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Saturday, August 10, 2013
[Review] Portabee 3D Printer - The most afforable in Singapore?
[ZOMBiE CyGiG] ranted at 2:27 AM --- Post#3100600041015214777

Note: Click on images to view them larger in a new tab.

Introduction

"Why do you need a 3D printer for?" is the most common question asked till today. "To make a dildo for my female friends of course!", I will answer with pride and sarcasm. How I wish I could ask a girl why she needs her collection of designer's bags when they are clearly not the most practical ones to use without getting slapped. The truth is, I got the 3D printer for love and joy, for experimentation and also to write a review to show future hipster that I was already using 3D printer before it was cool (I might be late already).

The Portabee.
The Portabee is a 3D printer assembled and sold in Singapore by Romscraj, otherwise stated as Orangeknob in billing. If you are a Singaporeans, the first ideas that come into your mind may be "free shipping" and "can cham xiong (discuss and bargain)". I paid S$647.00 for my printer which they charged US$490, and there was no need to pay additional shipping fee like overseas customers do. Although the physical store is in Yishun, Singapore, I was told that I can only buy the printer from the online store during my visit, however you can buy filaments from the physical store by cash. One spool of 1kg filament cost S$30 when bought at the physical store which is cheaper than their online store.

If you search for "Portabee" on Google, it is likely that you will see two online stores, portabee3dprinter.com and romscraj.com. I was told by one of the staff that romscraj.com is the official website and online store, and unsure about the other one, although both of them has the same address stated. The other store sells the Portabee for US$9 more.

The Portabee is advertised as a compact and portable 3D printer, thus the name. However, it seems to do quite badly at being portable due to reasons I will discuss later.

At the point of purchase (early June 2013), it seems like Portabee is the cheapest of all other 3D printers available in Singapore. You can get the Solidoodle from USA for roughly the same cost excluding shipping, which does not seem like a great deal when you find out the shipping fee to Singapore. 3dprinters.com.sg (that is their store name) told me they would charge a Up! Mini for S$2500, when it cost only USD899 (~S$1169) sans shipping from the US web store. They said I could use a $300 student discount and when I was about to put down my phone, the sales girl told me "Software is included!". I have yet to heard of any 3D printers that come without software, or not compatible to one free for use that you can download online. The Buccaneer was still raising funds and Portabee Go! was not ready to be shipped till October. I asked my good friend Dora if I should wait, and she threw a question back, "Do you think your cash would still be with you by then?" and I bought the Portabee shortly after without further consideration. Do note that US$490 buys you a kit, which you have to assemble, and not a ready-to-use one, I was more than happy with assembling the printer myself even if other purchase options might be more worth it if you factor in the labour and skill cost.

The Portabee is a Replicating Rapid Prototyper (RepRap) 3D printer. The "replication" part refers to self-replication, as the RepRap website says, "RepRap is humanity's first general-purpose self-replicating manufacturing machine". RepRap printers are often build with commonly found materials (for engineers and DIY hobbyist, still uncommon for common users), such as threaded rod, switches, stepper motors, bearings etc, with the other special made parts 3D printed. Therefore a 3D printer is needed to print a 3D printer, which then can print for other 3D printers.

The RepRap community makes open source (hardware and software) 3D printers, and as with many open source projects, there are many spin offs since anyone can access, modify and build their own 3D printers. Portabee is one of them and you can get full bill of materials and exact instructions on how to build one. It uses a modified RepRap Gen6 board, Gen6.d, where it boosts extra motor ports and compatible with many open source software used for 3D printing, as with other RepRap printers.

In general, the 3D printers we are talking about in this review are Fused Deposition Modelling (FDM) printers. The printer takes in plastic, heat them up till they melt, and squirt the molten plastic homogeneously to "draw" on the print bed via motors/pulleys/gears/belts etc. Then after when the first layer is cooled, the printer repeats the second layer, changing the shape slightly as per instructions generated by the computer, and repeats the process layer by layer to get a 3D object.

Before I review the Portabee, we should fix some misconceptions most people that I deal with have with 3D printers in general.

Misconceptions about 3D Printer

1. I can print everything
No, you cannot. Just like another other tools, there are many restrictions. You are basically stuck with PLA, ABS or Nylon, you cannot print bigger than your print bed, overhangs requiring supports are still issues many avoid and you can only print with one (at most a few) colour.

