Sintron 3D Printer Kossel Mini Reprap review

**DO NOT BUY this printer **

• No assembly instructions are provided with the components
• The instructions are only provided when you email the seller
• The instructions provided are for a different kit that has many different components
• The instructions provided are incomplete
• Does not show how to mount the printing bed
• Does not detail the connections correctly
• Does not detail the process of setting up the firmware
• The photo shown on the Ebay listing is not a working printer - the top platform is not mounted with the tensioning screws and there are a lot more wires!
• The design of the "auto-levelling probe" is unworkable - again configuration is not detailed in the instructions, but the main problem is that is simply too flimsy and grabs in the slot provided.
• Some of the nuts on the extruder holder cannot fit due to misshaped parts.
• The tie-rod ends bind and cause the extruder to jump.
• The aluminium arms do not tighten firmly against the plastic unless some of the plastic is filed off.
• Several of the nuts & bolts bind and are defective. The screws are obviously cheap and don't fit common drivers well.  Not enough washers were supplied.
• My unit was supplied with a faulty PTC fuse for the heat bed.

I am very dissatisfied with this printer.  Getting to the point of testing the printer has taken weeks, far longer than it should have.  The screws holding the tie-rod ends are not a neat fit and the binding on the tie-rods at the outer reaches of the printer causes the print head to jump and jerk the whole machine. The heating of the heat-bed has caused the stepper motors to get very hot and distort the corner pieces - now the stepper motors are angled which is distorting the drive belt.

The printer parts seem to be assembled in China and the design is of poor quality.
What a piece of crap!

If you have bought this printer....:

Here is how I mounted the top corners so that you can tension the belts - take care to install the corner pieces the right way up (nut hole towards the bottom):

You will need to cut the belts (this isn't explained in the instructions).  I think this uses washers that were supposed to be used for mounting the heat bed... need to find some more for there.  

Try to mount the heat bed away from the stepper motors (i.e. somehow lift it ~10mm).

Measure the heights from the bottom corners to the tops - these should all be the same to indicate the aluminium poles are inserted all the way in the bottom pieces. This is required to ensure a flat base platform which is essential to get the printing started.

Download the latest (1.6) Arduino software from www.arduino.cc - the 1.0.5 version gave me unresolvable G++ errors on my Linux system.  Use the Arduino software to compile & upload the Marlin firmware over USB - you will need to correct a few code errors - adding spaces or commenting out some lines.

Install Printrun, which provides Pronterface which can be used to send G-codes to control the printer. When you have Printrun working execute some commands to put the head near the plate like:

G28 ; find the home position (top)

G1 X0 Y0 Z50 ; go to 50mm above the bed

 - then step down towards zero - you will need to modify MANUAL_Z_HOME_POS in Configuration.h firmware file to calibrate the correct height of your printer.  Carefully send the printer to various positions to check your platform is level.

Install Slic3r which can be used to "slice" a STL file into G-code.

Configure Exim on Debian Wheezy

apt-get install exim4

To support recent IOS devices you need to generate a 2048-bit SSL certificate.

Add TCP port 587 to the listening ports by editing /etc/default/exim4.

To support local account authentication for SMTP over SSL submission port 587 uncomment out the sslauthd section, ref: https://wiki.debian.org/Exim%C2%A0

Exim defaults to IPv6 before IPv4. To ensure you can send mail to Gmail accounts and other systems review Google's identification guidelines: https://support.google.com/mail/answer/81126?p=ipv6_authentication_error&rd=1#authentication

To disable IPv6:

nano /etc/exim4/exim4.conf.template

   disable_ipv6 = true

update-exim4.conf

/etc/init.d/exim4 restart

Alternatively, you can disable just IPv6 DNS by only using the IPv4 DNS:

    dns_ipv4_lookup = *

If receiving email from the Internet, greylisting is a fairly effective anti-spam technique. Install greylistd and adjust the RetryMin to 60 (to minimise delays) and use greylistd-setup-exim4 to change the netmask to 16 to minimize issues with mail from large organisations such as Google, Yahoo and ISP's who use multiple servers for sending.

