New to these engines, curious about how to tweak them and care for them!

Welcome to the Forum JennyC6 !! Thats alot o questions but they can all bee answered in time using the search feature helps and reading on this forum .. The reset for the ball socket will come in time ,but you just have to check and see if it is getting slop in it . The Car/diesel cranks are stronger but heavier also , so the rpms will suffer a little , There are a few different style mufflers and defleters other there . some ene just don't have spi and suffer with a muff. if so . Nice Model , hang in here there is alot to learn

Do you have a pet cat or dog that you can torment with your wing demon?

That was a fun video to watch! Kept waiting for the power-up and take off!  Super Slick with twin 049’s, ok very similar 049’s anyway.  How’s the weight on that wing? Ya gotta have a reciever, battery pack, 3 or 4 servos, you using vectored steering, with the steering landing gear.? Sounds like one motor slows down as you turn. I have a couple of Zagi Wings that look sotra like yours, and have had thoughts of installing a TD or Medallion in place of the old electric motor.!  
Hey! Welcome to thr Forum!

Marleysky wrote:That was a fun video to watch! Kept waiting for the power-up and take off!  Super Slick with twin 049’s, ok very similar 049’s anyway.

Mm, thanks! Planning to maiden it tomorrow.

 How’s the weight on that wing?

I don't know for sure, but the empty weight is around 650 grams and the AUW with the recommended 2208 brushless system and 3s 2200mAh lipo is about 850.

This one's actually carrying two batteries, one for the servos/Rx, one for the FPV system. I might consolidate that, though, the flight controller I have in it has a 5v2a BEC meant for powering receivers so I could fly off just the FPV system battery if I wanted.

Not sure I will, though, it gets tailheavy pretty quick if I remove one of the two batteries up front.

Ya gotta have a reciever, battery pack, 3 or 4 servos,

4 servos, a Futaba S-FHSS 6ch receiver, a 2s 2200mAh LiFE receiver pack, a Matek F-411 flight controller, a 3s 1000mAh drone battery, a 1000tvl 1/3" FPV camera, and a lightweight 800mW VTx. FPV and flight systems are currently 100% seperate, but I could use the FC to run the wing if I so chose. It's designed primarily for fixed wing craft and has mixing in it for flying wings with differential thrust.

you using vectored steering, with the steering landing gear.?

Not currently, but I do have it set up such that I can do so in the future. My main concern with doing it would be extreme yaw inputs shutting an engine fully off mid-air. Atop that, the Futaba 6J I'm using doesn't have enough mixes to set up differential thrust, so I'd have to rewire the entire craft to run through the flight controller.

It's an upgrade path I have available to me, but it's not currently configured for it.

I have a couple of Zagi Wings that look sotra like yours, and have had thoughts of installing a TD or Medallion in place of the old electric motor.!  

Do it! By my...admittedly not the best trained...ear, he's not even using a TD or Medallion in that one, rather just a standard reedie. Sounds like he's turning even less RPM than I do. And it seems to fly just fine. And in fact, this exact video is what convinced me that I'd have enough power to fly a Spear on two of these engines. I figured if just one will fly that wing, two shouldn't have any trouble with this one.

Ahh, if only I could afford to, I'd swap over to TD power as well. Cox Intl is selling mint in box RC TD 0.049 engines, but they're 300 bucks a piece. If I had two of those on the back of this thing, though, I'd have near as makes no difference as much power as I'd have if I ran the recommended brushless setup!

Fun fact: This aircraft is built out of foamboard. Specifically, Flite Test's brown water-resistant custom foamboard. Was one of their speedbuild kits. Between their custom blend of foamboard being a bit more durable than the stuff you find at the dollar store and the layer of Rustoleum white I painted the airframe with, it really does not care about fuel or exhaust residue. It's no more susceptible to them than balsa-and-ply planes are. And I have another one sitting here waiting for enough money to roll in for me to buy it another throttleable reedie! That one's a Mini Sportster, which I'll be propping a bit differently. Thinking a 6x4 wood prop will both look boss on it(It very heavily resembles an interwar sport/race plane) and pull it through the air quite handily while not loading one of these throttled reedies down too hard.

Hey! Welcome to thr Forum!

Thanks! If nothing else, I'll have a ton of Cox powered aircraft coming in 2019, planning on doing a LOT of these foamboard conversions since the stuff takes to glow power surprisingly well. As long as there's a good layer of Rustoleum paint on the foam and the engine mount has some substantial wood reinforcement they run just fine!

