KosselClear

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Crystal Clear action run.png
Kossel Clear

Release status: Commercial (Kickstarter)

Kossel-ABS.JPG
Description
Delta robot 3D printer with extrusion frame.
License
to be defined.
Author
Contributors
Based-on
Categories
CAD Models
External Link


The Kossel Clear is a parametric delta robot 3D printer project funded through KickStarter in 2013 by Blue Eagle Labs, probably based on the Kossel printer. The printer has a relatively large printing envelope of 11" (diameter) and 11" height, which is smaller than the original Rostock delta printer but larger than the more recent Kossel. The design relies on aluminum beams, acrylic laser cut parts and printed parts.

Assembly guide and resources

A collection of videos has been made available by BlueEagle Labs. See [1] for a nice playlist.

  • Brackets
  • Rollers
  • Extrusions
  • Belts: to tighten them properly, use a guitar tuning application on your phone (gTune on Android) and tighten them to 80-110Hz.
  • Arms and Effector
  • Electronics
  • Extruder

Mechanical parts assembly

Extruder

  • Bowden tube pops up: you must use an M4 nut and thread the Bowden tube in it. See [2]
  • Some users have also had success modifying the extruder printed parts to accept a 4mm (OD of input) push fitting in a 5mm threaded hole along with an updated design to reduce skipping. Available both for the MK7 (original) and MK8 (higher torque) extruding gear here.

Electrical and Electronic parts assembly

Wiring Diagram

Go to this page: Instructions & Guides @BEL Homepage where you will find the wiring diagram. Direct link to PDF: Wiring Diagram.

Wiring the endstops for the X, Y, Z motors and the auto calibration probe

Wiring the 4 motors

The motors are driven by Polulu steppers. Their voltage usually needs to be adjusted. See here.

NOTE: the extruder motor's cable is plugged into the board in reverse orientation to the other 3 motors. Note carefully on the wiring diagram, how the red wire only for the extruder motor is not like the others.

While looking at the front of the printer, X = left axis, Y= right axis, Z = Back axis.

The LCD

1. Attach the square and triangular pieces with m3-10 screws. Make sure the triangular piece with the slot for the SD card is positioned to the left.

2. Mount them on the front of your printer, on the extrusions using M3-8 screws. Additional washers may be required to prevent the screws from bottoming out in the extrusions.

3. Screw the LCD to the faceplate. Spacers of some sort (not included) are recommended during this step to prevent the LCD assembly from being mounted warped or uneven. Spare nuts and washers have been used successfully, or any other type of spacer should do. Be aware that the length of spacers you choose will affect the SD card alignment with the gap in the left triangular part. Filing or grinding the SD card hole to enlarge it may be required for a completely flat LCD installation with SD access.

4. Attach the front plate with the LCD to the triangular pieces, and use m3-10 screws as well.

The thermistor probe and the extrusion head heater power wire

Wire the Hot end

Cable management

Software for the 3D Printer

The latest pre-packaged software can be found here: Software Download @BEL Homepage.

For now only windows package is supplied. Linux and Mac users can try finding the respective programs for their OS or just use a virtualbox virtual machine.

In the RAR archive file you will find:

  • the Marlin Arduino Firmware - you will have to install this into your arduino (aka flash it) using the video instructions in the main youtube video playlist. Its one of the end videos.
  • the Pronterface program ( for raw 3d printer head control and the printing itself)
  • the Kisslicer program - for STL files slicing

Here is how it works: 1. You install the Arduino program on your PC at the begining. It allows you to install the Marlin firmware onto the arduino. 2. You download an STL file from the internet 3. Using Kisslicer, you open the STL file, check your slicer settings and save a .gcode file 4. Using Pronterface, you open/load the .gcode file and print it

Repetier Firmware

An alternative is to use the repetier firmware in its Kossel Clear version. This version has been made for a modified KC with 1/32th micro-stepping by user Steffen from KC Google group. A "vanilla" version for the stock KC is available from GitHub here. Instructions to compile and install on Mac-OSX (Maverick) are available in this thread.

Usage after the printer is ready

(Auto) Calibration

See here: Auto Calibration Instructions @BEL Homepage.

