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[Ramon]

Hello - I have just begun rebuilding a small oscillating vee twin and thought that it might prove of interest for someone if only to show that reclaiming something is well worth the effort despite how bad it looks in the beginning not to mention the satisfaction of bringing something back from the brink of the scrap bin.





I bought this (what appears at first glance a reasonably nice looking) engine, sight unseen, from a deceased club members estate on the recommendation of another member. It was subsequently handed to me at an exhibition I was displaying at and as such it was not really looked at but brought home still in it's rag 'packaging' and left on the shelf for several weeks before actually taking a good look at it . By this time, far too late to say anything,  it was quickly obvious that things were not as they should be. Turning it over revealed 'wringing' and tight spots. At one point the steam faces could be seen to visible lift away from each other. More in desperation that anything thought likely it was connected up to the airline but despite varying amounts of pressure not so much a tweak of a rev emanated! Only slightly (you understand  ) miffed it was put back on the shelf with that resigned sigh of money wasted but the hope that maybe at a later date it could be resurrected.

Now to be fair to the guy who built it I don't know his background re machining nor the equipment he had available. He was a 'nice old boy' and loved his steam so this certainly isn't a whinge in his direction but it has to be said where this build was concerned 'things weren't too good'.

The slight angular displacement(s) can be seen here along with those soft soldered inlet and exhaust pipes.


and here the off set of the cylinder(s) to the centre line of the crank shaft


Stripping it down revealed more undesirable features not least on the cylinder faces .....


.... and on the port faces too. The steam port holes were well a kilter to the centre line and the base was still as cast.


The Glands were held in by small strips which in themselves were causing drag on the rods


And finally this looks worse than it is as the boss is actually offset to the centreline of the casting. The plates are soft soldered on to close off the steam passages



So that's what's available but I'm sure it can be reclaimed to a good working engine. Having taken a long look at it again a decision was made to mill off the port faces and silver solder new pads on before re-machining. But first the paint was removed by dunking in a jar of cellulose thinner then the pipes de-soldered .....


.... before milling the bottom face and front edge to give a datum surface from which to work to.


Well that's it for now - if this is of interest please do say as it's difficult to judge whether it's worth progressing. It's only a small engine but I know but if there isn't any interest I think you'd agree there isn't much point in continuing - posting is a great way of losing workshop time you know

Regards - Ramon

[tr7v8]

very interesting please keep posting

[derekwarner]

Yes please Ramon......steam is always interesting  ..... Derek

[ooyah/2]

Hi Ramon,

Yes go ahead and rebuild it will be good for some to see how such a poorly made engine can be refurbed.
I have made quite a few of these engines and the only part that I buy from Blackgates is the Standard casting, the cylinder castings are complete rubish, I have already told Blackgates so in the past and I fabricate the cylinders from brass stock.
Instead of having a packing gland on the piston rod I use a small Silicon "O" ring and the bottom bearings are split instaead of yokes.
I have some sketches of the drilling for the steam holes to allow a disc valve for reverse and forward, if you want them I will have to e-mail them to you as my scanner is not working at present.
Here is 3- pics of the "V" twin engine made resently for friends, at 9/16" bore x 5/8" stroke they make a very powerfull engine.

George.

[Ramon]

Hi guys - thanks for taking the time - it never fails to amaze me just how many people look at forum threads but so few acknowledge their interest but it's nice to know some do 

George - nice to hear from you, hope you are keeping well. That's some very nice examples you've built there - you have some lucky friends. I like the lagging - I hadn't even given that a thought 
Thank you for the offers  I'd like to take you up on the reverse valve if you'd be so kind. I'm afraid the porting has already been drilled as this is a day or two retrospective.

Anyway to follow on 
The first thing done was to fill in the over large two boltholes in the base with some gunmetal stubs Loctited in and peened over before machining and flushing off with a rotary burr then re drilling


With the base machined flat and the front edge trued to the back the casting was set on an angle plate set a 45 degrees to the table. This allowed the basic centrelines of the standards to be ascertained in order to bring the crankshaft hole true. It took a 10.5mm hole to take out the offset then a piece of gunmetal was turned to a close fit, Loctited in, and again lightly peened over at each end. The small boss had been milled off and the area counter-bored at true centre to take a small boss of gunmetal again Loctited in place.
The standard sides were then milled each side of the established centre lines at the same time removing those soft soldered plates covering the steam passages then the crankshaft hole was re-drilled and reamed 6.35mm to it's true centre.