2. I no longer need to buy anything from local stores
Many things are simply faster and cheaper to be bought from local stores. Are you going to print a 50cents cup cover, a dollar plastic ruler or a two dollars basin? Printing takes hours, the filaments are not that cheap and you need to find or design your own 3D models. You use 3D printers to print stuff that are NOT readily available, such as that personal cup cover with your own logo on it, a plastic ruler with gigantic debossed text for your grandma or a first-in-the-world basin you designed that also acts as a fish tank when not in use.

3. I can print guns
Sadly, the source files were taken offline. Even if you manage to find it somehow, where are you getting your ammo from?

4. I can print figurines
Unless you spend some serious cash on a really accurate and well designed 3D printer, loads of time optimising the 3D models, getting really good at smoothing and touching up the printed objects and
getting skilled at air brushing, most of the 3D printed stuff will not be able to be on par with high quality figurines. However, that does not mean you cannot print a simplified or lower quality one for keep sake if the figurine of that certain character or item isn't for sale or cost a bomb commercially.

5. I know I can print perfect objects with moving parts/multi-colours/smooth finishes because I saw those on the internet
I see perfect slimming results on the internet too! A lot of those pictures are really misleading, some of them are made by really high end 3D printers, which might be stereolithography printers (lasers and white powder type). Others took many engineers and trials to perfect. Many looks good by camera works (A large print shrunk to a small displayed image hides imperfection) or by digital imaging (Photoshop works).

6. I can print everything I find on the internet
Not every 3D models you find on the internet are printable. Some of them have too many intricate details which becomes a mess if your print is too small. Some require tremendous support which ends up ruining the final print. Some fail to assemble because the original creator simply posted a model with errors. However, there are many interesting objects like object-in-object, chain mails, flexible parts etc. that you can print.

7. Printing is easy, just one click of a button

Welcome to my collection of Companion Cubes. Though some of them are good prints, most are waste prints or printed for debugging, troubleshooting and experimentation.
Sadly, similar to your 2D printer, which jams the paper, clogs the print head, and gives you waste prints, the 3D printer requires much more operating attention. You need to troubleshoot mechanical faults when they happen, diagnose the reasons for bad prints, clear clogged nozzle, set a ton of parameters to slice your 3D object before printing etc. Those become vastly easy to do as you get used to the printer, but might still be steep learning for common users.

Specifications of Portabee

Printable Volume: 120mm x 120mm x 120mm
Print Bed Heater: Yes, built in
Print Material: PLA or ABS
Filament Diameter: 3.0mm
Nozzle Diameter: 0.5mm
Minimum Layer Height: 0.1mm
Power Supply: 12V 10A power brick, included
Recommended Speed: 30mm/s
Weight: ~2.8KG without filament and power supply

Print Volume
The maximum object size the printer can print. 120mm x 120mm x 120mm is a conservative size, if you turn off bream or raft, you can get around 10 mm more on the X and Y-axis. If you are not sure, just take 120mm x 120mm x 120mm as the absolute item size the printer can print.

Print Bed Heater
The print bed heater is to reduce the chances of the print object warping. You can set the temperature from the host software, Pronterface. Use around 50°C for PLA and 110°C for ABS.

Print Material
PLA and ABS are the most commonly printed materials, where PLA is harder and ABS is softer. PLA melts at around 185°C and ABS 210°C. I was told that Portabee might have problems with getting 110°C for the print bed and 210°C for the hot end to print ABS due to shortage of power from the stock PSU and requires an upgrade, but the website does not report that and I had yet to test it out. I am pretty happy with PLA for now.

Filament Diameter
The filament refers to the "ink" of the printer. It is really just a long noodle of plastic spun in a spool. The diameter of the filament usually varies with the nozzle diameter. In this case, 3mm filament is used to melt through a 0.5mm nozzle, producing hot molten 0.5mm plastic noodles for printing.

Nozzle Diameter
This refers to the diameter of the nozzle opening at the extruding end. As said, a 0.5mm nozzle diameter means 0.5mm diameter of molten plastic noodle will be pushed through to draw the layers. The nozzle diameter determines the resolution of the X and Y axis, the plane parallel to the print bed. Imagine a 0.5mm mechanical pencil and a 0.1mm one, the 0.1mm pencil will be able to draw details which are more intricate than the other. However, the 0.5mm pencil can shade a given area faster than the 0.1mm pencil, which means the larger the nozzle size, the faster the print, sacrificing details and that is why some printer with multiple extruders have a fine nozzle to draw the outer shell and a fat one for the infills.

