[bogstandard]

Just an update on how the engines are progressing. Nearly finished, just baseplates (couldn't be started before power takeoffs were made) and a bit of shafting to make.
Here are piccies of the now ball raced power takeoffs and the ready for silver soldering displacement lubricators.
Have had the engines running and they are very satisfactory, just a bit tight till they bed in.
Neither of the two items shown here are on the plan, both my own design.

John

[bogstandard]

Here is a finished engine.
Already had successful run on air, steam trials over the weekend.
A nice slow runner, just a bit tight, needs to bed in.
First pic showing inlet side, second showing exhaust side, third next to a very early Cheddar Puffin engine, showing the extra long stroke in almost the same height.
John

[bogstandard]

For those interested here is a short video showing the bedding in of one of the engines.
http://www.youtube.com/watch?v=zMYb-3WQQwY

[Speedygonzales]

very nice engine bogstandard!!! i like the vid also

[nick.gilling]

Very nice smooth runnning engines there, great job.

[bogstandard]

Hi Nick,
Thanks for the compliment.
At this moment I have the engines being run on steam, and everything as what was expected, they run really smooth and powerful on 25psi (2 bar), with good throttle control, what more could you ask for.
My next project is going to be a piston valve engine, hopefully the same bore and stroke as these. But it is going to take a bit of designing and a lot of developement.

John

[nick.gilling]

John,

A piston valve engine sounds interesting I was toying with the idea myself but decided I want to make a stirling engine instead.

How does the valve usually seal? Presumably it has some sort of piston ring? You could use 'o' rings as long as you pay a lot of attention getting the fit right. However, if you are doing this for a boat application again, I'm not sure whether 'o' rings would be suitable as you would need the engines to be self starting and the friction with 'o' rings is high initally until things start moving. However, I suppose also that you have more of a mechanical advantage on the valves since we're not talking about 'o' rings on the driving pistons.

I'll be interested to see your design and development of your next project. It's good that you share your knowledge on here as people like me can learn a lot from people like yourself!

Nick

[bogstandard]

Hi Nick,
Hopefully I won't be using piston rings on the piston valves, I hope to get the tolerance tight enough that the oil will make a good enough seal, but it will have a gland on the bottom and a sealing cap on the top, these may have a ring in them, it is too early to decide yet. I haven't even decided yet whether I am going to make the cylinder block out of brass or stainless steel.
The main priority at the moment is getting my workshop rekitted with new machinery so any new developements will go on the back burner, and played around with until I am ready to start in earnest, and when I do, I design and make as I go along, get one bit right and design the next bit to fix to it. Some people do full drawings first and hope they have got it right, the way I do it suits me. Don't get me wrong, I do drawings, it helps with the calculations, but I don't rigidly stick to them. If you stick to good general engineering practices you can't go far wrong, and don't take shortcuts, it usually has to have a fix on it later.

John

[bogstandard]

Just a little update on the engines I made. I decided to convert one to a horizontal engine for fitting into a model paddler.
It was a quickie exercise, with the criteria that the engine can be put back to how it was with just a few component changes.
This was achieved with great success and would take approx 20-30 mins to restore, and the engine turned out to be very powerful with the reduction gears on it.

John

[bogstandard]

Here is another little update.
This is one with a couple of videos of my own design 10mm bore by 20mm stroke piston valve steam engine. It still needs the control valve designing and making.
http://www.youtube.com/watch?v=QwOhxvGc5VY
and here -
http://www.youtube.com/watch?v=I8UCWr_BeqE

[nick.gilling]

Looks very smart indeed! Will have to watch the vid later, won't let me at work!

[Mcgyver]

Nick, O rings are used in steam engine valves, you get a double acting engine which has more than enough power to drive it.....but you've got to be carefully to use the right ones! using the wrong ones, vitrol, are potentially life threatening as super heated steam can get hot enough such that they can produce hydrofluoric acid which is nasty nasty stuff. usually you don't seem cylinder valves on smaller engines which will have a steam chest and slider valve but they are very very common on locomotives. better to do it properly and make cast iron rings imo

http://en.wikipedia.org/wiki/Hydrofluoric_acid

John, I see you are still having lots of fun! good stuff

[bogstandard]

Hi Mcgyver,
Nice to hear from you again. The only grinding I did on this one was the main cylinder block, the rest were as they came off the machine plus a bit of emery or steel wool.
I'm still having lots of fun, I have had a grin on my face just like a Cheshire cat since I got this one to run first time I put air onto it.
I just don't know what to tackle next, I don't fancy slide valves because I can't get my head round all the timing and reversing linkages, I've always fancied a turbine with a gearbox, or I could even start on my seal.
BTW Hemingway have released all the Woking engines now, and as suspected, LARGE increase in price - http://www.hemingwaykits.com/acatalog/Engine_Range.html

John

[Geof]

...I don't fancy slide valves because I can't get my head round all the timing and reversing linkages,...