A traditional calibration seems to bring the best results. See [3] and [4].

How to change filament rolls

1. heat up nozzle. (180 for PLA, 203 for ABS)

2. (optional) undo bowden tube from the hot end side.

3. undo the extruder.

4. pull out the old filament.

5. slide new filament into extruder, through bowden. If (optional) bowden undone: make sure there is extra filament sticking out of the hot end side of the bowden tube.

6. clamp down the extruder.

7. push the filament into the hoten. If (optional) bowden undone, push it all the way until the bowden tube inserts into the brass push to fit connector.

Mods

Autocalibration Probe Deployment Piece (APDP)

Print it

Modify your software to use it

  • You need to modify your calibration software routine ( g29 ) so that the printer head goes to the "autocalibration piece" to deploy the probe and after calibration is done, go there again to retract it. To do this, open the file KC_Software/KOSSEL CLEAR ABS/Marlin/Marlin_main.cpp from the software archive you downloaded from the BEL homepage. Open this file with a text editor and find the lines (around line 1070) :


      //deploy_z_probe();
...
      calibrate_print_surface(z_probe_offset[Z_AXIS] + (code_seen(axis_codes[Z_AXIS]) ? code_value() : 0.0));
      //retract_z_probe();
...
  • There, delete the "//" before "deploy_z_probe();" and "retract_z_probe();" , so that the two lines become uncommented. Save the file.
  • Then open the Arduino software and install the Marlin firmware again onto your arduino.
  • Then carefully watch how the calibration with G29 happens and be ready to manually flip the probe with one hand and press the arduino reset button with the other. This is while/if you have no actual probe deployer created/installed in place. This precaution should be taken, because if something goes wrong, the extruder end might crash into the bed, having no endstops probe to tell it to stop.

Fans

  • One fan to cool the extrusion head's top-part and 2 or 3 fans to cool the just printed layers on the bed. See this mod by Shane : Print head fans plus lights mod


Filament Spool Holder

Bowden restrictor - to not allow bowden getting torn out by one of the rollers

Bowden-restrictor.jpg

Sometimes after auto calibration the bowden gets strained and may pop-out some day off of the extruder head. To restrict the bowden from getting broken by the roller - just put a pencil on the roller and a clothespin. See picture.


The idea is to not allow the bowden tube to get torn by the roller in some occasions. Things to test: roll the roller to the top and watch if the pencil hits the frame. Also roll to the downside and watch for problems.



Troubleshooting

LCD becomes scrambled
This is caused by interference with a stepper motor. Move the LCD cable away from the motor or wrap the LCD cable in aluminum foil. If you are printing from an LCD, you can pull out the SD mid print, put it back in to refresh the LCD, then continue the print.

Auto level probe doesn't reach the bed
open Marlin_main.cpp find "destination[Z_AXIS] = -20;" and make it a more negative number.

Auto level probe misses a click
This is ok, sometimes the electrical connection is made before the mechanism in the switch makes a click noise.

Filament drooping on overhangs
Try printing with a cooling fan. Try this mod by Shane : Print head fans plus lights mod

Motors dont stop at top endstops and stutter very loudly there``` You have mis-wired your endstops. Additionally you may have the endstop and roller screw mis-aligned.

To fix the wiring - either try and double check against the Wiring Diagram ( found on the BEL website under instructions ) or do it via trial and error. NOTE: always change wiring plugs when all the system is powered OFF.

To fix the alignment - you can put 2 3mm nuts in between endstops and the acrylic part they are attached. Photo later.

Auto level probe is digging into tape on bed

Use the offset (aka Z ) parameter when doing auto-calibration - for example "G29 Z0.1" means that when you do auto calibration (G29 command ), you are telling the printer that the Z=0 level is 0.1 mm higher than normal. Begin experimenting with G29 Z10.0 or Z1.0 and then issuing g1 Z5.0 , then g1 z1.0 and on and on with little increments until you go to z=0 with g1 z0. For futher info see the block scheme at [http://www.blueeaglelabs.com/blogs/news/10017821-auto-calibration-instructions Auto Calibration Instructions @BEL homepage]

Links