Shell Shocks First Cox Build

I will by this afternoon. my scanner is broken so i have to use the schools.

So some quick info in the mean time:
Radio: Spektrum DX5
Receiver: Spektrum 6 channel park module
Servos: 3 9gram mystery (yes thats the company) brand servos.
Engine: .049 throttled cox engine (the generic no tank from coxs international)

cheers
SS

*edit* it is now at my house. i wont see it till bout 10pm tnigh though due to the fact that i have work.... DANG DAB NABIT DAMN IT! :3

*edit #2* plane (like in the youube video) will be made out of coreflute

SOOOOOO i got the engine last night! little bugger is smaller then i though ^_^. I only had 10% nitro, 50% caster on me, so i tried to run it off a tank of that. It ran for like 10 secs (just wanted to make sure it wasnt a dud). man, what a sweet little engine. Was up to 1am cutting out the body . Is going to be a compact stick plane.
I know i said i would have scetches, but no time to scan.

Here is a quick Microsoft Paint look XP[img][/img]

[quote="shell shock"]" I only had 10% nitro, 50% caster on me"

HINT: It's supposed to go in the engine and not on you!

Don't you need a shower now????? You must feel pretty slippery.

SS: Recommend that you bench-run several tanks of fuel through the engine before trying it on an actual plane. A ten-second burst isn't a good measure how how well an engine runs. It may not even run the tank out of fuel for example.

ADVICE: Personally I completely disassemble and check every new engine that I get; strange things have been know to be found like metal shavings (NOT good).

[quote="SuperDave"]

shell shock wrote:" I only had 10% nitro, 50% caster on me"

HINT: It's supposed to go in the engine and not on you!

Don't you need a shower now????? You must feel pretty slippery.

HA
HA...
oh yah... HA (actually that was pretty smart XP)

and what i ment by running for 10 seconds is due to the low nitro content, it would only run for 10 seconds. he he he. have to go pick up some higher nitro content fuel. and yes, its mounted on my bench (the engine that is)
thanks for the advice though, is there any way to dis assemble without the wrench? (i plan on ordering it, but im between pay cheques, and im planning on doing another big order soon).

Caution you to use ONLY the appropriate Cox wrench to remove the cylinder head as doing otherwise can damage the aluminum cooling fins. They are only $3 from the vendors and well worth the investment in damage prevented.

I also recommend the correct fitting screwdivers; I use gunsmithing screw drivers that fit properly and cause no damage to the screws. On a nice engine "butchering" the screw heads detracts considerably from the engine's appearance and $$$ value.

ahh, so this will be an exercise in patience i see... i need to wait 1 week from the day of ordering. actually that is quite perfect, i can finish building the plane by then.

shell shock wrote:ahh, so this will be an exercise in patience i see... i need to wait 1 week from the day of ordering. actually that is quite perfect, i can finish building the plane by then.

Most everything worth doing right requires patience. Can you name an eception?

My name comes from my Mil Sim regiment. You cant pin me down. But yes, usually i run blind into things XP this will not be one of those times!

My impatience: this is stupid
Me: stupid?
Me:THIS IS COX! *sits at desk putting in an order*

shell shock wrote:

.........and what i ment by running for 10 seconds is due to the low nitro content, it would only run for 10 seconds. he he he. have to go pick up some higher nitro content fuel. and yes, its mounted on my bench (the engine that is)
thanks for the advice though, is there any way to dis assemble without the wrench? (i plan on ordering it, but im between pay cheques, and im planning on doing another big order soon).

The 10% nitro is not the cause for the short run. While higher nitro content will ease starting and broaden the needle, these engines will run OK on 10% -- you won't ring the last RPM out of it, but your cause for a short run is located somewhere else.

You mentioned in an earlier post that you had 10% nitro/50% castor fuel. I must confess that I've never come across a commercial fuel with that high an oil content. Is this some that you mixed yourself or perhaps misread the label.

You also said your engine came from COX International with a throttle. Does yours have an exhaust sleeve or the rear mounted restrictor throttle that attaches to the choke tube? Either way, SuperDave's advice to flush the engine before too much running is excellent. You can remove the backplate without any special tools, just a good quality Phillips head screwdriver that fits the screws well. I usually use either acetone or denatured alcohol for internal cleaning.

1. Remove the backplate (retained by 4 screws). Once the screws are removed, the backplate can be pulled straight out. There is a gasket between the backplate and case. Take care that you don't tear this gasket in the process. Since it's a new engine, it likely won't be stuck too tightly, but if it is, I like to use a toothpick to help release the gasket, either from the backplate or case, whereever it is stuck the least.

2. The engine likely won't be at TDC, but just make sure the piston covers the exhaust slits. With the nose pointed down, fill the case about 1/3 to 1/2 full of acetone or denatured alcohol. Place your thumb over the opening in the crankcase and forefinger on the thrust plate and give it a good shaking for about a minute and pour out. Flip the engine over a few times and repeat two more times. You can use a Q-tip to wipe around on the inside to see if you have any discoloration -- if you do, clean again.