Click on the diagram to get a better view.
The nozzle diameter also affects the layer height of the print. Ideally, the layer height should be around 80% of the nozzle diameter for a print with good strength. Given a plastic noodle of diameter 0.5mm and the layer height of 0.2mm, the printer will have to press down the noodle from 0.5mm to 0.2mm, thereby pressing it into layer below, giving a better bond among the layers. Likewise, a 0.5mm noodle and a 0.5mm layer height will mean the layers are only touching each other briefly, and will not bond well. Thus the smaller the nozzle diameter, the smaller the layer height you have to print, the finer the print but takes a lot longer time. Common nozzle size range from 0.5mm to 0.3mm.

Minimum Layer Height

Octopus model printed at 0.1mm layer height, compare that resolution to the spacing of my finger prints. You might want to click on the image to get a better view.
The minimum layer height refers to the shortest height each layer can achieve. Tall layer height makes the finished object looks, well, layered but takes a shorter time to print. Low layer height makes the layer less distinguishable from human eyes but takes a longer time. 0.1mm is the standard minimum layer height at the point of writing. Although the minimum layer height is 0.1mm, you can print at heights above that, but subjected to limitation of your nozzle diameter as explained above.

Power Supply
Power supply is the source of electricity for your printer. Most printer works on low voltages and requires a step down transformer.

Recommended Speed
The recommended speed is the speed at which the motors can move while maintaining a good quality print. Similar to 2D printers, the faster the print, the worst the quality. This value is determined by how well designed the printer is, including if it has a stable structure, precision of motors, how much the printer vibrates, if the firmware allows acceleration and deceleration etc. The speed is measured in millimeters per second (mm/s). The Portabee was demonstrated to be able to go as fast as 450mm/s, but above 40mm/s, the print quality degrades significantly, where the layers have bumps and become out of shape.

Weight
The reading of the printer on a weighing machine.

Unboxing

As mentioned before, you have to order the kit online instead at the physical store. This section shows the unboxing images of the Portabee kit. The items are listen from left to right, top to bottom.

The kit comes in a 41x21x22cm box, delivered to my house during one of the extremely hazy days in Singapore. The courier company is Ta-Q-Bin.

Inside the box. Yes, that is a packet of instant coffee. It is meant to be drank at the final step of the assembly as stated in the assembly instruction manual.

A packet of tools (spirit level, Kapton tape, allen keys etc), print bed, power supply unit, three packets of bolts/nuts/washers, a packet of bearings, a packet of smooth and threaded rods.

A spool of airtight sealed 1kg blue filament, a box of plastic printed parts and electronics, five stepper motors on their bubble wrap.

This are the items from the box of plastic printed parts and electronics. Gen6.d PCB, a packet of three end switches, all the required plastic parts, a packet of belts and Teflon tubes, a packet of wires for hot end, a packet of wires for connecting endstops to PCB, a packet of resistor, thermistors and wires for heated bed, a packet of fasteners for hot end, small fan, a packet of insulator barrel, nozzle and heat block.

Assembly

As mentioned before, you are getting a kit for US$490, not a fully assembled machine. Detailed assembly instructions could be found on their website in PDF, which I printed into a booklet for easy reference. I took around 15 hours across a few days to finish the assembly. I feel that the assembly part is extremely educational, and building your own 3D printer teaches you learn how it works, which will help you to troubleshoot later on. I feel that this is the kind of education that people (not just children) lack in Singapore. However, this might be too difficult for people who do not have any technical background even though one of the staff at the store reassured me that it is "very easy to assemble one!". If you can assemble your own PC or hobby-grade remote-control helicopter, this should be fine for you, given ample time to understand and follow the instructions to a tee. Unfortunately (fortunately for me), soldering is required.

Here is a time lapse video of me assembling the Portabee. Sorry for the poor quality as it was shot with an old Logitech webcam.

Closer Look at the Hardware

You would have seen the hero shot of the printer at the beginning, now we shall take a look at some of the components in details.

An z-axis endstop that signals to the printer that this is the lowest point the hot end can go.

