Would you like to meet our new product - Beam Steam Engine?

[Daniel Ho]

Hello all!
Here is our Beam Steam Engine design, we hope you like it. Can you guys give some advice? Is there anything else that needs to be modified?
Please feel free to let us know what you think. Any ideas are welcome. Let's build a great steam engine together! Thank you all in advance!

Cheers,
Daniel

 

[stevehuckss396]

I don't know enough about steam to advise one way or another but it looks good.

 

[Daniel Ho]

I don't know enough about steam to advise one way or another but it looks good.

Hi Steve!Thank you for your reply!

 

[Jasonb]

You need to look at the joint where the piston rod joins the beam as the movement of piston & rod is not vertical due to the arc that the end of the beam moves in.

 

[Steamchick]

As Jason says... James Watt invented the parallel motion linkage to make the connection to the piston rod run a straight line. This piece of ingenious design is an important part of the mechanical beauty of this engine. Previous engines used chains over curved beam ends to get a tension link that agreed with the straight line motion of the piston rod. Then James Watt resolved this to permit compression as well as tension forces to be transmitted from the curved (arc) motion of the beam end to the straight motion of the piston rod.
On boiler and steam supply. I suggest:
- run the steam pipe between the boiler and engine and shorten the pipe run as much as possible. Fully lag the steam pipe and valve where outside the heat source. Fit the regulator valve at the steam take-off at the boiler, otherwise, when closed, the pie will col and fill with condensate (water) which will damage the engine when you open the valve. It will cause what we call an hydraulic lock, and can break or bend components.
- run the steam feed pipe via the firebox to add heat to the supplied steam and reduce (problematic) condensate at the engine cylinder. Fit auto-drain relief-valves to both ends of the cylinder, to relieve the condensate while the engine warms up.
- fit a water gauge to the boiler.
Fit a pressure gauge to the boiler.
- fit a blow-down valve at the bottom of the boiler to empty it after use.
- fit a feed water pump and reservoir to maintain boiler water level. The boiler will use water much faster than you expect!
That's a start.
K2

 

[Daniel Ho]

You need to look at the joint where the piston rod joins the beam as the movement of piston & rod is not vertical due to the arc that the end of the beam moves in.

Thank you Jason!

 

[Daniel Ho]

As Jason says... James Watt invented the parallel motion linkage to make the connection to the piston rod run a straight line. This piece of ingenious design is an important part of the mechanical beauty of this engine. Previous engines used chains over curved beam ends to get a tension link that agreed with the straight line motion of the piston rod. Then James Watt resolved this to permit compression as well as tension forces to be transmitted from the curved (arc) motion of the beam end to the straight motion of the piston rod.
On boiler and steam supply. I suggest:
- run the steam pipe between the boiler and engine and shorten the pipe run as much as possible. Fully lag the steam pipe and valve where outside the heat source. Fit the regulator valve at the steam take-off at the boiler, otherwise, when closed, the pie will col and fill with condensate (water) which will damage the engine when you open the valve. It will cause what we call an hydraulic lock, and can break or bend components.
- run the steam feed pipe via the firebox to add heat to the supplied steam and reduce (problematic) condensate at the engine cylinder. Fit auto-drain relief-valves to both ends of the cylinder, to relieve the condensate while the engine warms up.
- fit a water gauge to the boiler.
Fit a pressure gauge to the boiler.
- fit a blow-down valve at the bottom of the boiler to empty it after use.
- fit a feed water pump and reservoir to maintain boiler water level. The boiler will use water much faster than you expect!
That's a start.
K2

Thank you so much! We will make improvements!

