Treasures are where you find them

cool if there is anything tiny or diesel please report it to us i love them.

nitro:

As you may realize, the principle advantage of diesels in model aviation it is that diesels may swing a larger prop which particularly useful in applications like scale aircraft where excessive weight is often a problem.

As in car/trucks, diesels are noteable for their ability to to pull heavy loads at low RPM's; far more so than "gassers" of even greater engine displacement.

SD

Another aspect of them in our particular sport is that folks that fly both glow and diesel must keep the fuel accessories entirely separate from each other...lest you get some unattractive swelling of components !

Kim:

That is implicit in the use alternative fuels; i.e. automotive/truck fueling station fuel pumps have differing colored handles.

SD

Yeah...goes all across the board.

We sell 100 oct. avgas to stock car racers who bring jugs to the airport. One evening, I was filling a couple of jugs for a guy when he noticed our Jet A truck parked in the next bay. He asked if he could buy jet fuel and I said, "Yeah. You got a diesel tractor or something?" He replied that he thought it might help running it in his stock car!

When I told him it'd run great...right up 'till it hit his carb, and then NOTHING would run for a good while, he actually tried to argue with me that he'd seen an episode of Miami CSI where some dope runners or such were using it in their little rice cars to outrun the D.E.A.

When I told him that was TOTAL B.S. and he might as well put five gallons of diesel or kerosene (Jet A is also referred to as Aviation Kerosine) in his car, he STILL argued that it has to be at least 'a little true' or they couldn't put it on TV ! These folks get to vote...no WONDER we've got the deal we've got in our country...

I finally talked him out of it, but still wonder if he might have come back later and bought some from one of my buds who wouldn't put up a fight. Haven't seen him in a long time !

A good nano 0.1cc can turn a cox .010 prop at over 40,000 rpm.

nitroairplane wrote:A good nano 0.1cc can turn a cox .010 prop at over 40,000 rpm.

So what's the big deal about high engine RPM which, in some ways, is similar to voltage. Amperage, not voltage, is the measurement of electicity's ability perfom work.

(Ohm's law rocks)

So of what practical importance is high engine RPM? After you "eyeball" the torque curve of an engine, explain that one to me.

Anyone?

SD

well if it spins a 3 by 1.25 inch prop at 40,000 rpm would still make more thrust than a tee dee .010 turning 27,000 on the same prop so installed on the same plane the one with the nano would be faster and lighter as it only weighs 10 grams compared to the .010's 19g so a way better thrust to weight ratio on the engine.
so it is important.

An engine's pulling power (torque) is far more than a function of it's RPM. Torque does not increase proportionate to RPM but peaks and then falls as RPM's are increased even further, thus the term "torque curve".

A drag racer knows this well and will shift gears rather than over-rev an engine causing it's destruction. In actual airplanes this may be accomplished with a variable-pitched propellor which, in a sense, allows the pilot to "shift gears" to achieve the greatest pulling power at the lower RPM but so as to not "lug" the engine below it's maximum torque.

SD

SuperDave wrote:

nitroairplane wrote:A good nano 0.1cc can turn a cox .010 prop at over 40,000 rpm.

So what's the big deal about high engine RPM which, in some ways, is similar to voltage. Amperage, not voltage, is the measurement of electicity's ability perfom work.

(Ohm's law rocks)

So of what practical importance is high engine RPM? After you "eyeball" the torque curve of an engine, explain that one to me.

Anyone?

SD

Cool how the sciences all overlap with the same equations. A bouncing ball is a sinusoidal wave.
And I'm an old drag racer from way back. We didn't use shift lights back then.

That is not what i am saying what I am saying is that when you have two engines turning the same prop one at 27,000 rpm the other at 40,000 rpm the one turning at 40,000 creates way more thrust than the one turning 27,000.

nitroairplane wrote:well if it spins a 3 by 1.25 inch prop at 40,000 rpm would still make more thrust than a tee dee .010 turning 27,000 on the same prop

That's assuming the same prop efficency at the stated RPM's. Air props can cavitate just like marine props.

SD

Let's assume it's a grey cox prop that should have the same efficiency the nano will create more thrust than the tee dee .010

When I returned to the site of the party today to get engines, which I yet to examine closely, I was handed a bag containg 19 Torando 6X3 wooden props new and unmounted for gratis.

