Matthew Fiedler – re:3D | Life-Sized Affordable 3D Printing

GB3+ Introductions

Fall is in the air and re:3D is very excited to introduce you to the latest updates for Gigabot. Over the past year we have been working hard to provide you with enhancements for Gigabot to print at a higher resolution, faster, and with better quality. Additionally, we have improved the user interface, made it easier to change filament and level the print bed. Here are the upgrades you have been waiting for!

New bed side plates with two more guide wheels. Now with six wheels on each bed side plate the additional stability gives higher quality print throughout the Z axis travel.

re:Designed cold end extruder with thumb tab for easily filament loading and unloading. New extruder design is more simplified with reduced number of parts, as well as more open and accessible.

re:3D all metal hot end designed for reliability and quality
- Electroless nickel plating on the hot end nozzle and thermal tube offer higher lubricity and higher hardness over standard hot ends, giving smoother flow of plastic with less wear and maintenance.
- Screw-in thermocouple temperature sensors offer industrial reliability.
- Interchangeable nozzle for printing with 0.4mm or 0.8mm extrusion diameter.
- Heater cartridge is almost completely captured inside the heater block for better thermal efficiency in the hot end.

New filament tubes are lighter weight and more flexible while reducing the load on the print head.

New Viki enclosure allows more room for wires and connectors and presents itself ergonomically for the operator.
Filament Detection units have been revised for easier filament feeding/more reliable detection.
Easier to use filament spool holders on the back side of Gigabot are modular and now accommodate multiple 15lb spools for printing huge!

The new GB3+ is dressed up and looking sharp with a new Gigabot nameplate, engraved corner logo plate, and XL/XLT badge corner plate. The serial number plate also proudly displays the flag and Made in America tag.

LED lights on every Gigabot shine bright and will show off your latest print.

Updated bed leveling allows simple and easy adjustments for bed leveling with the new four point bed leveling.

Wow, I know that is quite a bit of upgrade for the new 3+ and I am super excited for all of you to see the REAL benefits! To make sure that none of our customers are being left out we are offering all the upgrades as a bolt-on package starting next month. Happy Printing!

-Chief Hacker

Pitching for a Circular Economy Part 1: Why We Went to Aruba

As I sit on a plane flying in the opposite direction of Aruba I feel there is nothing more important than finding a way back. You see, Samantha & I spent the past three days as co-founders immersed in a new culture with new people and pitching an idea that is new and maybe just ahead of it’s time. The event that brought us all together is Atech2016. There exist in the paradise of an island nation of Aruba a group of inspiring founders who for the second year now have decided to put their money on the table. These visionaries invite tech savvy entrepreneurs and guest speakers to discuss thoughts and ideas on topics ranging from mobile banking & blockchain technology. I’m just glad we did research into sites like https://beincrypto.com/tag/coinbase/, as this meant that we were kept up to date with all things relating to the blockchain industry. We even looked into wearable tech & social inclusion from the perspective of Burning Man to inspire each other as well as the local Arubans how we as a society maintain relevance in the age of acceleration that we are living.

Gatherings like Atech2016 are really the nexus, bringing together in one place a group of young individuals with passion, focus, and hunger for change. With connections made, and new ideas formed we are all contemplating our next steps as we fly in the opposite direction of Aruba. We feel honored to have been part of such an event and encouraged by many Arubans who resonated with re:3D’s vision and our pitch for the Atech and Aruban communities. We were stoked to be named finalists in the pitch competition, and, while we didn’t win left more determined than when we arrived.

Several things became clear to us in the few short days we spent on the island:

Arubans are ready, in fact hungry, for greater technology. Meeting and talking to the young men and women volunteering at the conference we felt their excitement for 3D printing as well as other technology on display.
The island nation of Aruba is resource constrained and imports the vast majority of all their physical goods. There is very limited manufacturing on the island.
With an economy largely based on tourism and very little to nonexistent recycling program there is a growing problem with trash and landfill space.

Our goal and dream, that which we pitched to Aruba, was that re:3D would engineer and manufacture the prototype hardware needed to take the first step in 3D printing useful objects from plastic trash. During our few short days at the conference, we reached out to community leaders, local entrepreneurs, Aruban schools and universities and well as hotels to partner in the effort of recycling, re-using and re: imagining the possibilities to own their our factory as well as the supply chain. The response was super positive and affirmed for us first – hand there was a HUGE opportunity to leverage trash for a more circular economy.

Why is this important?

Sustainability goals are a priority in Aruba
Island communities are significantly dependent on imports
Arubas are actively innovating new solutions to reduce landfill size
Several groups all already considering 3D printing from reclaimed plastic (and we hope to someday partner with them!)

