Apart from some cosmetic detail Opus P. is now completed but steadfastly refuses to show any signs of life. Examinations will continue but my suspicions lie with the porting arrangements.
I am concious of the fact that a number of people have been following the build of Stan Bray’s Opus Proximum and that they may be wondering why this thread has ground to a halt.
The truth of the matter is that so far, despite, my best efforts, Opus refuses to run. Not only will it not run there is absolutely no sign of life. My suspicions focus on the inlet and exit porting arrangements and I need to carry out some visual comparison tests against similar valve arrangements on one or two of my Elmer engines. Even before I attempted to put some air through my Opus P. the opening and closing of ports didn’t seem to be quite right. When air was connected up it appeared to run straight through and out of the exhaust regardless of the stage in the cycle. There is a slight change in note as the valve moves in the chest but there is clearly something basic that is not right.
As readers will know I did discover a number of anomalies with the plans for Opus P. and I am beginning to wonder if this string of errors includes the critical porting arrangement.
It may be a few days before I am able to continue further examination if meanwhile any readers have any thoughts or ideas I would be very interested to hear from you. Indeed I would be interested to hear from anyone building the Opus P. and to hear of their experiences.
Hi John,
Good to see your not letting it beat you. Having been enthused by the ‘Best of Model Engineer , Volume 1′ I have just brought my 1st lathe and was considering this as a first engine but will, with due regard to your findings, now attempt the oscillator as a first engine, probably followed by the horizontal mill engine as a second.
All the best
Pete
Hi Pete,
No I intend to perservere with OP until it runs but I am waiting until the weather warms up a little !
Congratulations on the aquisition of your first lathe – I am sure you will have many hours of fun. A simple oscillator is definitely the way to go for your first engine. You stand a much better chance of it being a runner. It shouldn’t take you too long to build and the satisfaction you will gain when your first engine bursts into life will carry you forward to bigger and better things. The horizontal mill engine is a great project but has the complication of a sliding valve and a steam chest (as does the Opus Proximum) it is also likely to take you considerably longer to build.
Let me know how you get on and do get in touch if you think I may be able to help. Perhaps you could send me a pic to put on the site when you’ve completed your first engine.
John
I have been collecting various bits of steel and brass with the intention of making Stan’s Opus Proximum. Quite by chance I recently stumbled on your excellent website and have eagerly read your write-up of your experiences with this attractive engine. Your photos show that your engine has been beautifully made, far better than mine will be, so from what you have said so far it seems that there isn’t much chance of mine working. I have added your site to my ‘Favorites’ and will be checking regularly to see if and when you solve the problem(s). It would be nice to see a video of it working and this might encourage me to actually start making it. Best wishes for success.
Hi Ken
I find it hard to recommend to anyone to take on ‘Opus Proximum’ as a build project because of the innacuracies and confusing plans and build notes. If however you decide to continue I would recommend you build 50% up on size or even 100%. Whilst I am clearly not infallible I did machine components as accurately as possible to size and on first assembly air simply ran thro the steam chest and out of the exhaust regardless of the position of the valve. I have since gone back to the drawing board and following slide valve theory have produced two or three valves which now do their intended job of opening and closing ports.
Innacuracies apart there are a couple of procedures which I think are a little tricky. The first is the silver soldering of the two small lugs to the comparitively large mass of the cylinder. The other relates to the fixing of the bottom cylinder end cover.
I do intend to perservere and feel reasonably confident that I shall get my OP running but I would not be happy in encouraging others to have a go at this engine. Most of my engines have been to Elmer Verburg’s plans and I can truthfully say I have never experienced any difficulties over building to plan.
I would suggest you take a look Elmer’s #32 Tall Vertical Open Column Engine which is very similar in appearance and should be relatively straightforward to build. I haven’t attempted it yet but I have seen a running version and it is a most attractive engine. Whatever you decide do consider increasing in size and ideally to suit available flywheels. Currently RDG Tools are selling 4″ cast iron flywheels for around £7 each which I think are very good value.
Let me know how you get on and if I can help further just give me a shout.
Just discovered your site tonight and like the look of the three cylinder radial steam engine. Where did you get the plans or is it an adaption of Liney Machines design?
My Website is seriously in need of an update but since I’ve retired all the spare time has disappeared!
I felt that making five of everything was pushing my luck a little so I adapted the Liney plans for a less ambitious 3 cylinder version and I am delighted with the final result. No one is more astonished than me at how well it runs !
However any of us retirees managed to find the time to go to work is completely beyond me. Let me have a link to your website Alistair, I would be interested in having a look.
John S