Using a low-cost 3D printer like CTC DIY I3 Pro B (Geeetech I3 Pro B clone) with M8 threaded rods as Z axis with loose or floating ends is what you get – and so also some wobble or banding on the X axis due slightly bent M8 threaded rods – they barely come straight. I hesitated to use lead screws due decrease of resolution (M8: 1 cycle = 1.25mm height, lead screw like TR8x8 (8mm dia, 4 starts, 2mm pitch, 8mm lead => 1 cycle = 8mm height) but otherwise gaining pretty straight lead.

Anyway, I searched Thingiverse for Z mounts for the CTC DIY and found a few, and adapted one design and made a remix Geeetech / CTC Prusa i3 DIY – Z Axis Bracket Remix with printable Bearing:

• changed structural holes (larger hole -> smaller holes)
• bearing hole widened to have more floating
• printable bearing added to restrict end (optional)

New Z bracket mounts (black), without/with printed bearing (white):

And I did a few tests:

Left to right (close-ups photos below):

1. original Z bracket (wood) apprx. 4mm play
2. new Z bracket without printed bearing, apprx. 10mm play
3. new Z bracket with printed bearings (with loose tolerance)
4. new Z bracket with printed bearings (tight tolerance)

Now comes the surprise, the best surface (best to worst):

1. no bearings / open floating: gives the smoothest surface, most straight Z edge
2. tight bearings: gives very good surface, slightly worse than with no bearings
3. loose bearings: noticeable artifacts / wobble, Z edge wobbly
4. original bracket: worst wobble of all, Z edge wobbly

Which means, either give it a lot of space so the upper end of the Z threaded rods can float, and thereby the X gantry can stay fixed (and not wobble) – or – fix the threaded rods and suppress wobble (there is still wobble but restricted).  Giving it some space on the top means the inherent wobble of the rod is distributed between top and X gantry – giving wobble artifacts on the print . . .

The issue isn’t simple: with or without fixation gives good results, some fixation gives more bad print results.

Open Ends / Floating

The new Z bracket provides more space for the threaded M8 rods than the original wooden bracket:

Printed Bearings

You may print two bearings (OD 22mm, ID 8mm), make sure to test inner diameter, so the threaded rod slides smoothly – if required use a 8mm drill to widen the inner hole.

Conclusion

Worst Z wobble was with original Z mount with ~4mm play or the loose bearing with apprx. 1-2mm play.

Best results I achieved with floating ends or with tight bearing – in other words, either leave it open or make it stay close, but worst is to give it a little play and threaded rods will show their unevenness on the prints.

I would also guess, the unevenness of the threaded rods and their position to each other also matters, e.g. whether left and right go the same way or cancel each other wobble out. What I noticed was, once I used the printable bearings for a print, and removed it, the threaded rods wobble already less – but as said, best results I achieved with no bearing and wide floating ends or with the tight bearings.

Recommendation: print the mounts, print the two bearings, and print the XYZ Calibration Cube or whatever reference item, and see yourself which option works better for you.

Addendum: M6 Z Axis Conversion

I made a small package Geeetech / CTC DIY I3 Pro B M6 Z Axis Conversion to use M6 threaded rods instead of M8. It made little difference:

• less wobble, but still wobble despite of “straight” M6 threaded rods
• wobble seems mostly introduced by the couplers (either printed or PVC pipe):
  • out of center alignment = wobble
  • tilted mounted rods = wobble

It is hard to mount the rods perfectly with the couplers, a little misalignment and one introduces wobble (X/Y wiggle).

Anyway, M6 gives slightly higher resolution in Z axis with 0.005mm per motor step.

Printing with different layer heights with the same nozzle diameter (e.g. 0.4mm) gives quite a range of printing quality and printing time – the higher the quality or lower the layer height the more printing time it takes, the 20mm height XYZ Calibration Cube as an example:

0.05mm layer height / 398 layers / 1.38 hrs

0.1mm lh / 200 layers / 0.73 hrs

0.2mm lh / 100 layers / 0.37 hrs

0.3mm lh / 66 layers / 0.25 hrs

0.32mm lh / 62 layers / 0.23 hrs

0.32mm layer height is 80% of the nozzle diameter, and supposed to be the maximum of layer height.

