3D Printer, MegaPrinter


I saw Aki’s post, and decided to post about a project of mine and of Juha Koljonen, although many other people were also involved.

Our University’s space technology hobby club, Castor, had been donated an aluminum extrusion frame, originally configured as a material dispenser in some lab at the university. Around 10 years ago, some previous Castor student members reconfigured it as a CNC milling machine, but the aluminum frame was seen as too flexible for this purpose. However, some titanium parts were more or less succesfully milled back then.

3D printing was seen as a popular thing among the students, so the servoaxis were reconfigured, a material pulling strength testing axis was configured as Z-axis for the printer, and Granite Devices Argon servo drives were installed in place of the original drives. Dynomotion’s kFlop and kAnalog control boards were acquired to handle the motion. The actual buildup of the printer was then realized as a student project in relatively short period of time in the Autumn 2015 and early 2016. The MegaPrinter is now available at the Castor’s clubroom for every member to use.

Parts acquired new:
Argon Servo Drives x2 (Thanks Granite Devices!)
small stepper motor controllers for extrusion and Z axis (M542H for Z, and some smaller one for extrusion axis, and power supplies for these)
Dynomotion KFlop and KAnalog motion control system (Thanks to department of Automation Science and Engineering at Tampere University of Technology)
Extruder, bed heating elements, bed glass, terminal blocks etc…
Thanks to the Student Union for the project sponsorship!

Recycled parts, found over the years from the university’s backyards:
Original X and Y axis: Lenze MDSKSRS056-23 and Lenze MDSKSR3036-23 (both with resolver feedback device)
Z-axis: Zwick Material Testing model 1435 frame, installed upside down.
Stepper motors for Z-axis: MAE HY200-2220-0210-AX08 Stepper Motor x2

Currently, the printer is configured to print 1.75 mm filaments with 0.8 mm nozzle and 0.5 mm layer thickness, resulting in a very speedy, although somewhat coarse prints. The positioning accuracy has been measured to be in the < 20 um range!

But now the best bit of the printer: Thanks to the roomy frame and the huge Z-axis, the printing area is 500 mm x 500 mm x 1000 mm! This makes the printer capable of very large prints, and ideal for fast prototyping.

I will add many pictures in the post.


Here we see the electronics board installed in place:

Making new stuff fit, and making sense of the relay schematics…

Starting from scratch turned out to be faster:

Installation of the Argon servo drives:

Typical first “print”:

Other pictures can be found on our website at

and there is a Twitch stream whenever the printer is printing something:


Just some more history of the device, a few more reasons why the original device was not so good for CNC machining; lead of the ball screws is 10 mm or more (not so good for machining but good for 3D-printing and faster positioning with light loads) and the spindle motor was a low power high speed spindle. Also the Lenze servos are not original for the linear axes, they are retrofitted later to replace small servo motors inside the axis enclosures.


Good corrections. I don’t know everything about the history of the device, but I think the current configuration will last a long time compared to the previous incarnations!


Nice printer! Maybe post some photos of the huge prints you made? :slight_smile:


I don’t actually have many pictures of the prints right now, but this is a good example:

This was one of the first demo prints, using a smaller nozzle. Printing time was around 6-7 hours at this point. These days, a similar print would be done in 4 hours or less.

The extrusion system has been updated since this print with a belt-driven system and the attachment system to the axises is also revised; but as in every project, it is always the first success that gives that lasting wow effect.


Small update on this project:

We have printed some very successful large prints this fall. The printer has also gotten a secondary extruder temperature monitoring system and a filament sensor. These will actuate the feed hold of the cnc control system, and also cut off power from the extruder if required.

Simtronix SinCos Encoder with Small Mige and SimuCube