Missing parts

Xmas holiday, family illnesses and some missing bits have kept this project on hold for a moment. I was about to assemble X and Z axises but the horrible quality of LM8UU put me off. I decided to order another batch of bearings from a different seller. Hopefully they will a bit better quality. I have been also waiting quite long some electrical supplies like heat protective sleeving and heat shrinking tube. Finally,  those arrived today and I will be able to solder some of the wires soon.

A4988 drivers and Vref adjustment

After verifying the LCD works I went forward with electronics. I placed the heat sinks on the A4988 drivers and plugged them on the RAMPS board. Based on the instructions and markings I placed them right way and started to think about Vref adjustment. This is for the motor current and I followed the instructions on the RepRapWiki. My drivers have Rs=100 Ohm and I wanted to start safe with 0.7A so I adjusted them to have Vref of 570mV.

A4988 drives with heat sinks

Marlin firmware

In order to get Arduino Mega clone and RAMPS board to function properly I need to install a firmware to Arduino. There are several choices but I decided to start with Marlin. It seems to be actively maintained and has good support.

I downloaded release version 1.0.2 and started to work with the configuration file. I did not modify too many settings at this point. I only selected correct motherboard settings and enabled LCD support. After uploading the firmware I disconnected Arduino and pressed the RAMPS board on it. I also hooked up the LCD screen cables and powered everything up. The LCD lit up and the menu was operational so I guess it works ok.

Electronics arrived

We had a postal strike here in Finland so not much happened for a while. But today I got some packages! My Arduino Mega clone, RAMPS and bunch of other stuff arrived.

I have an original Arduino UNO so the Arduino IDE was already familiar to me. I'll leave installation of the electronics for the weekend but I wanted to test the Mega board first. But it did not work straight away with OS X 10.9. The simple LED blinking code refused to upload to the board. The error was following:

avrdude: ser_open(): can't open device "COM1": No such file or directory ioctl("TIOCMGET"): Inappropriate ioctl for device

So after a couple searches I learnt I should install a new USB driver. The instructions and driver can be found here: http://kiguino.moos.io/2014/12/31/how-to-use-arduino-nano-mini-pro-with-CH340G-on-mac-osx-yosemite.html

After running the installer and reboot the Arduino IDE was able to upload the code and LED blinker works fine now.