Crossplane I4 by chrisklam

Last crawled date: 3 years ago

Part List:
1X Crankcase
1X Upper Crankcase
1X Crankshaft
4X Piston Head
4X Wrist Pin
4X Connecting Rod
4X Rod cap
8X Connecting Rod Pin
3X Bearing Cap
1X Crank Lever
4X Crankcase Stud
Notes:
-The pins may take several prints to get right, since they are all slight press fits. Print all pins fully solid, they can break easily if you get them stuck in a part and try and finagle it out.
-Print the crankshaft standing up. Yes that'll be a lot of support, but it'll print more accurately
-Print the upper crankcase upside down (mating face of the head touching buildplate). This will also generate a lot of support material, but the bearing surfaces for the crankshaft need to be accurate
-Print the connecting rod with the upper hole vertical on the buildplate. Print the rod cap and bearing cap in the same fashion
-Print the piston head with the top of the cylinder against the build plate
-The connecting rod pins are slightly tapered. Make sure the larger diameter end of the pin is against the buildplate
-The lower crankcase can be printed normally with no supports needed
-The connecting rods & rod caps may need some slight sanding/filing to fit into the crankshaft. They should rotate smoothly when put together
-The connecting rod should also rotate freely around the wrist pin
-The engine can only spin one clockwise. Otherwise the pistons will detach from the cylinder walls (not a big deal)
-Lubrication might be a good idea, but I have not tried it
-Printed with a layer height of 0.8mm (pins printed at 0.1mm)
-If everything is goes right, you can spin it up reaaaaally freakin' fast with an electric drill
Assembly Order & Instructions:
Piston Assembly:Print Piston heads, connecting rods, and wrist pinsLine up upper connecting rod hole with piston head hole. Insert and press in wrist pin
*Connecting rod & piston head should rotate smoothly
Crankshaft Assembly:Print the lower crankcase (named Crankcase.stl), bearing caps, and crankshaftPlace crankshaft onto the lower crankcase and line up the grooves on both the crankshaft and crankcasePress bearing caps onto the crankcase pinsCrankshaft should rotate smoothly
Connecting Rod Assembly:This part can be a bit trickyPrint connecting rod pinsSlide piston assembly onto crankshaftTurn the crankshaft as much as necessary and press in the connecting rod pins
*Repeat 4X
Upper Crankcase Assembly:Print upper crankcase and crankcase pinsPress crankcase pins half way into the lower crankcaseWith all four pistons attached to the crankshaft, slide the upper crankcase over the pistons, lining up the pistons with the cylinder walls. Pistons may need to be snapped into the cylinder wallPress upper crankcase onto lower crankcase pinsAttach crank lever onto the square hole of the crankshaftMake sure everything rotates smoothly, if not, go back and sand/file the necessary parts