Why the cast aluminum body on new engines?

Xtal

From much of my reading Mr Cox designed many of the different machines...remember decades ago and no computers yet to anyone but military, Colleges, and government ---and even then computers were in their infancy used mostly for tabulation of large data bases

I also know that a LOT of the precision came from the Ladies he hired to assemble the dinky engines.... Yes good QC and machining keep tolerances low but the trick really was the ladies had fitting each Piston to each cylinder

I still have no idea how an air gap Gage works,... but he claimed millionth of an inch .00001 tolerances for some components..

I did a few years helping as re-builder and tuner for racing Motor cycles and Drag / stock cars... owners bought us best of the best of every tool... and machine... we could keep engine bores and pistons to very precise .001 tolerances when in reality .01 was close enough to matter in most dimensions

In the photos you really need to find the original history of the factory.... many of those machines were rotary multi step on one platform...then once proven... many more identical machines were added to up the production rate

Even in the 60~70 s a Christmas Toy Cox RTF was available from hundreds of sources...Base Exchange, Wool Worths, Western Auto, Sears, JC Penney, every ma and pa dime store, Maceys, and on and on....thousands sold per day to a 168 Million USA population and some significant Over seas dealers who actually had to start factories to meet demand...Australia as example

I personally know two government (Army) Industry officers who were sent to interview and learn from Leroy Cox on "Modern Production" automation and techniques

He is not the only guy in the 50~60s who managed every large scale production with excellent Quality but was indeed one of the innovators -----the Military desired to learn from ...simply to better understand the fast moving world of MODERN production and be able to write sensible Military Specifications for government contracts

I learned all this later in my career as a Army Operational Test Command Test Officer

If the precision of these dinky engines are interesting... the field trials for the M16 5.56 mm Assault Rifle will blow your mind

What do you mean by that Fred? I would assume the tolerances of a COX engine where gas tight fitting with minimal friction between the cylinder and piston was essentially secured by very fine tolerances, in the barrel of a gun where the metal jacket of the projectile is smeared in the rifling by abrasion to prevent gas blowby, tolerances are much less stringent...or maybe I am totally wrong?

I think Fred means the gas mechanism that actuates the automatic action of the M16, and not the fit between the bullet and the barrel. I am not familiar with the M16, but I have heard that the parts are made in rather close tolerances and high precision. That was not entirely a good thing as it made the rifle quite sensitive to debris and generally slightly unreliable. But it was improve over time, chromed internals to prevent corrosion and so on.

I had a Valmet RK-62 as a service rifle, it had similar mechanism as the more famous AK-47. Not so high precision in fit and finish, but I could take it apart and put it back together in 40 seconds blindfolded And it could have sand inside the ”box” and still fire. I did not like the sights on it but was pretty accurate up to 300m. The caliber is 7.62, works better in the woods than the smaller caliber of M16.

Yes I remember those "assemble and disassemble the Kalashnikov" drills in the army...I was wondering how the gases could recoil the mechanism at all with the piston practically dancing in that cylinder.

Another firearm puzzle for me is how Colt and other revolvers can be so powerful if gases can freely escape in the visibly wide gap left between the drum type magazine and the entrance of the barrel? Yes I know the cartridge of revolvers holds extra amount of powder but one would expect most of the gases escape...

Sorry for hijacking the thread...

So was each cox cylinder hand matched to a piston?

Does anyone know the what the "recommended" (or what was on the cox drawings) as far as fit size and tolerance?

I guess I never thought about it but are the pistons a ground finish and the cylinder reamed and then lapped or honed or ?????

I watched a show on AK's once. They suggested that they actually designed them to be as loose a tolerance as possible. This made them easy to manufacture (tolerance = $) and less susceptible to dirt.

There is a Russian revolver the 1895 Nagant ... you may want to look it up. The brass cartridge actually extends past the bullet. The cylinder moves back and then forward as it rotates to go into the barrel. the creates a seal and thus no loss between the cylinder and the barrel. I have not seen one in person but read about it.

Mike

Yes Mike the pistons were ground and cylinders honed as far as I know. Brand new cylinders show the criss-cross pattern of the final machining that also help keep oil in these micro scratches..sorry for my poor machining vocabulary..