The original port faces were milled away to take the pads ready for silver soldering and all the existing holes were drilled out to remove any trace of soft solder. Two pads were cut from slices of gunmetal bar and small stubs of gunmetal turned to fit all the holes before fluxing up and silver soldering one pad at a time. It was at this point I realised I had overlooked the fact that some parts had been Loctited but by shielding everything other than the area concerned no adverse affects to those parts occurred. I was expecting it to degrade and the parts loosen with the heat of soldering but there's not a trace of such.

This after milling to size and drilling the port holes. The hole for the pivot may look large but I'll come back to that later.


Taken after all work was carried out this image shows the set up used for all the different ops described.


All holes re-drilled and ready for final finishing


The dark discolouration is from the pickle - a nice coppery coat before smoothing out the surface with a rotary burr


Next up were some new cylinders as the originals are beyond redemption


Made from gunmetal bar with the steam port faces made from slices of the same these were silver soldered together ...


... before more rotary burr clean up


Held gingerly in the 4 jaw so as not to distort them the bore and one face was turned


An expanding mandrel was turned up and the cylinders held on it to bring the other end to length and square to the bore then transferred to the mill for the port face to be milled and the relevant holes to be drilled


The set up for drilling the steam passages was simple enough - just milling through to give a small flat surface to start the drill on first.


Back on the lathe to have the end holes drilled and tapped the cylinders are finished all bar lapping the bores and port faces - Nice as yours look George I don't think I shall lag these.



Well that's it for tonight guy's - nothing done today as I drove to Boston to pick up a rather nice (r/c) yacht 

I've been a bit vague on anything on I'll be pleased to answer any questions

Regards - Ramon

[ooyah/2]

Hi Ramon,
What an improvement since your first pics, in pic No6 it shows what a stae the cylinder faces were in and as you proceed the difference is amazing.
You have just given me the idea in how to support the over hang of the cylinder faces to stop flexing while drilling and Machining.
I machine the faces with the standard mounted on a mandril thro' the shaft bore but there can be a bit of deflexion while taking a cut across the faces, next time I will use your idea of the adjusting bolt.

My cylinders don't have any lagging in them it's just covers made from Ali strip, I make the top and bottom covers 1" dia and the cylinders 15/16" dia so the overlap makes a neat finish.

Great save Ramon I look forward to your progress.

Regards
George

P.S.  e-mail sent.

[Ramon]

Hi George - Thanks for the email and drawings 

Yes it surprising just how much rigidity such a simple aid brings. It's just a tee nut and a bolt from the 'clamping kit' (all 6mm cap heads) just lightly brought into contact with the lower surface

Due to 'seasonal distractions' not much done today save the top and bottom covers but at least that's still a step forward


I decided to make screwed glands so as to accommodate some PTFE packing. I prefer to use this over O rings due to it's lack of friction but good sealing properties. The pistons will use the same. The glands were made first then screwed in tight before drilling and reaming in situ to keep things in line.

I need to give some time to the new yacht tomorrow but I'll get back to finish this off as soon as I can.

Regards - Ramon

[ballastanksian]

You keep on posting Ramon! It is good to see steam subjects developed and described in the model boat sphere as it is one of the most inclusive areas in RC. I appreciate that RC aircraft and RC cars/trucks etc can have parts engineered by their owners, but they needn't. With model boats the addition of steam is more extensive, as an engine or turbine needs a boiler and fuel and water feed systems all linked by lots of pipes and valves etc!

Did you see the article in December's Model boats about model steam turbines? Very interesting.

Keep up the good work Ramon, it is very interesting and educational.

[ooyah/2]

Ramon,
I must congratulate you on your machine finishes, it's guys like you that makes me try harder to get a good finish.

Best wishes and a Happy New Year to all.

George.

[Landlocked]

Great thread and great work!


Learning to be a machinist is on my retirement bucket list (still a few years away).  Your thread is helping believe I could do it.


Congrats.