0.14mm – 0.39mm lh / 64 layers / 0.21 hrs

using the Adaptive Layer Height feature of Cura.

0.4mm lh / 50 layers / 0.18 hrs

obviously too high layer height with 0.4mm on a 0.4mm nozzle, some layers have gaps.

0.4mm w/ 0.6mm nozzle / 50 layers / 0.11 hrs

using 0.6mm nozzle on E3D Volcano clone – not quite tuned with under extrusion on the top (90% flow, with 100% flow the X/Y surfaces were terribly over extruded).

All printed with

• 60mm/s print @ 190C
• 80mm/s infill
• 150mm/s travel
• 1st layer: 20mm/s print @ 200C

on

• a heavily improved CTC DIY I3 Pro B (Geeetech DIY I3 Pro B clone) with
• Bowden setup and E3D V6 clone hotend,
• sliced with Cura 3.4,
• printed with white PLA-R (recycled PLA) by Fabru – it was a custom extrusion based on recycled white PLA, they usually sell only black recycled PLA as of 2018.

While reviewing all the samples, I noticed I could improve the Z banding issue, which still showed a bit – addressed in 3D Printing: Fixing Z Banding; done after all my layer tests.

Conclusion

Layer height 0.05mm and 0.1mm look very alike with this XYZ Calibration Cube – so it’s not really worth 0.05mm but 0.1mm would be sufficient. The Adaptive Layer Height turned out quite well, near the same speed as 0.32mm layer height.

The top surfaces of 0.05mm and 0.1mm are very nice, whereas 0.2mm already shows significant artifacts – best choice would be to print the last layer at 0.1mm layer height.

If one prints large volume, it’s worth to consider a larger nozzle, e.g. 0.6mm nozzle diameter, which outputs 2.25x more material already yet direct drive recommended – I struggled with complex prints with retractions with the Bowden setup.

I usually print at 0.2mm layer height, and if a larger piece is required I increase to 0.3mm – for the future I might switch the Adaptive Layer Height feature in Cura in that case.

The CTC DIY I3 Pro B, a Geeetech I3 Pro clone, is the very low-end of 3d printers – quality and pricewise, and uses a direct drive to feed the filament aka “MK8 Extruder”.  I ordered an E3D V6 clone with 0.2mm-0.4mm short nozzles with optional Volcano hotend for larger diameter nozzles (0.6mm – 1.0mm) from China, at EUR 9 price, as I wanted to

• print faster, above 100mm/s if possible
• print thicker or larger layer height to reduce print time for larger volume prints, e.g. 0.6mm – 1.0mm nozzles

and E3D V6 hotend seemed to be the remedy.

First I tried the Bowden setup, then printed an adapter so E3D V6 works with original extruder as well, e.g. direct drive is recommended when printing with flexible filament.

2-in-1 Fan Setup for E3D V6

I used the 2-in-1 fan duct: extruder and filament cooler for E3D V6, it’s low complexity and low mass makes it quite suitable, yet, since only one fan is used, it cools at the first layer already and likely reduce adhesion – not optimal but for now an acceptable compromise. The cooling otherwise is excellent, as good as my “duck beak” fan I had with original setup.

To secure the fan better, I used some rubbery-like glue (when dried) and put it on the end of the clamp of the fan adapter (let it dry first before using), to increase the grip on the hotend – as the fan once fell off while printing when it ran off failed printed filament which was cool and hard already – which would have caused quite a chain of dangerous events (hotend no longer cooled, melting the mounts, falling on the heatbed and heat whatever lies on the bed if the print(er) would have let be unattended).

E3D V6 Radial Fan Fang

After some time I switched to E3D V6 Radial Fan Fang, which uses 5015 radial fan, which turns on at 2nd layer – I used a remix which uses 40x40x10mm fan for the heatsink and replaces the small E3D V6 fan.

If you choose this, file the grip a bit so it attached smoother to the heatsink – my first print broke while attaching.

 

Quality of E3D V6 Clone

Before I go into the details, let me comment of the overall building quality of those E3D V6 clones: you get what you pay for, a compromise. My hotend leaked like crazy, at the junction of heatblock & nozzle, and heatblock & heatbreak – which is most annoying, and that did not happen with the original MK8 Extruder.

