Engines > Restoration of Model Engines
James Booth 1843 Rectilinear Engine - Orphan
Jo:
I can't say I have ever seen a full sized engine Per.
I started the morning by setting up the electrolysis tank:
Then started the dismantling using a few tools to help with the loose rust removal:
I think the bearing are on their last legs on my angle grinder :Doh:
These tools were supplemented with a bit of draw filing along the edges. Clearly who ever applied the special coating needs more practise as it is coming off without any need to apply elbow grease ::)
The tank has had each "cleaned bit added and you can see it has already started working :ThumbsUp:
Now to test this cylinder casting :thinking:
Jo
Jasonb:
Did you not get your sand blast cabinet out? would give a nice key for the paint.
Per, I think there may be a full size that uses the same principal but with just one set of guides, more like Anthony's later "cross engine" that could have also been by booth as they had the patent.
Jo:
It is much quicker to clean it up this way than get the blaster out.
Knowing that Jason is holding his breath hoping that my cylinder is full of gritty bits like his I thought it was only fair that I machined the cylinder so he could gloat sympathise with me if mine was the same..
Anthony suggests you mount the cylinder on a face plate :thinking: The problem there is that it has two non square ends and a bump in the middle of the valve port face. It is therefore much easier to carefully set up in a three jaw.
The gunmetal has been slightly protected by using a piece of old coke tin between the three jaws and the gun metal. I did look at holding the cylinder beyond the rim but having looked at the final target wall thickness decided against that. First square up the bottom - the side away from the crankshaft:
You can see that it is still rough and it is also over length - this end will need to be faced again. This cut is just so the casting will sit flat against the chuck:
Now I have turned it round, used a copper mallet to ensure it is firmly against the chuck and then turned the outside of the rim round (but still oversized). I then cleaned up the outer face so that the face was not too rough and supported the end of the cylinder in the fixed steady on that over diameter surface I just turned circular so now with support in place I can start boring:
Yes there is some grittiness in the bronze but I am now 0.5mm away from the diameter on the drawing - the actual measurement is not critical it can be plus or minus 1mm but watch the remaining cylinder wall thickness if you go lots over dimension ;))
Now that my Takeaway Delivered Curry has arrived for tonight's dinner I might think about doing a final bore :thinking: Then we can discuss the cons of having pot holes in the bore of a steam cylinder and the techniques that can be used to overcome them ;)
Jo
Jo:
I have just taken another cut and the bore is still 0.3mm undersized:
As you can see there are a number of holes in the casting. This is only on one side so it has probably been caused by gassing.
Does it matter? On a steam engine, that fine, with no sharp edges, probably not. During normal running they would gunge up and seal on their own.
Bigger holes or huge lumps out of the bore would: Its a bit like driving down the road big pot holes can do damage, small holes your tyres would run over them without noticing. If the holes were big or the bore had a sharp/gritty texture I would probably line the bore with a sleeve.
But I will fill these to show how you could do it for yourself. The options: Soft solder or as I am going to use JB Weld ::) Soft solder is much better but that would require taking the cylinder down, heating it up applying the solder and then remounting it perfectly in the chuck. The cheats way to do it is to smear JB weld over the offending marks and let it slump into the holes:
I am now going to leave the JB weld for 2 days to go really hard and then do a final skim taking another 0.1mm off the bore. I do not care about the wear properties of JB Weld as it is just filling the holes like gunge would normally and I know that JB Weld is good for the sort of temperatures that this engine may be subjected to if it was run on steam. It should stick like the proverbial, if it comes out it won't do any harm before it is blown out of the exhaust ;) .
Jo
Admiral_dk:
Nice that the parts cleaned up so easily from the 'coating' :)
I'm sure that you are happy the the 'blow holes' are so small.
Will certainly follow your progress Jo :cheers:
Jason - that could the reason I thought it looked familiar.
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