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And now for something completely different!
- Thread starter Doc James Hammond
- Start date
Konrad
Very Strong User
That is Real Control!! One gets a real visceral connection with C/L. None of these waves or radiating connections.
All the best,
Konrad
All the best,
Konrad
Doc James Hammond
Very Strong User
Actually, to be honest, Konrad I used to do it because being a poor scholar, as well as a mad keen aeromodeller, I had no money for radio control sets!
However once you get into it, it takes hold of you - then of course you go to competitions, then the rest is history.
Hooked.
Fondest of memories; I have to say I really did enjoy my competitive (FAI Team Race - later F2c) control line in the mid to late seventies. I was incredibly lucky to team up with a really good pitman (Peter Williams) who by pure chance picked me up one day when I was a PhD student hitchhiking back to Cambridge - unbelievably he was looking for a pilot!.
We had a lot of success, and even more fun - briefly holding the UK Final record at 9:12 - desperately slow by today's standards, but fast for the time. Funny, when we won that competition, for the first, and only time, my Mother, My sister, And my Fiancé were also present.
We designed and made our own models, and engines too - you simply couldn't buy them.
So it became a real multi faceted competition:
I really loved it.
Then life got in the way, as it mostly does and we drifted out of it.
But...this year in August, for the fist time in over 40 years, the old, well remembered and hopefully still formidable team of Hammond/Williams will rise again! We are going to compete at the British National Championships!
I just cannot imagine how much fun thats going to be.
Cheers,
Doc.
However once you get into it, it takes hold of you - then of course you go to competitions, then the rest is history.
Hooked.
Fondest of memories; I have to say I really did enjoy my competitive (FAI Team Race - later F2c) control line in the mid to late seventies. I was incredibly lucky to team up with a really good pitman (Peter Williams) who by pure chance picked me up one day when I was a PhD student hitchhiking back to Cambridge - unbelievably he was looking for a pilot!.
We had a lot of success, and even more fun - briefly holding the UK Final record at 9:12 - desperately slow by today's standards, but fast for the time. Funny, when we won that competition, for the first, and only time, my Mother, My sister, And my Fiancé were also present.
We designed and made our own models, and engines too - you simply couldn't buy them.
So it became a real multi faceted competition:
- Who could design and make the lightest, best handling, and fastest model
- Who could make the fastest, most economical engine.
- Who could do the fastest pit stops (Peter averaged 6 seconds)
- Who could fly the best, and sometimes most aggressive 100 laps.
I really loved it.
Then life got in the way, as it mostly does and we drifted out of it.
But...this year in August, for the fist time in over 40 years, the old, well remembered and hopefully still formidable team of Hammond/Williams will rise again! We are going to compete at the British National Championships!
I just cannot imagine how much fun thats going to be.
Cheers,
Doc.
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Super nice! Looking forward to seeing photos from this event. 
Doc James Hammond
Very Strong User
Don't look now, but I can see your toes..
Looks really cool I look forward to watching the build.
Looks really cool I look forward to watching the build.
Doc James Hammond
Very Strong User
Don't look now, but I can see your toes..
Looks really cool I look forward to watching the build.
I know...aren't they twinkly?
Yes I think this one will be one for the builders as I intend to document the construction of the pan pattern too.
VERY old skool.
Cheers,
Doc J.
Konrad
Very Strong User
Doc,
For what its worth I spent hours on a flow bench during the development of my FAI F3D engine. One of the things I noticed is that the addition of an inlet guide cone can add 3% to the inlet flow.
Back in those days we ran rear rotor engines. This often meant that the inlet was often up against the firewall. These inlet cone made a noticable difference on the possitive side to the rpm reading. It looks like in your drawing that the inlet is also next to an obstruction. If running rear induction engine you might want to give this a try.
For what its worth I spent hours on a flow bench during the development of my FAI F3D engine. One of the things I noticed is that the addition of an inlet guide cone can add 3% to the inlet flow.
Back in those days we ran rear rotor engines. This often meant that the inlet was often up against the firewall. These inlet cone made a noticable difference on the possitive side to the rpm reading. It looks like in your drawing that the inlet is also next to an obstruction. If running rear induction engine you might want to give this a try.
Doc James Hammond
Very Strong User
Woo Konrad that's really Helpful! Thanks. I did do a bit of work years ago with Burt Metkemeyer on silicon pistons for .40 pylon engines.Thanks for the useful info - I can easily see how it would work.
Cheers,
Doc.
Konrad
Very Strong User
I saw 3% improvement for constant flow. When dealing with pulsed and reversionary flow the improvements weren't as high, but they were still noticeable.
For those who are interested, the use of silicon in the aluminum alloy is to make the aluminum harder resulting in a lowwer coefficient of drag (friction). It also helps controls the thermal expansion. The down side is that high silicon aluminums are brittle. (Engineering is hard, if it wasn't everyone could do it)
In my day I got the 28% and higher silicon content aluminum for Russia. I couldn't find any American mills that had real high silicon aluminums.