The air gauge to check tolerances was supposed - as far as I know - to measure how the piston could keep pressure in the cylinder for a certain time...dry fit components needed to have very precise tolerance to pass the test.

Gentlemen users of Cox engines,

Cox was always looking for ways to lower production costs. You see, at the time the production run of engines was 12,000 at a time! I had the extreme pleasure of visiting the factory in the 1990's about 3 times with Master Dale Kirn whose title I believe was head of Quality Control. Dale was an AWESOME tour guide & among other things would fill up your pockets with all kinds of parts and pieces from all those bins containing thousands of parts. It was like Christmas in the summer! Dales office desk was filled chock full of prototype parts including among other things a NIB Rossi 15, that I can only imagine was obtained for examination purposes. It was perhaps no coincidence that the Cox Conquest piston/cylinder assemblies,bore and stroke, mounting holes and glowhead was was interchangeable with the Rossi 15N.

But back to the .049's. Circa 1994 I think the R/C Bee was about to be released. Dale gave me all the parts (from the various production lines) with which to build one with. He figured it would give me a superior mouse race engine. The advantages being, a huge venturi ( .123" ID is what I remember). Also the RC Bee tank was larger capacity for better range as the 8cc black Widow tank was marginal on range. So when I returned to my friend John McCollum's house in Orange County, I couldn't wait to assemble an engine (with my TeeDee top end) and test it.
The initial few runs on 50% nitro fuel showed a very impressive steady state 24,400 RPM on a Cox nylon 5D X 3P prop. That was exceptional! One thing became quite apparent was that at that RPM, the crankcase wore noticeably after ~ 6 runs! Mind you Dale gave me a half dozen c/case assemblies, so I carried on with flight testing. Unfortunately, at the time I did not know about proper tank feeding & sealing. As supplied, the R/C tank leaked like a sieve. I cut my own gaskets & used RTV silicone to try & get the tank sealed.  In spite of that, it never ran steady in the air on a model & so I gave up on the concept. What I know now, is that if the tank could have been properly sealed AND uniflow vented, it may very well have worked!  SO, I agree that such a c/case needs to be bronze bushed for it to have a useful life when run at 24,000 RPM . THAT mod would have sadly made the production cost too much, and therefore defeat the whole purpose of the exercise. BTW, I know from experience that when installing a bronze bushing in an aluminum c/case. It simply must be perfectly centered. If slightly off center, it will run OK but cost you several thousand RPM.

I did see the piston/cylinder fitting lady in action using an "Air Gauge" with which to find the proper fit with. She was also an excellent honer, as generally the cylinders needed one or more passes of the cylinder hone before the fit was deemed to be correct. My own recent attempts to hone Cox cylinders with a honing machine more often that not resulted in over-honing, rendering the cylinders oversized and therefore junk.

The assembly line was huge with a majority of the assembly people being Hispanics, who worked hard with not great pay. Dale mentioned that the assembly staff were regularly rotated through various assembly lines. I just assumed that was to relieve the boredom of repeatedly assembling thousands of things per production run.
One young fellow there had a job hand deburring cylinders... Not sure how cylinders would get burrs in them after honing, but possibly he was fixing returns ruined by customers??
When asked about the machinery, Dale said the majority of them were what he referred to as screw cutting machines. So, when I asked why doesn't Cox go with modern CNC machines, Dales reply was that CNC machines were TOO SLOW compared to their current equipment. Again, with the highest engine production rate in the world at the time, this was indeed a consideration. That extreme production rate allowed for those expensive machines while maintaining a cheap selling price for the engines.
One especially interesting machine was an Optical Comparator. Dale claimed that if there was ever a dispute over part dimensions or tolerances, the comparator was the final arbiter as it could measure extremely precisely. I don't recall the tolerance but wouldn't be surprised if it was in the millionths of an inch.

