Single cylinder steam engine

thingiverse

This is a vertical single cylinder model steam engine translated from the plans posted at www.john-tom.com/MyPlans/SteamPlans3/GermanSingleVertical/BP-Dampf.pdf. Besides an assortment of M3 bolts, you'll want some basic machine tools to make this run. The piston rod, crank shaft, crank pin, and valve rod are included here for completeness but I'd really recommend cutting these from brass rod unless you have a mini-lathe to turn them accurately. Brass rod can be cut quite easily with the same sort of cutter that plumbers use to cut copper pipe. The parts here are all transcribed exactly from the plans with no tolerances added for printing. Cutting gaskets for the steam chest and cylinder heads is recommended. I don't know yet if piston rings or o-rings are a good idea. Mine is leaking past the piston a good bit so rings will probably be required. I've printed mine in pla with default .2mm settings for slic3r with the exception of bumping perimeters to 6 and setting "seam position" to random. This last setting in particular is helpful as each layer will be started from a different position so you don't get those vertical seams throwing all the holes off center. So far I can get about a half-turn with lung power but haven't been able to turn it over yet as I don't have a compressor. The crosshead turning guide is a sacrificial part to make it easier to sand/turn down the crosshead without rounding the edges and to make it easier to keep it round. Print the two parts of the turning guide and fit them to the crosshead to form one cylinder. Turn down the cylinder to fit, give it a polish and then remove and discard the two turning guide pieces. Eccentric rod - There are two versions of this. Use eccentric_rod_solid if you want to print the whole rod as one piece. Use eccentric_rod if you want to cut and thread your own brass rod. Cutting your own rod would let you adjust the rod length a little while fitting the engine. I don't think this is actually necessary, there seems to be enough room for adjustment of the crossbar on the valve rod. Brass rod set can be found at https://www.amazon.com/gp/product/B0748DCBHQ/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1. Metric drill bit set is available at https://www.amazon.com/gp/product/B071ZRMWBN/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1. Metric tap and die set can be purchased at https://www.amazon.com/gp/product/B0000DD4KV/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1. Metric reamer set is available at https://www.amazon.com/gp/product/B074M3WJC5/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1. Comically terrible expanding reamer set, theoretically usable for boring the cylinder to precisely 17mm, can be found at https://www.amazon.com/gp/product/B01CEJG0AS/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1. Here's a discussion and pictures of the source model Stehende Einzylinder - Dampfmaschine (I don't speak German but the pictures are helpful): http://modell-dampf-forum.info/wbb4/index.php?thread/6768-stehende-einzylinder-dampfmaschine/&pageNo=4.