3D Printing

Homemade LEGObot 3D printer does 3D printing on the cheap

Homemade LEGObot 3D printer do...
The LEGObot still has some wobble, but Krueger is hoping tighten the X and Y axes soon, making prints more precise
The LEGObot still has some wobble, but Krueger is hoping tighten the X and Y axes soon, making prints more precise
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Krueger used repurposed elements to build his LEGObot, like the motor pictured here
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Krueger used repurposed elements to build his LEGObot, like the motor pictured here
Each movement of the extruder has to be manually programmed on the LEGObot
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Each movement of the extruder has to be manually programmed on the LEGObot
Krueger utilized his LEGO collection for most of the hardware on his 3D printer
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Krueger utilized his LEGO collection for most of the hardware on his 3D printer
The LEGObot uses a hot glue gun as an extruder
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The LEGObot uses a hot glue gun as an extruder
For programming, the LEGObot uses a LEGO MINDSTORMS NXT module
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For programming, the LEGObot uses a LEGO MINDSTORMS NXT module
The LEGO and 3D-printed gear racks side by side
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The LEGO and 3D-printed gear racks side by side
3D-printed gear racks didn't perfectly match the LEGO parts, causing a bit of a wobble on the X and Y axes
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3D-printed gear racks didn't perfectly match the LEGO parts, causing a bit of a wobble on the X and Y axes
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The LEGObot prints with hot glue and utilizes a hot glue gun as an extruder
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The LEGObot prints with hot glue and utilizes a hot glue gun as an extruder
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A block 3D-printed by the LEGObot with hot glue
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A block 3D-printed by the LEGObot with hot glue
Basic 3D printed figures are illuminated to reveal the layers of hot glue
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Basic 3D printed figures are illuminated to reveal the layers of hot glue
Pre- and post-print version of the LEGObot's hot glue medium
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Pre- and post-print version of the LEGObot's hot glue medium
Using hot glue to 3D print is a bit complicated, as it isn't as rigid and stable as ABS or PLM material
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Using hot glue to 3D print is a bit complicated, as it isn't as rigid and stable as ABS or PLM material
The LEGObot still has some wobble, but Krueger is hoping tighten the X and Y axes soon, making prints more precise
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The LEGObot still has some wobble, but Krueger is hoping tighten the X and Y axes soon, making prints more precise
Krueger built the LEGObot with a $0 budget, using only materials he had on hand
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Krueger built the LEGObot with a $0 budget, using only materials he had on hand
The LEGObot uses an NXT for operation, making programming a bit of a challenge
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The LEGObot uses an NXT for operation, making programming a bit of a challenge
View gallery - 17 images

As the 3D printing revolution continues, prices of 3D printers have continued to fall, with devices such as the Buccaneer 3D printer set to sell for under US$400. But even that is still too expensive for many people – students in particular. That's why Matthew Krueger, also known as matstermind at instructables.com, has created a 3D printer for next to nothing from everyone's favorite childhood toy, LEGO.

Krueger has had an obsession with 3D printing since he first came upon the original Makerbot Thing-O-Matic, but as a student, he lacked the funds to purchase a 3D printer of his own. Since his education was based in engineering, Krueger started making attempts at creating his own 3D printer with limited funds and what he had on hand. After attempts with an Arduino and parallel port, 3D printing on the cheap seemed like it would remain out of reach, but then Krueger pulled out his LEGOs and started building.

What he created is the LEGObot, an NXT-powered 3D printer that is roughly based on the original Makerbot. Instead of plastic, the LEGObot currently prints with hot glue, which although a usable medium, has a rubbery consistency that leads to a lack of practical uses.

Krueger tells Gizmag, "I am currently building a machine to recycle milk bottles into filament, based off of Lyman's designs. Once I am able to make filament, then I will try to adapt my LEGO printer to use the filament."

Krueger built the LEGObot with a $0 budget, using only materials he had on hand
Krueger built the LEGObot with a $0 budget, using only materials he had on hand

Krueger is currently limited to utilizing what he has on hand for production, relying on friends with 3D printers for additional parts, but for now, his extruder is made from a hot glue gun so that was the natural material of choice. "I spent a total of $0 on parts for this. I already had everything and didn't want to spend extra. I used hot glue because it was fairly cheap, but mainly because it is what I had on hand," Krueger says.

Beyond the challenges of hot glue, Krueger also had some difficulty with programming. "Due to my lack of programming skills, every move has to be manually programmed from the NXT programming software. I have yet to find a g-code interpreter for the NXT."

Usually, a 3D printer is controlled by connecting it to a computer via a g-code interpreter program that takes a 3D model (typically an .stl file) and splits it into layers that the printer can understand. These instructions are what is called g-code form, but the NXT system, used to operate the LEGObot, is not very open-source.

"I would need to completely re-write the firmware for it to accept g-code files, which is currently beyond my level of programming expertise," Krueger explains. "I recently stumbled on someone who is working on a g-code interpreter for the NXT. If he gets his interpreter working, then this will be a fully operational 3D printer."

The LEGObot prints with hot glue and utilizes a hot glue gun as an extruder
The LEGObot prints with hot glue and utilizes a hot glue gun as an extruder

The LEGObot also has a bit of a wobble issue on the X and Y axes, since the gear racks are 3D printed parts that don't perfectly fit to LEGOs. One of Krueger's goals as he continues to develop his LEGObot is to reduce this wobble, which would result in cleaner, more precise prints.

"I enjoy using old, unused, and recycled items in ways to reduce cost while keeping our landfills clean," Krueger says. It's clear that he is not only reducing cost while repurposing items, he is virtually eliminating the cost of creating a 3D printer for those that have some LEGOs laying around.

The video below shows the LEGObot at work.

Source: Instructables

LEGObot 3D Printer

View gallery - 17 images
5 comments
BigGoofyGuy
Lego's seems to be like duct tape, has a lot of uses. I think Lego's has a lot of potential. It seems limited only by ones imagination.
I think this 3D printer is really cool. I hope he is able to do all that he wants to do with it.
Randel Faarkin
Unless you've got lego lying around, it'd probably cost you more than $400 in lego blocks...
The Skud
Oh come on! Yet another poor excuse to make something that "almost" works using Lego! He did not even think it through enough to hot glue the Lego together to remove the wobble? A few scrap bits of pipe or box tubing - from a junkyard or the nearest vacant lot - would be much more efficient - or 'recycle' an old shopping trolley?
bergamot69
@The Skud,
I think you've missed the point- whilst mechanical machinery made from Lego might often lack the ultimate performance of a more bespoke approach- using and overcoming the limitations of the Lego system takes ingenuity- and making use of such a system is very good training for an engineer- as they don't always get to use optimum materials in the 'real world'. He has created this from materials he already has (or can blag from friends) so his budget for this project was $0.
The article makes it clear that this is very much a 'work in progress' and is not the finished article. And the wobble is, as has been pointed out, due to imprecise gear meshing- how could hot glue, as you suggest using, improve that?
Matt Fletcher
I like this project but it's like saying It cost me $0 dollars to build my car because I made it from the parts I had lying around. I might happen to have an engine, transmission, suspension, tires, and a frame lying around but most people won't be able to build a car for less than they could buy a car already made. Same thing here. Unless you already have $700-900 of the correct Lego parts lying around most people are better off buying a 3D printer kit.
None the less it is interesting that an adult choose to waste his time on a project (for teenagers) with such poor results. I started reading this because I thought a kid was doing this project. I hope someone writes a story about me a 41 year old man building a street legal go cart from spare parts I have lying around (a project on the same level of complexity) and then we can rename Gizmag to HobbyLobby.