Plan quality

[Bogstandard]

I personally have great difficulty understanding this sort of thing.

If his plans are such crap, I could have made a fortune selling mine, at least I know that whoever uses them has a chance of getting a runner.

In all fairness, all people who sell plans and the like should always have some freebies on their site, just so people can see the quality they are getting.

I have seen almost all plans that are available, and to me only about 10% of them are worth buying. All the little wobblers just aren't worth buying, you can usually get better quality free plans. I do buy plans, if I think they are worth the money. Just look at Bill Reichart, god bless him, but at least his spouse is most probably getting a few bucks out of them.

http://www.billreichart.com/engines.shtml

Very well laid out plans, good build description, and not a lot of readies. What more could you ask for.

Another one is Jan Ridders. A true master of design and accomplishment in my opinion, great plans and descriptions as far as his English will take him. How much does he charge - zilch, nothing, gratis. That is a true model engineer. Satisfaction from sharing, not ripping people off.

http://heetgasmodelbouw.ridders.nu/index_framelinks_english.htm

And he also answers emails when you ask a question.

Sermon over, back to the Green gripe.

Bogs

 

[rake60]

I'm a player!

I just sent Mr. Green $45 to see what I get.

If it is not enough information to successfully build the
engine my legal team will take it from there.

This is a dying craft that deserves to be protected.

We can do that!

Rick

 

[CrewCab]

This is a dying craft that deserves to be protected.

Can we start a fund ........... ............ put me down for $5 and send me your paypal details

CC

 

[rake60]

I just received the plans for this engine from Mr Green via email.
They were in the form of two zip files. 3.52MB and 3.22MB in size.

The plans are more photographs than drawings.

Many of the parts used in the engine are standard hardware and plumbing
fittings. The photos show any modifications needed to them with sizes
marked on the pictures themselves.

Parts that require machining do have dimensioned line drawings in the
plans.

There is no text but I believe the engine can be built with the information
contained in the pictures and line drawings.

Is it worth $45?
That would be a personal choice.

It just may be my next project.

Rick

 

[NickG]

Just had a look at the example drawings on his website ... they are a joke! Worth nowhere near $45 but just looks like one of those things, what a rip off!

 

[rake60]

Just had a look at the example drawings on his website ... they are a joke! Worth nowhere near $45 but just looks like one of those things, what a rip off!

When something is accused of being a rip off I will buy it to prove or disprove that.
I have already done exactly that.

While they may not be the best plans for a beginner to work from, they are complete
and contain all the information needed to successfully build the engine.

I'm NOT trying to say they are worth the cost.
I AM saying they are complete and concise.

Rick

 

[NickG]

The example drawings on his website don't look complete or concise to me, but maybe he's omitted information on those to protect his design.

I don't think any model engineering drawing pack I've seen has all the information to sucessfully build a working engine. None I've seen have dimensional tolerances let alone geometric tolerances, they assume knowledge of limits and fits and often there is an article or building instructions to back the drawings up, it is a hobby after all.

This engine however, is aimed at commercial applications as much as it is model engineers. Therefore I think if you're marketing something like this as a patented design with as many applications as the designer says it has, it should be done properly with a full set of accurate and concise drawings. I don't think he has gone about this in the right way, he is trying to market a prototype (proof of concept type thing) that has been bodged together with existing parts. That's just my opinion though so will leave that there.

I would agree with Rick's point above, by the sound of it there is enough information there for the experienced model engineer to build the engine, however, whether it's worth the money is up to the individual to decide.

Nick

 

[IanN]

Hi,

OK - this may be a bit of a rant but I need to voice my opinion about Mr Green's engine.

I've visited Mr Green's website a number of times, and each time I notice more errors and misleading statements.

I think it is a bad idea to buy these plans (in whatever form they may be) as it seems that the designer has some rather misguided ideas and a poor understanding of both mechanics and basic steam-engine concepts.

This website / engine design has been discussed in another thread in this forum (see under "Novel steam engine transmission to rotary motion idea"). I stated my initial opinions in that other thread.

In the website the designer makes a number of unsubstansiated claims that are worded in a way that seems to be deliberately misleading:

1) He claims that the engine will run on a couple of PSI with low steam consumption ("low volume" to quote the site) but you cannot change the laws of physics or thermodynamics - the available output power at the shaft will be very small and the motor will not be able to do any useful work under these contitions.

2) He talks about "efficiency" without defining how it is measured, and makes illogical statements such as "The output shaft continues rotation while the pistons stand still. The result is that the efficiency is increased dramatically." - I am lost for words......

3) He claims the design "eliminates the crank" yet the animated gif clearly shows that the flex rod connects to an off-set pin (a crank) on the flywheel.

4) He claims the design "eliminates side force" but the cyliders oscillate (and so are subject to side forces) and at the base of each cylinder there is a bearing tube to prevent the side forces twisting the pistons out of alignement within the cylinders (the equivilent of a crosshead in a normal engine).

5) He claims the design is a great step forward because it does away with the lower cylinder glands and seals (in other words it has single acting rather than double acting cylinders) as if this is a new concept.

6) He claims the advantages of low maintenance - but ignores the boiler maintenance required.

7) He lists benefits of:
- Costs little to build,
- Extremely lightweight,
- Very small profile for economy of space.
All of which ignore the requirement for a boiler - note the picture of the engine installed in a boat.

8 ) He states "The flex rod is nearly frictionless as the flexing is like a spring in which the energy required to flex it is returned in equal amounts." but if you look at the operation of the unit, one end of the flex rod is at a fixed point on the frame on the axis of the output shaft and the other on the (non-existant) crank - a fixed radial displacement from the axis of the output shaft. In other words the rod does not oscillate and bend from side to side, but twists maintaining a fixed curve. There is no "spring action" involved at all.

It just goes on and on.


For me, two of the most worrying issues are:

He dismisses problems of steam generation with the statement that "the boiler requirements are minimal". (If he applies the same level of engineering theory to his boiler design and construction as he shows in the rest of his website, I would imagine that most members of this group would take care to stay as far away from any of Mr Green's boilers as possible.)

Second,he claims that:

"The unique feature of the "Flex Rod Transmission" is that it produces an intermittent movement whereby the valve movement is stopped in its open and closed position during the power and exhaust strokes. This gives prolonged, fully opened valve timing."

Most steam engine designs go to great lengths to REDUCE the valve open times (through the use of variable "cut-off") to get maximum energy from the steam expansion - it seems the designer of this device does not understand this rather basic concept.


Given the points above, I suspect that any plans produced by the designer will have many errors and ommisions.

This sort of poor presentation of ideas and design gives engineering a bad name.

Finally, the design has been patented for five years, but Mr Green does not give any instances of satisfied commercial users on his website.......

Ian.

 

[NickG]

Well said Ian, I noticed a couple of these points myself but agree with all of them!