Painting the engine

Now that it all fits together, the engine can't be painted without taking it apart again!
It is now split up into sub-assemblies ready to be painted.
I shall use WaxOyl for hidden parts and mating parts where a layer of paint might otherwise upset the spacing achieved without a thick layer of paint.
Silver barbecue paint will be used for surfaces likely to get hot (e.g. cylinders and nearby structures).
I thought yellow would be good for moving parts - I have been aware that there are heavy fast moving parts which could damage the unwary: yellow is a suitable warning colour?  If I have some left over I can use it for lining on the outside panels to provide extra visibility.
The rest will be dark green as before.
Copper and brass may be left untreated and available for polishing.
Parts to be treated will have to be rubbed down and washed (I am reminded of a children's story in which dirty pigs did not want to be washed, and responded to the idea of soap with "Oofy, Poofy, nope")
While re-assembling, steam sealing will take place - valve chest, cylinder ends, inlet and outlet pipe fittings + piston rings, and piston and pump rod glands.  Any parts which might come loose will need to be thread locked or punched into place.
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Wed 22nd May
Work in progress.
One side of the engine is painted and re-assembled - this time with piston rings, gland stuffing and "Steam Seal".  I was forgetting how much assembly I had achieved, and now have to repeat! I am so pleased that I had bought a hub puller and other useful tools to help with assembly and dis-assembly.
I wish I had used gloves when handling the Steam Seal; it is designed to withstand hot pressurised steam, and easily resists any attempt to remove it from hands using domestic hot water and soap/ detergent - I suppose I should be pleased that it performs.
I have also filed small slots in the  cylinder end covers so that I can insert a screwdriver to lever off these bits for future maintenance activities.

Picture of completed and painted engine is awaited!

The engine is assembled

Now that I have made everything fit together to form an engine I now have to dis-assemble it for painting/ rustproofing/ sealing.  There are no parts left over. As promised in the assembly instructions, it took a while to get the valve rods lined up with the bearing; I ended up having to make the circular piston mounting holes into slots to enable some sideways movement.  One piston was shimmed out from the central column with washers so that the valve rods were the correct distance apart.  The eccentrics are not yet in place as they need a hub puller to dis-assemble them - I am treating that as a one-off exercise.

 

 The hot parts will be silver, as I have some high temperature paint that colour.  I was thinking of  painting moving parts a distinctive colour - yellow perhaps?

Everything that can leak steam will need to be sealed.  Inaccessible surfaces will be coated to resist rust.  Glands will be sealed, piston rings are to be fitted.

I have procured some batteries as recommended.  I note that the batteries need to be kept charged to preserve their condition.

If there is a battery, then electric lights are an option - will try to find (or make) some that look as if they come from the right era, but will use LEDs for efficiency and safety. In the short term, some bicycle accessories may be pressed into service.

I have got to have a steam whistle!  According to 19th century legislation, one is not allowed to use a steam whistle so as to frighten animals (e.g. the horses of the Lord of the Manor)

I note that the battery box is watertight, as it was directly under a hole in the tarpaulin when it rained.  A hole will be needed,

Next steps:  fit the disk brakes; fit the controls; wire up the batteries.  That should keep me out of mischief for a while!

Progress

Thank you to all my contacts who were concerned about the absence of posts in this blog.  I have given priority to family matters, so the Lykamobile has been languishing with little attention.

The wild winter winds have played havoc with the tarpaulin, so I must either repair it with duct tape or replace it with something which is fit for purpose ( and more expensive!)

Although I must be well behind some of my more capable fellow builders, I feel that progress is being made.

 The first stage has been reached, with a trial fit of the main moving parts, without piston rings or gland packing.  Bearings were fitted without too much of a problem, once the plain bearings had been put in the freezer for a while.  I had the right tools to drill and tap the mountings for the updated water pump design. I was also reminded from a long time ago the advice that an undersize tapping drill makes the operation much more difficult.  I re-finished the steam ways through the valves, to reduce possible drag.  My biggest challenge was to enable the crank pins through the cross heads to be a good fit without movement but enabling a push fit by hand. 
I also had to avoid screwing the piston rod too far into the crosshead as the small end of the connecting rod wanted to be in the same place.

