Baldrick - A Two Cylinder Single-Acting Rotary Valve Engine

[PaulR]

Hopefully this will work out better than the eponymous character's plans... even though mine is only about half drawn so far!

Made a start on some of the basics yesterday and continued today. Chopped off and filed to length one of my last pieces of recycled suspension-file hangers for the base and faced two pieces of brass angle to length for the cylinder supports. Faced the cylinder blanks to length and bored them. Drilled pilot holes for fixing the cylinders to the angle, superglued them together then enlarged the holes. Separated one pair, made the clearance holes and threaded those in the cylinder. Made the cylinder end caps which are just a push fit for now, will fix later.

Facing the angle (there's something strangely satisfying about holding angle in a 3 jaw chuck!)


Parting off one of the end caps. Had some nasty squealing when I started but it disappeared after regrinding the tool


Gotta love superglue...


The parts so far. The angle will fit on top of the base, just arranged like this for a blurry photo!

[crueby]

Looks (and hopefully smells) a lot cleaner than he does too!   

[PaulR]

Today was just a case of marking out, drilling and threading holes. I've ordered some copper tube to connect things up, in the meantime I can start on the pistons and rods and try to figure out what to do in the middle bit!

[PaulR]

First piston and basic rod finished. Not very exciting to look at I'm afraid 

[PaulR]

Just a bit of progress today: made the second piston/rod and started on the end for the other. Still need to cut the clevis slot but I'll do the two together rather than set up the vertical slide twice. Might also do some rounding to make it look a little less brutalist!

[Michael S.]

Good progress. I'm very curious to see how it develops.

Michael

[PaulR]

I'm very curious to see how it develops.

Me too!! 

Today I finished the essential parts of the fiddly middly bits. Next will be the bearing/valve block although I've yet to decide exactly what that's going to look like 

[Sanjay F]

I like the design and build as you go methodology 

[PaulR]

I like the design and build as you go methodology 

Can be a bit scary but touch wood no major design flaws have materialised yet!

Today I made a flywheel and was about to make the connecting rods when I found I have no 1/4" square brass so went for round bar instead  Just need to mill the flats on the overlapping ends and they'll be done. I'm still waiting on the copper tube but as it's coming by Royal Mail it's probably delayed by them having to change horses on the mail coach and deal with our 18th century quality roads. Utter crap.

[PaulR]

Finished the connecting rods and made the shaft/valve. I milled part of the (longer) inlet slot in the vertical slide but finished it by file as it was chattering badly. I couldn't find a way to mount it for milling the narrower exhaust flat so I did that with two careful hacksaw cuts and some filing. Just need to drill the central exhaust hole and that's done. The copper tube finally turned up so now I need to tackle the last part, the bearing/valve block, which I still haven't quite decided on how to make.

[Roger B]

It's a cunning plan, does it involve a turnip?

Nice start 

[PaulR]

It's a cunning plan, does it involve a turnip?

Nice start 

I suppose I could put a blade on the flywheel and make it a turnip slicer? 

[PaulR]

After a weekend of mental faffing about, today I just picked up some bits of brass and made the bearing/valve block, soldering the two parts, threading holes for mounting and making the hole for the shaft/valve. Here it is loosely put together with temp screws etc. I just need to make the inlets and air tubes and some holes to solder them into and it'll just about be done.

[Sanjay F]

Great job Paul, looking forward to seeing her run 

[vtsteam]

Me, too.   

[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.

[Stan Stocker]

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 posh version?  Perhaps the next one should be called Percy?

[crueby]

Or a lot more posh? The oscillator from the Diesbar paddlewheeler...   

[Sanjay F]

Wow, that's a piece of kit and surely must be called Lord Melchett? 

[PaulR]

A posh version?  Perhaps the next one should be called Percy?

Or Queenie? 

[Jeff123]

Hi Paul, 
Just to say I really enjoyed this thread, kept me guessing, what's coming next.
Looking forward to your next build log and also you r name choice.
Baldrick I  liked, loved his poetry.

Boom, boom, boom.
Boom, boom , boom.

That's it can't remember the next line
Geoff

[PaulR]

Hi Paul, 
Just to say I really enjoyed this thread, kept me guessing, what's coming next.
Looking forward to your next build log and also you r name choice.
Baldrick I  liked, loved his poetry.

Boom, boom, boom.
Boom, boom , boom.

That's it can't remember the next line
Geoff

Cheers Geoff. Yeah I remember that poem but damned if I can remember any more of it either 

[Jasonb]

Well if you were thinking of a marine engine there are ones more closer to the original Baldrick, how about a Baucher outboard.

As for a name, I'd go with Wibble as it suits a wobbler. But then again you could run it from a" Flash" boiler

[vtsteam]

Love the outboard!

[PaulR]

That one could be shorty greasy spot spot (or maybe putt putt?). And with rust like that disc it could be Speckled Jim!