I spent the summer building a 3D printer. I bought the kit off of Folgertech, although at the time their documentation incomplete for building. Also, I bought this kit with 2 other people here at work all within 6 months of each other and all had a different bill of materials. Challenge accepted!
Completed kit before custom improvements:
The kit is a standard delta type printer with the extrusion motor mounted to the side. Zprobing was done by a drop arm that worked pretty well. The power is run by a standard 350w power supply. Out of the box, the firmware on it’s arduino board is of the Marlin flavor. Default layer height is 0.3. The 3d printed parts like the extrusion corners were of a very poor quality and had to be drilled and sanded. I’ve read on forums they have overcome some of the quality issues now, however.
The first thing I did was to change the effector plate to rid myself of that Zprobe arm. I found the Snow Effector on thingiverse that hinges the effector plate so the nozzle becomes the zprobe. The Marlin firmware allows for zprobe offset but the servo that came with the kit did not create a consistent stop location for the zprobe. By removing all that, the offset is simply “0” which helps remove variables that come up in reducing layer height. 0.3 is too high and its stock configuration is unable to get much lower than that. The Snow Effector is great but needed to have some resistance. Any travel during print would mess it up. I gave it a return spring to keep it forced down. only a good bump will move it. The set screw gives a difficult to measure (somewehre around .1mm) travel to register with the zprobe.
After that, I created some fan shrouds and mounted some 40mm fans on the backs of the stepper motors to keep them cool during long prints. The initial configuration would start generating heat after a few hours, causing slipping which ruins the entire print. As layer height goes down, the time to print goes up. Since I wanted accuracy over speed I needed a longer run time.
THe extrusion corners that came with the printer were not good. They caused the printer to be ever so slightly uneven which is a real killer for accuracy. I replaced the corners with metal ones which required the whole thing rebuilt. This time I took a picture of the deconstructed mess.
After that I had removed most of the variables in construction that could mess up the print accuracy. The firmware is great, as you can modify the variables used in the delta calculations to fix the concave/convex issues. After getting a very level print surface I started slowly bringing the layer height down and printing things. Below is a little gallery of what I had the mind to take a photo of after printing.