controlliner

"Push them into 35 - 50k rpm range, and the glow plug packing material fails".

I have used Black Widows a lot in mouse racing. Used a lot of different fuel blends, all with castor oil. Never have I had an engine that would come even near 50k without catastrophic failure of the piston or crank pin. Interesting ???

dcbdbis

For Jim Thomerson:

There were variations of manufacture. I've witnessed some great spirited arguments in QC about this or that.... I'm going back far into my memory. I am not aware of all the mfg methods Roy used. You are likely to be correct. I can only speak for what I witnessed during my tenure. I was NOT on the design/engineering team so I can't speak to other mfg methods that may have been used that I wasn't aware of. I was friends with one of the engineers. Otherwise, it was restricted space and our badges were color coded. Most folks, myself included were not allowed in engineering regularly.

The pistons that were made during my tenure were a copper alloy base, which were then plated, which then went into heat-treat (on-site), which were then put into large vibrating tumblers and polished. Then the connecting rods were attached and pressed into place. I ran this machine for a part of my tour for both .049/51 and .020 engines. Then the piston assemblies went into stock. The cylinders were fabricated to finish tolerances in the honing room. It was temperature controlled. A machine then put the pistons and cylinders together and measured the leakage pneumatically, rejects were taken apart by hand and the cylinders and pistons returned to their hoppers by hand for mating with a different part under the hopes that the mfg differences would produce a winning set.

At this time, Cox was located off of Warner ave in Santa Ana. Don was the Customer service mgr, Kit was the customer service engine tech, and I split my time between the engine salvage department (which I started and setup), the new engine assembly line, customer service hot line, and various machines on the main floor that were misbehaving and needed some TLC.

During this time period (some more trivia) Cox hosted a quarter midget race. I can't recall if it was covered by Model aviation, or this was a write up in the companies journal......We "Entered" one of our foam Cessna's in the race as a deliberate PR stunt. On the nose end was a V-12 that I had fabricated from old scabbed engine parts. The prop was a 12x8 Wood. The exhaust stacks were pinched from the old string drag racer (car). It sure looked real. heavy as a rock, long...... Non-running obviously. There was a photo and a caption that stated "...A ringer was disqualified."

It was humorous how many folks thought it ran! It was so heavy, I had to attach the nose wheel from the Cessna to about the middle of the engine, otherwise the aircraft would fall on it's nose end. About the only thing it was good for was for looks. It sure got plenty that day!



Dave

dcbdbis

One other way to identify me if anyone is an old cox employee..... At my workstation I had a .049 that had been modified to run on compressed air. The porting was cut into the crankshaft by hand. It was the base of the old reed valve c'case. I had that setup next to my workstation running a large prop as a fan. If you ever walked the main floor of the factory, you couldn't miss it. I still have that "engine".

I was kinda obvious too. Fresh out of the USMC. The haircut at that time wasn't exactly in vogue. This was right after 'Nam wound down.


Dave

66Malibu

Dave, Really enjoy the insiders stories about Cox during your tenure..
Since I would probably never have a chance to ask questions from someone "inside" the cox operation, here are a couple that I've been holding for a while:
Do you and Cox recommend use of the anvil supplied in the Cox piston reset tool kits for the .020/.049/.09 ?

Can you shed any light on several Cox items that to me are "oddities"?
A)PeeWee .020 "SureStart" with white delrin backplate and orange choke tube.
B)TD.049 with a brass cylinder ( no it is not magnetic and is definitely shiney brass).
C)High Compression 5 fin Texaco Heads complete with knurling on top and HC combustion chamber.
I have accumulated these over the years.( Sorry no pic until a new camera arrives).
Thanks for your insights, Steve

dckrsn

None the less, I'd pay to hear one sing like that.

combatpigg

My Feedback: (3)

Save your money. Just take a 5x3 prop and trim it down to 3 inches.