Remedy: I used teflon thread tape used to seal threads of the heatbreak, on both nozzle and heatbreak thread – this is really suboptimal. The teflon thread melted over time (not right away but after days/weeks), so I didn’t keep it.

Update 2: the real problem of leaking was the PTFE/teflon inliner, the end toward the nozzle wasn’t perpendicular sufficiently and likely a bit too short (by less than 1mm) and it was too narrow tube with 3mm OD instead of 4mm and be more tight – so the PLA leaked between the inliner and the threads of the heatbreak and nozzle – so the real remedy is to pay close attention of the length of the inliner (in case the E3D V6 clone comes without it as in my case), and give it 0.5mm to 1mm extend with a clean cut and preferably a conic end which presses then toward the nozzle.

Further, I had to use again a teflon inliner/tube – this wasn’t an all metal hotend, means, I am still limited with limited material choices, staying below 240C to preserve the teflon tube.

But on the upside, the quality of the extrusion was excellent, there was an significant improvement of print quality compared to the old “MK8 Extruder” setup, and I seemed to increase printing speed as I desired:

E3D V6 with Original Extruder

I used an adapter but altered it so it prints without support Simplified E3D V6 mount for CTC Prusa i3 Pro B with original extruder, fortunately it maintains the similar Z and Y distance to the bed as the original hotend, so there is little to change.

And the usual XYZ calibration cube at 60mm/s and 120mm/s:

Since I didn’t upgrade or customize my firmware yet, my thermistor likely reported wrong temperature, as the possibly new type wasn’t properly assigned in the firmware – and I had to reduce print temperature, too much stringing otherwise occured:

The tests reveals that stringing is mainly a problem of nozzle temperature, and much less of retraction length.

XYZ Calibration Cube

Left to right: 60mm/s, 120mm/s and 150mm/s:

Surprisingly it still performed quite well with 120mm/s and 150mm/s, although I doubt 150mm/s were really achieved at this small print.

E3D V6 MK 7 Extruder Settings

• Printing speed: 60mm/s – 150mm/s
• Infill speed: 100mm/s – 150mm/s
• Motion speed: 120mm/s – 150mm/s
• Retraction distance: 1.5mm

E3D V6 with Bowden Setup

With the Bowden setup one uses a teflon/PTFE tube to put the extruder motor stationary aside and push from there, reducing the moving mass on the X axis and so faster printing speed is possible – but as I found out, with faster printing speed more pressure in the hotend and if the hotend isn’t properly sealed, it will leak quickly.

The first run with Bowden setup, the extruder stepper motor not yet mounted but sitting aside:

With the direct drive I printed at 60mm/s as default, now printing at 80mm/s the XYZ Calibration Cube:

and the results are impressive, left 60mm/s, right 120mm/s:

The two E3D V6 bowden adapters I first printed and used required quite some change in Z height, bringing my Z stopper screw to its limits and also were off in the Y axis – so I designed a more suitable adapter with multiple mounting holes: CTC Prusa I3 Pro B E3D V6 Extruder Adapter V2.2 with a simple extruder motor mount at the top left-hand side of the XZ frame.

E3D V6 Bowden Settings

• Printing speed: 60mm/s – 150mm/s
• Infill speed: 100mm/s – 150mm/s
• Motion speed: 120mm/s – 150mm/s
• Retraction distance: 2.5mm – 4mm (really depends on the length of the Bowden tube)

Conclusion

Using E3D V6 with a low cost and low quality 3d printer:

Faster printing with improved overall print quality.

Aside of the leaking, which was fixed with teflon thread tape, the E3D V6 clone is a great addition to the CTC DIY I3 Pro B – true added value, but comes with more cumbersome handling with sealing threads when exchanging nozzles.

Btw, in this setup I still use M8 threaded rods in the Z axis, and you see no Z wobble artifacts, the linear threads for the Z axis are overrated – it works with simple M8 threads, if you let the couplers flexible enough, like with this “cheap” clear PVC tube, and not fasten the threads on the top, they have to stay floating.