3. Any manufacturing swarf, grit or debris should now be flushed out, but so will all the protective oil. Re-oil! I use Marvel Mystery Oil, but air-tool or a good sewing machine oil will also work. Don't use WD-40. Make sure the crank pin and rod/piston joint get a shot; you can add a couple of drops to the exhaust ports and the bearing surface behind the thrust plate. Flip the engine over several times to redistribute the oil and reassemble the backplate. These were not intended to be used by gorillas and the backplate screws need not be tightened by one. There are other things that can be done, but for right now, your engine should be clean enough to run without problems.

I've found everything from discolored machining oil to chips inside.

If you're still getting short runs, there may be debris blocking the venturi or under the reed. We'll wait to see how it goes before tackling those.

andrew

SuperDave wrote:

shell shock wrote:ahh, so this will be an exercise in patience i see... i need to wait 1 week from the day of ordering. actually that is quite perfect, i can finish building the plane by then.

Most everything worth doing right requires patience. Can you name an eception?

HHMMM i could but then i wouldnt be doing my jod

andrew wrote:

shell shock wrote:

.........and what i ment by running for 10 seconds is due to the low nitro content, it would only run for 10 seconds. he he he. have to go pick up some higher nitro content fuel. and yes, its mounted on my bench (the engine that is)
thanks for the advice though, is there any way to dis assemble without the wrench? (i plan on ordering it, but im between pay cheques, and im planning on doing another big order soon).

The 10% nitro is not the cause for the short run. While higher nitro content will ease starting and broaden the needle, these engines will run OK on 10% -- you won't ring the last RPM out of it, but your cause for a short run is located somewhere else.

You mentioned in an earlier post that you had 10% nitro/50% castor fuel. I must confess that I've never come across a commercial fuel with that high an oil content. Is this some that you mixed yourself or perhaps misread the label.

You also said your engine came from COX International with a throttle. Does yours have an exhaust sleeve or the rear mounted restrictor throttle that attaches to the choke tube? Either way, SuperDave's advice to flush the engine before too much running is excellent. You can remove the backplate without any special tools, just a good quality Phillips head screwdriver that fits the screws well. I usually use either acetone or denatured alcohol for internal cleaning.

1. Remove the backplate (retained by 4 screws). Once the screws are removed, the backplate can be pulled straight out. There is a gasket between the backplate and case. Take care that you don't tear this gasket in the process. Since it's a new engine, it likely won't be stuck too tightly, but if it is, I like to use a toothpick to help release the gasket, either from the backplate or case, whereever it is stuck the least.

2. The engine likely won't be at TDC, but just make sure the piston covers the exhaust slits. With the nose pointed down, fill the case about 1/3 to 1/2 full of acetone or denatured alcohol. Place your thumb over the opening in the crankcase and forefinger on the thrust plate and give it a good shaking for about a minute and pour out. Flip the engine over a few times and repeat two more times. You can use a Q-tip to wipe around on the inside to see if you have any discoloration -- if you do, clean again.

3. Any manufacturing swarf, grit or debris should now be flushed out, but so will all the protective oil. Re-oil! I use Marvel Mystery Oil, but air-tool or a good sewing machine oil will also work. Don't use WD-40. Make sure the crank pin and rod/piston joint get a shot; you can add a couple of drops to the exhaust ports and the bearing surface behind the thrust plate. Flip the engine over several times to redistribute the oil and reassemble the backplate. These were not intended to be used by gorillas and the backplate screws need not be tightened by one. There are other things that can be done, but for right now, your engine should be clean enough to run without problems.

I've found everything from discolored machining oil to chips inside.

If you're still getting short runs, there may be debris blocking the venturi or under the reed. We'll wait to see how it goes before tackling those.

andrew

yep the highest ive seen in comercial fuel is 28% and the highest ive run in a cox engine is 33.333333%

Thankyou so much andrew! This js real good info!

well guys, picture time! like legit camera pictures! here we go!

proto layout

Dat body

dat body x2

cross beams in the wings

shell shock wrote:well guys, picture time! like legit camera pictures! here we go!

proto layout

Dat body

dat body x2

cross beams in the wings

Nice but you may fid that the tail is a little small.
But i cant tell.

yah i was thinking that too. though the back does not have any flaps yet. with out the dihedral, the wing span is 98cm. also, if any of you know, what is a safe limit for the standard .049 engine?

shell shock wrote:yah i was thinking that too. though the back does not have any flaps yet. with out the dihedral, the wing span is 98cm. also, if any of you know, what is a safe limit for the standard .049 engine?

Depends on the wing span but if i were you i would try for around the 18 oz mark.

wow, thats a pretty good haul for this small of an engine! with that in mind, as long as i get lipo double cells, my weight should not be a problem

thanks nitro

shell shock wrote:wow, thats a pretty good haul for this small of an engine! with that in mind, as long as i get lipo double cells, my weight should not be a problem

thanks nitro

Yeah i have used 1 cell and been fine.

ahh, see im using a dsm2 RX. i think i need min 2 cell, but i will see.

shell shock wrote:ahh, see im using a dsm2 RX. i think i need min 2 cell, but i will see.

No i ran the spektrum AR61000e on a 1s lipo.

oh cool. thanks man. helps to keep weight down.

shell shock wrote:oh cool. thanks man. helps to keep weight down.

Turnigy makes a small voltage booster. Get two of their 1s 400mah lipos and connect them in parallels. Works great.