Awe go on, do it...and then explain to us how it works. I once spent hours on a big steam engine in a museum in Ottawa trying to figure out what all the knobs and levers and links and things did without success.

[bogstandard]

Hi Geof,
Most of the twiddley doodah bits in an engine cab (at least in the UK) of a locomotive are to alter the timing of the steam inlet into the cylinder. Say when they pull away they wack 100% steam in, but when up to cruising speed (if thats what they call it in loco terms) they regulate the steam to the cylinders to say only 15%, and alter the timing as well, allowing it to expand a lot more efficiently. So they get better economy, or more chuffs to the buck.
Anyway, don't want to go down that road, I come from a railway town from the beginning of steam locos, and every model engineer around here builds locos, very boring. I need something different. Maybe I will try a single cylinder, single acting wobbler for a change, that will pass a minute or two (no disregards to all the single cylinder wobbler makers of the world).

John

[Geof]

Okay here is something different which, if I had the time and energy, I would like to play with someday. Make a compound expansion internal combustion engine; apply some of the principles from steam into the petrol or diesel engine field.

I figure this would work to dramatically enhance the ICE efficiency because the final venting of exhaust would occur at a much lower pressure and temperature. It is not likely it would be suitable for mobile applications but for stationary applications such as electricity generation it could be worthwhile.

[Mcgyver]

its the twiddley doodah bits that make it interesting. ok, loco's are out. head ye to the coast and become a sea faring man. not wait, more reversing gear! mill engines, thats the ticket. I'm gluten for punishment, when/if i ever get the triple done, its on to a Corliss.

here, the twiddley doodah bits are done and the engine awaits the top half chunky bits, cylinders, pistons, covers, steam chests etc.

http://i20.photobucket.com/albums/b2...uarttriple.jpg

http://i20.photobucket.com/albums/b2...uarttriple.jpg

I've been working on this forever, seems like each little part sends me off on a 6 month project to make some piece of tooling or another that would be just the thing. making perfect pipe flanges for this was i think what originally started onto cnc, then i have to learn electronics, and for that needed a benchtop power supply, for that needed an enclosure, for that a sheet metal brake, tubing bender to make what the flanges get silver soldered to etc etc etc. taken my 6+ years to make a couple of pipe flanges for it and they've not done yet! yes it's disease

[bogstandard]

Mcgyver,
Awesome, impressed, drooling down my t-shirt. You have made all the bits that I don't like doing, so send it to me and I'll finish it off. Just one problem, will it fit into my model boat.
With regards to your flanges, it just so happens that today I have to make 20 of them to finish the two engines I am building. Going by your building rate of six years, mine will be 2190 times quicker to make, so maybe there is a moral here, go manual young man. I think you have fallen into the trap of why do today what you can put off until tomorrow.:stickpoke

Geof,
Great idea about the expansion engine being used for petrol and diesel, one major flaw though, it would use fossil fuels so I think the idea would be fairly short lived.
Here is an idea I passed between the two brain cells I have left.
A self contained package.
Solar power -> split water to component parts, hydrogen & oxygen -> use to fuel flash boiler -> turn steam turbine -> power out.
Water in, water in the middle, water out, great all round, keeps the green party off your back, except -----
Designed for use in the third world, plenty of sunshine but can only be used during daylight hours.
Third world has a shortage of water, so use engine to pump up water from deep underground.
Because the engine is being used to pump water, need to buy another engine to do the first job it was originally designed for.
Great for the manufacturer, lousy for the consumer.
All good ideas usually have a down side.
As the old saying goes, there is nothing new in this world, it is just reinvented. Old ideas are usually the best.:banana:

John

[Mcgyver]

hehe, my shop is manual......its been a multi year diversion that started with the idea of hey, forget the file, i could do a bang up job on those flanges if i had a cnc.......... still working on it. picked up the pace recently, been debugging (bought a scope as part of learning electronics) the controller boards and I'm close. was all said tongue in cheek of course, us hobby guys have distinct advantage of getting to make whatever the heck we want without a deadline. numerous machines devices and tooling has been made in those years as well as a lot progress on other projects, I'm just 2190x slower than you at flanges

[bogstandard]

Point taken.