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Updates

2018/03/26: Initial post with description, assembling and first test print.
2018/03/27: Board identified as “Anet A1284-Base-Control Board V1.0”. More details on adding a printer to Cura and included brief video of the first print.
2018/03/28: fan duct added, replaced broken extruder fan (see section “Fixes & Upgrades”)
2018/03/29: added white LED near nozzle, XYZ calibration cube fan vs fanless printing.
2018/03/30: added serial plate and label plate, calibrating X and Y axis properly.
2018/04/19: cables sorting
2018/04/23: printed X gantry/axis parts and replaced them
2018/04/25: refasten screws & cable binders of Y carriage

Introduction

Back in 2013 I’ve got pulled into 3D Printing and did some work on

• theoretical issues (2013) and
• software (coauthor of OpenJSCAD.org, 2013-2016)
• and briefly cooperated with a small 3d printer company, where I printed my first pieces as part of testing 3d printers

but I didn’t own a 3d printer myself until 2018/03/21 – roughly 5 years later – when I ordered an “DE A8 3D Printer DIY i3 Upgradest High Precision Reprap Prusa 3d Drucker” for EUR 99.00 (apprx. USD 120) shipment from and to Germany included – that is by far the most affordable 3d printer I ever saw (2018/03).

As the product image shows – it is hastly translated from english to german, and doesn’t make a very serious impression. After some research I realized it’s an CTC DIY Prusa i3 aka CTC DIY i3 Pro B (product link valid 2018/03/22) sold for USD 140, produced by Zhuhai CTC Electronic Ltd located at Zhuhai City, Guangdong, China – located at another peninsula west of Shenzen and Hong Kong. On further investigation I found out that the CTC DIY I3 Pro B is a clone of Geeetech DIY I3 Pro B, which is advertised as “Geeetech I3 pro is based on the Reprap open source project. Geeetech I3 is highly recommended for students and beginners who want to start journey in 3d printing technology.”

Technical Specifications

• Method: FDM (Fused Deposition Method)
• Volume: 200mm x 200mm x 180mm (X Y Z)
• Printing Resolution: 100um
• Layer Precision: 50-100um
• Filament Diameter: 1.75mm
• Material: PLA (platform 50-60C), ABS (platform 110C)
• Nozzle Diameter: 0.4mm
• Mechanical Positioning:
  • XY: 11um
  • Z: 25um
• Speed Positioning: 300mm/s, 100mm/s
• Recommended Nozzle Speed: 35-40mm/s
• Power: 220V / 80W
• Connectivity: USB & SD Card
• Product Size: 36cm x 38cm x 43cm
• Transport Package: 50cm x 42cm x 23cm, 9.13kg

(Numbers taken from the flyer 2018/03/24)

Unpacking

After 2 days, after ordering on Ebay.de, it arrived with DHL, a 9kg (20lbs) package.

The package is well composed, most parts are marked, some of the labels didn’t stick to the parts though. The controller board is orange with an ATMEGA 1284P in the center, with all connectors well labeled – it seems it’s loosely identified as “Anet A1284-Base-Control Board V1.0”. Gcode M115, which identifies the firmware, responds as

Marlin V1; Sprinter/grbl mashup for gen6 FIRMWARE_URL:https://github.com/ErikZalm/Marlin/ PROTOCOL_VERSION:1.0 MACHINE_TYPE:I3 Pro B EXTRUDER_COUNT:1 UUID:00000000-0000-0000-0000-000000000000

The shipped 3d printer does not match the photos in the Ebay posting, therefore the product link to the CTC manufacturer is also not correct. It turns out it’s either another version of the “CTC DIY I3 Pro B” or a remix of another line, the included manual states it’s a “CTC DIY Printer” by “Zhuhai CTC Electronic Co., Ltd”.

Here the main differences:

• LCD has 5 buttons – advertising shows a dialer with integrated push button
• controller board is orange with green power connectors, stepper motors drivers are soldered on (cannot be replaced) – advertising shows board with replaceable stepper motor drivers
• heating bed is aluminium with blue tape already on – advertising shows orange/red heating bed with a glass plate

The only things I thought was missing was

1. the small fan near the controller board, the screws and distance tubes were included (stepper motors drivers have passive coolers attached), perhaps they meant the fan attached to the extruder (which is included) . . .
2. on/off switch for the main power, a small hole (~4.8cm x ~2.6cm) is prepared, but none was included

The XZ frame comes with a small plate “CTC Y 3228”, which likely is the serial number of this frame/printer.