Whoa yeah! That sounds like fun times ahead! I been following some of the Flite Test  shenanigans on their website. I recently tile printed the plans for the Cessna 337 Skymaster at about 50% scale for about a 22 inch wingspan. Thought I might try a push poll arrangement or even just a single rear engine. I’m waiting for them to publish
the plans on the P 38 they showed two of them one was a glider the other was a powered plane.
Let me try to answer a couple of your questions;  piston reset.  Piston reset will need to be done when the slop between  The connecting rod and cop in bottom of piston causes a  Drop in performance. This needs to be done before the connecting rod beats a hole through the bottom of the piston. Once reset it probably won’t be in need again.

Removing the slit/slot can and has been done. It does not induce SPI.  You can get SPI by removing additional material at the bottom of the opening. See this link;
https://www.coxengineforum.com/t12140-what-is-spi#154917


Choke tube throttles. I do not have any experience with these.  Hopefully somebody will jump in and provide knowledgeable experience on these.

Swapping out standard cranks for the heavy duty killer bee or diesel cranks are an option if you’re going to run your engines very hard under high nitro powered  High rpm applications, or diesel.   I don’t know of any benefit they would provide, but then again I don’t race or fly competitively.

Exhaust management:  Cox makes a couple different styles of mufflers. The one the probability fit your application is called an exhaust collector. It has a collar around the cylinder and a extension tube to direct the.exhaust away from the engine.  One of our members Roddie has developed a muffler from rubber innertube with 22 shell casings that do essentially the same thing.
https://www.ebay.com/itm/Cox-049-Exhaust-Extractors-2/382822988896?hash=item5922073c60:g:48gAAOSwddpcfrPq


Here’s Roddie’s
https://www.coxengineforum.com/t5505p20-a-cheap-sport-muffler#70808


Ok i’m going to submit this before I hit the wrong button to delete everything. I’ll come back and edit and add the links and some pictures

Marleysky wrote:Whoa yeah! That sounds like fun times ahead! I been following some of the Flite Test  shenanigans on their website. I recently tile printed the plans for the Cessna 337 Skymaster at about 50% scale for about a 22 inch wingspan. Thought I might try a push poll arrangement or even just a single rear engine. I’m waiting for them to publish
the plans on the P 38 they showed two of them one was a glider the other was a powered plane.

Surprisingly enough I've gotten nothing but positivity about my Spear build! And I may or may not have convinced at least two more people on their forums to try putting a Cox mill on a Mighty Mini    

Also not the only one. This mad lad put a Pee Wee on a mighty mini and it flew nicely!

OH! Regarding the Lightning...go check out the latest Drive On video, about the Merc SLS AMG drift car. Around 6 minutes 40 in you'll see a 'standard scale' foamboard B-17g leaned up on a wall and you'll see that P-38 a few moments later.

Let me try to answer a couple of your questions;  piston reset.  Piston reset will need to be done when the slop between  The connecting rod and cop in bottom of piston causes a  Drop in performance. This needs to be done before the connecting rod beats a hole through the bottom of the piston. Once reset it probably won’t be in need again.

Ahh, so it's just a case of 'when it starts being cantankerous reset the socket' then. Good to know.

Removing the slit/slot can and has been done. It does not induce SPI.

Good, good. If itt'l give me a little more power I might have it done. I kinda wonder what other tweaks I could do to these things to get some more punch out of 'em. Running TD heads, perhaps? Ideal non-SPI cylinder to use?

 You can get SPI by removing additional material at the bottom of the opening. See this link;
https://www.coxengineforum.com/t12140-what-is-spi#154917

I don't want SPI on my engines. The choke tube throttle is incompatible with SPI per Cox Intl and the whole reason I bought the RC Ranger engines was so I could throttle them.

Swapping out standard cranks for the heavy duty killer bee or diesel cranks are an option if you’re going to run your engines very hard under high nitro powered  High rpm applications, or diesel.   I don’t know of any benefit they would provide, but then again I don’t race or fly competitively.

I'm running these two on 5x3 3-blade props and 24% nitro on a pretty sizeable bird. I don't expect to be running them WOT all the time but they're not exactly gonna be lazing along either. The standard cranks in my engines are probably okay but I'm of the 'belt-and-bracers overbuilt' approach when it comes to engines. I want 'em bulletproof.