 The whole thing will need to be dis-assembled, cleaned and painted before putting it back together again, not forgetting to make everything tight and secure - loctite will be good on all but high temperature parts.
I think I shall press on with the next stage before taking anything apart; I really want to see how the 'modified Hackworth' valve gear works in practice.
Putting everything together is a bit like those metal puzzles sometimes found in party crackers.

 As another builder has commented, the engine is getting heavy.  I am using a block and tackle to help me.  I had my eye on some high temperature paint just at the time when Bunnings gave up and sold out to Homebase, so I have stockpiled some cut-price spray cans of paint for the cylinders and anything hot nearby which might need paint.  I was thinking of making a wooden cover for the hot bits, which should reduce heat loss and reduce the risk of getting burnt.  It might help with reducing condensation in the steam ways and cylinders - we don't want hydraulic lock in the cyclinders, although I have been assured that the slide valve to be used does help to minimise the effects.

The engine can be turned over by hand, but will be much easier when there is some steam pressure available.

As an aside, I have been thinking about moving the steam car when it is not 'alive'.  The obvious answer is a trailer, but a local supplier advises that there are too many people about who like the idea of driving off with someone else's trailer.  With that thought in mind, plus the lack of space for a trailer, it occurs to me that an A-Frame towbar would work and take up less space.  It works for motor homes towing small cars, so should work for a Lykamobile (with the chain removed, of course).  There only need be two fittings at each end of teh front axle.

Hackworth valve gear etc.

As the build notes for the engine mentioned the inherent inaccuracy of the 'modified Hackworth' valve gear, I thought it would be interesting to simulate the gear - here are the results.

This first clip shows how the motion works going forwards, as seen from the right hand side of the loco.  (I am using my own terms in the description, and I have made some assumptions about the dimensions of various parts).  The 'connecting rod' from the crank to the piston slide is shown in blue.  The video clip starts with the piston at bottom dead centre with the eccentric at top dead centre. As the eccentric goes round, it drives the motion with the 'eccentric rod' linked to the 'motion arm' .  The motion arm is attached to the 'reversing arm', which is as far back as it will go for the engine to go forwards.   The 'valve rod' is attached to the eccentric rod not far from the motion arm, so that the resulting movement at the valve slide is a combination of the vertical position of the eccentric (matching the crank position) and the movement resulting from the swing of the motion arm (out of phase with the crank).  The movement at the valve slide is such that when it is up, the piston will be forced up by steam from the slide valve; when the valve slide is down, the exhaust is open to let the steam out as the piston goes down.  In between, the steam expands to provide force for the engine.  

The next clip shows the engine in reverse, with the reversing arm as far forward as possible.

The graph shows:

- in mid blue, the position of the piston slide;

- in red, the valve slide positions when going forwards;

- in light green, the valve slide positions in 'neutral'; 

- in purple, the valve slide positions when reversing (look at the chart from right to left).

The horizontal lines show possible positions for inlet and exhaust port positions - the exact dimensions of the slide valve will determine if my assumptions are realistic.

(the valve slide positions are not to the same scale as the piston slide, and are adjusted to fit on the same area of the chart)

I think I can now see why Steve at STW was talking about inherent inaccuracies of the valve gear.  I think that designers aim for symmetry to enable the best control and efficiency.  This can be seen to not be the case here.  The red line shows that when going forwards, the valve is being pushed much further than in all the other cases.  This seems to arise from the eccentric rod over-reaching and forcing the motion arm too far up.  This could be relieved by rotating the Crank Bearing Housing by about 15 degrees (anti-clockwise in the clips).  I am not sure if I have the confidence, knowledge or skills to do this successfully.  (If it works don't fix it!).  I have seen images of Hackworth valve gear in which the slide valve is positioned at an angle to the cylinders to align it directly with the centre of the valve gear - to achieve this would mean inserting a wedge across the slide valve mating surface (not my idea of a risk free improvement).
I have been worrying about the effects of condensed steam forming an hydraulic lock in the cylinders, but I have been told that slide valves are able to cope with this situation.  If (incompressible) water forms inside the cylinder, the excess pressure lifts the valve which is normally held down by steam pressure.  The excess water is supposed to be released and pushed to the exhaust by the steam which rushes through.  I would like to run the engine really slowly if this situation occurs.

I was also wondering about putting the cylinders in a wooden casing or box so that heat losses can be reduced and the risk of burns be lessened.

