Mini Fabrikator 3D Printer By Tiny Boy

[Balu]

I've been thinking about buying or building something "to make stuff" for years. It started with a 3D printer, then I thought a CNC mill would be nice - not long before I digressed towards just a plotter to draw plans on foamboard (because a mill would make too much noise and dust...). I even started to build a micro plotter of DVD-drive parts to play with steppers and gcode like jhitesma did, but I got a motor shield for the Arduino that was incompatible with all the gcode software...

Anyway - a while ago Hobbyking announced that they are going to sell the Mini Fabrikator 3D Printer by Tiny Boy a very small open design 3D printer designed to be easy to build so that kids can use it in schools. It has very small print area, but it should be fine for parts like mounts for motors, cameras, antennas or cases for flight controllers, etc... (I've already been asked to print figurines for board games ). Best of all - it is cheap: $179.77 from the international warehouse.

I still wasn't sure if I wanted to dive in head first, but after a few weeks the first reviews seem nice and since it got available in the European store I just ordered it together with some "ESUN 3D Printer Filament Grey 1.75mm PLA 0.5kg spool" - because that was the only 1.75mm PLA available in the European warehouse...

In this thread I'll try to collect additional information (therefore the two reserved posts) on this 3D printer and the journey of an absolute newbie (me) into the world of 3D printing.

Reasons for buying:

• First reviews are pretty good even though it has some drawbacks (just as you'd expect from HobbyKing... :-/)
• Open design (CC-BY-SA) - community will (and already does) invent upgrades
• Marlin based, therefore compatible with commonly used software on Windows, OSX and Linux
• Portable(!)
• Fully assembled, but looks simple enough to be taken apart and be put together again
• Beginner friendly(?)

Specs:

• Size: 15cm(W) x 15cm(D) x 22cm(H) (excl. filament holder)
• Print size: 80mm x 80mm x 80mm (actually a few mm smaller because of the design - more later)
• Filament: 1.75mm PLA
• Board: mega2560 ramps1.4 with 4 A4988 stepstick (clone?)
  • can control two extruders(?)
  • allows upgrade with SD card reader and display
• Power supply: External 12V 6A Transformer
• Suggested software: Repetier-Host
• Minimum layer-Height: 0,1mm (?)
• Bowden extruder
• Hotend: E3Dv6 clone (?), 0.4mm outlet

Ressources:

• Original design files and info: http://github.com/HKCOTA/TinyBoy
• Original Website: http://www.tinyboy.net/
• Original Community: http://www.tinyboy.org/
• Hobbyking Website: http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=80713
• Hobbyking Daily Video: https://www.youtube.com/watch?v=R6Ej88hYdYU
• Thread on RCGroups: http://www.rcgroups.com/forums/showthread.php?t=2469638
• Very good review: https://www.youtube.com/watch?v=Owja1jn0LL0

Hobbyking videos:

• Set-Up Video: http://youtu.be/JodDOfOiqEQ
• Bed Leveling: http://youtu.be/v1aLddsEQu0
• Printing Guide: http://youtu.be/EIGfol2M1sI
• Filament Jams: http://youtu.be/5EAQzrFKiwM
• Print Adhesion: http://youtu.be/k86xRBMekLw
• Loading Filament: http://youtu.be/GsDW5xS5Mag
• Changing Filament: http://youtu.be/jTtxXcuKEy8
• Unusual Noises: http://youtu.be/DxfpRcR8FvI

http://www.thingiverse.com/thing:957550

 

[Balu]

This page intentionally left blank.

 

[Balu]

This page intentionally left blank!

 

[jhitesma]

Look forward to seeing how this goes!

 

[Spastickitten]

Same here.

 

[Balu]

I'm still waiting for the delivery, but I've read through the RCGroups thread to collect some information for now. The initial setup of the printer doesn't seem to complicated, but the first thing I'll have to do is to check and adjust the current for the X, Y and Z stepper motors.