Just imagine today, that not only the parts need to be machined, but they also have to be hand assembled as well. That was labour intensive. Labour intensive equals vastly higher costs. My Mexican girlfriend at the time knew friends that worked at Cox. They lived in high density conditions found in third world countries. K&B was similar in that Hispanic workers would drag themselves into work even if sick, just to maintain their jobs...
This explains easily why today most all the modern engine companies produce in China/Korea and Russia. Labour is simply a lot cheaper. Makes me wonder how those remaining non East Block/Chinese engine manufacturers can keep up.

Those made today in non "Eastern" countries are no cheap stuff..take OS engines still made in Japan. My OS56 four-stroker cost me 300+ Euros ..but they are worth the money if you are looking for quality and longevity...I am not sure how Chinese engines compare to OS....

balogh wrote:Those made today in non "Eastern" countries are no cheap stuff..take OS engines still made in Japan. My OS56 four-stroker cost me 300+ Euros ..but they are worth the money if you are looking for quality and longevity...I am not sure how Chinese engines compare to OS....

Quite true Andras. I personally think Quality is always worth paying more for. Performance people have always felt this way as Nelson Competition Engine users have shown. But Nelson was a relatively quite a small shop, plus Nelson needed to supplement his Income with well paying Military contracts.

I don't personally believe Chinese metallurgy is up to that of O.S. But when Mr. Ogawa (owner of O.S.) fired a bunch of engine staff because he wanted to concentrate his business on trains, they quickly found work in Korea and really improved those engines.  I believe Mr. Ogawa's son returned more priority back to the model engines which continue to be excellent. One think not liked by us North Americans, especially those of us who race O.S. sport engines, is their use of cheaper Nickel plating instead of the more expensive but better Chrome plating. I'm no authority, but some claim they've had the nickel plating peel off and others claim the piston life is shorter than expected. Many don't like their use of plastic backplates either. All measures to reduce the price (or keep it lower relative to inflation). There are small cottage industries that supply aftermarket O.S. true ABC piston/cylinder assemblies and metal backplates for those discerning modellers. It's too bad that these " upgraded parts" aren't sold by O.S. as specialty or high performance parts. Sadly, I suppose there is no money to be made in supplying these specialty parts...
Rossi and Novarossi continue to thrive in Italy which is great. One thing they do however is produce a myriad of engines under other names for car and marine applications. That's got to help.
SuperTigre moved production to China a long time ago.
Progress Aero Works ( P.A.W.) in England is just hanging in there, but absolutely need outside contact work to stay in business as the model engine production,
just by itself is not enough to sustain the business. Interestingly P.A.W. produces some auto parts that are used in F-1 racing engines. Tony Eiflander (owner) has produced valve train components that have demonstrated over twice the lifespan as the equivalent F-1 Japanese parts. So evidently their metallurgy is better in that regard.
Like many industries in this world, the model engine producers are facing huge competition to stay competitive and the race to the bottom to produce cheap usable engines remains relentless. That being said, the Chinese CS company was tasked many years ago by a Canadian modeller to reproduce a Cox Venom .049 mouse race engine. Their 2 reproduction prototypes fell quite short in performance and so the project was terminated. That kind of told me that the old Cox design was indeed quite advanced for its time!
Cheers,
Paul G.

Great stuff in this thread! Thanks to all for the good pics and reading.

In terms of pure industrial design watchmaker beauty and functionality in mass produced miniature glow engines (when adjusted for pre-Cox technology) it's hard to beat the Anderson Baby Spitfire .045 with it's cast crankcase. It is uniquely pure Art Deco in its product category.

http://www.sceptreflight.com/Model%20Engine%20Tests/Anderson%20Royal%20Baby%20Spitfire.html

That one is good one too but too late to beat Cox. The art deco .045 I was describing can be viewed here:

https://www.google.es/search?q=Anderson+Baby+spitfire&rlz=1T4VSNH_enUS777US777&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjurZ_AzvnZAhVBwFkKHXcSBwgQ7AkIRA&biw=1440&bih=698

She can hear you!
Bob

Wow … and to think this thread all started because I wanted to know about the cast body engines.

The pictures and discussion has been fantastic! Where did you ever come up with pictures of the plant?

With so many engines, did they get better and better over the years ... or did everyone just put them out, some good and some junk? Is the Tee Dee more or less the last word in 049 performance or ?

You guys are the best!

