Generator exhaust extender ( model 88 spark arrestor pattern )

thingiverse

Wanting to add a metal muffler extension pipe to my Champion brand 3400W inverting generator, I removed the model 88 spark arrester cover (which is very common) to scan & draw a CAD drawing for an extension. The design was rather straightforward; it was the remaining casting with aluminum which was more challenging. The parts provided here are the mold pieces to be used in a sand-casting process. The two-part core is what provides the hollow portion of this part - you could opt to drill that part out instead of fussing with making a sand core. The part was cast using scrap aluminum and works beautifully when coupled with a 1" metal flexible exhaust pipe / hose.