For those who are interested, the use of silicon in the aluminum alloy is to make the aluminum harder resulting in a lowwer coefficient of drag (friction). It also helps controls the thermal expansion. The down side is that high silicon aluminums are brittle. (Engineering is hard, if it wasn't everyone could do it)
In my day I got the 28% and higher silicon content aluminum for Russia. I couldn't find any American mills that had real high silicon aluminums.
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Doc James Hammond
Very Strong User
Aha - like many things, you couldn't buy it at the time so I used to make it.
Then we used aluminium liners with chroming at first, then later a plasma oxidation process.
When you think that aluminium oxide is a sapphire which has a Moh hardness of 8 then you are getting up there. The other good thing is that the surface was pretty controllable so you could almost pit it at will.
Worked pretty well.
Cheers,
Doc.
Konrad
Very Strong User
You could make high silicon aluminum at home? I thought it required vacuum furnaces and a heat treat oven to keep the stuff from falling out of suspension
I too tried thermal barrier coatings. I never got them to work. (I was forced to stay with chrome, and all the issues associated with it!) I think the latest engines from Russia had the aluminum oxide P&Ls. If one can get the process to work it sure beats the electroless nickel process that is masquerading as high performance plating!
What we are talking about is material science and process development. This really is the key to advancement.
I too tried thermal barrier coatings. I never got them to work. (I was forced to stay with chrome, and all the issues associated with it!) I think the latest engines from Russia had the aluminum oxide P&Ls. If one can get the process to work it sure beats the electroless nickel process that is masquerading as high performance plating!
What we are talking about is material science and process development. This really is the key to advancement.
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Doc James Hammond
Very Strong User
I have a PhD in Materials Science from Cambridge, Konrad, so I had some idea what I was doing, but as to facility, I don't know if you have ever heard of a UK company in a village called Melbourn (without the "e") close to Cambridge, called Metals Research?
It's gone now more's the pity, but I used to work there until it merged with Cambridge Scientific Instrument Company (Electron microscopes. EBMF etc) - where I worked for a further 10 years developing Nd doped YAG/YIG laser crystals and III-V semiconductors.
I can tell you that at MR we could make almost anything metallic - and did.
Ever heard a single crystal of lead ring like a bell...? REALLY weird!
Anyway, before the advent of ABC and AAC engines, we had to use steel liners and cast iron pistons - so being smart fellows, we nitrided the steel liners and used ultra stable cast iron for the pistons. Where to find the super stable cast iron you might ask?
Window sash weights!
Turns out that the sash weights cast 100 or more years ago are not only really age stabilised, but made of very high quality Meehanite. One of my better ideas as it turned out. Many wondered why we could sometimes be seen skulking around very old houses that were under demolition in the Cambridge area - They probably thought we were Ghost hunting!
Now there's some neat materials science development!
I loved it.
Cheers,
Doc.
Konrad
Very Strong User
Well, that's a heck of a home!!
The closest single crystal I've dealt with are turbine blades.
Don't know about the window sashes from the country that spawned the industrial revolution. But the window sashes from the old Victorians around here are riddled with porosity, slag, sand and other impurities as to make them worthless as anything other than ballast/counter weights.
The closest single crystal I've dealt with are turbine blades.
Don't know about the window sashes from the country that spawned the industrial revolution. But the window sashes from the old Victorians around here are riddled with porosity, slag, sand and other impurities as to make them worthless as anything other than ballast/counter weights.
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Doc James Hammond
Very Strong User
I did a lot of work on S/C turbine blades as a student. Very tricky to grow.
Our meehanite was fabulous sometimes but at others like you say it was mainly waste.
Halcyon days...
Doc.
Doc James Hammond
Very Strong User
Vintage B, and Barton B team trace Crutches I made yesterday.
I don't do much metalwork these days, especially not by hand with a toolmakers vice and hacksaw and a handful of files!
But with some perseverance...
Cheers,
Doc.
I don't do much metalwork these days, especially not by hand with a toolmakers vice and hacksaw and a handful of files!
But with some perseverance...
Cheers,
Doc.
Konrad
Very Strong User
Loved the pig tails.
It is funny (sad) that the USA D.O.D. still has restrictions on this technology, even though it is all in the literature. Bureaucrats are loath to declassify data. Hey, it's no longer the 60's! Love the concept of military intelligence, it is so helpful to the advancement of mankind.
Oh, the good old days!
It's been a while since I've seen a timed pressure port, like on the Enya. I'm a bit surprised that the more modern Irvine doesn't have front bearing support mounting lugs.
With all the emphasis on CNC's, folks often forget how much can actually be done with a file and grinding stones.
All the best,
Konrad
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Hank
Active User
Fellas! Keep this going, I'm eating this up. I love glow engines. I tossed out my electrics and am about dump my gassers. Nothing better than glow engines.
BTW, I'm also an engineer but I didn't seem to enjoy metallurgy until I got into glow engines.
BTW, I'm also an engineer but I didn't seem to enjoy metallurgy until I got into glow engines.