 

[terryd]

Hi,
I can't see any cylinder valves to control the steam . A beam engine is dual acting, steam should be controlled to enter the lower and upper chambers of the cylinder in a controlled manner and usually this is done with a steam chest on the cylinder with a sliding valve with an operating mechanism linked to the piston movement which controls the steam flow to produce smooth movement - of course there may be some 'magic mechanism' in the cylinder plinth which I am unaware of.
Also the beam will not work as shown in your drawing, as Jason says the piston rod will jam as the beam reciprocates up and down. As K2 suggests the most common solution is the Watts linkage, relatively simple and reliable.
Consider a ceramic gas burner rather than the spirit one you appear to have drawn. You should also incorporate a displacement lubricator for steam oil to lubricate the cylinder to prevent excessive wear.
The design is not too elegant aesthetically, there are a lot of engines and kits similar to this which are much more appealing.
I suggest that you do a lot more research into how steam engines, especially beam engines work.

Here are views of StuartTurner engines similar to yours, the steam valve with it's associated operating mechanism is the grey part attached to the front of the cylinder on the lower example, the brass part in front of that looks like the displacement lubricator and the Watts linkage, made up of 8 links and two side arms (called the entablature) is also shown clearly on the upper example. I think that you have some work to do.
Also a simple 'pot' boiler like the one you have shown may not produce enough steam to drive the engine, the Stuart boilers like this are of 'Babcock' design with external water tubes attached below to increase the heating area. Again I suggest research. to see more about boilers here is an excellent series to start your researches.




Best of luck with your project

TerryD

 

[Steamchick]

Hi Terry, perhaps I have spotted a valve rod? On the plan drawing, there is what appears to be a valve rod from an eccentric on the crankshaft to what could be a valve chest beneath the cylinder? That would make it single acting....
With a small bore (say 1/2" ?) and stroke (3/4" ?) It could work with a pot boiler and meths burner, like a Mamod toy engine?

Daniel, is this engine planned as a toy model for sale?
K2

 

[Steamchick]

Daniel Ho. Is this your website?
enginediyshop.com
K2

 

[Jasonb]

It's got a piston valve driven by an eccentric and could well be single acting or double.

Watt linkage is not the only way to deal with the way the piston rod joins the beam and as this is quite a "simple" design of engine other means of pivot can be used, take a look at something like Elmers #24 beam engine

 

[terryd]

Hi Terry, perhaps I have spotted a valve rod? On the plan drawing, there is what appears to be a valve rod from an eccentric on the crankshaft to what could be a valve chest beneath the cylinder? That would make it single acting....
With a small bore (say 1/2" ?) and stroke (3/4" ?) It could work with a pot boiler and meths burner, like a Mamod toy engine?

Daniel, is this engine planned as a toy model for sale?
K2

Hi K2,
Yes I spotted the valve rod on the plan view. but as you say it would probably be single acting unless a steam way is drilled vertically in the cylinder block wall, but from the drawing that appears to be too thin to drill. A single acting beam engine would be a bit 'lumpy' in action though unless the flywheel is very heavy. I can see no method of valve timing adjustment but I suppose that is determined during detail design stage. It looks more than a toy though as there's a govenor which actually appears to control the flow of steam.

Mamod type toy engines tend to be simple oscillating cylinder engines, a beam engine has many more moving parts, hence more friction, it would take some experimentation to prove the boiler concept. I think that a displacement oiler is a good idea though

 

[terryd]

It's got a piston valve driven by an eccentric and could well be single acting or double.

Watt linkage is not the only way to deal with the way the piston rod joins the beam and as this is quite a "simple" design of engine other means of pivot can be used, take a look at something like Elmers #24 beam engine

Hi Jason,
Thanks for the response, I must admit to following your projects, articles and efforts on Model Engineering mag. for many years now.

I see what you mean about the linkage. I've seen Elmer's models previously, unfortunately my views are a little biased as a qualified mechanical engineer who has worked on both large and small projects in my career I tend to look at things from a real engineering perspective rather than a modellers and such a mechanism as Elmers just would not be viable in the real world of mechanical engineering which is why we don't see full size examples of such simple solutions, but I concede that it obviously works as a toy. I must admit to a preference for more elegant solutions and was commenting, perhaps unfairly on that basis.

I commented on the valve operation in an earlier posting but the cylinder wall appears from the drawing to be rather thin for drilling to create an upper port.