Ken/Landlocked

[southsteyne2]

Nice work Ramon ,just a tip for what it;s worth I use t bag string soaked in steam oil for glands ,I haven't tried it on pistons yet but might be worth a go cheap too
Cheers
John.

[Ramon]

Hi again - just a quick update on current state of play but first a thanks 'Ballast', George, Ken and John for taking the time to comment.

'Ballast' - Though I was an avid reader of Model Boats for many years through the late sixties seventies I haven't bought one for quite some time. Occasionally someone brings a recent issue to the club room at Norwich which is about as close as I get these days.

George - finishing is not something I think about unless the tool ground gives a bad one! Except for very rare instances I never use carbide tooling and all tools are ground from High Speed Steel on an off hand bench grinder. I don't spend long grinding tools - most are very old with just the cutting point getting a tweak as that's all that does the cutting. A nice radius is usually the key to a good finish however

Ken, good luck with your intentions in your retirement. Making something from a drawing and an inanimate piece of material has always given me a great feeling of satisfaction so I hope you are successful with your intent

John - thanks for the tip. I can see that the string you mention would be ideal - Unfortunately we use bags without string but I get the idea. I have a small jar of a PTFE filled grease which together would probably be an ideal combination.

One or two 'external' matters have slowed things a tad but I've had a reasonable session yesterday and a bit more today 

The pistons, rods and bottom ends were made yesterday. The white material is PTFE impregnated and coated yarn to be used as a piston seal.


The pistons screw onto the rods and a thin locknut holds them tight. The threaded portion needs to be reduced slightly in length as yet


The standard was spot faced to take the springs and the pivot pins etc made today.


The larger diameter than usual pins are made for a reason. Firstly it gives a much better bearing surface than the usual stud. but more importantly by facing the end before tapping when it is screwed onto the stud set in the cylinder it pulls the pin perfectly square to the face as well as ensuring the stud is not inducing any pressure point toward the bore. The back portion is just a standard 5BA stud screwed in to lock against the end of the thread.

Finally a 'blank' was silver soldered up tonight from which to make the crankshaft - I hope to get that finished tomorrow if all goes well.


Thanks again for looking in

Regards - Ramon

[Tim_M]

Fascinating! I never realised there was so much in a small steam engine. Watch and learn.....

BTW, Bluebird has been neglected for a few weeks due to some domestic issues but the project is not dead. The sandpaper will be out this weekend (I hope) and I'll post progress - when there is some lol.

[ballastanksian]

Are you a member of the club that has that envy inducing raised lake Ramon? I would love something like that for my association to sail in:O)

You are getting on with that engineering mate, very clean and well finished.

[Ramon]

Thanks for looking in Tim - thought it had been a bit quiet lately but we all get those periods of external interference. I'll look forwards to your next update.

'Ballast' - yes we do have a lovely facility and not just the lake. There's a super warm, nicely furnished clubroom, two boat setting up rooms and a on site toilet too. All for a very reasonable club fee. We are lucky boys (and girls) indeeed

A bit more progress now has the bottom end complete. That crank blank was turned first and a couple of centres put in each end. The web was milled to shape using a rotary table...

...before setting between centres to finish off the shaft proper.

A new flywheel was turned along with a coupling and the shaft relieved to take the pinch of the grub screws. The coupling pins, along with the crankpin were made from hardened steel dowels pressed in place with a dab of Loctite 601


Finally a first assembly of sorts




It all spins over nicely without any wobble so not to far to go now - next up are the inlet/exhaust manifolds then finally the reverser and pipe work. If all goes well it shouldn't be too long before the airline gets coupled up 

Regards - Ramon

[Ramon]

Following on from the last post a strip of gunmetal was machined for the inlet/exhaust manifolds then cut into four and all holes drilled before silver soldering the unions in to place.


With these fitted the distribution manifold and associated pipework was tackled and soldered up using a simple jig to ensure correct spacing


Unfortunately some solder managed to creep into the end of one of the pipes rendering it in operative, The only solution was to cut the pipe, drill out the offending blockage and re-join the pipe with a sleeve. This was turned from hex to look like a pipe union and both pipes were cut to give a 'designed' effect. Though difficult to solder due to the block acting as a heat sink it proved successful with good airflow through all passages


A trial on air was in order at this stage and though it started easily enough one side was definitely driving the other. A strip down revealed two tiny burrs from drilling the passages in the standard which were restricting the porting holes. With these removed every thing worked well with both cylinders working together. Tick over is very good - I have no idea what pressure it was running on but no more that 20-25 psi  probably less.

