Baldrick - A Two Cylinder Single-Acting Rotary Valve Engine

[PaulR]

Cheers chaps. Made the four holes for the air pipes this evening then modified the pipe bending former which didn't quite work for the 1/8" pipe to see if I could get a better result with the 4mm tube for this engine. While the sides of the groove in the former aren't upright enough just yet, I got some pretty good multi-directional bends on a very short test piece. Slight problem is that two of the pipes need to be small 'U' shapes which are too small for this former so I'll either have to make another one or perhaps make some elbows and forget the bending.

[PaulR]

Got the first pair of tubes made and soldered in place - had to make the bend quite gentle so as not to occlude the screws below (oops slight design flaw). Just the inlets to figure out and the end caps to Loctite in place then I can give it a blast and see if it works.

[vtsteam]

Looking good, Paul.  If a screw does get inadvertently covered, and you're using allen screws, you can always grind the arm of its wrench shorter to fit in the space. Never done that personally of course....   

[PaulR]

Looking good, Paul.  If a screw does get inadvertently covered, and you're using allen screws, you can always grind the arm of its wrench shorter to fit in the space. Never done that personally of course....   

I do that all the time anyway as the ends gradually get worn 

[PaulR]

Made a nice little inlet manifold to sit on top of the valve block but just couldn't make an accurate pair of copper tubes to hook it up, probably because each arm of the L-shaped 4mm dia tube was only about 8mm long. In the end I gave up and went for a pair of inlets but then found there was barely room to get the hose clips in place! No matter, I connected the compressor and found there was no sign of life at all. After about an hour the penny dropped - I'd completely forgotten to drill the longitudinal exhaust hole in the valve 

Once that was done I put it back together and could tell that it would go once a bit of binding here and there was overcome. After half an hour of turning by hand it finally took off, runs on very little pressure and makes a pretty good sound (I think it sounds like an old aero engine but no doubt vtsteam will tell me it sounds like some domestic appliance  ).

As you can see it was running without any nuts holding the con rods on and the crank pin needs sorting as the rods have a tendency to climb up it. Also need to clean up the solder and flux residue but I'm happier doing that now I know it's a runner 

I think the next project will be a different/improved version of this concept, using passages rather than exposed tubes to conduct the air and incorporating a single inlet etc

<a href="https://www.youtube.com/watch?v=VvXTj-BGKiU" target="_blank">http://www.youtube.com/watch?v=VvXTj-BGKiU</a>

[Sanjay F]

Fantastic Paul, you certainly got that from head, to paper, to build and finish in record time and she runs great .......can't keep up with you! 

Look forward to seeing the MkII variant 

[vtsteam]

Hey, great Paul!  You know I like your engines, and this one sounds like.... itself. 

[Kim]

That's a cute little guy!  And he runs too!  What more could you ask for  

Kim

[PaulR]

Thanks all, here's a slightly better view (fixed to a bit of scrap wood for now)

<a href="https://www.youtube.com/watch?v=ZUnnN13iAu4" target="_blank">http://www.youtube.com/watch?v=ZUnnN13iAu4</a>

[Michael S.]

Well done! Not everyone has an engine like that.

Regards, Michael

[PaulR]

Well done! Not everyone has an engine like that.

Regards, Michael

Cheers Michael (although I'm not sure everyone would want one either!!  )

[PaulR]

At the risk of boring people to death with another video, after a bit more running in I'm finding that this little engine is a great runner despite there still being a tiny bit of binding at one end of the stroke. It will run quite slowly and, being pretty much leak free as far as I can tell, it consumes very little air. Thinking how to make a more attractive version rather than this crude design.

<a href="https://www.youtube.com/watch?v=kEi00zwRmcU" target="_blank">http://www.youtube.com/watch?v=kEi00zwRmcU</a>

[Sanjay F]

Beauty is in the eye of the beholder as they always say! Your engine reminded me of this little Reeves Twin Oscillator I restored some time ago. I appreciate the mechanics are different, but wondered if the layout gave you some ideas?

[PaulR]

Beauty is in the eye of the beholder as they always say! Your engine reminded me of this little Reeves Twin Oscillator I restored some time ago. I appreciate the mechanics are different, but wondered if the layout gave you some ideas?

I just used small pieces of brass angle as it was an easy option  I really like that Reeves engine but I'm not a fan of the pipework over the top - lots of V arrangement wobblers have the same but it's hard to do it any other way in that case. I guess for powering a boat a connection at the top might also be convenient.