Recent content by Kjetil

Topic removed :-X

I'm starting to feel confident on the scale so consider topic solved. I'm gonna start with the crank casing as it's really a frame for everything else, and also the biggest, most complex part. Thanks to Stew for showing how to do this in his build thread, which was very helpful when making a CAD...

Seems like I can expect the mean effective pressure to be in the ballpark of 1/4 valve chest pressure on these types of engines, judging by random observations. This means scale will have to be 2.5 to get targeted power, and this will give satisfactory results even down to a ratio of 1/6 so...

Looking at the Stuart Sirius (similar rpm but very different setup), claims span from 1/3HP to 0.4HP at 2800rpm / 80psi with 2 cylinders and 1” bore / 1” stroke. Reverse solving the 2PLAN formula for the Sirius’ ratio valve chest pressure to mean effective pressure yields 1 / 4.45 to 1 / 5.34...

Stirling would be cool, but suggest to me a 1HP+ Stirling engine suitable for a wood burning stove. I've seen Volo's project, but that is a work in development. Steam just seem much easier to realize. EDIT: When it comes to efficiency, I had an idea about an operating mode I might try, to...

I have to make the engine and the boiler a common module possible to detach, since the canoe must be transported upside down on a car roof, as a typical vertical fire tube boiler or a monotube boiler as I have in mind will both be a good bit higher than the canoe hull thus making upside-down...

Thanks. I'll probably not go your route with a flashy cylinder using inlays etc, just plain iron cylinders (and pistons) keeping it simple and solid, alu is i guess OK for cylinder cover where you don't have the thermal expansion concerns. But I'll go for external copper tubing like you did...

Guess I'll just go for 2:1 scale, doubling the drawing dimensions. It is such a compact nice little engine, and there is no harm in overdimensioning it a bit. Will it be OK to ask advice on this forum during build (regarding materials, etc), or should I try elsewhere?

I can assure that this is a 100% non-commercial hobby project. Since you question my motives; I plan to run a steam-electric canoe (cedar strip epoxy canoe actually, with a few reinforcements) with battery pack (12V-48V, >1000Wh) and outboard electric motor. I think the commercial value of such...

I guess it would act a bit different with steam as it expands, but take those numbers as a reasonable operating point (exercise), and make the assumption the piston mean pressure over the entire stroke is half the valve chest pressure (guesstimate), using the 2PLAN formula with metric units I...

I've already read your build thread, stunning work! I noticed the inlet/exhaust swap reverse, but I will have no use for it generating electricity. Nice feature thou.

Does anyone have any experience with the work this machine is able to produce? From simple computations I get about 200W-ish at 80psi and 3000RPM, but I don't even know if that's satisfying operation conditions. I am looking to build a bigger scale version of this engine, with a guesstimate of...

Contrary to most people here I'm not a machinist at all :P, I did however have SolidWorks training at engineering school (I'm in electronics) and the folks I work for (small company, close connections) runs a state of the art CNC workshop. Being such nice employers they are sometimes helpful...