After watching the great success Stephan has been having using Model Plane Foam (MPF) for fuselages and canopies with his builds, I decided to give a similar product a try. After some research on other RC forums and discussion with Stephan, I decided to try Fli-Power Value XPS from RC Foam. I have been a customer of RC Foam for a very long time, purchasing my Depron and carbon fiber from them since I have been scratch building. Their shipping to Canada is quick and customer service excellent, so once I found out that this XPS foam was essentially Grade B MPF, I ordered a box.
XPS definitely has a "wavy" side and a smooth side compared to Depron or dollar store foam, you can see the difference in these side by side comparison photos.
By mistake, I actually put the "wavy" side out on the bottom portion of the fuselage, but with very little effort, it sanded up very smoothly. This is what the "wavy" side looks like after some sanding with 150 and 220 grit sandpaper.
The XPS foam is a bit lighter than Depron, compared to a previous prototype of the Mig-FA that I built, using the XPS for the fuselage and canopy saved about 6 grams in weight before assembly.
Cost wise there is also a big saving, the XPS foam shipped to my door in Canada is approx $0.65 USD per sq ft compared to $1.25 USD sq ft for Depron, but I think I will stick with Depron for those areas of builds I mention above because for strength, the extra cost is worth it to me.
What is a big winner for anyone building NAMC planes who want to do either a composite build using several different types of foam or using MPF/XPS exclusively is that Stephan has gone the extra mile to make the NAMC plans very user friendly for either option. When you buy the Mig-35 plans for example, you have the option of printing both tiled (on your home computer) or non-tiled (from a print shop) that will fit perfectly on the 24" x 48" sheets of XPS/MPF.
If you want to build the main areas of the plane like wings, stabilizers, control surfaces, and intakes/nacelles from Depron, you have the option of printing tiled or untiled plans for Depron, the main parts listed will fit on one 27" x 39" sheet of Depron. Then the other parts are on a second sheet laid out so that you can make the fuselage of MPF/XPS and the KF airfoils from this or dollar store type foam that we prefer. To my knowledge, no other park jet company goes to this extra effort to suit individual customer needs and we have already received very positive feedback for providing those options and will continue to do so as we can with future NAMC products. Stephan has really put a lot of thought and effort into the plans to make it not only easier for the builder, but to cut down on wasted foam, something we all can appreciate.
So for my use, this XPS/MPF foam is a real winner for use in plane parts where I don't need the extra strength and stiffness of Depron. Added to that the way Stephan has laid our our NAMC plans, one sheet of Depron only is needed to build my planes in future, the rest will be XPS and dollar store foam. Given the projects we are already "thinking" about here at NAMC, I will have lots of planes to build and test in the coming months ;).
Stay tuned to this website for more NAMC products as Stephan and Dave are busy in the NAMC "skunk works" designing new high performance park jets.