66Malibu

For dcbdbis:
I think we have all heard of Cox supposedly running an endurance test by hooking up an .049 to a drum of fuel and letting it run until it either runs out of fuel or catastrophic failure occurs. Can you confirm such a thing ? How long did it run? How did the piston / rod socket fare? Was there measurable wear on the components at the end?
It would be interesting to know as part of this thread particularly.....

dckrsn

Hmmm. May just give that a shot.
I see a victim in the junk box.
I'll tach it.

dcbdbis

OK, lets see if I can catch everyone's questions....

For 66Malibu: None of the product that you mention above rings a bell. During my time, we had the TeeDee .020, TeeDee .010, and the .049/51/.09/.15 series, and of course the Conquest .15. Maybe a pic would jar my memory, but I can't imagine a brass cylinder. The metalurgies don't make sense. I'm not saying it didn't exist. Folks in engineering could do what they wanted. It's possible that it existed in that department. But given the heat expansion characteristics and wear characteristics....It would have had to be a novelty. Even Roy's old and original ThimbleDrome's had steel cylinders. I'm saying I never saw those products. We had an attic above the offices which we were allowed to "raid" and submit for company approval to purchase. Approvals were not always granted, especially for product that was never released. I've done my share of raiding and never came across anything like that.

As far as endurance tests, the drum of fuel is new to me. When design changes took place, occasionally, and only occasionally you'd go home with an engine wailing away in the test cell, and then still running when you came back in the following morning.....But that's about the extent of it. I never did that type of testing. In customer service we had one sound-dampened test cell. and in the main factory, we had I believe 4 (don't quote me on that). They were all ventilated and sound dampened. It wasn't loud orr anything like that. It was all environmentally controlled in the test cell. The folks I spoke to in engineering would do this and then a tear down. They would bluepprint the engine pre-run, and then after the run, do it again and compare notes on the high-wear item.....But to run it on a drum (55 gal) until empty or death......I don't think the glow plugs would have lasted long enough. The glow plugs in that day was a pure platinum wire. No iridium alloys or other metalurgies. I'd put a keg of beer that the 55gal drum thing was never done.

An all night run? Certainly when appropriate.

Kit who was the engine tech in Customer service in those days would occasionally do an all nighter, but they were rarer than the engineering folks. The Conquest .15 was one of those occasions. You either got one that screamed like a banshee, or ran like a turd. There was a lot of warranty repairs/returns. Kit (the tech's name) would take his dremel and jewelers files and work magic. I have a vague and probably not accurate memory of a Conquest droning all night long in Kit's test cell in Customer Service. Something had changed in design, and the returns skyrocketed. Kit was methodical. He could grab one from the engine line, and then run the soup out of it, tear it down, so he knew how to support folks over the phone, and best how to tweak the engine when they were shipped back to us. Kit was all about quality. Kit could grind the ports by eye, and turn a turd into a monster. Something I didn't learn to do for about another five years.

I owned only one Conquest 15. I played all the games on it's construction, and had a blistering screamer. I had Kit "bless" it before I bought it. It was one wild engine. Can't remember what happened to it..... In fact, can't even remember the bird it went into.

Pretty much what I do today for modelers. Take an engine, and set the curve for their flying style. Convert glow to spark, mod the carbs for gas (requires machining if a walbro can't be fit to the engine), etc. Funny, in those days, I still flew an Ohlson and Rice .19 ignition. Today, you'll see my Saito 150 4C running on similar fuels. White gas (Coleman lantern fuel) and 20:1 Valvoline TC-W3 oil. It doesn't slobber, and after I flow-port the heads, I don't loose any performance over nitro. can still run on glow (with a plug temp range change) or spark.

The all time record RPM that I personally observed was an after-hours fun test. Had nothing to do with the company. I took a reeded .049, spooked the carb up as previously documented, put the heat sink on the glow plug from one of our car models, and just the flywheel off of the dragster. In front of the engine was a fan. The only friction for the engine, was itself. I was using the "racing" variety of fuel.