The heated print bed which is covered in Kapton tape as both a protection as well as to increase object adhesion.

"mee siam mai hum", guess the nationality of the engineer/designer of Portabee?

The extruder viewed from the left. The filament is absent.

The extruder from the right, contradictory to what most people thought, the printed gears are not the first to break. The four springs and bolts are to tension the space between the gear and the filament to effectively push the filament down.

The z-coupler in the middle of picture connects the motor shaft and the threaded rods. This was one of the first part to break when building the printer, it snaps off easily at the intersection between the octagonal and cylindrical part. They do provide me with an updated version which is cylindrical with rounded sides on top but did not post the STL file for me to make more of them.

The wiring to the PCB, I labelled the cables as they would be difficult to differentiate once I bundle them together.

Good to have machined metal gears for the X-axis motor.

The hot end. On the left is the thermistor and on the right is a resistor, current is pumped into the resistor till the thermistor register a satisfactory value, then the temperature is held via constant feedback through PID control. The hot end is wrapped with Kapton tape to decrease heat loss to surrounding.

Printing Process

Generally speaking, you download a STL 3D model file, probably from Thingiverse, then you feed the 3D model into a slicer. A slicer is a program that first prepare the 3D model for printing. In the slicer program, you can:
- choose how thick the shell (walls of the object) or top and bottom is
- the layer height
- the scaling (bigger or smaller)
- rotation of the object
- put more than one object in one print job
- tweak the amount of filament that is extruded (not recommended unless you know what you are doing)
- tweak the the amount of filament that retracts when the hot end move across parts to reduce the chances of oozing
- select infill percentage
- select the printing speed
- select the speed of infill
- select the speed of first layer
- select the speed of travelling only
- create bream or rafts
- create supports

You can set the infill from 0% (hollow object) to 100% (solid object), or somewhere in between. This is 20% infill and you can see the slicer fills the inside with grids that gradually shifts left and right.

Then after, the slicer "slices" the model into tool paths based on the information you input about the printer (nozzle size, filament size, print bed size, available of heated bed etc). These tooth paths are instructions for the printer to print: move according to the coordinates to get the correct shape, to extrude filament, increase/decrease layer height, set speed etc. They are store in a G-code file with extension .gcode.

For Portabee, the G-code file will then be loaded into another program, Pronterface, the host, which connects and controls the printer via USB. You use Pronterface to:
- set the printing temperature
- set bed temperature
- initialise printing from the loaded G-code
- store G-code to SD card
- print G-code from SD card
- pause printing
- resume a paused printing job (not recommended, it often get misaligned after that)
- manually enter G-code
- visualise printing progress
- manual motor operation
- on/off motors

There are other 3D printers where the slicer and host is one single program and you set the temperature in the slicer program rather than the host.

Here is a video of Portabee printing a Companion Cube, note that the video is sped up and the original print time is around 21 minutes at 30mm/s. The Companion Cube is around 25mm on each side, printed at 0.3mm layer height using PLA with 20% infill.

0:00 - Clearing the nozzle before printing by extruding 20mm of filament.
0:06 - Printing started, the extruder moves left and right (X axis) on a support that moves up and down (Z axis) and the print bed moves front and back (Y axis).
0:10 - Printing of a skirt to visualise the print area and prime the nozzle.
0:15 - Printing the base of the object.
0:57 - Printing the diamond shaped infill pattern.
1:28 - Printing the side of the cube which the top is larger than the bottom.
2:03 - Bridging the infill pattern gap to form a solid top.
2:37 - Print ending.
2:42 - Removing the print object from print bed using a knife
2:51 - Inspecting the printed object.

Sample Prints

Here are some of the stuff I printed. They are pretty small, mostly fits in half a palm. They are all printed at a layer height of 0.2mm and they are all NOT designed by me unless otherwise stated. You can download the STL files for these items from Thingiverse. The dimensions are in LengthxWidthxHeight format.

A Mayan artifact scan from a museum. 54x34x40mm.

The Companion Cube from Portal. This is one of my favourite thing to print, not only it makes a good test to troubleshoot and debug the printer, my friends love them as well. This is printed from natural coloured PLA, which is translucent. You can see past the outer layers at some parts while it sort of sparkles beautifully under sunlight. 40x40x40mm.

Sphinx. 90x41x47mm.

