Construction work has been spotty for the past few months due to some work commitments. Time to catch up on a few posts.
I received the prototype 3D printed inlet plenum, after a very long delay caused by Covid-19, a shipment lost in customs, reprinting a replacement, more shipping delays etc. This part was printed in ASA material by a vendor in Sweden. Quality is good apart from some areas where the wall thickness should have been greater.
The part fitted perfectly around / through the compressor, the air filter shroud mount etc. The inlet ramp was also good, perfectly horizontal and lined up with the opposite side (standard Showplanes fiberglass plenum) within 1mm, which is good enough for me. The front edge of the inlet ramp is too far forward, requiring me to trim too much of the cowling. While it would work, it doesn’t leave as much of the cowling inlet hole as I’d like, to get nutplates and some sort of overlapping seal in there. This is one of the areas where the wall thickness is also a bit low. Clearance on the bottom side to the cowling is good, a bit over 1/8″ at the closest point. The rear scat tube connection for a heat muff is also good.
Overall, close to a hole in one which I’m relieved about given how complex the part is. I can now proceed to finish the front of the baffles and around the governor. I’m going to need to address the wall thickness issue and trim back the front edge, which means re-printing the part. These are simple adjustments but I’m going to also look at whether any better alternatives exist than the ASA material I’ve used.
It’s really hard to see much from the pictures, because the 3D printed part is black, but they show the general idea.
