The Bolton -Bertinat -Bailey Triple expansion engine

[Chipswitheverything]

This complex engine is really building up into a piece of machinery now, looks very impressive.  As you have said, makes a bit of a milestone on the progress towards your finished triple engine. Dave

[steam guy willy]

Thanks Dave and I need to take it all apart and make a few adjustments to the middle crankshaft bearing to fit the IP eccentric straps centrally
cheers willy

[steam guy willy]

I have now taken the engine apart to adjust the 3rd and 4th main bearings to accommodate the eccentric straps. I made all these bearing blocks larger so when I fitted the crankshaft I made them to actually let them act rather like endways thrust blocks, as there is not separate thrust blocks as used on ships that have propellers that can put a lot of pressure on the con rods ..

Willy

[steam guy willy]

I am now trying to figure out how to attach the IP eccentrics ...?? The HP andLP were made as solid items as they just push onto the crankshaft ends ..howerver the central ones are made in two parts screwed together and so the pins that join them together go through where the screws that join the parts are.and so they have to be very short.  I have made a drawing showing where the parts fit and I will have to use a very short pin to line them up. I also made the jig to align the the two eccentrics accurately.

[crueby]

Very tricky fitting!   

[steam guy willy]

Here are the drawings of the IP eccentric showing the construction of the parts  so continuing with the construction......And ......ready to watch the England  Mexico football match ..with a cup of tea and a pile of tissues ??!!!
Willy

[steam guy willy]

Very tricky fitting!   

Hi Chris,  yes and the pin will be about 3/32nd long ...also how I install it will be tricky ?? quite a lot of other people have been making the engine over the last 40 years so it would be interesting to hear how other people have tackled this ??!!!!
Willy

[Chipswitheverything]

Looks like a nice result on these rather demanding small parts, not just the machining of them but the keeping track of alignments. At some future time I will be attempting the combined eccentrics for the Stuart triple engine, which also has the split middle component. I have been able to read a certain amount about making them, thanks to articles and blogs, but I can see that full attention is going to be needed.
 
  You are right that in the case of some of these fairly popular models that have been around for very many years, there must be a fund of knowledge held by builders who have had to think aspects of the machining through, but I suppose that all the scheming mostly never gets further than the notes and sketches that they made at the time, and which are probably chucked out eventually ,  by them or by others clearing out the workshop paperwork.
 
 This forum is the ideal place for information to be shared, but it's a pity that so many registered members, many of whom are possibly doing interesting things, and maybe working on the same model engines, don't seem inclined to join in with the communication. There does seem to be a rather small core of those active on it these days ...  Dave

[internal_fire]

I did this quite a few years ago, and I do not remember any special problems. It is tricky to get everything aligned, but I followed Bertinat's discussion, and it worked.

I first made each split eccentric (separately) with the joining screws, and I finished each one completely. Then I drilled the linking pin hole in one of the eccentrics. Of course the location needs to be well-planned.

Followed by the setup for precise angular alignment.

Finished by clamping the two (aligned) eccentrics together with a toolmaker's parallel clamp and drilled through the second eccentric. Added the pin (probably a spring pin). Done.

I recall there may have been some manipulation required to get both eccentrics attached to the crankshaft at the same time, but I do not recall that there were any significant problems.

Gene

[steam guy willy]

Thankyou Dave and Gene  and what I have done is made a large drawing using a 10mm per 1/16th inch rule to calculate other dimensions , I drilled the first pin hole as close as possible then joined them together to drill No 52  through the other one using the central grub screw.to hold them in alignment. For the pin i will tap one of the holes  No 52 for 10BA and loctite
 it in place to stop it dislodging whilst assembling . You can see where the drill goes through the 6 BA hole that joins them together.
Willy
The pin hole been tapped 10 BA and the screw  has been loctited in and the adjacent holes opened up and the parts are now assembled ready to attach to the crankshaft after the securing 6 BA bolts are filed down to fit

[steam guy willy]

I have attached the IP eccentrics and put on the reversing gear parts but I need to make some special spanners and nut runners to make the assembly a lot easier!!  so getting things moving along ...................slowly...............

thanks for all the comments from our colleagues that have also been making this engine

Willy

[Roger B]

Excellent, another tricky set up completed   

[steam guy willy]

Excellent, another tricky set up completed    :wine

Thanks Roger  and still lots to think about and make  and it should be finished for the Forncett Model Engineers day on the 4th October ???!!!!
Cheers

Willy

[steam guy willy]

I have taken the cylinders apart and am making the parts for the valves including theLower valve rod guides. the are needed as   there is a lot of sideways pressure due to the reversing linkage. I have Almohad to reduce the length of the bolt and have used button magnets to hold steel strips in the vice jaws to prevent damage to the threads...

Willy

[steam guy willy]

I have finished the parts for the IP cylinder  and the position  of the valve has tu be positioned by sight as when the whole engine is bolted together you cannot see what is happening or adjust the valve ....t have made the valve rod and threaded part longer to allow for final   adjustments. The lower  valve rod guide has also been fitted so I need to assemble part of the engine to finalise the valve rod ..............

Willy