With the running ability established the parts for the reverser were made.......


.......and the whole lot mounted on an ali plate.



The caps to seal the passage ways BTW are temporary and will be remade on re-assembly


Well that's basically it - I now have to strip it down to paint it. Talking about it with some ME friends it appears that PTFE packing on the pistons, whilst superb for running on air, will quickly swell and possibly lock once on steam so that will be placed with graphite yarn as I am not a lover of O rings in this capacity.

With the rather quiet lack of feedback it's difficult to know if this has been of general interest but I hope so. Once completely finished I'll try to get a short video of it running if possible.


Regards for now - Ramon

[ballastanksian]

Definitly Ramon. The engine looks as if you just started a fresh with a new kit, well stock metal really.

Lovely work and well worth reading

I know that there are hot periods when people log on that may not correspond with when we post our bits thus making it feel like no one is reading the posts especially, if like me, you use the unread posts facility.

I don't like to comment on every brushload of glue applied or strake of wood cut, so sometimes study a few progress posts before hopefully being constructive or supportive. If this is common amongst us mayhemists then it will occasionally feel like no one gives an 'Ertha kit' about what you are doing, but I am sure many follow the work which is good in its self.

I look forward to seeing more model engineering on this forum

[derekwarner]

Ramon....today you have 756 views of the thread....so many are watching ..& yes a beautifully set of reconstructed components or near brand new!...as with all of your work, the photographic images add inspiration for viewers [even down to the image of the engine with the port side cylinder cap with each of the cap retaining hex bolts flats aligned]

The progression and series of the postings are really enlightening ...thankyou

That Chesterton type twisted Teflon cord will swell at elevated temperatures, however at the intended pressure & temperature here [40 PSI & 140 degrees C?]  I would have thought, with a light mist of steam oil would not cause any concern with binding

Derek

[tr7v8]

This has been an impressive rebuild & I have learnt a lot. Thanks

[ooyah/2]

Hi Ramon,
In pic No 4 you show a Silicone "O" ring, what does it do? if it is fitted to the shaft of the reversing block is there a need for a seal there as there will be no steam entry to that hole.

You say that you don't like "O" rings for pistons, any reason why?
I have been using them on steam cylinders for the past 15 years after being recommended by a Loco enthusiest and to date it's a matter of fitting and forgeting, the only place that I use something different is on my flashsteam engine which has Cast iron rings.
I have never tried P.T.F. packing and stopped using graphited cotton string years ago on pistons.

You have made a great save on the original engine that you had, if I may make one last comment that where you have fitted the steam reverse valve  there will be a great heat loss thro' the Ali plate to the main casting and from the block holding the steam pipes to the engine.
Otherwise a great job and your machining finish will be very hard to copy, but I shall keep trying.

Well done.

George.

[Tim_M]

Really interesting article. At the risk of appearing very stupid, I have a question. How did you drill and tap the hole for the grub screw in the flywheel? I don't get it!

Rgds,

[Big Ada]

Really interesting article. At the risk of appearing very stupid, I have a question. How did you drill and tap the hole for the grub screw in the flywheel? I don't get it!

Rgds,

I think it may be at an angle.

Len. A Great Build Ramon, you are very Skilled.

[Ramon]

Hi Guys - it's been a long day none of which has been spent in the workshop 

Firstly thanks for all your comments which are all much appreciated. My comment about lack of feedback was exactly that - not a whinge in any way I assure you nor a desire for platitudes either. I admit I have always found it a bit disconcerting when I see the numbers of visits and nothing is said. To me posting on a forum is about sharing and communication. I may be seeing myself wrong but I do always try to post as if I'm talking to someone so when very little response is there I begin to have self doubts as to the worth of the post. I do appreciate the fact that there is 'X' number of visits and that in itself shows a relative degree of interest but imagine taking a subject to a club meeting (which is what I feel a forum is) and having talked to the meeting virtually no one responds. Posting about a project does take time especially when images are required so a little feed back as to it's value to someone would go a long way to any would-be poster. Like I said that's not a whinge or indeed a rant - just an observation - hope it's seen as such.

