PEE WEE help?

Admin wrote:If you are trying to stop a engine that is running without tossing a rag in it or closing the needle, just place your fingers over the backplate fuel vents and hold them there until it stops. I have been told that it could flood the engine but I have never had any issues with it before.

that wouldnt flood the engine because you create a vacuum and the fuel will not flow into the engine i have only flooded engines by restricting the airflow but event hen only when running very rich.

SuperDave wrote:If anyone is interested a have OEM .049 snap starter for CCW rotation. It was mistakenly purchased by a friend and then passed on to me.

Their most common application is in twin-engine planes where two engine running in the same direction creates torque problems.

I think I have one of those too.

Admin wrote:If you are trying to stop a engine that is running without tossing a rag in it or closing the needle, just place your fingers over the backplate fuel vents and hold them there until it stops. I have been told that it could flood the engine but I have never had any issues with it before.

At one time the Cox instruction sheets said to gasp the spinner to stop the engine. At SMALL a few years ago I did just that in the pits while prepping/tuning an .010 plane prior to flight. I pretended not to hear the comments of the old pros sitting nearby discussing how stupid and dangerous this was.
Anyone else have a copy of those early instruction sheets?
Al

Big Al wrote:

Admin wrote:If you are trying to stop a engine that is running without tossing a rag in it or closing the needle, just place your fingers over the backplate fuel vents and hold them there until it stops. I have been told that it could flood the engine but I have never had any issues with it before.

At one time the Cox instruction sheets said to gasp the spinner to stop the engine. At SMALL a few years ago I did just that in the pits while prepping/tuning an .010 plane prior to flight. I pretended not to hear the comments of the old pros sitting nearby discussing how stupid and dangerous this was.
Anyone else have a copy of those early instruction sheets?
Al

I have 1965 set of .010 instruction sheets I can check them later.

SuperDave wrote:If used, the engine MAY have enlarged mounting lugs to accomodate more common screw sizes. Better check and see before you buy screws. DON"T ream out the holes to a larger size than you have!

IIRC, size #52 is standard for the .020.

Totally agree with Dave on NEVER EVER enlarging the mounting holes on any of these engines. I think though that #2 socket screws from these folks will work: http://www.microfasteners.com/ .

Please be extra sure that you copy the hole pattern as precisely as possible so that you're not binding the lugs against each other as you tighten the screws.

I tried some #2 self tapping socket screws in this new .020, and they seemed to work just fine...with just enough "allowance slop". Also, after a few decades of scratching tanks and stabbing airplanes with flat screwdrivers, I discovered socket screws and balldrivers, and never looked back. I now use these things on everything I bolt down. They are WELL worth the price of converting your hardware collection. Micro Fasterners has a directory table that lets you order the proper size driver to go with the socket screws you order.

yah, when i took the .049 to the local hobby shop, they all had fond memories and warm stories of these little beasts (and the scars to prove em).

Regarding "ball-head" drivers, be sure to NOT "torque" on them excessively as the head will snap of and leave with a hex head only.

"Over-torqing" often happens when the hole for the fastener is too small causing an over-tight fit.

I THINK I remember Cox recommending putting pressure on the spinner. It was probably back in the Space Bug, Thermal Hopper, Space Bug Junior days when the prop was held on by an Acorn nut. These were smooth and would not injure your fingers.

Those instructions were probably dropped when Cox went to the screw instead of the nut.

If you prefer the Acorn nut, Cox International sells acorn nuts that will fit the old engines, and also includes a screw that makes it work with newer engines. I got a few of those for my Space Bug Juniors.

George

Kim wrote:

I tried some #2 self tapping socket screws in this new .020, and they seemed to work just fine...with just enough "allowance slop". Also, after a few decades of scratching tanks and stabbing airplanes with flat screwdrivers, I discovered socket screws and balldrivers, and never looked back. I now use these things on everything I bolt down.

Same here. I use socket head screws in every location possible and replace slotted screws on engines with equivalent socket heads. It's so much easier to put the screw on a long allen wrench and get it started in a hard to reach place. Some of the slotted screws today are so soft or the slot is so shallow that it's easy to bugger up the head.

One screw that always get replaced immediately is the prop screw on COX .049 --- screw size is 5-40. Normally I bulk buy long fully threaded screws, then cut them to length using a Dremel cutoff wheel. That way, I don't need to keep a lot of different lengths on hand.

I generally buy from McMaster-Carr, but if they don't carry what I need, I also use Microfasteners. Two other supplies of bulk screws are Fastener Express and RTL Fasteners.

Those argued but I find it a lot easier to over tighten with them.

this is all good news. and with the angine arriving any day now, perfect time as well. i cant wait to finish my build tonight (minus electronics and engine) and then mount the engine to the body. my poor .049 might feel abit left out for a while ^_^

Although it is just a guess, I always thought Cox switched to a prop screw to replace the threaded shaft when the Babe Bee came out because so many beginners were bending the prop shaft when crashing...especially if flying their plane over concrete. I have one Space Bug Junior with a slightly bent crankshaft. Still usable though.

If that is true, switching to a stronger screw can defeat the "save the crankshaft" idea. For experienced folks it makes sense, for those who still frequently crash, perhaps not. Your choice.

I have some of each. To avoid trouble in that area, I always make sure I have only the correct size screwdriver in my flight kit. Other screwdrivers stay with the repair stuff.

George

Kim wrote:

SuperDave wrote:If used, the engine MAY have enlarged mounting lugs to accomodate more common screw sizes. Better check and see before you buy screws. DON"T ream out the holes to a larger size than you have!

IIRC, size #52 is standard for the .020.

Totally agree with Dave on NEVER EVER enlarging the mounting holes on any of these engines. I think though that #2 socket screws from these folks will work: http://www.microfasteners.com/ .

Please be extra sure that you copy the hole pattern as precisely as possible so that you're not binding the lugs against each other as you tighten the screws.

I tried some #2 self tapping socket screws in this new .020, and they seemed to work just fine...with just enough "allowance slop". Also, after a few decades of scratching tanks and stabbing airplanes with flat screwdrivers, I discovered socket screws and balldrivers, and never looked back. I now use these things on everything I bolt down. They are WELL worth the price of converting your hardware collection. Micro Fasterners has a directory table that lets you order the proper size driver to go with the socket screws you order.

Oh that is what you call a socket i call that an ALLEN KEY.

nitroairplane wrote:[Oh that is what you call a socket i call that an ALLEN KEY.

derp, how did i not see that?

well guys.. the night ended on a bitter sweet note. I finally got the lil .020! woo what a beauty of an engine. Some minor scratches and stuff, but meh. Bad news is, all the seals and tubes are dead and dried up. I have ordered the Coxinternational 3.--$ rebuild kit. hope to have her running by the time im done my p 51

Closely exmine the very TIP of a ball-driver and you'll find that it has a rounded end (unlike a conventional Allen wrench) allowing a fastener to be driven from an angle. Very useful in close places where a slipping screwdriver could cause engine and plane damage.

I have set of five ball-drivers and use them often enough to justifiy their cost.

Yep, they're worth every penny!

You can swap out a engine in the field or shop in 1/10th the time, and not scratch or damage anything in the process.

If your ball driver gets pretty worn out, grab the Dremel and a thin cutting disc, cut the 'ball' off and on low speed carefully cut a new groove the same height as before!

Mark

hey thats pretty smart! any website where i can pick these up? or would a hobby shop carry em?

-Edit: never mind, just read your thread on em SuperDave. Thanks for the help