Engine in assembly

Before I started assembling the engine, I tried to make sure everything so far was able to be assembled. I am in two minds about the benefits of good daylight: you can see what you're doing, but you can see what has gone wrong with the paintwork.  On examination, I find the paintwork needs to be improved for complete coverage, and then another coat is likely to be needed to make a good presentation: I even have a better brush with which to apply a final coat. I shall need to look critically at all the details to make sure that potential dirt traps are suitably filled. The domed nuts for fixing on the sides can be seen.  The central tube of the engine has been put in place temporarily - it seems to be a good fit, but the upper fixing may need to be filed out so that the mid-way support fits the superstructure comfortably.  Although the tanks are stainless I thought they would look better with  the same finish as the rest of the car.

...and a view of the rear of the car so far.  Some paintwork is not yet finished.

Now for the newly arrived parts:  This shows the arrangement of the steams ports in the cylinder. Not shown is the work I have done to widen the central hole to 6.5 mm diameter and tapered the cylinder ends of the holes to improve the steam flow (without any experiment I don't really know how effective this work will be)

This last picture shows that I have started on re-shaping and polishing the central exhaust port to hopefully improve the outgoing steam flow.

The next task will be to fit and assemble the crank shaft and bearings - I have little experience of fitting parts which have an interference fit, so I am hoping that my efforts will be successful without needing to use too much hammer aided persuasion.  The next instalment is expected imminently, as long as FedEx don't lose it!  So I am assuming that I shall soon have the pistons and connecting parts in place, and then some more painting.  Some of the engine parts are likely to get warm, so I shall look out for some higher temperature paints for them.

Engine Coming

FedEx lost part of my engine. The latest kit contained 2 packages; one was delivered.  They have now said that the 2nd package has been traced. The missing part was the frame - I now have the cylinder blocks and crankshaft pieces.  It is no real hardship to be delayed as I have some extra time to finish some more painting.  I am painting over any bolts which form part of the main assembly and which I do not intend to undo again.  I have gained some bumps and chips to the paintwork, so another coat will go on when the re-assembly has been done.
Thinking about the next stage. ... In principle , I believe that all steam channels should offer the least resistance to the passage of steam.  The routes should be free from any unnecessary constriction and should be smooth with no sharp edges.  An opening with sharp edges has a discharge coefficient of about 0.6, but that for a smooth opening is about 0.98.  I think that any "fitting" activities will involve smoothing sharp edges and irregularities, polishing the sides and maximising the opening area - all to reduce pressure losses.  I was surprised to see that the steam route from the port to the cylinder end comprised three drilled holes next to each other.  To reduce pressure loss along the way, I shall taper (/streamline) the ends of the holes so that they more resemble a venturi,  the holes might allow for some widening, and the holes could be smoothed, probably with a needle file.  I am not sure if there would be any undesirable side effects from combining the 3 holes into a single slot - could it reduce the strength of the cylinder, or cause distortion, or cause a stress concentration/ fatigue cracks?  I shan't be touching the steam ports as I don't want to upset any valve timings.  The GA of the engine gives an indication as to the dimensions of the valve gear - it should be possible to make a simulation.to better understand any problems with timing set-up.
The exhaust port is not centred on the exhaust pipe fitting - I shall try to reduce any irregularities by filing and smoothing. 
Pictures to come.

Trial assembly of superstructure

The superstructure is now assembled and suspended ready to trial fit onto the lower chassis.

There was a certain amount of filing needed to enable the bolts to align with their holes.  The plywood sides fit nicely and add some rigidity.  

The next job after the final trial fitting will be to dismantle it partly and do some painting.

Trial assembly completed, front view.

Rear view - the inside looks empty now!

shows how the battery box is too far to the left - I shall need to touch up some paint where the box jammed against existing paintwork. I have sorted out the positioning by using some longer bolts and spacing washers to attach the pedal mounting to the box. (The packet of new bolts can be seen in the box, next to the sealant to be used for keeping out dirt and wet)

The rear left spring mounting was welded to the chassis with not quite enough clearance for the nut.  After filing a little bit, the nut fitted snugly, as shown.  Now I can start to dismantle and paint.  I must remember to use WaxOyl on parts that the paintbrush won't reach, and to use some silicone sealant wherever there seems to be a risk of dirt and moisture getting in.  The chassis side members will need a piece of cord, so that wires can be fed through at a later stage.