Where do we go next?

While we left Aruba affirmed that 3D printing from waste is inherently right, we unfortunately did not secure the resources we needed to complete a prototype to leverage reclaimed plastic using Gigabot. Stayed tuned to upcoming blogs in our series as we continue to share our vision in future competitions and pursue partners to donate post-manufacturing waste streams to test. With a little luck, we will raise enough support to partner with Aruba on a pilot!

~Happy Printing!

Matthew aka @chief_hacker

Stepper Motors vs Servo Motors

One question we sometimes get relates to our choice to use stepper motors over servos. We’d like to explain our rationale behind that, as well as why we personally prefer stepper motors to their servo counterpart.

I think the biggest advantage for servo systems is its ability to produce higher levels of torque at high RPM whereas stepper motors produce the most torque at low RPM. You might want to look into something similar to propshaft services for more information on what might be able to help. More torque at higher RPM means having a higher degree of certainty of achieving the desired position in high speed movements, i.e. accuracy and repeatability. If you have any more questions about servo motors or just need a repair check out the Servo Motor Repair Experts. In order to achieve potential benefits of closed loop control you must be willing to make some trade-offs:

Increased cost
More parts and more complicated system (ie more parts that can break)
Decreased low end torque and power

Stepper motors on the other hand give time-proven reliability at a lower cost and provide a more robust system with fewer moving and electromechanical parts that can break. Some will point to servo closed loop control as being superior to steppers because it can correct positional errors should they happen. This may be helpful in traditional manufacturing technologies, but I challenge that a great majority of print failures and positional inaccuracies are caused by the 3D printer operators’ (in)ability to anticipate and control the thermodynamics occurring during the additive manufacturing process.

All plastic shrinks as it cools. Parts that warp and curl can become dislodged from the print surface, cause interference with the print head, and result in a loss of positional accuracy. Here are two reasons it does not help to have closed loop servo control: 1) If the part is warped and dimensionally deformed then the part will be scrapped anyway 2) If the part comes loose from the print surface and effectively causes the print head to loose position relative to your part, then your part will be scrapped. In the majority of causes of print failure, servo control has not saved your part.

If the size of the stepper motor is correctly chosen based upon the loads of the system, and appropriate limits are placed on acceleration and velocity, you will have the same reliability as a closed loop system. I have two large CNC mills driven by stepper motors that will drive a 1/2″ EM through steel at amazing rates machining parts to greater than 0.001″ tolerance. Stepper motors – we went to the moon on this technology!

Material Testing & Heat Treating Natureworks PLA 3D850

Manufacturer: Coex

Filament Name: PLA Prime

Color Tested: Natural

Date Received: 6/10/2016

Date Tested: 6/16/2016

Ease of use: Excellent

Appearance: Clearer than regular PLA

Size consistency: Great

Color consistency: Great

Odor: None

Manufacturer’s recommendations

Speed: none given mm/s
Temperature: has a higher MFI so should be able to print slightly cooler than regular PLA C
Infill %: any
Layer Height: tested at 0.3175mm
Printer Used: GB # 004
Print temperature used: 200 C (nozzle) /55C (bed)
Speed used: 60 mm/s
Layer Height:0.3175 mm
Infill: 15%
Odor: none
Type(s) of print surface used: Print n Z

FINDINGS

Bed adhesion (1: terrible-5: fabulous!)

5

Stringing (1: lots -5: none!)

4

Shrinkage (1: lots-5: none!)

4: None!

Interlayer adhesion (1: terrible-5: fabulous!)

4: Perfect!

The technical datasheet for the pellets that the filament is derived from can be found here.

I suspect that most, if not all the temperature resistant PLA uses the 3D850 as its base. There is very little information out there for recommended heat treat methods.

Here are a couple pictures from a recent experiment I did with Natureworks PLA 3D850 that claims increased crystallization with heat treat. I used a wall oven to heat treat the parts at 200F but please note that I did not verify with a second thermometer.

The three parts on the top row are not heat treated and the three on the bottom row are heat treated at 200F for 15 minutes. I placed the parts into a cold oven and let the oven heat to temp and maintained temp for 15 minutes then removed the parts to air cool. The color change and warping happened while the parts were in the oven not after they were removed.The top two parts were made with one perimeter (0.48mm width). The center two are two perimeters and the bottom two have three perimeters. Interestingly enough the part with two perimeters warped the least. I also heat treated a couple objects with more structural integrity and found little to no warping (small 5″ Moai statue and the re3D logo placard).

I think the next steps are to control the rate of heating to see if the amount of warping can be reduced. Would love to hear other’s experience with heat treating the PLA 3D850.

