User:Vincenticart

Vincent Icart RepRap Wiki

RepRap User: Vincent Icart
University	Penn State
Class of	Summer Internship 2014
Major	General Engineering, École Centrale de Marseille [1]

About

The purpose of my internship is to do research on open-source 3D printing. I was involved in a Fablab in my university back in France where we used an Ultimaker and CubeX Duo. I didn't have any hands on experience on Repraps before arriving here, so the first weeks were dedicated to understand and get confortable with the use of these machines. Then, I could start trying to fix the different machines in the lab along by working on anxiliary projects. Below are the main progresses on the printers.

Rainbow

Rainbow was close from working when I got here. Here is a list of the most important works done on the printer:

1. Equipped with the fan.
2. Reflashing the arduino as connection issues were experienced.
3. Calibration.
4. Squarring of the frame.
5. Removing and putting back on the extruder as it was clogged, and rewiring of the hot tip as a short kept triggering a "Max temperature" reached while printing.

The printer is now printing well, although the calibration part shows that best results could be acquired if the axis were squarred more accurately. Besides, on some specific areas, the infill doesn't reach the perimeters.

McDonalds

This printer required some work to get it back working.

1. There was a lot of slack for the carriage which could rotate a little around the Z axis. Actually, a all new carriage was printed. Also, the long arm was printed with a new version of the file. The new version is the same as the old one, except that the four or five last layers that made the middle of the part higher where cut. This allows a tighter assembly to the main part of the carriage around the rod. This way the slack issue was fixed. As the carriage was removed, this was also the occasion to add a heat exchanger on the carriage.
2. The bed was replaced by a polycarbonate one in order to prevent warpage issues. This allows better print results as first layers stick better to this kind of beds.
3. X and Z axes motor drivers were replaced.
4. Squarring of the frame and calibration of X axis (multiplication factor: 1.039).
5. The hot tip had to be undone and the rewired, in an attempt to tighten the end of the hot tip as there was a PLA leakage during prints.

3D printed boards

Dual Extrusion

The Dual extruder was close to working when I got here and dual calibration cubes had already printed a few times. T0 extruder had to be rewired, and both extruders are now working well. However, the thermocouple boards should be handle with a lot of care as they seem to be very sensitive (especially T0) and tend to induce "Max temp." errors. New designs could be of good help in that matter as the carriage is very busy and one of the board is in the air.

After running some test, the correct setting for the X offset between the two nozzles is 59.5 mm: extruder 0 (right one) is set as the origin, and extruder 1 (left one) is set with the 59.5 mm X offset is Sclic3r. This could be implemented in the firmware, but it is interesting to have it set this way in Slic3r as it allows to display the two different part of the assembly seperated in Pronterface or Repetier. Below are two parts that display the correct first results of dual extruding.

Below are the STL files for those two designs taken from Thingiverse:

Part	Description	File Link
Testcube1	Colour 1	Media:testcube1.stl
Testcube2	Colour 2	Media:testcube2.stl
Testcube Amf	Assembly	Media:testcube.amf

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