Hobbyking manufacturing doesn't seem to care about that, so people are reporting their steppers are getting way too hot and are missing steps. That's not only bad for the steppers in the long run, but it also got hot enough that parts of the acrylic case got deformed for some people.

To adjust the current, you need a multimeter that can measure mV and a small philips screwdriver.

Steps to adjust the current:

• measure the voltage between the metal housing of the USB socket and philips head part of X,Y and Z trim pots
• note each value (probably around 0.85V which results in 1.05A going through the stepper, 0.75A should be enough)
• to lower the voltage, the pots need to be turned clockwise about 45° until it's between 0.5 and 0.6V (0.6V is suggested)

I'll update this with some pictures and more details as soon as I get my printer...

 

[Basscor]

Subbed! I have an old printrbot+ from their kickstarter, looking forward to see how this one compares

 

[ZoomNBoom]

$180 is unbelievable. The E3DV6 hotend alone costs $75! (and is worth it)
There are a few things I dont really understand, like why they make it in a closed case when it doesnt print ABS anyway, and why it needs to have such a tiny print area; a bit longer rods and belts surely wouldnt make much difference in price, but tons in usability. Not related to the product itself, but I also fail to see why every kid needs a 3D printer at school?

Anyway, if you can live with the small print volume, for that price and apparent print quality, its a steal.

 

[Basscor]

I find a lot of the prints that I do would fit nicely in this tiny build plate. Granted you could only print them one at a time... For just getting started you don't want to be doing huge, long duration prints until you have the experience to get the parameters just so

 

[Balu]

$180 is unbelievable. The E3DV6 hotend alone costs $75! (and is worth it)

It's not the original, but seems to be a clone. At least that's what people report. The hole where the filament feeds through seems to be different. I'm not sure how to explain it here, but it seems to get narrow and then open up again, with some tubing inside(?). But that's something I'm not going to look into for now.

Copied from the RCgroups thread (original vs. HK clone):

T| |p p| |T        T| |p  p| |T        T = thread that goes into Heatsink
T| \   / |T        T| \    / |T        t = thread that goes into head block
T|  | |  |T        T|  |  |  |T        p = PTFE Bowden tube (goes all the way through the heatsink into the heatbreak)
T|  | |  |T        T|  |  |  |T        ? = Liner on the HK heatbreak?
T|  | |  |T        T|  /  \  |T
 |  | |  |          | |?  ?| |
t|  | |  |t        t| |?  ?| |t

But yes, even if I don't like it, I then have an extruder, small steppers and the electronics to build a different model myself.

There are a few things I dont really understand, like why they make it in a closed case when it doesnt print ABS anyway, and why it needs to have such a tiny print area; a bit longer rods and belts surely wouldnt make much difference in price, but tons in usability. Not related to the product itself, but I also fail to see why every kid needs a 3D printer at school.

Both sides are open, because the bed moves through those "windows". I'm guessing the closed front and back are there to have a more rigid case. But people are already removing the front too: https://www.thingiverse.com/thing:1006317

It prints ABS just fine btw - even without a heated bed:

The small footprint really is there to save some space I guess. In the school environment it was designed for, you don't have a lot of space on the kids' desks besides a PC and it's possible for the kids to take it home. Also a larger printing area wouldn't work anyway since you don't have the time for a big print in class. A printer for every kid allows all of them to work with the tools at the same time, not design something in parallel and then wait in line for it to be printed as our design students have to.

 

[Balu]

After waiting for a week for Hobbyking to pack my stuff, I contacted the customer service in a chat to ask about the whereabouts.

Looks like the European Warehouse didn't have the PLA I ordered (the only roll that was in stock at that time), so it just put my order "on hold" until it received a new shipping. My order status still said everything was fine and "IN STOCK" even though it wasn't. I hate when that happens, because I could just order it from the international warehouse instead which quite often is faster than waiting for the warehouses to stock up.

