http://start-model-engineering.co.uk/films/Halo-3-cylinder-radial-engine[www.savevid.com].flv
This is a selection of the engines I have built since 2007. One or two have been ‘non-starters’ but generally I have managed to get most of them up and running and each one has given me an enormous feeling of satisfaction.
I have learned many lessons in the course of building each of these engines. The most significant is not to become impatient. Rather than accept a part which is not quite good enough I will toss it in the scrap bin and start again. This is based on the principle that I prefer to produce something to the best of my ability than accept something of lesser quality.
I would rather spend an entire day (and I frequently do) making just one small component to the best of my ability rather than making a pile of inferior bits. I have tended to be impatient throughout my life but my experience with model engineering, perhaps aided by increasing maturity, has changed all that giving me greater satisfaction in the projects I undertake.
Click on any picture for larger image
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- My first engine – it did run for a short while before self destructing
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- Elmers ‘Wobbler’ an ideal first engine project which is relatively quick and simple to build.
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- Elmers ‘Twin Wobbler’ a lovely engine and an ideal second project
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- My first attempt at a twin cylinder double acting oscillating engine – sadly a non runner
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- A twin cylinder oscillator which due to simplified crankshaft joined the ranks of runners
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- A Mill Engine, my first with sliding valve for input/exhaust, steam chest and reverse running.
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- A three cylinder rotary engine adapted from a 5 cylinder design by Liney USA
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- Elmers ‘Tiny’, a lovely little engine well worth adding to your ‘to do’ list
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- A V-twin poppet valve engine that steadfastly refuses to run despite many hours of work.
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- Elmer’s #33 Mill Engine at original size
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- Elmer’s Mill Engine #33 built 50% larger than plan
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- Little and large – Elmer’s #33 Mill Engine
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- Beam Engine, a more recent project built to a French design and mounted on an acrylic base.
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- My ‘art deco’ version of the currently popular Rocking Engine which employs a novel method of input and exhaust.
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- Elmer’s ‘Standby’ engine with inlet and exhaust control via crankshaft porting.
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- Another one of Elmer’s little engines – #3 Open Column with reverse with added finning detail to cylinder barrel and head.
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- An attractive double acting oscillator engines – see my build notes under ‘Step by Step Projects’
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- Elmers #32 vertical open column mill engine built 50% up on original plan size
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- The baby on the right is Stan Bray’s Opus Proximum compared with Elmers vertical mill engine on the left.
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- ‘Debbie’ a two stroke engine to a design by Jan Ridders completed March 2011
Hi John,
I have finished my 2nd wobbler and am ready for a bit more challenge. Where can I get plans for the three cylinder Radial you display? My wife loves the look of the radial engines.
Thanks,
John
Hi John
Congratulations on the completion of your second wobbler.
Yes the 3 cylinder radial engine looks good and runs really well. My design was based on plans for a five cylinder engine produced by Liney Machine. I found it quite a challenge adapting the plans and fairly intricate machining, I recall making three cranckcases before I was happy. Let me know how you get on.
John
Hi John,
You have a nice web site, so much useful info.
If you want to talk about your V-twin poppet valve engine, I might have some ideas for modifications to make it run.
Best regards,
Dennis
Hi Dennis
Thank you very much for your kind offer. Whilst I did try a number of modifications to get it running I eventually and reluctantly admitted defeat. I would certainly be interested to hear of any ideas you may have though my current commitments are not giving me much workshop time – life keeps getting in the way !
With thanks
John
Hi John,
I’ll make some assumptions concerning the engine. Guessing it is a uniflo type with piston actuated valve at TDC and exhaust ports thru the cylinder wall at BDC.
Well one of the major differences with the uniflow compared to standard steam engines is the requirement for high pressure air supply. So first would be to calculate the compression ratio. Each step up in compression ratio requires a 15 PSI increase in supply pressure. Actually that just gets you to the break even point – more pressure is required to actually get power output.
For example: Say an engine has a cylinder that is 1 inch from the top of the piston at BDC to the cylinder head. With a 3/4 inch stroke it will have a 4:1 compression ratio. After the exhaust ports are closed by the piston traveling up, the air in the cylinder is trapped and compressed. At 4:1 compression ratio the pressure will be about 60 PSI by the time the piston gets to TDC and opens the poppet valve. So the air supply would need to be greater then 60 PSI to have a chance of running. If the calculated compression ratio is 8:1 then 120 PSI would be required. So make sure the engine’s compression ratio is not too high.
Next is the exhaust ports. They need to be large enough to allow the pressure in the cylinder to decrease all the way to atmospheric pressure during the time they are open. Ports that are too small will hurt the engine’s performance, but they probably would not keep it from running.
Last item is the piston actuated valve. It has to be free flowing since the pressure in the cylinder is already high as noted in the compression ratio note above. If the supply pressure is adequate but the engine still refuses to run, see what can be changed to allow faster flow. Also the duration can be increased. How many degrees of shaft rotation is the intake open?
That pretty much covers the potential problem areas for this type of engine. If you want to send me a sketch of the cylinder layout that shows all the parameters discussed above, maybe we can work out a plan to get the engine running.