After a slobberingly rich breakin...I slowly played the needle. 30k, 35k, 40k, back and forth. Our tach was a large hand-held reed tach that you held up to the engine's casing. The appropriate reed would vibrate. Once the engine was broken in, I had less than one minute before the glow plug packing material overheated and puked. I achieved 57,500 ish RPM, and then the engine basically disintegrated. Parts went everywhere. I wasn't in the test cell. I was standing outside because I was a coward and didn't feel like getting hit with flying fragments of very hot engine parts. The crank failed at the connecting rod, the ball joint and the bottom end of the connecting rod survived, but the con-rod was broken in the middle, and was discharged out the bottom of the engine rather violently. The c'case bushing area was no longer round. It was oval. Aluminum shavings everywhere. Astonishingly...the piston itself did NOT seize nor fail. And of course the packing burned out of the glow plug.




Now back to some more serious matters and back on topic.....as for resetting the ball joint. Be careful. The top of the connecting rod (the ball area) was never machined smooth. It has little rings on it from the CNC machines. If you tighten the socket too much to the point that the rod cannot move freely....It becomes a virtual file, and will carve itself clearance if you don't maintain some clearance when you do the resetting. Not pretty. The resultant copper shavings then get lodged between the piston and cylinder and damage them. They can only be replaced, not repaired or resurfaced. At those speeds, the stuff basically welds itself to the steel and gouges the piston side.


Another word for those wishing to spook up today's smaller engines: Polish the transfer ports. What seems like a miniscule imperfection to us, is a Grand Canyon to these little engines. Purchase some 8000 grit grease polishing compound from a lapidary supplier. Get in there with a dremel and a felt tip. Polish it until it is a near mirror. Follow it up with 20-30,000 grit diamond grease from the same lapidary supplier. It's going to take time. The point is NOT to remove material, just change the topography. DO NOT grind on the cylinder. Only the transfer ports.

The lubricant in the fuel forms a film, and the airflow is much smoother across these area. This means increased fuel flow, and improved scavenging efficiency. All of this equates out to increased RPM measurable at the prop. There is of course more to porting than that, but at least most folks can do that without an elongated lecture about how to tune and tweak port flow directionality and such....


Hope this helps.


Dave............

AndyW

My Feedback: (1)

Many thanks for this, Dave. You've dispelled a couple of myths. I marvel at the effort Cox and the guys who worked there put in to deliver superior quality and support.

That Cox did much that we know little about is evident. I have a light, .049 piston with an aluminum rod. I can't recall where I got it but I assume that it wouldn't hold up under huge RPMs. For my part, it ran stronger than stock pistons.

Some things I've often wondered about. What if you made a chromed, brass cylinder to take a high silicon piston? What if you cut the cylinder with ONE exhaust port and three transfer ports? What if you made the cylinder a bolt on affair allowing for normal orientation of the exhaust port? Were some of these ideas tried and sent 'upstairs"?

build light

I would be interested any information regarding any multicylinder attempts and I also wonder that Cox never produced any of these or outboard engines. Surely these were consided at some point.

I would also like to hear about testing competitor's engines. Cox surely wojuld have done that and of particular interest would be any recollection of the Fox.07 engine.

Thanks for all you have offered and I hope you will stay with us for a while, Robert

dcbdbis

Hello Bud Light,


Multi-cylinder attempts? Yes. There was plans on the table to make 2-stroke boxer twins out of the .049/51/.09/,15 TeeDee style of engines. This was considered during my tenure. Issue: The entire crankshaft wasn't strong enough to support two journals. And without a boxer style, you had no c'case low pressure with which to draw fuel/air. The design would have required a complete redesign of the crankshaft, and the addition of a rear bushing. Then the issue was raised up as to how you would assemble the same. Press fit? All in all, in the little engine, the logistics could not be worked out, and according to my engineering friend, never made if off the drawing boards. Just too much costs in tooling, too much costs in design, and no one was convinced that a twin (a very niche market at that time) was going to produce an ROI (Return On Investment). The whole idea was scrapped.

