One of the compelling reasons for buying a Reprap Mondo was the potential for printing aircraft molds and parts.   Keeping with this goal, the Reprap Mondo was used to print the nose cone shown below in white ABS.  Its basic geometry is based on my senior design aircraft’s nose.  Recently I obtained access to an Ultimaker via the Entrepreneurship Initiative’s Garage.  Using the Ultimaker an elliptical nose cone was printed in black PLA.

Printed Nose Cones

Printed Nose Cones

The white nose cone pictured has been sanded and polished while the black cone is raw off the printer.  Overall the surface finish was similar between the two pieces.  Both did suffer from surface defects including an instance on both prints when their respective printers stopped extruding for a moment causing a large defect.  The white ABS cone did have the advantage that most of its defects were positive allowing them to be sanded while the black PLA cone has regular pit defects.  This is attributed to the ultimaker switching from the outer shell to the inner surface at such high speed.

Since the quality of the finished parts is rather close, the biggest difference between them is the time it took to print.  While the Mondo spent 6 hours printing the ABS piece, the Ultimaker only took 1.5 hours.  The comparison is not the best since the objects are distinctly different, but the conclusion stands that the Ultimaker is much much faster than the Mondo.

The difference in the materials is not particularly apparent in the final products.  Both parts are rigid, easy to sand, and fairly indestructible.  Since the parts are intended for use as molds, the strength to weight consideration is not present as it would be in flyable parts.  The important difference during this experiment was the ease of printing.  To prevent the ABS cone from warping it needed a heated bed, a heat gun, and super glue to ensure that it stayed on the platform.  The PLA cone needed none of this and printed just fine.

The one advantage that the Mondo has over the Ultimaker is its larger print volume.  However, the difficulties of printing in ABS have precluding actually using that greater volume.  Based on this, further work shall focus on the use of PLA as the material of choice.