Stuart 10v

[Steamchick]

Sorry, I was told of the root by a very clever Greek guy.. (ex college anyway, not sure doctor or professor of Engineering) We were debating the quality of Engineers and how they are respected and titled in some countries, but not others.
But as the quality of Engineers is variable I don't claim to be the most knowledgable anyway. Although clever people told me to do Engineering at college I did Physics - and not being clever enough to succeed in that I spent my career as an engineer, in various fields.
Thanks for the correction...
Did I get anything else wrong?
K2

 

[Richard Hed]

Sorry, I was told of the root by a very clever Greek guy.. (ex college anyway, not sure doctor or professor of Engineering) We were debating the quality of Engineers and how they are respected and titled in some countries, but not others.
But as the quality of Engineers is variable I don't claim to be the most knowledgable anyway. Although clever people told me to do Engineering at college I did Physics - and not being clever enough to succeed in that I spent my career as an engineer, in various fields.
Thanks for the correction...
Did I get anything else wrong?
K2

I don't know for sure, but the first engineers were military people who built machines of war (engtines) such as ballistas, onager, catapults, ramps, and other things for making war. These things were called "engines", so eventually, any kind of machine with moving parts could be called an "engine". I often call an electric motor an engine and some peeps get upset insisting that it is a "motor". Oh how silly.

 

[swarf]

Hi Swarf.
Here is the Enginineering bit that goes with Machining in the title of the website.... (My corruption of "Engine" - You can't have an Engine unless it is Engineered!

Aside: Engineering comes from ancient Greek for Ingenuity... I.E. the application of Ingenuity to solve problems is Engineering. And engineering is an Ingeneous device to convert energy in one form to another form. Boiling water from a "low pressure heat source" to make steam at a "high pressure gas supply", or expanding that hot steam into cooler water and developing a mechanical force on a piston. Both of these are "Heat Engines".).
Back to your problem:
Brass expands at:
"the coefficient of linear expansion of brass is 0.0000189 per °C." - So for 100 deg. C temperature rise it will expand a 1" diameter piston to 1.00189" - nearly 2 thou expansion.
Cast iron, on a 1" bore expanding 100deg.C. has "the coefficient of linear expansion of cast iron is 0.00001 per °C." - So it will expand to 1.001" = 1 thou expansion.
Therefore you need 2 - 1 = 1 thou clearance. ( or may be 1.5~2 to be sure and so you can hear the piston slapping about?).

I suggest you tin plate the piston skirt with a "lead-wipe" of Tin based solder.
I.E. flux the piston, tin it with solder, and while the solder is HOT and liquid, wipe it quickly with a dry leather cloth (Chamois leather is OK). WEAR GLOVES so you do not burn your hands! SKIN BURNS AND HURTS when touching metal as hot as molten solder. But this is how Plumbers made their soldered joints before factory pre-soldered fittings were available.
Then check there are no blobs or high spots of tin solder on the piston, and mic it to see if it needs linishing to size, around 0.001 to 0.0015" smaller than the bore - if it is a 1" diameter piston. (Linishing can be simply done by someone skilled and careful, using a file, but only as a rigid flat holder for a very fine emery paper to take off the tiniest amount of solder to reduce the diameter by a fraction of 0.001", while turning the piston at only 100~200rpm or so in the lathe).
I expect this tinning technique to increase the diameter of the piston by something like 0.0005" either side = 0.001" diameter.
The tin-solder in application in the engine is good for maybe 130 deg C - and I doubt you'll be doing enough work with the engine to need over 30psi steam!! (3 ~5 psi more like if just idling!). The tin is also a good bearing surface to slide in the bore.
Or you can make a new piston... with 0.001" clearance.
Of course, if it is a 2" bore engine then the clearance is about right...
But be cautious, measuring fractions of 0.001" requires very good measuring equipment and technique... Often not available to the Home machinist! (re: controlled temperature, slip gauges for calibration, etc.).
Take 10 measurements of the piston diameter, putting everything (piston, measuring tools) on the bench and turn around every time. Then do some statistics to see if you can measure the same thing repeatably. And I don't mean "can you repeatably turn the knob on the micrometer to the same number every time". I mean will the micrometer give you the same reading every time you pick-up it and the workpiece, and measure the part? Some micrometers have a vernier calibration around the barrel to achieve 0.0001" increments, but I am not that repeatable! And how repeatable are you at measuring the bore? Usually dial gauges to measure bores need to be set to the micrometer.. Set the micrometer to the piston diameter +0.001". Insert the bore gauge to the micrometer and set its DTI at zero. Compare this to the bore and see what size it really is... I was doing this at 12 years old, but all my work was double checked until I was 14 or so and was allowed to re=bore and hone engine blocks for cars on my own...
Give me a thumbs up if that makes sense to you? - Or I can accept a thumbs-down and corrective criticism from anyone who has more expertise than I. - Let's get it right.
K2