Assembling

The included manual (diy-manual) on the CD is cumbersome to read – so here the assembling procedure which worked for me and for my own future reference:

Mechanical Assembling

I realized to first assemble mechanically and then electrical (wires) is the best procedure; also re-fasten all screws of the preassembled pieces to ensure the stability.

Here as reference the 3 axis as mentioned further below:

1. use the two sheets/feets so the XZ frame stands upward, the larger ventilation grill comes to the right-hand side when looking to the front; use M3 with washer on the front, and the nut within the sheets/feet; don’t tighten it too much otherwise you will crush the wood.

   

   XZ Frame

   

   XZ Frame with two sheets attached

   
   
2. the right-hand middle screw at the XZ frame has to be flat without a washer this screw otherwise crashes later with the X axis moving up/down the Z axis.
3. add the two Z axis stepper motors, the one with the end stopper switch comes at the left-hand side, again M3 with washers and nuts.

   

   

   

   
   
4. add the X axis:
   1. the X axis stepper motor goes on the left-hand side
   2. insert the threaded rods, the flexible tubes looking downside (thread them from bottom to top) – a bit time consuming
   3. the X axis with the threaded rods push unto the flexible couplers on the stepper motors, at least 1cm or 1/2″ on the stepper motor, leave 0.5-1.0cm or 1/4″-1/2″ spacing between stepper motor shaft and threaded rods (I have seen others leaving little space, but larger distance worked for me so far)
   4. twist threaded rods so X axis is visually horizontal (fine tuning comes later)
   5. insert the smooth rods (no threads), the holes at the stepper motors require some filing (use the included grater), the smooth rods get pushed apprx. 5mm in
   6. insert the top ends which fixates the smooth rods but not the threaded rods (those have to stay floating)

      

      

      

      
      

      

      
      
5. add Y axis, since it’s mostly prepared already you just lay it into the XZ frame, with the stepper motor behind, two additional (unfastened) sheets to attach the Y axis with its larger threaded rods to the XZ frame

   

   

   

   
   
6. add printer head: take it apart (first the nozzle and then L shaped support), use prepared M3 to attach the L and then add the printer head (without nozzle) to it, and then add the nozzle again (screw it with the cable looking left-hand side, once fully screwed on they look on the left-hand side again).

   

   

   

   
   

   

   

   

   
   
7. add LCD screen on the top of the XZ frame
8. add power supply on the right-hand side (looking from the front), just three M3 (one corner of the power supply is in the air), the electrical connectors are looking downward

   

   

   

   
   
9. add controller board on the left-hand side

   

   

   
   

this finishes the mechanical assembling.

Electrical Assembling

Attaching all the cables to the controller board is easy since all connectors are labeled:

1. add main 12V power from the power supply to the controller board

   

   

   
   
2. attach the 2 long stepper motor cables (one end fits stepper motor, other connector to board – not interchangeable) to
   1. the right Z axis stepper motor (not moving)
   2. the extruder stepper motor (moving)
3. attach the shorter stepper motor cables to
   1. the left Z axis stepper motor (not moving)
   2. the X axis stepper motor (moving)
   3. the Y axis stepper motor (not moving)
4. attach the thermistors
   1. E/T: extruder thermistor
   2. B/T: bed thermistor
5. attach the stopper switches:
   1. S/X: stop X axis
   2. S/Y: stop Y axis
   3. S/Z: stop Z axis
6. attach extruder fan to “FAN2” on the controller (always on, but anoying but if you print larger pieces, the extrude fan must be running at first layer already)
7. attach heating bed power to “BED” (polarity doesn’t matter here)
8. attach extruder heating power

   

   
   
9. attach LCD display with marked “LCD” on the controller (one connector aside remains empty)
10. attach main power cable 110V / 220V to the power supply (don’t plug power yet): european standard: green/yellow = GROUND(3), blue = NEUTRAL(2), brown = LIVE(1)

before you bundle the cables, control all connections again – missing or mixing up just one connector can damage the 3d printer once powered on.