The Legend of Zelda: Skyward Sword Goddess Chest. This is printed in six parts, the top, the bottom and four legs. Since the top and bottom are separate pieces, I am looking to attaching hinges to make it a real mini chest. I scaled it down by quite a lot from the original STL file. 66x48x54mm.

No 3D printing demonstration is complete without printing a working adjustable spanner right? Here you go. This print demonstrates that you can cut off your 3D objects in Netfabb if your print bed is not big enough, and that is why you see two join lines along the spanner. I think some people out there use such images to fool others into thinking that this was printed as a whole - it isn't. Ignoring the fact I cut the spanner into smaller pieces, there are six parts: The top of the body, bottom of the body, the top of the worm, bottom of the worm, top of the movable jaw and bottom of the movable jaw. They are assembled after printing with dowels (which are conveniently the 3mm filament) and super glue. 221x56x11mm.

A fully working minimalistic ocarina with four holes. Assembled from four printed pieces. The original version was meant to be laser cut on a piece of wood, I took the vectors and recreate it into a 3D object for print in Google SketchUp. Sadly, my musical skills only allow me to play a badly timed "Twinkle Twinkle Little Star". I also learnt from printing this that an ocarina is just a large whistle with many holes. 72x38x37mm.

Starry Starry Night lithophane. 88x74x2mm .

Octopus. You can see how low polygon count 3D models affect the printed object in this one, as some parts are getting blocky. This is printed with 0.1mm layer height and looks great. 103x103x29mm.

Product Evaluation

I have never owned a 3D printer before but had seen samples and demonstrations of other printers in live, that would make it difficult for me to evaluate the printer. However, I will try my best and evaluate whatever I could. A plus sign indicate a positive attribute while a minus sign indicates a negative one. I try to make one attribute as important as another by splitting an attribute of importance into many points or combining many minor attributes into one point.

Build Quality
+ Stainless steel bolts, nuts, washers and threaded rods, great for humid Singapore
+ Majority of the printed part works and last
+ You can print your own spare plastic parts
- A few parts are exceptionally problematic and require extensive self modification
- Smooth rod not stainless steel, rusted in a week or so
- Constructions does not seem sturdy enough

Remarks: The original z-coupler broke as I was assembling, although they supplied another version of the new coupler, the STL file are not available. The lock clips on the Y-axis broke three times simply due to the normal vibration and motor movement. You can replace them with cable ties but in that way you cannot remove the print bed easily for keeping.

Print Quality
+ Decent overall print quality, but not very good
- Slow print speed compare to other printers for the same quality
- The layers are not neat enough, you can see that the layers seemed to be randomly off by hundreds of microns from each other

Remarks: I feel that the layers are not neat because there is no stable structure supporting the axis of the printer. The Y-axis, being removable, feels shaky.

Portability
+ Y axis and print bed can be removed to compact the printer to be placed in a 14" laptop bag.
- Impractical as the lock clip for the print bed keeps breaking
- Impractical to print at client's premises or cafe as suggest on the website due to slow print speed
- Inconvenient as tools for troubleshooting and filaments are required which quickly add on weight

Remarks: Just treat the Portabee as a desktop printer.

Pricing
+ One of the cheapest for the set of features at the point of writing
+ No need to pay extra shipping if you live in Singapore

Remarks: Worth the dough.

Instructions for Kit Assembly
+ Excellent in clarity
+ Adequately illustrated
+ Good touch of humour
- Could have been more specific on some parts of the BOM like the values of resistor and thermistors used
- Could have included a printed copy in the box, not everyone knows how to print booklet from PDF pages

Remarks: Overall, excellent work on the instructions manuals.

Customer Service
+ Staffs have excellent knowledge and deliver great answers to queries
- Understaffed; I walk into the store many times with everyone busy, and I have no idea who do approach to seek help
- Understaffed; And when I finally got hold of someone to ask questions, that person is most likely to be busy and could not tend to you for long
- Replied email once, and staff stopped replying after that for many occasions

Remarks: I have a love-hate relationship with their customer service. On one hand, their staffs are really knowledgeable, they are able to answer questions down right to geek levels, which is totally cool. On the other hand, it is difficult to get their attention be it in store, on phone or through email. I walk in to the store with everyone so busy that I need to find someone and forcefully ask my questions while they are still working on their task. Over the phone, their staff sounded the similarly hasty. While they do answer emails, they tend to stop communication after their first replies, and I have to email their main address and every staff that I know of to desperately get reply again.