Exhaust management:  Cox makes a couple different styles of mufflers. The one the probability fit your application is called an exhaust collector. It has a collar around the cylinder and a extension tube to direct the.exhaust away from the engine.  One of our members Roddie has developed a muffler from rubber innertube with 22 shell casings that do essentially the same thing.
https://www.ebay.com/itm/Cox-049-Exhaust-Extractors-2/382822988896?hash=item5922073c60:g:48gAAOSwddpcfrPq


Here’s Roddie’s
https://www.coxengineforum.com/t5505p20-a-cheap-sport-muffler#70808

Yeah I had stumbled across those extractors browsing eBay and figured they'd be perfect for my needs, but they seem to be stupid rare. Cox Intl doesn't sell them and that seems to be the only listing eBay has for them. Noise isn't an issue....I live and fly where neighbors are a quarter mile apart or more...but being able to mount engines on tractor planes without sliming up FPV camera lenses is. That round muffler wouldn't do me any more good than nothing at all in that vein, but the collectors would let me direct the exhaust overboard and down, where it won't get up onto the camera lens even if the engine is mounted normally in a single engine tractor plane. My next FT build...my Spear is literally just waiting on clear weather for a maiden and my Mini Sportster is awaiting an engine but otherwise ready to maiden...is likely going to be a Mini Scout. If I can mount the engine 'normally' on it with one of these collectors controlling the slime I'll go for it. I love seeing the engine in the camera view!

Matt at EX Engines has them.  

http://www.exmodelengines.com/product.php?productid=17862&cat=267&page=1

Welcome to the Forum!

I got a couple of them.  I polished one of them up and ported it like 1/2A Nut showed in one of his high performance threads.  I added a pressure tap as well, but the position isn't right. I seem to have installed it right where a Venturi effect exists as it necks down.  It doesn't produce much pressure. The next one will have the tap on the side of the body, opposite an exhaust port on the cylinder.

For goo control, especially with a camera directly behind the cylinder, you may want to plug the priming hole in the front.  It lets a pretty steady stream of goo out.

Welcome to the forum. Tee Dee 049 engines sell in NIB condition on ebay at around $75+shipping.

Dave P. wrote:I got a couple of them.  I polished one of them up and ported it like 1/2A Nut showed in one of his high performance threads.  I added a pressure tap as well, but the position isn't right. I seem to have installed it right where a Venturi effect exists as it necks down.  It doesn't produce much pressure. The next one will have the tap on the side of the body, opposite an exhaust port on the cylinder.

For goo control, especially with a camera directly behind the cylinder, you may want to plug the priming hole in the front.  It lets a pretty steady stream of goo out.

Why not kill two birds with one stone and use the pressure tap to plug that priming port? I don't really need it...my engines prime up like a dream, all I do is push fuel from the tank to the needle by pressurizing it during fuelling and then by just closing the throttle on the choke tube fully and flipping them 3-5x I have raw fuel spitting out the exhaust slits...would be super super neat to have a pressure tap on them as well. Give me a lot more leeway on fuel tank placement! Especially on twins.

My Nitro Spear feeds off a single 4oz slant tank mounted right on CG and I got real damn lucky in that I could still place it close enough to the engines that they'd draw reliably from it, but if I were to pressuretap it like one does with larger engines...mmmm.

JennyC6 wrote:

Why not kill two birds with one stone and use the pressure tap to plug that priming port?

I considered that, but it would put the tap and line in an awkward location.  I guess I'm still a slave to vanity.  

Dave P. wrote:

JennyC6 wrote:

Why not kill two birds with one stone and use the pressure tap to plug that priming port?

I considered that, but it would put the tap and line in an awkward location.  I guess I'm still a slave to vanity.  

I'm guessing the airframe you're using it in ends up wanting that angle, then. It'd actually look quite smart with the pressure tap in the priming hole if the exhaust was vented directly left or directly right~.

Hi JennyC6, welcome to CEF.
You asked a bunch of questions that haven't been answered yet. If you can wait till the first half of the coming week, I will give you a detailed line-by-line list of answers. Sorry I can't do it right now, but stand by and I'll give you what I know from experience. Years of pushing Cox engines to their maximum limits.
Rusty

RknRusty wrote:Hi JennyC6, welcome to CEF.
You asked a bunch of questions that haven't been answered yet. If you can wait till the first half of the coming week, I will give you a detailed line-by-line list of answers. Sorry I can't do it right now, but stand by and I'll give you what I know from experience. Years of pushing Cox engines to their maximum limits.
Rusty

Sounds great to me! I'm not waiting on anything that'd keep me from running my engines. Weather's lookin' great for a maiden this tuesday(Fri, Sat were a wash, literally, can't fly a 0.049 powered plane in a literal thunderstorm lol), and I just pulled the trigger on a third RC Ranger for my Mini Sportster!