Have a good day,
Dennis
Hi Dennis
Many thanks for your very interesting response to my non functioning poppet engine. There’s certainly much food for thought and introduces some logic that I had not considered. When I can get some workshop time I will have a fresh look at the engine in the light of your most informed comments.
Most grateful for the trouble you have taken to help me.
John
Hi John , trying to find plans to build Elmers #33 . Tried searching the site but unable to find any. Very good site , help very much apprieciated
regards frank
Hi Frank
Hope this link gets you there. Let me know if you have any problems.
John
Thanks for the reply .Sorry John could not find the link .Regards Frank.
John. thank you for this websight.I have just retired (age 67) and have bought a mini lathe & mill.Not having used a metal lathe before this site is a good source of information.There was not a lot of information to be sourced locally (australia) to assist the hobbiest,so thanks once again. cheers peter
Thanks Peter
Very best wishes on your retirement. I have been retired for over 10 years and it still feels like a holiday everyday, except when I have to go household shopping of course !
Good luck with your new hobby and I am pleased to say this site receives many visitors on a daily basis from ‘down under’.
John
Wow briliant and accurate machining. I lave the accuracy and art of your models. They are really fantastic……..love this site. it will be my homepage now…..
An inspiring and very well present site. Great engines.
Hi John.Your first attempt at the D/A oscillator seems similar to Stan Bray’s in”Model Marine Steam”.Any suggestions on how to avoid the crankshaft alignment problems,please?Did you have any concerns regarding expansion at the port block face,given the absence in the design of spring-loaded pivots?(Or did you intend to run it on air rather than steam?)Funds are low,and won’t run to a compressor yet-was boiler-failure the cause of your very first model’s self-destruction?For my money,one of the best characteristics of your site is an apparent recognition that many newbies just can’t afford all the desirable equipment to say nothing of sets of castings.
Hi Peter
If you look at My Engines page you will see that my first twin oscillator was a non runner due to difficulty in making the crankshaft which is the very point you are making. My second twin oscillator did run due to the simplified crankshaft arrangement. Plans of this engine are available to download free of charge from . I am not too clear on your point relating to air versus steam and in my experience models that run on air will run on equally well on steam and visa versa.
My first oscillating engine self destructed due to the weakness of soft soldering of the cylinder pivot. I would stress that in my opinion you should not attempt to construct a boiler using soft soldering techniques – extremely dangerous !
John
Hi,
Found your site by accident, I have built Jan Ridders 2 stroke, the vertical option and am now on to the horizontal version. The vertical one did run eventualy. but is a bit difficult to start, I use a motor and pulley, needs about 1000 revs to get going and will run for about 10 minutes. Speed control is not very good but it will run. I am using a motor cycle coil and 12 volt battery with cam operated micro switch. Spark plug is from a Ford escort.Hope I have better luck with the current engine. Great site now in the favorites.
Regards
Brian W
Hi Brian
Good to hear from you and pleased to hear of your success with Jan’s 2 stroke. As you may have seen the problem with ‘Aussie’ Jim’s engine was insufficient compression and he solved it by making a new flat top piston with just a 5mm transfer channel. This might be worth considering with your current build.
I was interested in that you use a micro switch as your contact breaker. I found that the ones I was using were not up to the job so after destroying half a dozen I changed to a CDI unit.
John
Great site John, thanks for sharing.
Are there any plans available for your first slide-valve/reversible mill engine (second image down in righthand column above)?
Hello Paul
This is Elmer’s #43 Mill Engine with reverse. Plans are available to download free from John-Toms site
John
Hi John.
I love this website. I’ve just gotten hooked to machining and using the skill eventually to making model steam engines. And i should warn you that i’m saying this without any machining skills whatsoever, no hardware tools besides a drill for making holes on the wall now and then, no money (yet!… i hope) for purchasing a lathe to start with let alone mill, and so much more handicaps.
But i’m reading your builds and other articles here one by one to familiarize myself with hardware terms and methods. I have so many questions reserved for you especially on how to make certain shapes from a block and what tools/accessories to use, but i’m holding back hoping that i’ll get the answers by reading (eventhough Bogs said it should be 75% doing and 25% reading, hehe).
Sorry for the long post.
Best regards,
Lutfi
Hi Lufti
Glad you like the site which was set up to help people just like yourself. I look forward to hearing from you when you eventually make a start. Good luck.
John
Hi.
I am normaly a ticker and make clocks. Interested in your elmer 33 mill engine and would like to make, have a a fully stocked workshop, CNC,manual mill, Bantam, mini lathe, dividing heads, etc
and the nice part, fully retired, just.
Do you have plans for this mill, or where did you get yours, any help would be appreciated.
Best regards
George
Hello George
Good to hear from you and congratulations to you on your retirement – now the real work starts !
The plans for Elmers #33 mill engine are available to download at simply scroll down the page until you come to #33.
As you may have seen I built this first at plan size and I was so pleased with the engine I built another at 50% up on size and it ran even better ! Sounds as though you have a well equipped workshop and I look forward to hearing how you progress – please remember pictures are always welcome.
best wishes
John
I love this stuff, it makes engineering come alive.
Glad you like it Dave !