Make sure the correct voltage 110V or 220V is chosen at the power supply (default 220V).

As next bundle

• all wires from the print head, with the black plastic wire bundler, these wires move the most
• all wires from the heating bed (heating and thermistor) with zip ties, and slightly lift them up so they don’t lay on the Y axis frame near the bottom otherwise the zip ties will eventually hang themselves there and block Y movement
• bundle the other wires neatly with isolated wires or zip ties spiral cable wrappers (only one is included, so get 2m extra) – on a 2nd thought avoid zip ties as they tend to hang somewhere when on moving parts

Adjusting X axis Height

This part is crucial for the geometric accuracy of all your prints:

• use any kind of item with a certain length, a pencil, a stick, or a ruler – whatever, long and short enough to match the height of your X axis (moving up/down the Z axis)
• put the item on the bottom of the left Z axis stepper motor and adjust the height manually by twisting the Z axis manually until the item touches the X axis; you might have to adjust the right side as well to stay somewhat horizonally
• now move the item to the right side of the X axis, and measure the same distance and adjust the height of the right side
• now both sides have the same distance to the bottom (the stepper motors at the bottom) – which means, the X axis is now perfectly horizontal

As next make sure the Z axis stopper on the left-hand side near the bottom, that screw coming down on the X axis is fully extended: move the nuts up so the screws extends down and reaches the stopper early.

Adjusting Printing Bed aka Bed Leveling

When all is assembled mechanically and electrically, you turn on the machine; the LCD display should light up in blue with white letters.

Note: when the printer is powered on, the stepper motors become active and hold their position, you can’t or shouldn’t move the X or Y axis manually anymore, unless you choose in the menu “Prepare -> Disable Stepper Motors”

• choose “Prepare -> Auto Home”; and carefully watch the printing head moving left to X axis home, moving backward with Y axis to home and Z axis downward:
  • if the screw hitting the Z axis end stopper missed, push the stopper before with your fingers, you otherwise damage your printer
  • if the screw hits the stopper, good
• you likely have too much space between the nozzle and the printing bed
  1. adjust the screw hitting the stopper to minimize the distance of the nozzle to the end, hit “Prepare -> Auto Home” until the nozzle is within 0-3mm distance of the bed
  2. hit “Prepare -> Disable Stepper Motors”,
     1. adjust the bed with the manual fly nuts, put a piece of paper on the bed, and adjust distance so the nozzle barely touches the paper (left/front side of the bed), then
     2. move the printer head on the X axis manually to the right side, and adjust right/front side alike , then
     3. move the Y axis forward manually so you reach the end of bed (right/end side), adjust height, and
     4. move the printer head on the X axis so you reach (left/end side) and adjust the height as well,
     5. and repeat it once more to make sure the nozzle is 0.1mm distance from the bed (that’s the thickness of a piece of paper)

You have now adjusted the printing bed, you are ready to print now.

Installing Cura

The included Cura slicer and front-end on the CD (as in my case) is of version 14.07 (roughly 5 years old) and has no Linux version, as of 2018 I can’t even find a binary anymore for Linux – so I installed the latest on my Linux laptop; you download Cura-3.2.1.AppImage or something newer, once downloaded you execute it direct (it does no install) with right mouse click and “Execute”; under Windows or Mac it may install differently.

Once Cura started up:

1. add a new printer
   1. choose “Other” -> “Prusa i3 Mk2” as type
   2. name it “CTC DIY i3 Pro B” or something like this
   3. Printer Setting:
      • enter as printing volume: X = 200mm, Y = 200mm, Z = 180mm
      • select “Reprap” or “Marlin” as GCode flavor
      • select “[x] Heated Bed”
      • you don’t have to edit the Start or End Gcode
   4. Extruder Setting:
      • define the nozzle 0.4mm and filament 1.75mm diameter

        

        

        
        
2. open xyzCalibrationcube.stl (download .zip and unpack it)
3. it will slice right away once it appears on the virtual printing bed

First Test Print

Best choose PLA in Cura as a first test print, it’s easier to print.