I don't understand why HobbyKing has no way of contacting the customer when something like that happens. Even though the service via chat was nice and the agent was able to cancel the item (because I couldn't since it was still "in stock"), I'm quite disappointed with that.

Long story short, I'm still waiting and have to find a different source for PLA. Any suggestions for a reliable brand?

 

[Corbarrad]

After waiting for a week for Hobbyking to pack my stuff, I contacted the customer service in a chat to ask about the whereabouts.

Looks like the European Warehouse didn't have the PLA I ordered (the only roll that was in stock at that time), so it just put my order "on hold" until it received a new shipping. My order status still said everything was fine and "IN STOCK" even though it wasn't. I hate when that happens, because I could just order it from the international warehouse instead which quite often is faster than waiting for the warehouses to stock up.

I don't understand why HobbyKing has no way of contacting the customer when something like that happens. Even though the service via chat was nice and the agent was able to cancel the item (because I couldn't since it was still "in stock"), I'm quite disappointed with that.

Long story short, I'm still waiting and have to find a different source for PLA. Any suggestions for a reliable brand?

I was hoping to get a hands-on review from you before sprining on one of these when shopping for my birthday unfortunately the b-day's come and gone and by now they're out of stock in the EU warehouse anyway.

I did have a look around for PLA filament, though and it seems the stuff's mainstream enough that big retailers like conrad and pollin are carrying the stuff at reasonable prices.

 

[Balu]

Happy belated birthday .

Yeah, I probably got the last one from the European Warehouse. I wanted to have a transparent one first, but since orange was the only one in stock - listed with "1 available", I ordered that. The European Warehouse somehow seems always understocked with everything... :-/

Yes, PLA is quite available, but the quality seems to differ quite a bit. The ESUN filament is listed with a uniform diameter tolerance of 0.05mm. In German stores I've found some PLA with 0.1mm which seems to make a difference. People told me to look out for that, because it will affect the print quality.

 

[Corbarrad]

Happy belated birthday .

Thank you.

Yeah, I probably got the last one from the European Warehouse. I wanted to have a transparent one first, but since orange was the only one in stock - listed with "1 available", I ordered that. The European Warehouse somehow seems always understocked with everything... :-/

Yes, PLA is quite available, but the quality seems to differ quite a bit. The ESUN filament is listed with a uniform diameter tolerance of 0.05mm. In German stores I've found some PLA with 0.1mm which seems to make a difference. People told me to look out for that, because it will affect the print quality.

I hadn't heard of that, but it kinda makes sense. The force needed to feed the filament will porbably vary if the diameter of your filament is not uniform.
The amount extruded will fluctuate even if the extruder stepper runs at a constant speed because the filament between the drive and the nozzle will act as a spring so I assume bowden type extruders will be more affected by that.

The question, of course is will that really be noticeable during the setup phase of your printer where misprints, failed adhesion and so on will probably be the order of the day? Will it affect the structural integrity of your pieces or only the esthetics?

Wish I had an answer to that. Maybe I should have not only frequented the "builders" part of the reprap forum, but also the "users" section...

Speaking of that, a while ago, when I still had delusions of designing and building my own repstrap I went and joinded the reprap.org irc channel and everybody there was very helpful and willing to share their knowledge. Unless that's where you got your info on filament why not visit there?

 

[Basscor]

So the main thing the diameter variance in the filament causes is over or under extrusion depending on the average used. The more consistent the diameter the better the flow, and then the prints. If it is off a lot it will show up as weird blobs or voids in parts of the layers. You might also see inconsistency in the fill.

I usually err on the smaller side of the filament average, as it tends workout better to over extrude than under in this type of printer. This all more of a fine tuning parameter tho, and you just have to be in the ballpark to get decent prints.

 

[Balu]

Stepper motors current

So, I finally got mine today and started to check a few things before my first prints. First thing was to test the motor currents calibration.