To use SpamAssassin with Exim, the easiest way is to install exim4-daemon-heavy and spamassassin.  The daemon-heavy package is required because it provides the exiscan-acl feature which allows the data content to be scanned during receival. Copy the applicable block from here into exim4.conf.template: https://wiki.bitlair.nl/Pages/Projects/Mailserver_with_Debian,_Exim,_spamassassin,_greylistd,_DKIM,_SRS,_SPF,_DMARC,_forwarding,_LDAP,_dovecot,_LMTP,_disk_crypto#Exim_spamd_integration

If setting up a Backup MX, you will probably want to create a file containing a list of email addresses to accept mail for since they are not local users. Be aware there is a bug in the exim4.conf.template if you use CHECK_RCPT_LOCAL_ACL_FILE because update-exim.conf will insist you use a ACL name in the file, but that will cause the acl_check_rcpt to return an implicit deny, stopping all incoming emails since it no longer reaches the accept that is at the end of that ACL. Just add the deny line into the template near that section. E.g:

deny
 message That user is not in my list.
 !recipients = /etc/exim4/recipients_whitelist

Run your own DynDNS server on Debian Linux

This outline assumes you own your own domain and manage the DNS servers running Debian Wheezy or Jessie with:

• bind9 for DNS
• lighttp for webserver
• php5

apt-get install bind9

 - configure your zone.

apt-get install lighttp php5-cgi

Configure SSL:

 lighty-enable-mod ssl

 openssl ...

Configure authentication:

 lighty-enable-mod auth

 echo username:realm:`md5sum password | cut -b -32` >> /etc/lighttpd/.htpasswd/htdigest.user

Enable PHP:

 lighty-enable-mod fastcgi

 lighty-enable-mod fastcgi-php

Configure Virtual Hosting:

 lighty-enable-mod simple-vhost

 mkdir -p /srv/yourdomain.com/htdocs/update

Copy nsupdate.php from:

 https://github.com/chip-rosenthal/web-nsupdate

Modify the nsupdate.php:

 nsupdate -l

Allow www-data to read the session key to perform updates:

 chgrp www-data /var/run/named/session.key

 chmod g+r /var/run/named/session.key

Installing Horde on Debian Jessie

Starting with base system installed.
Install the Email server (MTA):
We need a working mail system, here we use sendmail with dovecot providing IMAP:
 apt-get install sendmail

Configure domain & SMTP settings:
 nano /etc/mail/local-host-names
   mydomain.com
 nano /etc/sendmail.mc
   MASQUERADE_DOMAIN(mydomain.com)
 make -C /etc/mail
 /etc/init.d/sendmail reload

Install an IMAP provider:
 apt-get install dovecot-imapd
Allow plaintext authentication temporarily (or configure TLS certificate?):
 nano /etc/mail/...
Test a local user authentication:
 telnet 143
 a login
 b select inbox

Install the web server:
 apt-get install apache2

Install the database server:
There are no instructions or guides explaining how to use sqlite, so we will use postgresql since it has fewer dependencies than mysql. We need to create a user and a blank database that will be used by Horde.
 apt-get install postgresql
  su - postgres
  psql
  ALTER USER horde PASSWORD 'new-password';
  CREATE horde
  \q
Test the new postgresql user:

psql -U horde -W 

Install Horde:
 apt-get install php-horde-webmail
 apt-get install php5-postgres
 webmail-install
 cd /etc/horde/imp
 cp backends.php backends.local.php
 nano backends.local.php
  (remove unnecessary lines)
  (change the imap 'secure' setting from 'tls' to 'no security')
 /etc/init.d/apache2 restart

Try to log in via web interface, using a local user account:
 http://server/horde/

Create an Administrator:
 ???
*Debian php-horde includes a script at /usr/share/php/data/horde/scripts/sql
that sets an Administrator user, but it's use is not documented.

Try to access the admin site:
 http://server/horde/admin/config

Enable SMTP
Set up the receive domain:
 nano /etc/mail/local-host-names
   mydomain.com

Set up the email address aliases:
 nano /etc/mail/aliases
  aliasname: username

Enable SMTP daemon to listen on all IP addresses:
 nano /etc/mail/sendmail.mc
   DAEMON_OPTIONS(`Family=inet,  Name=MTA-v4, Port=smtp, Addr=0.0.0.0')dnl

 /etc/init.d/sendmail restart

LXDE lxpolkit no session for pid

301 - This page has moved permanently to http://www.digitalfoundations.com.au/blog/lxde-lxpolkit-no-session-for-pid

CD-ROM won't mount, I/O error dev sr0 sector

Some CD's I have burnt myself do not mount in Sabayon Linux. dmesg shows the following errors:

end_request: I/O error, dev sr0, sector nnnnnnn

Buffer I/O error on device sr0, logical block nnnnnnn

 Specifying the type (iso9660) and uid & gid allows the CD's to mount:

sudo mount -t iso9660 /dev/sr0 /media/cd -o uid=`id -u`,gid=`id -g`

Not sure if this is a result of the media (Imation) or Linux/Windows burning - suspect it is the Gnome Disk Utility - Disk Image Writer.

