Es lebt! - it's alive

The monster is alive!

Like Dr. Frankenstein while waking up his monster the first time we felt as the printer was connected the frist time to the power supply and the motors started to turn on command....

Working on the last saturday started with soldering the connectors, because all connections between motors and sensors must be done.

We used CV Connectors with 1/10th inch grid, just like the ones used at RC models. Matching connectors are on the RAMPS. So everything should fit.

The connectors are little pieces of platic, the contacs came on a long ribbon. So we need the soldering iron first.

The motors are connected with 4 contact, all the sensors used 2. Everything fine and clear.

Ramps with (nealry) all cables

Ok, wirklich ordentlich sieht es noch nicht aus, die Kabel müssen noch ein wenig besser verlegt werden, aber ehe alles befestigt wird, soll es erst mal funktionieren, denn die Verbindungen sind ja noch nicht getestet. Am linken Bildrand ist das Flachbandkabel zu sehen, an dem die X Achse und der Extruder hängen. Das Kabel wird kurz vor dem Ramps aufgetrennt und auch auf einzelne Stecker für alle daran angeschlossenen Komponenten gelötet.

everything connected - except the display

X carriage and extruder

While Torsten were soldering, i fixed the extruder. In the last two weeks i was searching for M4x20 screws with hex-head. I've seen everything in this dimensions, but not this head. These screws should keep the extruder in place on the carriage. Because the heads of the screws are unter the motor and fixed with wingnuts on the other side, there will be no other possibility to fix it with other heads.

By coincidence i came to a (real) hardware store (Eisenwarenladen in german) where i got the screws! I was really happy about that.
With this we can also connect the fan which should cool the print and the printhead to save the X carriage / extruder.

Install the firmware

As we were ready with the hardware, we started to configure the software. We decided to use the Repetier Firmware. Mainly because we liked the matching GUI to control it. With the GUI, Repetier Host we can do everything to print objects: place them on the printbed, do the slicing, make printer configuration and send them all to the printer. You can also send commands by hand (via G-Code or predefined) to send the axis to the home or set the temperatures. It also shows the complete status of the printer like current temperatures.

Before the firmware can be send to the printer, there are a lot of adjustments to do because every printer is different. The main part can be configured on the homepage of the repetier firmware, after this is done the whole firmware or only the configuration can be downloaded.
Some points can't be configured there, e.g. the heated bed. Therefore you must edit the configuration.h file by hand. If anybody is interested in our config file i will be happy to send it by mail.

We have configured the software to use the EEPROM, with this many of the configuration settings are saved into a non volatile memory into the Arduino. if the EEPROM is not used it is necessary to edit the configuration.h, compile the firmware and install it every time you edit a setting. So the EEPROM make life easier.

i'm meltinnnnggg...... slightly out of focus

After the first installation the games could begin. First we need to check if the endswitches are working. Therefore we used the command M119. If you send this command to the printer it responds with the status of the endswitches. So we got Y_min, X_min and Z_max. The endswitches keep care that the motors stop spinning before anything gets damaged. Beneath of this, the endstops define fixed points into the printspace so they are used to calculate the current position of the hotend.
Directly after this check we set the whole thing on power.Now we can control the motors by software and let them run thru the printspace. Movement in Z axis was very slow, it was set to 2 mm per second to waiting while its moving the whole 300 mm was a pita. Later we speeded it up to 4mm / second.

The tests showed that a few motors are running into the wrong direction. The Z motors and the extruder motor. So we had to possibilities. First we could turn the connectors on the Ramps or second to set an entry into the firmware. We wanted all connectors to be in the same direction so we use the software way.

After some time playing with it, we tried to calibrate the printer. The dimensions were already saved into the firmware in a rough way. But there are some variables which must be tried on the printer.

Nophead has an excellent description how to do this onto his webside.

Fertig zum Druck

With done calibration we tried our first print. We gut a calibration model, sliced it and  send it to the printer.
Heated bed got heated, first try with 55°C, then the hotend (230°C). Filament is moving, the hotend rushes over the printbed, drawing lines onto the printbed. But there is not really plastics on the bed.... so for the next try we move the head about 2/10mm higher. Next try, fine blue lines on the printbed, looks good but we don't have adhesion and the whole extruded material is pulled away with the hotend.
So we made some tape on the printbed. This time the plastics stick on the bed, but we had a massive warping. Rising the temperature of the heated bed to 110°C helps, but it still warps.

So the first tries weren't successful. Its getting late and we decided to stop for this day.

No success but a lot of hope. The prints we could see are looking really nice. We only need some fine tuning to get the last glitches out. The 0.2mm layers are looking good, also the amount of filament and the temperature.

Mayor problem is the warping. Its a known problem when printing ABS. PLA would be easier but because we wanted to print a second printer we needed ABS.