Mike

xtal_01 wrote:Wow … and to think this thread all started because I wanted to know about the cast body engines.
The pictures and discussion has been fantastic!  
With so many engines, did they get better and better over the years ... or did everyone just put them out, some good and some junk?  Is the Tee Dee more or less the last word in 049 performance or ?  You guys are the best!
Mike

Hi Mike. Such interesting questions you have.

There has been discussion over which years produced the best TeeDee's. I don't remember which. I do know for sure that there were no superior Estes produced TeeDee engines. That was because their cost saving measures, caused the essential fits to go "out the window". Estes peddled product, not performance. Like ALL production engines, some were better, some were worse than others due to the "ganging of tolerances". Some were better because of a PROPER BREAK-IN , and because of scrupulous care to keep them CLEAN, proper to exotic fuel use, and matched (often highly trimmed) propellers, AND a frequently reset ball-socket joint and de-carboning of the piston and cylinder.  A superior engine is only mediocre in performance if it's fitted with the wrong gear ( i.e. wrong and /or unbalanced propellor), lousy (stale/dirty) fuel, had dirt/sand run through it and so on...

Onto your question: NO, the TeeDee is not, the last word in .049 engine performance. Tee Dee's were first outclassed by the Leningrad built VA ( Valentin Aloshin designed & built) plain bearing AAC ( Alum. piston and Chromed alum. cylinder) engine. Russian AME & early Norvel ABC and AAC plain bearing engines were soon to follow. In the 1990's, the fully swiss instrumented dual ball bearing American built Shuriken ABC engine was in a higher power class of its own. Note: the TeeDee retailed for ~ $30 whereas the Shuriken retailed for ~ $220. That's over 7 TIMES the price! But, it put out over 50% more reliable power & had superior longevity.
Shortly thereafter, the China Shanghai CS dual BB ABC engine came out. Much heavier, but again much more powerful. Once "re-worked" (to correct the tolerance flaws) and a better head design, ( increasing RPM by ~ 5,000)  the CS stole the 1/2A speed records. The updated G-Z followed, again from China. Then the Russian/Ukrainian engine manufacturers got into the act with the Cyclon .049 built in Novosibirsk and the Profi built in the Ukraine. These again produced serious HP without needing rework out of the box at 30-36,000 RPM (on toothpick props of course). They ran sickly on TeeDee sized props! Other East Block engine manufactures also produced their versions like the Ukrainian Fora (very similar to the  Cyclon). The North American .049 has since fallen out of favour to the 1 cc ( .061) size which is now the world Free Flight (FIJ Class) standard. Lastly the Italian made PICCO 1 cc is a powerhouse when de-stroked to .049 by Doug Galbraith of California. BTW, the ONLY engines to offer a full wave tuned pipe are the CS-GZ and the Profi. All others are designed to run Open Face. The difference being about 10 MPH in an Open Class C/L speed model. I've probably omitted an engine or two, but the above is essentially the evolution of .049's after the Cox Tee Dee.
I hope I've been able to shed some info on your question of OR...

Cheers,  Paul G.

Shown below is my competition BV (Gibeault modified) Shuriken .049. CNC machined c/case from billet, high 22% silicone alloyed alum piston, Chrome plated brass cylinder, steel conrod and wrist pin, and high performance Swiss bearings. This engine turns an APC 4.4D X 4P prop at 33,000 RPM on the ground (more in the air), on 10% regulation nitro fuel. Speed on this model is 97+ MPH timed for 1 mile from a standing start. IT'S CRAZY FUN!!

Always a pleasure to see his photo galleries. That O&R Midjet has got to be one of the most bizarre things ever created. Somebody went around a whole lot of ass to get to very little elbow with that thing.

Thanks...youtube offers tons of videos on giant Magnum and similar revolvers having horrible firepower despite the gas-saving feature of this Russian thing missing:

https://www.youtube.com/watch?v=30LOq1-8uhs

Sorry again for hijacking this thread...at the end this revolver thing is also about tolrrances, compression, gas retaining capabilities....relevant to the topic of COX engine manufacturing tolerances...

Oh dear God!! Please don't put pictures of guns here for us to see. Quick get me to the fainting couch!!