Also began work on an airboat for one of these engines. Have the hull built, but that's it. Mmm. Prolly gonna throw a MAS 6x4 triblade on that.

Another RC Ranger breathes life! Whoo! Bit of a *$%( to get primed as my fat fingers don't really fit down where the intake throat is, but once it does prime it holds prime fine, starts easy, ran great. Only stalled twice, and both times were my fault; first time I was trying to taxi it around and nosed it over into some leaves second time I had it a little too rich and didn't get it thinned out quickly enough.

Even with it set stupid rich for break-in it was trying to pull the plane out of my hand(Top Flite 6x4 wood prop), too! She should fly great, and be quite fast indeed!

I'm not entirely sure how long break-in is supposed to be. I found an original Cox instruction sheet which said to run it like this for several tanks, but it was assuming a fuel load of ~5cc as it was a scan of the sheet that came with an engine with a rear mounted tank. This plane's tank has 60cc or so of fuel in it, and my wing is twice that. On the wing, I ran each engine for one complete 4oz tank, on this plane, I'll run it like this for two complete tanks.

Ah, shoot, C6, I made a promise of information and never followed through, How embarrassing. I do have answers you probably need, as do many others here. I'll try to make good in the near future, because you had good questions, and there are many others who could benefit too. I'll just avoid promising a time frame this time, as I've got a lot going on.
Rusty... Livin' on Carolina time. That's even slower than Tulsa time... maybe even Caribbean time.

RknRusty wrote:Ah, shoot, C6, I made a promise of information and never followed through, How embarrassing. I do have answers you probably need, as do many others here. I'll try to make good in the near future, because you had good questions, and there are many others who could benefit too. I'll just avoid promising a time frame this time, as I've got a lot going on.
Rusty... Livin' on Carolina time. That's even slower than Tulsa time...  maybe even Caribbean time.

Bwahaha, it's all cool~. As I said, I know enough to run one without blowing it up just from my own research, so there's no rush.

The one I ran today ran like absolute clockwork, too. Minimal break-in pains. TBF it is the third one of these things I've run in, still, it pretty much kicked to life as soon as it got a whiff of nitro and it only died when I let it die. Can't wait to peak it out and start playing with the throttle on it!

It pulls HARD on that 6x4 prop, too. Truth be told I could have let go of the aircraft and it would have taken to the wild blue yonder like a dream despite being set rich enough to 4-stroke the whole time. I'm eagerly anticipating being able to tear the skies apart at something like 50-55MPH with this thing!


OH! In the interim I've actually remembered a couple other things I wanted to know that slipped my mind when I initially created the thread.

* I'd love to have a detailed explanation of the Cox wrench. It didn't take long for me to figure out the glow head portion and the flats that correspond with the cylinder so swapping glow heads is no big deal, but I'm not sure what any of the other cutouts on the thing do, and I can't google-fu up a decent explanation of the various cutouts on it.

* Tee Dee glow head on a Bee-style engine a good idea for power increase, or just a good way to burn up expensive glow heads?


I'm also struggling to come up with a suitable livery for it, and I kinda wanna change the landing gear to something a bit more proportional. Thinking Gee Bee style fixed mains would look nice on it, with 1.75" wheels tucked away in the pants?

.049 / .051 wrench:



Flywheel nut also for removing venturis. Glow head slots also fits on Medallion and TD back cover.

Ahh, perfect! Perfect! Perhaps that's something Bernie at Cox Intl could improve with the packaging of the wrenches on offer?

Users can find wrench description here:

https://coxengines.ca/files/EOG.pdf

Ran the sportster again!


Also did a duration test. Filled the 2oz tank to the brim, jammed 'er wide open, lit it off, and started a stopwatch. 23 minutes, 55 seconds later it sputtered out of fuel. Pretty good duration if I do say so myself!

I'm pretty sure that cutout for the car flywheel nut fits the Tee Dee venturi too.
For cylinders that do not have a flat on the top fin, the narrow gap on the end is for inserting into the exhaust ports... BAD idea. It will frequently gall the inside corner of the port and then the piston will drag on the burr. It can be fixed with a needle file. Or made worse. Alternate ways to get the stuck cylinder off are to heat it with a heat gun and use a home made strap wrench. I have clamped the cylinder between 2 pieces of pine wood in a vice and turned the crankcase to unscrew it.

A Tee Dee glow head will always run better on any Bee engine. It's higher compression, so you may want to adjust head gaskets and/or nitro content to suit the engine. Trial and error in that department.
Rusty