Good score, huh?

SD

Your just egging us, SD. Nobody scores like that. have yet to see pics...

No such thing as a stash of wooden tornado props that size anywhere on the planet.

Tell U what jet pack, as soon as I get the engines identified and cleaned up I'll take of picture of them AND the aforemention props. You can drool while I laugh.

"Truth is stranger than fiction" it's been said.

SD

lol I believe you I'm just a nut about wood props. I have a little stash like that of top flights that I cherish. They only come out to be looked at and maybe the less printed one will get used after I get confident with the small RC. Just because they are that awesome. I bet your thrilled to see that happen with the scoop.

I picked up two early Babe Bee's this week off of ebay. I got to digging around through all my Cox motors because of this place (the forum) and realized for as many as I had around as a kid, my current collection is almost empty of them. It's all TeeDee and Medallion land this time around.

I started thinking of the Bee's that I have now that I really dont want to fly and would like a few runners around to hang on the goldberg kits that are under my bench and in my goals.

I wanted to start backing off the screws on these two that came in this week but they have to go back in the box for now I cant start another motor job yet.

jetpack wrote:lol I believe you I'm just a nut about wood props. I have a little stash like that of top flights that I cherish. They only come out to be looked at and maybe the less printed one will get used after I get confident with the small RC. Just because they are that awesome. I bet your thrilled to see that happen with the scoop.

I picked up two early Babe Bee's this week off of ebay. I got to digging around through all my Cox motors because of this place (the forum) and realized for as many as I had around as a kid, my current collection is almost empty of them. It's all TeeDee and Medallion land this time around.

I started thinking of the Bee's that I have now that I really dont want to fly and would like a few runners around to hang on the goldberg kits that are under my bench and in my goals.

I wanted to start backing off the screws on these two that came in this week but they have to go back in the box for now I cant start another motor job yet.

Our hobby shop has a good sized box of wood top flight 6x3s. They are great for display engines or use! I still do use the black or gray Thimble Drome props when I bench run though.

I have never tried a wooden prop. Do they break really easy? If so, I'll have to stick to the black plastic.

Yes, they break like match sticks. When there is a prop strike you hope it kills the engine because they start to shake a little after that.

RknRusty wrote:I have never tried a wooden prop. Do they break really easy? If so, I'll have to stick to the black plastic.

Oh yeah! I was out at the field when a guy was test running an AP Hornet .09 when the stand shook loose and the engine fell to the ground. The prop flew apart and hit a guy in his arm! He was bleeding a lot so he ripped his sleeve off his shirt and tied it around his arm. One of his friends took him to the hospital to have it looked at. I couldn't imagine getting hit in the head with a busted prop flying at 600+ FPS

Admin wrote:

RknRusty wrote:I have never tried a wooden prop. Do they break really easy? If so, I'll have to stick to the black plastic.

Oh yeah! I was out at the field when a guy was test running an AP Hornet .09 when the stand shook loose and the engine fell to the ground. The prop flew apart and hit a guy in his arm! He was bleeding a lot so he ripped his sleeve off his shirt and tied it around his arm. One of his friends took him to the hospital to have it looked at. I couldn't imagine getting hit in the head with a busted prop flying at 600+ FPS

are you talking about fps=feet per second? i don't think a .09 could throw a prop at 600, a regular 9mm handgun shoots between 900-1400 fps. my pellet gun can do 800. i would say that it could throw a prop under 300 fps. I have a bb gun that can do 350 and i even think that is too fast for the engine to throw. dont get me wrong, it would hurt like hell to get a prop whipped at you, it cuts my finder to just to tap it in a td 049 swinging a master airscrew 5x4.5.


Carl

RknRusty wrote:I have never tried a wooden prop. Do they break really easy? If so, I'll have to stick to the black plastic.

Only if they hit something

I used to run them on TD in 1/2A combat. Wish I could remember the size. Seems it was 5 1/4 x 4

Flying CL "BC" combat, they were the ONLY way to go... Rev-up 8 x 8... It was rare to have one last two flights. I scored 3 of them at a LHS a couple weeks back