• Connect the controller board with your computer with the USB cable.
• Go into the menu of LCD display (with 5 buttons, “up/down/left/right” and “select” at the center), and choose “Prepare -> Preheat -> Preheat PLA 1”, and wait 60 seconds, then

1. cut the filament so you get a sharp pointy end
2. push the filament into the printing head (the 2nd hole closer to you)
3. start the print of the “XYZ Calibration Cube” on your computer:
   1. choose triangle near right-side bottom of the CURA window, deselect “save to …” but change to “print to USB”
   2. then press that button
4. the printer will now start to heat the bed to 55C (takes longer) and the printer head (faster heating because it’s a smaller heating mass) to 210C
5. after 60-90 seconds when those temperatures are reached your print will start
   1. it first auto home (X=Y=Z= 0) and then will try to push out some PLA just to clear the nozzle, at your first print this might not happen right away, because the filament isn’t far enough through the nozzle yet
   2. it will try to print a circumference of the test print, wait and see if any PLA comes out of the nozzle, if you see the actual cube or test print you chose is about to be printed, and still no PLA comes out, try to push the filament into the printer head or abort the print and when the printer head is stopped, push the filament into the printer head (perhaps try to pull and push again to see where the filament is blocked)
   3. start the test print again, eventually the PLA comes out of the nozzle
      • if no PLA comes out, repeat 5.1
      • if PLA comes out, and attaches to the bed, you likely have a successful first print ahead
      • if PLA comes out and doesn’t attach to the bed but creates a mess, abort the print and check “Adjusting Printing Bed” again

In my case the bed was too close to the bed, so the test cube was too firmly attached to the tape that I ripped the tape off the bed when removing the test cube.

The very first test print worked extremely well, beyond my expectations – no Z wobble at all, some stringing at “X” and “Y” though.

Fixes & Upgrades

Filament Guide & Cleaner

• filament guide and cleaner:

  

  

  
  
• 2nd filament guide for holding the wires of the printer head

Extruder & Part Fan

I had attached the extruder fan to “FAN2” which is an always on 12V source (surely can be turned off), the fan ran for few minutes and died; I replaced it and attached it to “FAN1” which turns on after 2nd layer of printing which is sufficient and kept it there, as I printed once a large piece which caused the extruder heat up so much that filament got stuck – so it’s remained on “FAN2” (always on).

• 40mm fan duct for CTC Prusa (printed with “support” enabled) as part fan attached electrically to extruder fan which is connected to “FAN1” on the controller, which turns on at 2nd layer printing
• after the 40mm fan duct “part fan” attached the prints significantly improved, for example #3dbenchy I would have dared to print without fan, still a bit stringing but overall a very good print:

  

  Printing #3dbenchy (challenging)

  

  Finished #3dbenchy with some “stringing”

  

  Manually cleaned up #3dbenchy

  
  
• fan vs fanless printing side-by-side:

  

  

  

  
  

  

  
  

White LED

Adding white LED near the nozzle for better viewing, attached to “FAN2” on the controller board (always on), 1K resistor in series with LED on 12V.

 

Labels

I thought the printer lacks proper labels, also one of the reasons it’s sold in so many variants and you don’t know what kind of “CTC DIY I3” you get.

• label plate “CTC DIY I3 Pro B”  (just press “Generate STL” -> “Download”) or download STL
  Hint: your printer must be calibrated, even 1% margin will make the label not fit – best print 2-3 layers first, then abort print and measure hole-to-hole (centers), and then rescale piece (100%/your-length*157.5) in Cura so the distance of the holes fit 157.5mm distance finally – see next section “X & Y Axis Calibration”.
• serial plate “CTC A9999” and check Description, edit your serial number & press “Update”, then press “Generate STL” -> “Download”

  

  

  
  

X & Y Axis Calibration

When I printed the labels I realized my X and Y axis were off by 1.49% each, which made more than 2mm on 150mm distance (way too much); I printed out an “L shape” of 150mm length 10mm wide X and Y axis, and measured the length, apprx, 147.8mm. I went into the LCD menu “Control -> Motion -> XSteps/mm & YSteps/mm”:

Current settings:

• XSteps/mm: 78.74
• YSteps/mm: 78.74

and calculated 78.74 / 147.8 (measured) * 150 (should be) = 79.91

New settings:

• XSteps/mm: 79.91
• YSteps/mm: 79.91

I printed out the “L 150mm” again, and remeasured: 147.8mm – it made no difference, checking back the settings they were reset back to 78.74. So, I could edit it, but it had no effect whatsoever . . .