Further information about annealing PLA is here: http://www.4spepro.org/view.php?article=005392-2014-03-28

Quesions or Comments?

Share your thoughts on the materials section of our forum:
- https://re3d.zendesk.com/hc/en-us/community/posts/206087383-Natureworks-3D850

Happy Printing!

~Matthew

3dprinting america Education engineering filament gigabot process R&D

How My Gigabot Fixed the Power Wagon

One of the realities of owning an old car is that they tend to wear out with time. In my case I am the fortunate owner of a 1949 Dodge Power Wagon that was originally purchased new by my grandfather Leo.

It happened last week when I first started the engine that I smelled the unmistakable odor of leaking fuel. Upon a little investigation I found the fuel bowl gasket had given up it’s ghost and was no longer providing an effective seal between the fuel pump and the sediment bowl. After calling a few automotive parts stores it quickly became evident that parts for a 1949 Dodge were not kept in stock.

Lucky for me and my normally trusty Power Wagon I have a Gigabot 3D printer and a stock of TPU filament from Fenner drives (https://ninjatek.com/) that I hoped to use for manufacturing a suitable replacement fuel gasket. A quick investigation of the chemical resistance for the TPU filament showed an “A” resistance to gasoline and I quickly set off to create the CAD model for the simple gasket. A few minutes later I had the Model processed for 3D printing using Simplify3D and was pressing the Print button on Gigabot.

The gasket was printed in under five minutes and I felt a great sense of accomplishment as I installed the gasket and started the old truck. No more leaking fuel and just for safe measure in another five minutes I had made myself a spare!

~Happy Printing

Matthew: @chief_hacker

3dprinting america Design engineering gigabot process

January Puzzler Solution re: Waavy Prints

Below is the solution to the Monthly Puzzler Chief Hacker presented in our January Newsletter. Unfortunately we didn’t have a winner, but look forward to receiving the entries in this month’s featured problem. Want to play? You can sign up to receive our monthly publication by submitting your email address in the sign up at the bottom of re:3D.org.

If you remember last month’s puzzler, I was asking why the top solid layer was making waves and not laying down flat. If we zoom in on the picture you may notice the last layer of infill is oriented parallel to the solid top layer. Some “roads” or “tracks” of the solid top layer have nothing underneath to bond to and lifted up as it cooled and contracted thus forming the waves.

To avoid this you will need to verify the last layer of infill is printed orthogonal to the solid top layer. In Simplify3D use the toolpath verification and visualization to ensure the correct orientation of the infill. If required, you can change the infill orientation on the “Infill” tab in Simplify3D.

Happy Printing!

~Matthew Fiedler

Twitter: @chief_hacker
Email: engineering@re3d.org

3dprint failure puzzler simplify3d solution

Getting a Grip : Part 2

Getting a grip on your 3D printer filament Part 2 by Chief Hacker, re:3D

One of the leading causes of print failure is the filament feeding mechanism. By surveying the literature and leveraging our current experience in hardware development we have identified a gap in the knowledgebase for understanding the mechanics and operations surrounding the extruder drive gear commonly used on FFF type 3D printers.
The goal of this work is to characterize the amount of force that can be generated by a custom machined extruder drive bolt, affectionately named “Jaws”. Details of the engineering development of Jaws is outlined in part 1 of this series. The testing outlined below was performed with a Greg’s Wade’s type extruder for 3mm PLA filament. See Figure 1 below.

The first objective of the multipart study is to determine the optimal tension setting for the Greg’s Wade extruder. Tension is adjusted by rotating a pair of screws that compresses a pair of springs that in turn presses the extruder’s idler bearing against the filament. See figure 2A below. This presses the filament into the teeth of the filament drive bolt seen in Figure 2B below.

If the tensioner is adjusted too loosely the filament will not fully engage against the teeth of the drive bolt. If the tensioner is adjusted too tightly there may be excessive friction and wear in the extruder. To accurately measure the force imparted to the filament by the extruder we felt it was important to measure the ability of the extruder to push the filament down into the hot-end. Previously, force measurements commonly seen in the literature measure the amount of pull the extruder imparts in the filament coming into the extruder. We felt that by measuring the amount of push we would obtain better real world operating conditions.

