Tarantula++obo ou prusa i3 tarantula like

Courroie en Z supprimée et remplacée par 2 moteurs et tige filetée

Tests d impression avec double extruder

Tarantula++ obo

So here is my new printer, largely inspired from the basic principles of Tarantula and also Prusa.
In fact I redesigned/redraw almost all printed parts. Only I reused the Bed from Tarantula, it works so well :)

Main changes are :

• 40x20 frame everywhere
• printed bracket corner very rigid and making alignment easier
• Rails for each axes (MGN12 from Hiwin)
• Motors 400 Steps/turn
• Dual extruder, dual hotend
• Horizontal Y belt with only two pulleys
• Z dual motors with leadscrew
• Electronic 32 bits MKS SBASE 

It's also on facebook https://www.facebook.com/groups/TEVO.3dprinter.owners/1242687839158521/

and on thingiverse:  http://www.thingiverse.com/thing:1983256

Tarantula++ obo

1er impression bicouleurs

Premier test d impression bicouleurs

Tarantula++

Bien avancé ma nouvelle imprimante 3d inspirée de la fameuse Tarantula. L objectif  est double tête et haute précision  (moteur 0.9degres/pas) électronique 32 bits . La courroie du Z à finalement été remplacée par de 2 moteurs et des tigestes filetées. 

Raspberry lcd

To configure this LCD on raspberry:
http://www.raspberrypiwiki.com/index.php/3.5_inch_TFT_LCD_Touch_Screen_SKU:363295


Start from a Raspbian jessie

Edit /boot/config.txt and add:

start_x=1
gpu_mem=128
core_freq=250
sdram_freq=400
over_voltage=0
dtparam=spi=on
dtoverlay=waveshare35a
dtoverlay=ads7846,cs=1,penirq=17,penirq_pull=2,speed=1000000,keep_vref_on=1,swapxy=1,pmax=255,xohms=60,xmin=200,xmax=3900,ymin=200,
dtparam=i2c_arm=on
dtoverlay=w1-gpio-pullup,gpiopin=4,extpullup=1

copy  waveshare35a-overlay.dtb   to /boot/overlays/waveshare35a.dtbo 
voir https://github.com/swkim01/waveshare-dtoverlays/blob/master/waveshare35a-overlay.dtb

get the package xinput-calibrator:
wget http://www.raspberrypiwiki.com/download/images/xinput-calibrator.deb

sudo DISPLAY=:0.0 xinput_calibrator

copy the result conf lines to:  /usr/share/X11/xorg.conf.d/01-input.conf

add to  01-input.conf  before end of section:
        Option "InvertX" "true"

        Option "InvertY" "true"

run raspi-config and set  boot option to "Desktop Autologin"

cat /usr/share/X11/xorg.conf.d/>> 99-fbturbo.conf 
# This is a minimal sample config file, which can be copied to
# /etc/X11/xorg.conf in order to make the Xorg server pick up
# and load xf86-video-fbturbo driver installed in the system.
#
# When troubleshooting, check /var/log/Xorg.0.log for the debugging
# output and error messages.
#
# Run "man fbturbo" to get additional information about the extra
# configuration options for tuning the driver.

Section "Device"
Identifier "Allwinner A10/A13 FBDEV"
Driver "fbturbo"
Option "fbdev" "/dev/fb1"

Option "SwapbuffersWait" "true"
EndSection

Continuing the search for good print

So, I ws not happy with this horizontal banding and very small waves on sides. so I went through a systematic and  looooooong test processing,  changing parameters and  hardware configuration one by one.  Now I have got more than 30 samples....
There is a good test on thingiverse for that : http://www.thingiverse.com/thing:277394
Most  samples are printer at  70mm/sec minimum

To summarize all changes I did:

• marlin parameters tuning, especially "Accelerations" and "Jerk"
• bed and Heater temperature
• filament flow extrusion rate  (80-120%)
• extrusion speed, retract speed
• infill 0 or 25%
• infill overlap
• perimeter after infill
• two types of motor controller (DRV8825, A4988)
• 2, 8, 16 or 32 bits motor substepping
• install the print on dampers to avoid vibration resonnance from the table
• belt tensioning
• install motors on antivibration support
• print on various places on the bed
• reinstall bowden vertically inside a cable chain
• add some grease to Z axis
• check all screws
• reinforce bed structure
• check and reduce extruder filament compression

and finally:

• replace sliders with bronze bearing tube by new slider with linear bearing LM8LUU
• replace Z axis leadscrew TR8x8 by TR8x2 

See pictures below, the black one has been printer with a small compact printer (minifabrikator)