Others
+ They gave some spare thermistors, lock clips (which all broke eventually), endstop clips and z-couplers (in green instead of red)
+ Parts are nicely packed and well labelled, and the instant coffee is a great inclusion
- They included most of the tools needed but fail to include two 5.5mm spanners for M3 nuts which is used so frequently in assembly
- They should inform customers that the kit involve soldering, as almost everyone can tighten bolts but not everyone can solder
- Not enough guides on troubleshooting, yet does not have very good email services

Tips on Printing with Portabee

The Companion Cube
For beginners, try to print the Companion Cube as it is an easy and fast print good for troubleshooting and debugging. Try printing it small first (25x25x25mm) then move on to bigger sizes.

RTFM and follow it to a tee
Do not try to be a hero and assemble the Portabee like you would with Legos, not unless you are a certified engineer or have experience with building 3D printers. Read the instructions and follow step by step.

Print big for better results
Faults in printing like occasional bumps, random gaps or not perfectly aligned layers do not seem to grow in size with object size, so the bigger you print, the less obvious those faults are. You should also print bigger if you are getting messy parts because the details are too intricate to print. Try to print something as big or bigger than 40x40x40mm.

Do not expect perfect prints
It is difficult to get perfect prints with Portabee. There are bound to be some imperfections, no matter how small. Learn post processing skills like filing, sanding, heating, painting etc. to better the outlook of your printed objects.

Use raft only when needed
Unlike what the Portabee instruction says, I feel that you should skip printing raft unless you are printing unstable items, which you should not be trying that for beginners. If some base adhesion support is needed, use a bream (layers of skirt connecting to the first layer) instead of raft. Bream is easy to remove unlike raft, which will almost certainly scar the bottom of the print.

Always print skirts
If you are not using a bream, always print a skirt. A skirt will prime the nozzle and will also let you know if the printer has any obvious faults. Two to three layers of skirt is enough for one print. The first layer usually has intermittent filament deposits, but it should get better after that. If the skirt does not stick at all then most probably your nozzle is too far away from the print bed at origin point and you should re-calibrate the Z-axis endstop.

Go support-less
Support is a fibrous structure the printer prints to hold up parts. Try to print objects without the need of support. Support is needed if there are overhanging parts. Usually the printer can handle overhangs of more than 60 degrees without support. Like raft, supports usually scar the item and the Portabee seems to be very bad in handling support, with most support ending up too difficult to remove, especially for small items. Please let me know if there are any tips in using support with Portabee.

Good 3D models for printing usually do not need support. A sphere would need support to print, but you could also print two hemispheres and glue them together later on without support. Remember to turn them off when not needed, as using support for parts not touching the print bed might cause support to be printed among details making them near impossible to remove.

Portabee stops printing when switching on/off room lights and fans
This is a irritating issue. The printer might stop printing when your turn on or off lights, fans or some other electrical appliances in your room, although so far it seems to be just larger lights and fans. Pronterface will report that it has errors connecting to the printer and seemingly repeat the error message without disconnecting from the printer. You may not even be able to quit Pronterface and you must power off the printer before doing so.

OrangeKnob acknowledge this issue and stated that "the reason is the power EMI effects to USB chip". There are two ways to remedy, either by printing from SD card or making a shielded case for the PCB with the shield connected to the GND pad. I tried the former and it works, and yet to try the latter.

Printing from SD card
To print from SD card,
- insert microSD card into Portabee (mine was 2GB formatted in FAT32)
- power on Portabee
- connect the USB cable
- launch Pronterface
- connect to your printer with the correct COM port and baud rate of 25000
- click "Load File" to load in a G-code
- click "SD" and select "SD Upload"
- enter a file name for the G-code in 8.3 format*
- wait as the printer simulate printing (no actual printing done by printer) with the visualization shown in Pronterface (it is saving the file to SD card)
- wait till Pronterface reports that the file has been saved
- heat up your hot end and print bed as per your preferences
- press "SD" and select "SD Print"
- now the printer will start to print from SD card

* It seems that the printer only reads file ending with extension ".g". Thus the file name should have eight or less characters, follow by ".g". Examples: "12345678.g" or "my_print.g" or "cuboid.g" without quotes.