Plymouth splash not correct in Sabayon

After a Sabayon 13 update in May 2015, new artwork is locked in the initrd file system.  Dracut builds of the initramfs kernal image file system are not used by the system.

To repair Plymouth functionality:

• Remove dracut
• Install updated gcc package
• Install genkernel-next
• Set the preferred theme in /etc/plymouth/plymouth.conf
• Backup the current initramfs file
• Run genkernel initramfs
• Reboot

xdg-su not decorated with theme

LXDE on OpenSuse 13.2 uses xdg-su ass the GUI frontend to run applications using sudo. If it can't load gnomesu or kdesu then it presents a bland undecorated xterm window. This can be neatened by simply installing libgnomesu which is small with only 1 dependancy (it doesn't need a full gnome desktop!).

Install Screengrab for screenshots on OpenSuse

LXDE doesn't have a default screenshot grabber. Here's how to install Screengrab from source on OpenSuse 13.2:

Download the source code from:

• http://screengrab.doomer.org/download/

Install dependencies to make the binaries:

• libqt4-devel
• gcc
• gcc-c++
• cmake

 Compile and install:

• cd ~/Downloads/Source/screengrab*
• mkdir build
• cd build
• cmake ../
• make
• sudo make install

The binaries are installed to /usr/local. 
A bug puts the libraries in the wrong location, we need to correct it:

• sudo mv /screengrab /usr/local/

The source package does not create a start menu shortcut, we need to create it manually:

•  leafpad ~/.local/share/applications/screengrab.desktop

[Desktop Entry]
Name=Screengrab
Comment=Capture screenshots
GenericName=Screengrab
Exec=screengrab
Icon=screengrab
Terminal=false
StartupNotify=true
Type=Application
Categories=Graphics;

Enjoy!

Remember screen brightness running Linux on MacBook

Running Sabayon Linux, with systemd, on a MacBook, the LCD backlight always resets to maximum brightness after reboot. This is an annoyance as it becomes necessary to adjust the brightness every time it is necessary to reboot the laptop.

To get the system to remember the brightness setting:

1. Create a script that can save or restore the setting when called with a parameter.
2. Create a (systemd) service that calls the script to save the setting on shutdown and restore the setting on startup.

Script: /usr/local/bin/my-settings.sh

#!/bin/sh
# Saves and restores settings for LCD and keyboard backlights.
if [ -z $1 ]; then
    echo "Usage: my-settings.sh [save|restore]"
fi
# Set variables:
export LCD_BRIGHTNESS="/sys/devices/virtual/backlight/apple_backlight/brightness"

# Save setting:
case $1 in
 "save")
    echo Saving settings...
    # if the settings folder does not exist, create it
    if [ ! -e /etc/my-settings ]; then
     mkdir /etc/my-settings
    fi
    # if the LCD_BRIGHTNESS file exists, then save a copy:
    if [ -e $LCD_BRIGHTNESS ]; then
     cat $LCD_BRIGHTNESS > /etc/my-settings/lcd
    fi
    ;;

 "restore")
    # if saved setting exists, if LCD_BRIGHTNESS exists, echo the contents into the system device:
    if [ -e /etc/my-settings/lcd ]; then
     if [ -e $LCD_BRIGHTNESS ]; then
      cat /etc/my-settings/lcd > $LCD_BRIGHTNESS
     fi
    fi
    ;;
esac

===============

Systemd service: /usr/lib/systemd/system/my-settings.service:

[Unit]
Description=Load/Save Keyboard & LCD backlight settings

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/bin/sh -c "/usr/local/bin/my-settings.sh restore"
ExecStop=/bin/sh -c "/usr/local/bin/my-settings.sh save"

[Install]
WantedBy=multi-user.target

================

Enable the script and service:

chmod +x /usr/local/bin/my-settings.sh
systemctl enable my-settings.service
systemctl start my-settings