Steam Test

[Tony Bird]

Hi,
It doesn't matter how many steam engines you have built or how simple they are its is always a thrill the first time you see them run by steam. Compressed air is OK for timing and tweeking them but they are steam engines and I think they look better being run as they are designed for by steam. Today I finished a very simple single cylinder oscillating steam engine with a 8mm bore and 16mm stroke (5/16" x 5/8" in old money). It was built to try something out, which I will now find that someone else has already done.
Most engines that I have built are for use in either steam locomotives or steam boats. This engines was designed as a simple high speed engine for use in a boat. I had noticed that these simple single acting engines start to loose out when the steam pressure is increased due to the cylinder being lifted off the port face. This is not suprising as there is bound to be a point when the steam pressure does this, however double acting engines seem to run better when in this condition than those with single acting cylinders. I think it could be due to the fact that the double acting cylinder is being pushed off the port face at both of its ends so it is being lifted parallel to the port face. Where as the single acting cylinder is being lifted at an angle using the trunnion pin as a fulcrum. If this is so, then it might effect the running of the engine when it isn't receiving too much steam.
So I have built this engine with a 4 port face of a double acting engine but fitted a single acting cylinder to see if there is an improvement over the standard arrangement of just 2 ports. If nothing else it will lubricate the other end of the cylinder. Later I intend to try try the same arrangement with 2 port block fitted to the same engine. The cylinder and piston are light weight, the cylinder uses a piece of K&S brass tube and the long piston to give a large wearing area, aluminium with an '0' ring and oil grooves.

Port face.

Video.



I will have to see after I have made another port face if it was worth the effort with this engine.

Regards Tony.

 

[Tony Bird]

Hello again,

I thought the way that the piston rod and big end of the engine was made might interest the group. It is made from 1/16" mild steel sheet.

Which was marked out.

Crank pin hole drilled one side cut out and roughly filed before cutting the other side.

The other side was then filed.

Filing buttons where then used to form the big end.

The piston rod was made round using a filing block and file.

The rod was then blued and loctited into the piston.

Photograph of finished engine and test boiler.

Regards Tony.

 

[Philjoe5]

That's a nice looking engine Tony and the video was nicely done. Did you build the boiler also? Looks right at home with your steam engine.

You are so right about running steam engines on steam versus air. As a friend of mine once said " the difference between running an engine on air versus steam is like the difference between kissing your mom versus kissing your girlfriend" :big:

Cheers,
Phil

 

[peatoluser]

Superb looking test boiler. I also liked your photo tutorial of using hand tools to make a simple crank, especialy the use of a filing block.
I sometimes think that we forget that for small items using hand tools can be just as quick, if not quicker, than setting up a machine.
Sometimes a lot more satisfying as well.
yours
peter

 

[bearcar1]

Phil. I believe the proper response to your friends remark would have been "I wouldn't know, I've never kissed your Mom" :hDe:

But then again, maybe you wouldn't want to. :big:

:bow:


BC1
Jim

 

[Philjoe5]

But then again, maybe you wouldn't want to

Jim,
I spend a lot of time in the shop so I give off a background odor of stale burnt sulfurous cutting oil and way oil along with my usual body odor. Therefore, I will kiss any willing female (female readers, please note and PM me if you wish) :big: :big:

Cheers,
Phil

 

[Tony Bird]

Hi,
Yes I did build the fire tube boiler not to any design just used what I had in the workshop.

Videos.

Regards Tony.

 

[SignalFailure]

Nice idea Tony, sort of a hover-cylinder!

 

[Tony Bird]

Hi Paul,
A good description. This is a piece of video that caused me to think about having the extra ports.



When the pressure is increased and steam comes off the port face it shows that extra pressure is using the bottom of the cylinder as its fulcrum so lifting the upper part of the cylinder. It is also shown by the greater wear on the lower port face. At the moment a similar engine is being built with extra ports, it will be interesting to see if there is any difference.
Regards Tony.