You can get temperature and progress feed from the printer even if it is printed from SD card. You can also interrupt the print as per normal.

When printing from SD card, the print continues even if Pronterface loses connection to the printer. If you have issues with the printer stopping when your switch on/off lights and fans in your room, when printing from SD card Pronterface will then tell you that it has problems connecting to the printer and self-disconnect after some time, with the printer still printing. The printer will maintain the set temperature even after disconnection. You will lose your temperature and progress feed from the printer.

Here are some things to take note when printing from SD card:
- You CANNOT unplug your USB cable, not even if Pronterface is disconnected from the printer and closed
- You CANNOT quit Pronterface unless it disconnects from the printer by itself

If you pull the USB connection or quit Pronterface before it disconnects itself from the printer, the printer will halt. It seems like there are some services running in the background even if the front end of Pronterface is closed.

Moisture in filament
This problem was puzzling me for quite some weeks. I bought two new spools of filaments from OrangeKnob's physical store and realised these filaments were not as well sealed as the one included in the kit and did not contain any desiccant. When I print right after I reach home, my objects had rough and uneven surfaces. Puffs of smoke, possibly steam, could be seen and sizzling sound could be heard. In the case of natural coloured filament, bubbles could be seen inside the molten noodle. I put the filament in an airtight container with silica gel and set up another container with just silica gel as a control. This is what I got after one week plus:

Spool of filament inside airtight container with silica gel.

On the left is the control box with only silica gel and on the right is the box with filament and silica gel. The small cap below contains fresh silica gel for reference.

The silica gel in the box with filament turned purple, indicating moisture in the filament. And it seems to have quite a lot of moisture from the looks of it. The print went fine after that, without seeing bubbles in the molten filament, steam puffing or hearing sizzling noise.

Sadly, the staff was unable to help me diagnose this problem immediately and took me quite a while to find out what actually went wrong. It was partly my fault as I was unwilling to carry the whole printer down to the store for diagnostic as I live quite far away and I do not own a car. When I presented the above images to OrangeKnob later on, they told me that they "...have noticed that and have informed our (their) supplier about this (that)".

Another work around is to cool down your printer to room temperature, heat it up again and purge your nozzle slowly, 20mm at 10mm/min, then immediately print after that. Purging the nozzle fast seems to introduce a lot of bubbles and splattering later on when printing.

Make a spool holder
A spool holder is more important than you think. Tangled filament and obstructed rotation of the spool will cause shifted layers or other positioning problems as the motor will have to combat with the tension from the spool and filament. Fortunately, you can make a spool holder cheap from PVC pipes. I used a meter of 15mm PVC pipes, six elbows and two tees to build mine and it costed around S$6 from a neighbourhood hardware store. You might want to invest in a PVC cutter, which cost around S$8, that allows you to cut PVC pipes cleanly, quickly and easily. PVC cement is optional as the joints are pretty tight. You will need to disassemble some parts to allow spool changing later on.

A spool holder.
I prefer the filament to be above the extruder and diameter of the pipe to be much smaller than the core of the spool. Do not worry that the spool will spin and jerk when the pipe holding it is much smaller than the core, as the spool will spin very slowly during printing, so it is beneficial to have less contact area for less friction. However, do take not that the smaller the pipe, the less mass it has and the less stable the entire structure it, the last thing you want is for the spool holder to fall onto your printer.

Tread-lock the set screws
The set screws that tighten the small gear to the extruder motor shaft and the z-couplers on the z-axis to their respective motor shafts tend to loosen quickly. Use a medium strength thread-locking fluid like Loctite to secure them. You may also want to put a dot on the gear or coupler and another on the motor shaft to ensure that they are tight during operation.

Flatness of print bed
Do not worry if you are unable to get perfect flatness of the print bed during assembly. What matter most is not the absolute flatness of the print bed, but the flatness in relation to the nozzle. You can check the flatness by first homing the axes, then move the X and Y axis to four corner spots on the print bed, then use a small strip of 80gsm office printing paper to feel how tight the paper is between the print bed and nozzle, like how you would to calibrate the Z-axis endstop.

Re-calibrate Z-axis endstop often
The Z-axis end stop tends to go upwards in my case due to vibration. You will need to calibrate the endstop position often as it determines the position of the nozzle at origin. When that position is off, the nozzle will either push the object too hard into the print bed or the first few layer will not adhere to the print bed.