Piston rings.
You can make (or BUY!) cast iron rings, steel wire rings, Viton O-rings, or PTFE.
PTFE is really good - but with all materials - including simple cast iron - wear breathing protection (a face mask, like for COVID) to avoid breathing-in any dust. Almost anything will clog lungs affecting later life, and some things, like carbon from machining cast iron (especially when it just looks like a bit of smoke off the tool) is carcinogenic, so worth avoiding. PTFE and some plastics give of nasty toxic fumes in certain conditions, so simply take the usual precautions. or "Buy" these cheap and precise little components.
Graphited string works fine on my engines, but is a bit of a fiddle to get right. Not too much = tight, or too little = doesn't seal effectively.
And I have some engines with just labyrinth seals. = a few grooves with sharp square corners. e.g. 0.020~0.40" wide and deep and spaced.... (I make grooving tools from hacksaw blades). These prevent gas flow dynamically, so 8 is the maximum number of grooves, but even 1 works OK on a simple steam engine just for bench idling. - e.g. (d) below:
View attachment 148104
You can use just grooves in the piston and a smooth bore which will be OK.

Hope this helps?
K2

Thanks Steamchick,
Plenty of info to mull over.
Think I'm going to make a new piston, and go with graphite packing for the seal.

 

[swarf]

Sorry, the word came from Latin not Greek, don't be a geek.

How about a Greek geek?

 

[Steamchick]

I tried to learn some basic Greek... Couldn't get past "Ouzo" and "Ef Kharisto" ... (Please excuse phonetic spelling). But I enjoyed the Ouzo!

Considering a bit of History, was it Archimedes or Euclid that was considered the first Engineer?
Archimedes - an Ancient Greek mathematician, physicist, engineer, astronomer, and inventor (c. 287~217 BC; Syracuse‎, ‎Sicily) invented a clever water pump (first application of a screw?), as well as a Greek Fire catapult, defined the principle of the lever and invented the compound pulley, etc... - He was born in Sicily, so may be he spoke Latin?
Euclid (c. 330~265BC) probably attended Plato's academy in Athens before moving to Alexandria, in Egypt. He was a Mathematician, not Engineer. Source: Euclid, the Father of Geometry - Greek Mathematics - invented geometry and clever calculations (Euclidian relation, theorem, formulae, etc.)
And Heron of Alexandria (c. 10-70 CE) invented the first (condensing?) steam engines to open and close the temple doors (with pulleys and counterweights and "steam-pumped" water). As well as the first steam reaction turbine. (Hero's engine).
So to Engineering: Having just read Wikipedia, it seems that Engineering first became a term used as today around 1250.... but I thought it was from ~1250 BC? - That's how wrong I was!
https://en.wikipedia.org/wiki/Histo...neering has,develop useful tools and objects.
But I was interested to read that "The lever was also used in the shadoof water-lifting device, the first crane machine, which appeared in Mesopotamia circa 3000 BC,[6] and then in ancient Egyptian technology circa 2000 BC.[8] The earliest evidence of pulleys date back to Mesopotamia in the early 2nd millennium BC". So maybe I am wrong and Engineering began in Mespotamia? Even though the word is much later from Latin. I was taught about the Greeks "Engineering mathematics" and Egyptian "Building engineering" using rollers, ramps, levers, counterbalance machines, squares, levels, angle and distance measuring devices, etc. before that, but not about Mesopotamia having the shadoof, etc. And "The screw, the last of the simple machines to be invented,[11] first appeared in Mesopotamia during the Neo-Assyrian period (911-609) BC"
Wow!
I have learned a lot of history from this one! Sorry if that is being a Geek... (I don't really know what a Geek is...).
thanks,
K2

 

[Richard Hed]

I tried to learn some basic Greek... Couldn't get past "Ouzo" and "Ef Kharisto" ... (Please excuse phonetic spelling). But I enjoyed the Ouzo!

