Grindingly slow, but the Victoria is coming together…

Shot from the front – a lot of “fitting” going on which is slow work.   There is a spacer behind the large bevel wheel on the crankshaft which needed thinning to ensure a good mesh between the two wheels,  got it right after two cuts,  but lots of ops to get it done,  on the lathe (setting up the backstop I used for turning the eccentric straps) and making a long handled 2mm allen key to get the screws in and out of the flywheel that secure the bevel wheel.

Having machined,  fitted, painted, woodworked and fitted,  I’m getting quickly towards the plumbing part.  Never ends this steam engine building.   I reckon my design changes to the basic Victoria have tripled the elapsed build time.

Nothing particular to remark on from this side,  I deliberately laid the engine out so everything was “happening” from the front,  as ultimately it’s a display piece.

I’ve tried running it a couple of times today,  but the timing keeps slipping,  so I’ve used Loctite in the offending places as advised by Stuart.   On the initial run a long while back,  I had flats on the shafts so the levers wouldn’t slip.  I’ve since remade the shafts,  without the flats and hence the slip.

Actually,  there is a comment – this side of the base has a Roman flute applied,  whereas the front is plain.  That’s me just fooling around with my router to see which looks best for the final version of the base.

Meyer Expansion Valve Arrangement – Lucky Find!

I’ve been spending some quiet time looking at Eric Whittle’s V8,  of which there is a wonderful video clip on Youtube:

http://www.youtube.com/watch?v=B-SNDErd1IM

I’d already built Nemett’s 15cc OHC engine before building Victoria,  and am planning to build another Internal Combustion engine.   I discovered that Mr. Whittle had published an earlier article in Volume 15 of Engineering in Miniature of a version of the “Cirrus”,   a 4 cylinder in line OHV aero engine,  upon which the V8 was based.   By good luck,  the large majority of the construction article is completed in volume 15,  but not quite,  as the article starts in Issue 2.

Having a look at issue 1,  there is an article under the non-descript heading of  “Odd Castings to a Finished Engine” by Don Unwin.   Mr. Unwin is clearly a master craftsman.    From his box of odd castings,  he describes the build of a horizontal engine,  complete with a working Meyer Expansion Valve.    This includes the manual adjustment of the valve.

He describes in the article that the cut-off is variable between 75% right down to 15% and he also confirms the timing arrangements.    The expansion valve eccentric he fixes at 180 degrees opposite the crankpin,  then the primary valve +/- 115 degrees depending on the direction of rotation required.

Mr Unwin also includes reference to a number of design references of the period:

Elements of Machine Design,  by WC Unwin (no relation!)  pub. 1883

Bailey’s Useful Inventions for Engineers pub. 1900

The article is not a cut by cut build,  but does provide a lot a detail around the Meyer arrangement.

Stuart Victoria – A Trial Fit of the Initial Components

Time is a precious and I’ve made some to move the build of my Victoria on a bit.

This is my Victoria in its first trial fit condition.    You will notice a number of differences to the standard Victoria build (and there are more to come).

The key differences are:

• The Steam Chest is configured to support the implementation of a Meyer Expansion valve arrangement;
• The Steam inlet is on the side of the upper part of the steam chest;
• The top of the steam chest is configured for the implementation of a “Shapely Lady” lubricator;
• The flywheel is being implemented to be “sub-grade”;
• Looking through te spokes of the flywheel the twin eccentrics can be seen;
• This configuration of the Victoria rules out the use of Stuart’s outboard bearing mount; and
• In the foreground are a pair of bevel gears which will drive the Stuart governor.

The modified bearing blck mounting is made by milling a piece of BMS flat to an “I” section,  then silver soldering a second piece of BMS to one end to create a base.   The top section of the “I” section is then tapped and drilled to take the bearing block.

Next task is to complete the valve drive from the eccentric.  Again this won’t be to the Stuart design – the plan is to use fishtail rods screwed into the eccentric straps and connected via a clevis at the valve end of things.   I think this will look pretty smart,  but importantly reduce the space needed to accomodate the two eccentrics.   Pictures to follow as soon as workshop time permits…