Make sure no plastic is sticking out of the nozzle and you may heat the nozzle to print temperature before calibration. Home the axes and move the extruder in the X and Y axis only to four corners of the print bed. Use a small strip of 80gsm office paper and try to slip it underneath the nozzle, in between the nozzle and the print bed. You might need to stiffen the paper by making a slight 'U' bend and insert the bottom of the 'U' under the nozzle. If you cannot insert the paper, it is too tight and if you can slip in without effort, it is too loose. I find that the best tightness to be when you can slip in the paper, feel resistance when moving it around, and the nozzle will make creases on the paper as you do so.

To adjust just one side, hold one z-coupler and adjusting another. It is easier to stare at the nozzle as you rotate the coupler to know which direction turns it up and which turns it down, than to keep moving the paper to feel for resistance. To adjust both sides simply rotate both together at the same speed with your fingers. I generally bolt the print bed at all maximum height on the Y-ends and adjust the two Z-couplers only.

Do not leave a heated nozzle still at home point or where the nozzle is very close to the print bed for more than a minute as it might melt and crush through the Kapton tape.

Re-tighten belts often
The X-axis belt should not touch each other when you press down from the top. The Y-axis belt should feel more taut than the X-axis one even when extended all the way in front. The Y-axis belt seems to get loose faster, so check their tension regularly. They do not have to be very tight to perform well, as the printer can print well even with some looseness in the belt.

Pay attention to easily broken plastic parts
The most easily broken parts are:
- The Z-coupler
- The print bed and Y-axis lock clips
- Y-end
- Z-endstop-holder

The Z-coupler breaks at the part where the cylinder meets the hexagonal prism, my kit came with two spare pieces which are the improved version that is a full cylinder with rounded end. No STL file is released to print more of those.

The print bed and Y-axis lock clips break simply from vibration and normal usage. My kit came with three pairs and all broke into half in the center. You can replace the clips with two small cable ties, but that will mean that your print bed could not be removed and compacted to be stored.

The Y-end splits at the part where the bolt and nut are. Mine started splitting after several rounds of tightening the bolt to fasten the belt. You can use a bulldog clip to temporary secure the belt while you print a replacement.

The Z-endstop-holder also splits at the part where the bolt and nut are, probably because I adjust the Z-endstop position frequently.

Tightening the extruder idler block properly
The instruction is ambiguous about how much to tighten the four nuts on the extruder idler block. Although it mentioned tightening till the springs are half their original length, it seems like the springs can only compress till around half their original length. For me, with a filament fed inside, I finger tighten the four nuts till it becomes significantly difficult to continue and then further tighten a little more beyond that. the sprints should not be fully compressed.

Purge the nozzle before printing
Purge the nozzle every time before printing by extruding 20mm of filament at 30mm/min. This will help get rid of charred deposit inside the nozzle and you can check if the nozzle is blocked.

Checking for nozzle clog
A normal nozzle should extrude a smooth stream of hot filament. A clogged nozzle will extrude in a very curly manner and might have more than one stream. For guys, a clogged nozzle looks like pee splitting into two streams.

Visit Solidoodle's troubleshooting guide
Solidoodle's Troubleshooting Guide comes in handy as Portabee does not come with any similar guide. Hopefully with the documentations in this review and Solidoodle's guide, you will be able to troubleshoot on your own easily.

Troubleshooting Printing

Conclusion
I highly recommend the Portabee 3D printer for someone looking to challenge himself to build something satisfying and useful. You can even go a step further and replicate another Portabee by sourcing for the parts online. I do not recommend it if you are not good with DIY, never assembled your own PC, no experience with building remote control vehicles, cannot even handle Ikea assembly work or failed DnT in Secondary School.

The Portabee has the potential to be compact and portable, but the poor quality of the lock clips prevent it from doing so. The print quality is not great and print speed is slow, but still decent considering that it is one of the cheapest 3D printer kit around at the time of purchase. To add on, the store sells affordable filament locally.

It is a plus point to have the store located in Singapore for Singaporeans, and armed with highly knowledgeable staffs, but the difficulty to get help in store and answering emails half way make the purchase experience not as desirable as it should be.

Ultimately, it is pretty fun and eye-opening to assemble a 3D printer and do 3D printing. It seems that it will be a great help as a method of construction for my DIY hobby.

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