Our main competitor in the "toy" market at that time was Testors. Their engine casing were junk, but they did turn a respectable RPM, if only for 5 or 6 tanks. There was only one serious competitor. Rumor had it that a competitor had offered to the new owners (Leisure Dynamics) a redesigned .049 and sent engineering a sample. It was turning about 25k with a 6x3 glass prop. I heard it run only once, and never got to see it. Dave, my engineering contact got real quiet about it, and whomever it was became a company mystery. And I never saw anything in the marketplace either. It remains a big mystery to this day. Hindsight being 20/20. I am going to speculate that the individuals design was bought, and promptly scuttled. Not unlike how Microsoft treated their competitors.

This is only conjecture. I have no real hard data for it. But I hear the SOB run.....It was a screamer for sure.....

I've still got some of my old engines, along with an original McCoy .35 red head, and a Fox 36x (finger killer). They run like champs after 40 years..... I haven't lit up one of my cox .049 engines for probably 30 years. They have run in oil in them......But I haven't benched them in a long, long time. They are of the enlarged carb/mylar reed/ hand fit cylinder and piston vintage. I don't have any TeeDee's left.

As far as the Fox .07..... Never had my hands on one.

Regarding boats: They DID produce for a short, short period a small cabin cruiser. I was able to nick one out of the attic. And there was a proto for a marine engine, but it was not an outboard. It was a through-hull. I electrified the boat and ran it for a while. it was nothing special and handled like a tranquilized albatros in the water.

The through hull shaft as you can imagine was a disaster. Turning a shaft @ 18~ k? Ate the shaft in one run. And management decided again not to go through the tooling and engineering costs to produce a water cooled outboard that they were unsure of had a market potential.

I DID have my hands on one rough sand casting for the outboard; obviously an engineering proof of concept thing that failed in some way......But I didn't see any potential. It remained in the attic until the end.

As far as serious engine testing of Testor's .049. It wasn't taken seriously by anyone because of the low quality of the pot-metal c'case. It just didn't live long enough as an engine.

But I am sure there were some jems left over in engineering when the company went under for rev #1.


Dave................

PS: If any of you have a .049 that is in good condition, and that you want spooked up. Please let me know. I now live @ 9165' of altitude so I can't bench at sea level......But I can certainly do a before and after at altitude.

dcbdbis

This is off topic......But does anyone see a benefit to inventorying what little I have left? I don't want the stuff. Perhaps some of you do?

Please let me know.



Dave.............

Remby

My Feedback: (3)

dcbdbis;

I enjoy your posts, and the info and data you are posting is very useful and welcome.

I use mostly Tee Dee based engines, but like to use Medallion carb setups, I find the runs are more consistant. I really do not see a issue with loss of power/RPM with this setup. The Needle valve/Spraybar used and looked for are pre '75 if they can be found. I feel the later ones had worn tooling with the spraybar, and feel that may be a factor to Cox dropping the Medallions from production. Perhaps you could add your thoughts, I would like to hear what you could add.

I am also interseted in hearing what you may have that you no longer have need for, parts are always needed and some are harder to find than others.

Thanks again for your information and insight!

Big Al-RCU

Dave, fantastic hearing it, is it were, from the horses mouth. Lots of myths abound around Cox engines history. Keep sharing the facts!

A bit OT, (there were probably lots of guys amed Dave at Cox). Some years ago I got a throttled Bee off the bay from a guy also named Dave (I am sure his last name started with an L) It was a rather bland description as an R/C 049. Photo was fuzzy. I got it for $12 and was flabbergasted to find that it was an obviously custom fitted Bee with a throttle sleeve and in perfect condition. Contacted the seller and found out that he had worked for Cox and had been responsible for assembling the engines that were used in Cox’s exhibits at Disneyland and the Mall parking lots of that era. It’s now one of my prized 049’s. Wish I could remember the guy’s last name.
Al

proptop

My Feedback: (8)

dcbdbis (Dave ) welcome, and thanks for the great stories...and the tips! [8D]
(the bit about the guy calling the "Cox action hot-line" cracked me up )
My first experiences with any sort of model engines were Cox powered controlliners...late 60's - early 70's...pleasant memories indeed.