Considering a bit of History, was it Archimedes or Euclid that was considered the first Engineer?
Archimedes - an Ancient Greek mathematician, physicist, engineer, astronomer, and inventor (c. 287~217 BC; Syracuse‎, ‎Sicily) invented a clever water pump (first application of a screw?), as well as a Greek Fire catapult, defined the principle of the lever and invented the compound pulley, etc... - He was born in Sicily, so may be he spoke Latin?
Euclid (c. 330~265BC) probably attended Plato's academy in Athens before moving to Alexandria, in Egypt. He was a Mathematician, not Engineer. Source: Euclid, the Father of Geometry - Greek Mathematics - invented geometry and clever calculations (Euclidian relation, theorem, formulae, etc.)
And Heron of Alexandria (c. 10-70 CE) invented the first (condensing?) steam engines to open and close the temple doors (with pulleys and counterweights and "steam-pumped" water). As well as the first steam reaction turbine. (Hero's engine).
So to Engineering: Having just read Wikipedia, it seems that Engineering first became a term used as today around 1250.... but I thought it was from ~1250 BC? - That's how wrong I was!
https://en.wikipedia.org/wiki/Histo...neering has,develop useful tools and objects.
But I was interested to read that "The lever was also used in the shadoof water-lifting device, the first crane machine, which appeared in Mesopotamia circa 3000 BC,[6] and then in ancient Egyptian technology circa 2000 BC.[8] The earliest evidence of pulleys date back to Mesopotamia in the early 2nd millennium BC". So maybe I am wrong and Engineering began in Mespotamia? Even though the word is much later from Latin. I was taught about the Greeks "Engineering mathematics" and Egyptian "Building engineering" using rollers, ramps, levers, counterbalance machines, squares, levels, angle and distance measuring devices, etc. before that, but not about Mesopotamia having the shadoof, etc. And "The screw, the last of the simple machines to be invented,[11] first appeared in Mesopotamia during the Neo-Assyrian period (911-609) BC"
Wow!
I have learned a lot of history from this one! Sorry if that is being a Geek... (I don't really know what a Geek is...).
thanks,
K2

AOne meaning of the word geek is a person who bites the heads off chickens. The more modern meaning is a very smart parson often socially awkward and has his/her nose into some subject obsessively, very much like a "nerd".

 

[Steamchick]

I am NOT a very clever person, hope I am not socially inept, and apologise if I appear obsessive. Really, I think I am curious to learn where I do not have the formal education. But call me a Geek if you think it appropriate
K2

 

[Richard Hed]

I am NOT a very clever person, hope I am not socially inept, and apologise if I appear obsessive. Really, I think I am curious to learn where I do not have the formal education. But call me a Geek if you think it appropriate
K2

Well, let me explain further: Obsessive is not necessarily what is meant in the vernacular. It might mean obsessive for more information, obsessive curiosity, obsessive for more detail. Who was that obsessive little man who got the nobel prize for Brownian Motion? tiny movements that one needs a microscope to see.

 

[Steamchick]

Thanks Richard. Well, that's me.. obsessive for more information, obsessive curiosity, obsessive for more detail. My wife calls me that and gets really frustrated by it sometimes.
But from you I'll take it as a compliment.
K2.

 

[Steamchick]

Maybe it was Brown who got the Nobel prize for Brownian motion?
"This motion is named after the botanist Robert Brown, who first described the phenomenon in 1827, while looking through a microscope at pollen of the plant Clarkia pulchella immersed in water."
- Wrong! - That's me again, impulsive and obsessive:
It was Jean Perrin in 1908. Perrin was awarded the Nobel Prize in Physics in 1926 "for his work on the discontinuous structure of matter"
(You know a hell of a lot of stuff!).
Let's get back to the thread of the Stuart 10V...
K2

 

[Jasonb]

If you are going to make a new piston then there is really no need for a piston ring or packing particularly if you just want and an engine that will tick over slow and smooth for display. 1000s have been built without rings as that is what is on the drawings.