Konrad
Very Strong User
Hum, most of us went the other way! That is we dumped glow for electrics. I only fly glow in some antiquated racing classes.
While I claim to have built the engines that won the USA NATS in FAI F3D around 1989. I've been challenged to get the most from our batteries since 1986, the year I escaped the 7 cell trap. I haven't built or used a glow engine in my sport ships since 2003.
The only magic of glow is the catalytic reaction between Methanol and Platinum.
Please give us an idea of what you are wanting to learn about. Just asking us to do a core dump of what we know really is a waste of our time and forum space. Please ask your questions by starting another thread specific to your line of inquiry
All the best,
Konrad
While I claim to have built the engines that won the USA NATS in FAI F3D around 1989. I've been challenged to get the most from our batteries since 1986, the year I escaped the 7 cell trap. I haven't built or used a glow engine in my sport ships since 2003.
The only magic of glow is the catalytic reaction between Methanol and Platinum.
Please give us an idea of what you are wanting to learn about. Just asking us to do a core dump of what we know really is a waste of our time and forum space. Please ask your questions by starting another thread specific to your line of inquiry
All the best,
Konrad
Doc James Hammond
Very Strong User
Here is an extract from an email I recently sent to a famous engine builder in the UK.
Just for interest he was asking me about the plasma deposition process.
Hi Guys,
Some explanation for you.
Plasma process:
I think the plasma process is just one kind of MOCVD, (Metal Oxide Chemical Vapour Deposition) process where the metal oxide is deposited on any exposed co-valent metal surface. Note co-valent - the oxide and the metal substrate have to be similar chemically and atomically.
Surfaces like the outside diameter of the aluminium liner would be masked in some way, possibly by setting the substrate liner inside some type of receptacle so that the outer surfaces were not exposed.
Aluminium is an alkali metal, and so many different types of similar oxides could be used, (Lithium, Magnesium, Sodium, Potassium, Caesium, Rubidium, and Francium) but aluminium (Al O2) is cheap and really hard (Moh 8) so basically ideal.
Actually, in theory you could do this with carbon - ie: diamond (!) But it would need a different kind of setup.
MOCVD is not a high pressure deposition process, but actually a low pressure more gentle regime involving vapour deposition rather than spraying.
Another way to do it would be by Sputtering but I think it might be difficult, as normally Sputtering requires fair conductivity between the substrate (Acceptor) and target (Donor) and most alkali metal oxides are insulating.
Again, Sputtering is essentially a plasma based process where the plasma is drawn at low pressure (less than one At) and electrically charged so that the vapour produced by the target + (A misnomer) is transferred by migration to the substrate -.
Cast Iron:
For nice Meehanite - try to find some very, very, old cast iron window sash weights. That stuff is of amazingly high quality, really dense, and is also really stable having been cycled inside the window frames for a hundred years or more. We used this stuff for pistons back in the day and I tell unto you - it takes a lot of beating.
If you machine the skin off, part it into billets and then bung them in a furnace at about 400 degrees C for a few hours its going to be as stable, and docile as a lump of lead.
BEAUTIFUL stuff.
Cheers,
Doc Hambone the inevitable...
Just for interest he was asking me about the plasma deposition process.
Hi Guys,
Some explanation for you.
Plasma process:
I think the plasma process is just one kind of MOCVD, (Metal Oxide Chemical Vapour Deposition) process where the metal oxide is deposited on any exposed co-valent metal surface. Note co-valent - the oxide and the metal substrate have to be similar chemically and atomically.
Surfaces like the outside diameter of the aluminium liner would be masked in some way, possibly by setting the substrate liner inside some type of receptacle so that the outer surfaces were not exposed.
Aluminium is an alkali metal, and so many different types of similar oxides could be used, (Lithium, Magnesium, Sodium, Potassium, Caesium, Rubidium, and Francium) but aluminium (Al O2) is cheap and really hard (Moh 8) so basically ideal.
Actually, in theory you could do this with carbon - ie: diamond (!) But it would need a different kind of setup.
MOCVD is not a high pressure deposition process, but actually a low pressure more gentle regime involving vapour deposition rather than spraying.
Another way to do it would be by Sputtering but I think it might be difficult, as normally Sputtering requires fair conductivity between the substrate (Acceptor) and target (Donor) and most alkali metal oxides are insulating.
Again, Sputtering is essentially a plasma based process where the plasma is drawn at low pressure (less than one At) and electrically charged so that the vapour produced by the target + (A misnomer) is transferred by migration to the substrate -.
Cast Iron:
For nice Meehanite - try to find some very, very, old cast iron window sash weights. That stuff is of amazingly high quality, really dense, and is also really stable having been cycled inside the window frames for a hundred years or more. We used this stuff for pistons back in the day and I tell unto you - it takes a lot of beating.
If you machine the skin off, part it into billets and then bung them in a furnace at about 400 degrees C for a few hours its going to be as stable, and docile as a lump of lead.
BEAUTIFUL stuff.
Cheers,
Doc Hambone the inevitable...