty, static display components.
What still scares me is some hobbyist using “carbon fiber” PLA and printing propellers for his drone or R/C aircraft engine with his $400 desktop hobby machine. Propeller failure at 20.000 rpm is lethal.
One guy writing about his Moai SLA printer, pretty much summed up what he has. (and all hobbyist have.) A tinkerer’s delight. A good first step in understanding the POTENTIAL of 3D additive manufacturing. The hobbyist grade hardware is basically a toy. A dental lab will not or should not be using a D7 or a Moai.
Technology junkies like myself are attracted to the 3D process and what we and a 3D printer can produce. We invest in our love of things technical and the low-cost desktop printer makes it possible, but so far it is mostly a hobby stuck in “demonstration mode” for me.
I like what I can do… not knocking my interest. Mostly making unnecessary plastic JUNQUE like 50+ plastic owls...
The kid who prints a dog cart, for the pup with no back legs, has not created anything new. The fact it was 3D printed doesn’t make it a better product. What it does show IMHO, is that this 3D print technology is getting these kids (and adults) into tangible, hands on making of things. The story gets press coverage because of the use of the “new” 3D print technology.
If hobbyist desktop 3D printing is anything, it is an enabler for tangible creative effort. It’s the new (toy maker) kid on the block. In an age where home machine shops are extremely rare, it brings affordable manufacturing onto a desktop in a home or a school. That’s what is good about 3D printing as a hobbyist.
What’s actually being printed is not necessarily the best way to make things, but it is a very satisfactory way to see designs come into tangible existance.
Zeitmeister (Not 3D Printed)Very high-resolution 3D printing is associated mostly with layer height designated as Z in most systems. There is also resolution in the X/Y plane. FDM filament printers control X/Y resolution with nozzle diameter and flow rates.
With SLA resin printers, X/Y resolution is the size of the laser spot or focus point. Laser power levels and slow travel can cause light “bleed” and affect the effective dot size very slightly. Generally, the spot size is fixed by the design of the machine and the laser.
DLP and DLM (Digital Light Projection and Digital Light Masking) resin printer dot size is fixed by the number of pixels and their projected size. One to one is the highest resolution but it is possible and common that the image has less pixels than the hardware. A 1K image on a 4k screen, enlarged to fill the screen, is still a 1k image.
By far the most common and manipulated resolution variable with every type of 3D printing is the Z layer height.
There is a very serious factor to consider when attempting very high-resolution 3D printing. That factor is printing time. Time increase as the cube of the size and in inverse proportion to the layer height with FDM printing. Double the size and halving the layer height (Four time the number of layers) could take 16 time longer!
Large FDM printers (prints) and super fine resolution are just not practical together.
DLP and DLM print time are ONLY affected by height and number of layers, and NOT X/Y size. Doubling the height doubles the time. Reducing layer height by 50% does not again double the time as exposure times decrease as layers become thinner. Rather than 200% longer print time, it may be 190% longer.
Doubling the size and reducing individual layer height by half will be 3.8, say... something less than four times longer print time.
Good FDM printers will produce 100um (micron) layers. I have seen claims for as small as 50um. But doing any print of reasonable size, say... within 64 cubic inches (4x4x4) at 50um will take (just for comparision) perhaps 32 hours. The Resin DLP/DLM printer could probably do it in half the time 16 hours) or better as it does a complete layer at once without X/Y travel.
My general rules:
Large prints, 100um to 400um layers then FDM (filament) printing
Small prints, very fine resolution 10um to 100um then SLA, DLP, DLM (resin) printing.
Otherwise, pay the Zeitmiester (time master) his due.
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