Using Repetier helped as I was able to manually send Gcode without actually printing anything and checking back with the LCD menu, and so reconfigured it to enter “M92 X79.91″ which was set as “XSteps/mm 79.9” when reading back in the LCD menu – when I printed with Repetier the L shape again I ended up with 149.5mm instead of 150mm, still a bit off.

I decided to stay for now with Cura – as I’m used to it right now – and after some additional test prints I ended up adding following “Start Code” in Cura at the bottom of the existing code:

M92 X80.27 ; change xsteps to 80.27 per mm
M92 Y80.27 ; change ysteps to 80.27 per mm

That finally worked, the L shape of 150mm ended up with 150.0mm (+/- 0.2mm) as measured with a ruler.

Even though I printed out the 20mm calibration cube, the 1% or 0.2mm I could hardly see with the simple ruler (right, require analog or digital caliper) – the Z axis seems fine but needs verification as well.

Update 2018/04/25

After a lot of tuning, I ended up with this single line

M92 X80 Y80 E96

which sets X & Y Steps per second as well the extrusion flow (instead using 105 steps as the default and reduce by 95% you define E96 and stay with 100% extrusion flow).

Cables

I used some more cable spirals to sort the cables better and give them some kind of stiffness while still being flexible, e.g. the Y axis cable I lifted up so it stays flexible and won’t catch on anything while moving:

What’s left to do it is a cover over the controller board.

Replacing X Gantry/Axis Parts

I finally dared to print the X gantry/axis parts as enclosed on the CD I received, and replaced the black parts:

I had to remove the XZ Frame flatter screw as it touched the X pulley on the right side slighly at the same Z height – and I didn’t want X position errors at that particular Z height. Also, the Z Stopper seemed now too far on the right, and the screw pushing on the stopper too far on the right, so I printed a 10mm wide 5mm height cylinder with 2.8mm hole inside, which I screwed on the bottom of the M3 Z Stopper screw which extends the area and now reliably pushes the X Stopper switch.

Loose Screws & Cablebinders: Y carriage

After roughly a month of usage, the printed started to make noises, more so the bed leveling was almost impossible to perform, after each print the level was misaligned and I wondered. Finally I removed the heatbed and retighten all screws and nuts and refastened the cable binders which held the linear bearings of the Y carriage.

That made a huge difference . . . I was finally to print again 60mm/s and most of the stringing went away due the higher speed; I even printed at 80mm/s at still acceptable quality. The entire printer sounded now differently, it mad an immense impact to retightend those screws, it did not just affect Y axis, but also the X axis – and the overall prints are cleaner, more precise and I’m able to print at higher speeds without loss but actual gain of printing quality.

Conclusion

This 3D Printer is the low cost hobbyist or entry-level “maker” approach to 3D printing – and even when you end up with a broken printer, the parts are worth it as you likely are unable to source the parts yourself for less than EUR 100 with shipment.

Expect to invest heavily in regards of time to educate yourself and fine-tune your printer and extend it so it becomes easy to use.

It is worth it – but what you order might not what you get . . . 

Notes

Material

• 1kg PLA “Sienoc” purple (2018/03): nice color, bed adhesion ok, printed at 200C, good flow
• 1kg PLA “Sienoc” black (2018/04): very good bed adhesion, fully opaque at 0.15mm layer already, very glossy, printed at 200C, very good flow
• 1kg PLA “Kaisertech” white (2018/04): adhesion ok, layers quite opaque (0.15mm partially transparent, 0.25mm already quite opaque), printed at 200C, flow not ideal
• 20 pieces/colors a 10m colored (incl. transparent, glowing, gold, silver) PLA of unknown brand (2018/04): 210-215C required, at 200C possible of non extruded filament (missing extruder steps) and therefore missing regions of material

Note: I will update this post with new discoveries and experiences, and see also additional blog posts with CTC DIY i3 Pro B tag.