Best regards

TerryD

 

[Jasonb]

Bit hard to tell from the drawings but does look like the top of the cylinder is open and of thin wall so would go with single acting being the more likely.

Valve timing would be easy enough to adjust simply by altering the position of the eccentric on the crankshaft. Not enough detail to see if overall length can be adjusted to get valve position correct but as they will be mass produced on CNC should not be hard to make to the 3D cad model length.

I'd put it a bit above Mamod, more a modern day Doll, Markin, Plank, etc

If it is indeed single acting with an open topped cylinder then another option would be to allow the piston to tilt as the angle will be quite small. Simply have a convex side to the piston and an O ring seal which will take up the minute amount of ovality at the tilted position. Other options would be to use a longer piston and have a wrist pin much like an IC engine or pivot the conrod at the piston end too the beam just becomes the guide rocker like you find on an Evans linkage

 

[abby]

I find this post strange , are you planning to manufacture what you refer to as "our beam engine" as a commercial enterprise ?
If this is the case are you already a manufacturer with production facilities ? If true then why are you pumping members of a model making forum for their views on your design?
If you are a newbie model maker looking for advice then fair enough , but if you are not then fund your own research like western manufacturers do.
Dan.

 

[Steamchick]

Abby, I think he is behind enginediyshop.com from looking at the logo on his I.D.?
K2

 

[abby]

Thanks KC , I hadn't read all the posts so I missed that.
I have to admit I joined several model forums to push my castings but I gave advice where I thought it might help.
Dan.

 

[Daniel Ho]

Daniel Ho. Is this your website?
enginediyshop.com
K2

Hi K2.Sorry for the late reply.I am the administrator of this website. We are developing this beam steam engine to sell as our new steam engine model toy. This post was posted to take in some of the advice from everyone. We also want to know if anyone will have expectations for this beam steam engine. Thank you for your reply.

Kind regards,
Daniel

 

[Daniel Ho]

I find this post strange , are you planning to manufacture what you refer to as "our beam engine" as a commercial enterprise ?
If this is the case are you already a manufacturer with production facilities ? If true then why are you pumping members of a model making forum for their views on your design?
If you are a newbie model maker looking for advice then fair enough , but if you are not then fund your own research like western manufacturers do.
Dan.

Hi Abby. We are a dealer of steam engine models.This post was posted to take in some of the advice from everyone. We also want to know if anyone will have expectations for this beam steam engine. Thank you for your reply.

Best regards,
Daniel

 

[Daniel Ho]

Hi,
I can't see any cylinder valves to control the steam . A beam engine is dual acting, steam should be controlled to enter the lower and upper chambers of the cylinder in a controlled manner and usually this is done with a steam chest on the cylinder with a sliding valve with an operating mechanism linked to the piston movement which controls the steam flow to produce smooth movement - of course there may be some 'magic mechanism' in the cylinder plinth which I am unaware of.
Also the beam will not work as shown in your drawing, as Jason says the piston rod will jam as the beam reciprocates up and down. As K2 suggests the most common solution is the Watts linkage, relatively simple and reliable.
Consider a ceramic gas burner rather than the spirit one you appear to have drawn. You should also incorporate a displacement lubricator for steam oil to lubricate the cylinder to prevent excessive wear.
The design is not too elegant aesthetically, there are a lot of engines and kits similar to this which are much more appealing.
I suggest that you do a lot more research into how steam engines, especially beam engines work.

Here are views of StuartTurner engines similar to yours, the steam valve with it's associated operating mechanism is the grey part attached to the front of the cylinder on the lower example, the brass part in front of that looks like the displacement lubricator and the Watts linkage, made up of 8 links and two side arms (called the entablature) is also shown clearly on the upper example. I think that you have some work to do.
Also a simple 'pot' boiler like the one you have shown may not produce enough steam to drive the engine, the Stuart boilers like this are of 'Babcock' design with external water tubes attached below to increase the heating area. Again I suggest research. to see more about boilers here is an excellent series to start your researches.

View attachment 140172
View attachment 140171

Best of luck with your project

TerryD

Thank you Terry!