Hobbyking sent some units out where the motor currents had not been calibrated and were so high, that the small steppers got extremely hot. That is not good for the acrylic case and of course not good for the lifetime of the steppers too. The TinyBoy website noted somewhere that the steppers they used require about 0.5A. The uncalibrated HK electronics sent about 1 A to 1.5 A through those poor buggers.

The RepRap wiki has info on the MKS_Base motor driver that shows how to measure and calculate this. You need a multimeter that can measure milivolts. The following picture shows the location of the pots and the USB casing which can be used for ground. You need to have the printer connected to 12 V for this.

I = V_REF / (8 × RS) where RS = 0.1

or

I x 8 x RS = V_REF

That formula says that if I want to have about 0.5 A, I need 0.5 x 8 x 0.1 = 0.4 V at those pots. I measured 0.6 V, 0.55 V and 0.6 V for the X, Y and Z steppers. This would result in currents of 0.75 A, 0.68 A and 0.75 A. Higher than I expected, but not nearly as high as the uncalibrated ones. They might have used different stepper motors than the original ones, so I left it unchanged for now. I'll check the temperatures of the motors after a longer run to see if I need to turn those numbers down a little.

The extruder motor E0 is set to 0.87 V / 0.7 A. It is a bigger stepper, so I think that's ok for now too.

 

[Balu]

X axis idler pulley

Next step was to look at the idler pulley for the X-axis (the bed). It has a small acrylic disc on top to guide the belt. There should be an M3 spacer between the acrylic on the bottom, the bearing and the small disc. Hobbyking sent some of the printers without those spacers which stops the bearing from rotating freely.

Mine has both though, so I'm fine. You need to check this bearing:

 

[Balu]

Problems

Problems I've experienced so far:

The Y travel is not 80 mm, you can hear the stepper skip over a few steps at around 70mm, because the carriage is blocked from moving further. I thought that it was the fan and had to remove a zip tie holding the wires for the fan and the hot end to be able to rotate it. That helped a little, but it's still not moving the advertised 80mm.

I've changed the settings in the software to "simulate" a smaller bed for now, so it doesn't always crash into the front panel. Some day I might do something about it - for example by cutting a window into the acrylic. But it looks like the carriage itself needs some modifications too.


Some elkos on my board look like they got pinched with a needle. Perhaps the pick and place machine drove into those or something. It's working for now, but... I might contact Hobbyking support and ask for a replacement board.




The suggested Repetier-Host software version for Macs is way behind the Windows version. Mac: 0.56 vs. Windows: 1.5.6. I was able to connect to the printer with it, but I had problems finding all the settings I was supposed to make. It also didn't include Cura as a slicing engine. My solution was to switch to a virtual Windows machine and run the newer version of the software. I'm probably going to replace it by a Raspberry Pi with OctoPi / OctoPrint soon anyway.

 

[Balu]

First print:

After calibrating the Z home position I tried my first prints - some feet for the TinyBoy case, so the electronics in the bottom get more air flow.

Note to myself: Delete the default printer and filament settings, so you don't use the wrong ones, but the ones you've created. Because the first print - the bad one on the right - was printed with some of those defaults that are clearly not for the Tiny Boy . It also came loose from the bed because I still had to move the home position for the hot end further down.



The second print on the left already was better, but it didn't fit on the case. I'm not sure if the file I got was for thinner acrylic plates or perhaps it shrunk a little, but the print itself looked nice.

I've used the pretty expensive "Makerbot Premium PLA - Pure White, 1.75mm" for now. Main reasons: availability and best test reviews. Layer height was the less fine, but faster 0.2 mm.

 

[ZoomNBoom]

Not bad for a first print. Looks like it may be extruding a bit too much. This video explains well how to calibrate the extrusion:
https://youtu.be/YUPfBJz3I6Y?list=PLDJMid0lOOYnRCAdbFfzECor3EbqF8euw

It also may be running a bit too hot. Also, when printing a small object like that with very little material per layer (especially at the end), it helps to print several instances at once so that the plastic has time to cool down.