Doc.316

Dcbdbis;
Been reading your posts...very interesting stuff. One of the guys that hangs out in the Vintage thread worked at Cox also. Maybe you know him...his
call sign on here is Jaymen. I don't know if he worked there at the same time frame or not. You might look him up and find out!

Steve

vlaluz

My Feedback: (1)

Greetings from Tokyo,
I've been lurking around this forum for years, (soaking up the knowledge) but yesterday I came across my Cox .05 R/C new in the box, and I had to dive into the 1/2A threads once again. What luck to stumble in at just the right time to catch this thread. Sincere thanks to Dave for the answers and especially for the stories.

I taught myself to fly with a 2ch EZ Bee II. Spent four years bashing balsa before “moving up� to a .25 CG Eaglet (peer pressure at the field). All I have to say is what were you guys doing to those poor little engines?!?[X(] In my 17 years (minus a four year break), across at least 20 engines, I have never had a Cox fail for anything more serious than a glow plug. They never gave me any trouble, but that's probably because I didn't know they were supposed to...

Just the thought of some poor little motor giving it’s all (and then some if your talkin’ 50k rpm[X(])… Really brings a tear to your eyes.

Remby

My Feedback: (3)

vlaluz;

Greetings!

Most of the engine guys here never go above 25-30,000 RPM so rest easy, we really do care for these small wonders! Like I posted, the Cox piston failure was my first in many decades of flying and using the Cox motors.

I look forward to a few more centurys before another failure, if I even have another go south on me.

A RC .05 is a great engine, the crank in that one is a treat to see, I have a engine with that setup but has never been run s yet. I look for a bit more power using that crankshaft.

Best;

vlaluz

My Feedback: (1)

I hear you Remby. I think it's because there were so many of these little engines that some thought they were disposable. It’s a little tough to find a flying field out here, but that .05 is going to have to fly eventually.

Remby

My Feedback: (3)

Mabye when I first started using them, but now these engines get respect and care. The season is fast starting, I hope you can find a place to use that .05, it belongs in the air. These small planes require small fields, I have high hopes for you to find a area to turn it loose apon!

ajcoholic

My Feedback: (10)

They had CNC machinery back then? Wow, I didnt know they had CNC machinery in the 60's. I assumed all Cox stuff was made on traditional lathes and mills, and machinery Leroy developed himself.

AJC

dcbdbis

I am probably misapplying the term "CNC". CNC like machinery was available for a long time. In the early 70's, it was done with 1" wide perforated paper tape. Not unlike the old punch cards for the early ENIACs. The tape had perf holes, and not unlike a player piano, the tape was "read" and the parts reproduced.

This early mechanism of automating a machining process was invented by my father and my Uncle in the early 1960's. They also applied it to secretarial typewriters. A master tape was produced, then the tape was archived. The typewrite size was monstrous and they were heavy....but the earliest form of "form letters" was born.

They also produced a duplicator. The weakness of the system, was if the "master" paper tape became damaged, it was necessary to reproduce a master tape by hand in the "record" mode. So the tapes were duplicated, and the masters kept in an archive.

Today, after doing a lot of programming....I would say it closest digital counterpart would be 10 bit (number of horizontal perf holes on the paper tape) resolution.

Hope the clarification helps.


Sincerely and respectfully,


Dave Babb

ajcoholic

My Feedback: (10)

Dave,
I would give anything to go back in time and get a tour of the Cox facilities... that stuff is so amazing to me.

Thanks for your posts, very interesting stuff indeed!

AJC

vlaluz

My Feedback: (1)

Thanks Dave for the insight. Never ceases to amaze me what folks came up with back then. It was once the state of the art and did everything we needed. I bet it still would if you had the machines and tuned them up... try doing that 40 or 50 years down the road with anything we make today... My programing ended at C+, with a little Arduino time thrown in for laughs. People say computers are unintelligible... but there are plenty who say these little engines are just as bad. I for one am grateful to only be confused by tax law and my wife.

I'm being a little wordy perhaps... You'll have to excuse me. The sakura blossoms are out and the sake has been flowing at the picnics... There's that progress again, saving me with spell checking.