George - many thanks for your valued advice once again. Whilst I'm fairly confident on machining skills my experience with the practical side of steam is very limited. The ali plate is just temporary but I had overlooked the fact that it would act as a heat sink. I wanted to take it to show a friend today hence the assembly. I was intending to mount the engine on hardwood beech bearers and called into a nearby model shop today to get some but no chance - "haven't stocked 'em for years" - no call for them these days. It's been a while since I built a control line model but I didn't think it was that long ago.
 I have some Tufnol sheet so will either insulate the valve or perhaps mount the whole unit on a piece. The small O ring fits in a recess in the back of the valve. The central pin has a large head that covers it and provides sufficient spring to keep the valve face in contact as well as providing a seal. Well that's the theory anyway 
With regard to using them as piston rings have anything against them being used per se it's just that I have always used packing with good results. 

Re the packing - your comments on this Derek are timely. On all the engines made so far (using PTFE) all have exhibited superb piston seal with extremely low friction. They have however only been run on air. My friends had experienced locking on a loco (piston valves) and a small ('full size') steam launch engine  This was the first time I had heard about PTFE acting in this way but of course as you say these would have been at much higher operating temperatures.  Given what you say I shall leave as is and see what occurs.

Tim - as is often said  "No question is stupid if you don't know the answer" Len has it right - the flywheel was set on a tilting angle plate and the screw put in at a slight angle such that the drill would just miss the inner edge of the rim. The crankshaft was relieved at the same angle so that the screw impinges on a surface square to itself.

Well now it's well and truly time I was in my bed - thanks again for your input and comments, it's been nice to have something to respond to 

Regards - Ramon

[Crossie]

 Hi Ramon,
                   I'm afraid that I am guilty of being one of 'the silent ones', having followed the transformation of a rather shabby model engine into a piece of functional metal art in the hope that I might get a new wave of enthusiasm to continue the 9 cylinder Radial engine that I started about two centuries ago and has languished in a box in the shed for the past four years! So thank you for your efforts both at the lathe and mill, and the keyboard.
                  If you want some 'olde worlde control line style beech bearers' then google  Balsa Cabin, they've a variety of sizes and you get a first class service too.

            Trevor

[ooyah/2]

George - many thanks for your valued advice once again. Whilst I'm fairly confident on machining skills my experience with the practical side of steam is very limited. The ali plate is just temporary but I had overlooked the fact that it would act as a heat sink. I wanted to take it to show a friend today hence the assembly. I was intending to mount the engine on hardwood beech bearers and called into a nearby model shop today to get some but no chance - "haven't stocked 'em for years" - no call for them these days. It's been a while since I built a control line model but I didn't think it was that long ago.
 I have some Tufnol sheet so will either insulate the valve or perhaps mount the whole unit on a piece. The small O ring fits in a recess in the back of the valve. The central pin has a large head that covers it and provides sufficient spring to keep the valve face in contact as well as providing a seal. Well that's the theory anyway 
With regard to using them as piston rings have anything against them being used per se it's just that I have always used packing with good results. 

Hi Ramon

If I can comment on your idea having the Silicone"O" ring at the back of the reverse block in my thoughts it's not a good idea.
Silicone "O" rings expand 100% under heat so when the valve block heats up it could jam the pivot pin and as there will be no ingress of steam into that pin I feel it's a bit pointless.

When I started using "O" rings I just did not beleave the tolerances of the ring groove, I thought that they were far to large so I made them with about .005" clearance, the result being that when the pistons came under steam they locked up, on cooling the engine would run again until it was up to heat and then it locked up again.
I then made the grooves as per the detailed dimensions for Silicone "O" rings and since then never had any trouble.
In Blackgates Cat there is a page with tolerances for Silicone"O" rings if you ever decide to use them in pistons.

I think that you should dispence with the "O" ring and make the pivot pin longer with it being spring loaded as your cylinders, otherwise you have no tension adjustment on the rotary valve

One last thing don't be surprised at how wet the engine will run on steam at start up as it gets rid of the condensate, I don't know what the steam pressure will be at the pistons but would guess that it will be at least 50% less than the boiler pressure but will rise a bit when the engine warms up.

George.