The downward force measurement was accomplished by a custom machined fixture that housed a small metal ring outfitted with a threaded tensioning system. The tensioning system is used to slowly grip the filament by turning a screw. As the ring increases its grip on the filament the force is transferred from the filament and onto a compression load cell (THA-100-Q from Transducer Techniques). The load cell was connected to a load cell amplifier (TMO-1 Transducer Techniques) and the analog output from the amplifier was measured by a 12bit A to D daq (USB-1208LS from Measurement Computing). Data was collected at 100 Hz and saved to csv file format. The daq was calibrated using a mass of solid brass and aluminum of known volume. Collected data was processed and graphed using custom Matlab code. The extruder is driven with a 1.68 A 72 oz-in NEMA 17 stepper motor powered at 24 volts. Test setup seen in Figure 3 below.

Three trials were performed at four different levels of tensioner adjustments. Tensioner adjustment levels were determined as 2, 4, 8 and 12 revolutions (1 revolution = 360 degrees of rotation) of the tensioner adjustment screw beyond full engagement into its corresponding nut. Example trials are shown in below. Notice in the data graph the period of zero force at the beginning of the trial followed by a gradual increase of force. The force curve shows the peak force imparted into the filament followed by a sharp drop in force where the filament drive gear stripped the filament and filament drive bolt was no longer able to impart a force into the filament. The graphs seen in Figures 4-7 below shows the ability of the filament drive bolt to drive the filament at increasingly greater forces with an increase of tension in the extruder tensioner system.

What does this mean for you? With the Greg’s Wade type extruder and the Jaws filament drive bolt we were able to push the PLA filament with over 50lbs of force when the extruder tensioner was advanced 12 revolutions. This researched establishes a baseline measurement for re:3D’s custom extruder bolt which was designed to maximize the grip on PLA filament and help ensure an error free printing experience. This research was conducted at the office of re:3D in Houston Texas.

Matthew: Chief Hacker, re:3D

matthew@re3d.org

Getting a Grip : Part 1

Getting a grip on your 3D printer filament-Part 1

With the rise in popularity of low cost 3D printers for use in homes and small business many new printer designs have recently arrived in the market. The cost of ownership for 3D printers is coming down which is driving up access in new markets. With a customer base growing outside of engineers and tinkerers it is important that 3D printers must remain near 100% reliable with near zero failed prints due to mechanical and electro-mechanical malfunctions.

One of the leading causes of print failure is the filament feeding mechanism. By surveying the literature and leveraging our current experience in hardware development we have identified a gap in the knowledgebase for understanding the mechanics and operations surrounding the extruder drive gear commonly used on FFF type 3D printers.

We have found reliability of the filament feed gear is dependent upon three factors 1) amount of contact surface are between the drive gear and the filament, 2) depth of the gear’s tooth engagement into the filament 3) number of teeth engaged in the filament at any one time and 4) the direction of the force vector imparted from the filament drive gear into the filament. R&D at re:3D delved into this problem and below is result of their work.

Figures 1 and 2 below shows a 3D rendering of the filament drive gear “Jaws” that will be mounted to the shaft of a geared NEMA 17 stepper motor.

Figure 2. Mid-section view of Jaws filament drive gear

The Jaws filament drive gear is machined using a four axis Bridgeport CNC milling machine. In the design process our aim was to optimize the four variables stated above.

The amount of contact between the drive gear and the filament is maximized by machining the gear teeth using a cutting tool of the same diameter as the filament it will drive. In our case the filament is 6.0mm in diameter.
The depth of tooth engagement was optimized by balancing greater tooth engagement with number of teeth engaged into the filament at any one time. If the tooth engagement is too shallow there will be too little surface area and force imparted to the filament and the teeth will slip and shred the filament. If the tooth engagement is too great the risk of plastic deformation causing the filament dimension to be out of spec for the hot-end and will cause jamming of the hot-end during printing.
The number of teeth engaged into the filament at any one time is important in maintaining a smooth and constant push of filament into the hot-end. Consider the job of the filament drive gear is to transform the rotational motion from the stepper motor into straight line movement of filament into the hot-end. If too few gear teeth are engaged into the filament the linear motion of the filament over time will assume more of a sine wave pattern than a constant straight line movement.
The force vectors should be directed in the downward direction as much as possible to increase the conservation of energy in the system. Any forces imparted into the filament in the lateral direction will cause plastic deformation of the filament and not translated into pure downward force of the filament feed. It should be noted there will always be a certain amount of lateral force experienced for the pure fact that the drive teeth will need to be engaged into the filament. By studying the section view in Figure 3 below you can see the depth of engagement, the number of teeth engaged and the force vector for a 25 tooth drive gear.

We are extremely excited to have optimized the design and manufacturing of this advanced filament drive gear for FFF style 3D printers. You can view a short video of the machining process on our re:Tech YouTube channel:

Stay tuned for part two in this series where we will perform data collection and force measurement in a real world application of the Jaws filament drive gear.