 

[Richard Hed]

Maybe it was Brown who got the Nobel prize for Brownian motion?
"This motion is named after the botanist Robert Brown, who first described the phenomenon in 1827, while looking through a microscope at pollen of the plant Clarkia pulchella immersed in water."
- Wrong! - That's me again, impulsive and obsessive:
It was Jean Perrin in 1908. Perrin was awarded the Nobel Prize in Physics in 1926 "for his work on the discontinuous structure of matter"
(You know a hell of a lot of stuff!).
Let's get back to the thread of the Stuart 10V...
K2

No, this obsessive fellow got his Nobel prize on Brownian motion which proved that molecules (or atoms) exist. The prize committee refused to give him a second prize for his most famous work because no one had ever been given a second prize before. Really, this fellow was a real jerk because when he wrote his papers, his wife's name did not appear on the work, but he didn't do the obsessive calculations, SHE DID but he got the credit. She divorced him for good reason and ended up with the Nobel prize $$. He may well have been the most famous man on the planet for a few decades.

Who was the most famous man in the world from 1868 to the end of that century?

 

[swarf]

Took two trys, but I got it.

 

[Steamchick]

No, this obsessive fellow got his Nobel prize on Brownian motion which proved that molecules (or atoms) exist. The prize committee refused to give him a second prize for his most famous work because no one had ever been given a second prize before. Really, this fellow was a real jerk because when he wrote his papers, his wife's name did not appear on the work, but he didn't do the obsessive calculations, SHE DID but he got the credit. She divorced him for good reason and ended up with the Nobel prize $$. He may well have been the most famous man on the planet for a few decades.

Who was the most famous man in the world from 1868 to the end of that century?

Abe Lincoln?

 

[Richard Hed]

Abe Lincoln?

The Nobel prizes weren't given out till the late 1890s. Lincoln was already ded. But for the most famous and well known person in the WHOLE world, was also the most photographed man in the 19th century. His photograph is today EXTREMELY pervasive, he is on the US 50$ bill. The Nobel prize person was Einstein. His wife did the difficult calculations and he gave her NO credit. What an a$$whole. On their divorce he gave her all the prize money.

Oddly, the prize was awarded for one of Einsteins least important contributions and CERTAILNLY not what he is remembered for now.

 

[swarf]

As mentioned, I got the piston on the second try. Have pics but can't post them, because the files are to big. Don't know how to correct that.

 

[swarf]

New problem.
After partially machining the connecting rod, I find that the hole on the small end of the connecting rod is nowhere near center.
I machined the big end to the point of having accurate dimensions after having split and mill it. After laying out for both holes, I find the hole for the little end way off center.
Double checked everything, can't figure it out, maybe a similar rod from another kit.
Don't know.

 

[Richard Hed]

New problem.
After partially machining the connecting rod, I find that the hole on the small end of the connecting rod is nowhere near center.
I machined the big end to the point of having accurate dimensions after having split and mill it. After laying out for both holes, I find the hole for the little end way off center.
Double checked everything, can't figure it out, maybe a similar rod from another kit.
Don't know.

cAN you send a photo? What are you using to measure with? And when you say "way off", how far do you mean?

 

[swarf]

cAN you send a photo? What are you using to measure with? And when you say "way off", how far do you mean?

Hi Richard, suppose to be 1 11/16" or 1.687". I used digital calipers. Then checked with a height gage on a surface plate.
In order to center the little end I had to take off 50 thou on each half of the big end
That worked, but now there's not enuf meat for the hole on the big end. Will see if I can send a pic. My phone takes pics that make files to big to upload.

 

[Richard Hed]

Hi Richard, suppose to be 1 11/16" or 1.687". I used digital calipers. Then checked with a height gage on a surface plate.
In order to center the little end I had to take off 50 thou on each half of the big end
That worked, but now there's not enuf meat for the hole on the big end. Will see if I can send a pic. My phone takes pics that make files to big to upload.

You can download for free GIMP which is as good or better than the expensive photo manipulation programs. Open your files with GIMP then find the "resize" function. It's easy but may be intimidating at first. I often make two or three sizes for various purposes. The worst part of the whole is that GIMP wants to "save as" it's own file preferences. Use "save as" and find *.jpg or jpeg. If you don't want to download GIMP, then try microsux's photo bitmap program