I agree completely. I got a similar result (289 grams for a substance with a specific gravity of 20, or slightly heavier than tungsten). HO would be more feasible, as it has 6.22X the volume of N.
Tungsten, gold and platinum all have specific gravities of about 19.25. Anything higher is usually very rare, such as osmium or iridium. Lead's specific gravity is somewhere in the 12s. Nickel is around 10. The equation to calculate weight is pretty simple. Volume in cubic centimeters x specific gravity = weight in grams. I cannot imagine a substance with a specific gravity of 140 or so that would be needed to make a 4 lb N scale 2-8-2.
What about depleted uranium? But still, the Cotton Brute only weighed in at 24 oz, IIRC. Even still, DU isn't exactly something you find at the local DIY home supply store.
I must say that I don't remember. I would say it is about average for a loco that size, but not exceptional without more weight. The upper cavity is completely empty, so there is a lot of room for extra weight.
** Grabs a bucket of buttery popcorn...a large soda...and gets comfy on the couch. ** All this high tech talk reminds me of watching "House" on TV. The jargon is baffling but the results are simply amazing! Honestly...No disrespect. I find it all very fascinating...even if I do have to look up 85% of what you guys are talking about ! :thumbs_up::tb-cool::tb-wacky: . .
A bad truck gear? Is it one of the idler gears? I bought a U50 that didn't pull right either, and whoever had it before me had removed one idler gear frome each truck (who knows why). I found that the double gear from an Atlas/Kato RSD4 truck works if you sand off the smaller gear to achieve the right width. It runs perfectly now.
George,ever hear the saying:"believe half of what you see,and none of what you read"..? Well,there ya go..You see now guys,I figured it out..He's weighing it on Jupiter,the gravity there is 2.364 times our gravity..Yep..That's gotta be it..Yessir... Reminds me of an old cartoon I saw,where a bunch of teenage aliens came here to dragrace..Their 3 second car from their planet was running 18 seconds here..They couldn't figure out why..The car weighed 18,000 pounds,but was built from the lightest metal on their planet..CAST IRON...
DU is in the 18.7 range--lighter than pure tungsten. But I think it's a bit easier to work, and might be more abundant, although tungsten is not considered that rare. I believe you can cast DU, but tungsten's high melting point (why it has served as a filament for light bulbs all these years) essentially prevents it--what's going to hold the casting? I was being understated, Hemi, when I mentioned a material with a specific gravity of 140. Specific gravity is the weight of a material compared to water. Water is 1.0. Gold is 19.25. I think tungsten is either 19.25 or 19.32. The highest specific gravity in nature is perhaps 23--there are plenty of tables online. I'm not sure an alloy can be heavier than its constituents--chemistry was just too long ago--but achieving a specific gravity of 140 or so would result in an instant Nobel prize.And totally revolutionize standard chemistry and physics. The only things I can imagine with a specific gravity of about 140 would be the core of a nuclear weapon just prior to explosion--not a stable state, exactly--or space around a black hole, which is also not stable. I don't have time to run the weapons equations tonight. I can imagine an HO heavy 2-8-2 weighing in at 4 lbs or so. I've also got problems with the motors with 4.2 ft-lbs of torque at 12 VDC that would fit in a max 20mm diameter core. Most N scale motors are in the 12-16mm range. I've always worked in the metric scale (newton-meters), and don't have time tonight to convert, or figure it out, but this seems as totally unrealistic as the weight claims. I mean, my Hemi in my Dodge Magnum is a 5.7 liter eight cylinder combustion engine that produces 390 ft-lbs of torque at maximum power. It weighs about 500 pounds or 225 kilograms. Something weighing perhaps 10,000 times less is going to produce 1/100 of the torque? Jeez, I'll buy 100 of those and a few 12 v batteries and have a dragster Magnum that will outrace a fuelie! And these are order of magnitude guesses. It's not going to happen, unless you are talking the output of explosive batteries. And, if that's been harnessed, we are home free on the energy front.
Most likely, I'd believe these claims of weight and power to push the limit of HO, become feasible in S, and would be routine in O.
Sometimes I have to look up 90% of what I post. It's called research. Or it's called confirming what you think you know and, you're right, it's fun and worth the popcorn. If someone is claiming that an N-scale size motor can produce 4.2 ft-lbs of torque on this forum, I'd like to look into it. It could change my life. I wish it were true. It would solve a lot of problems in the world. But the claim is at least 10,000 times beyond the state-of-the-art, and perhaps 1,000,000 times beyond, at least the last time I looked. These kinds of advances do occur and, thankfully, more often than is generally recognized. But there are some physics limits to what has been claimed here for materials weight and motor performance. If these claims are true, I'll be delighted, as that means someone has pierced previous limits by many orders of magnitude. That happened with the atomic bomb, the electronics industry, and the biotechnology industries. Hard to imagine it will happen in the materials sciences.
This gets funnier by the minute..CSX Robert brings up a good pont..What's the point of bringing up the weight of the tender,the technically largest,most useless part of a steam locomotive? Certainly,a team leader of an aerospace company would see the uselessness of that,so that means his figures are even MORE absurd,since we're talking about a 4 pound LOCOMOTIVE,not loco and tender,unless he's not smart enough to realize the tender is dead weight? Guess the boys really were "thinking backwards"..LOL!!! Pete,a motor that small with 64+oz. inches of torque is NONSENSE...I own a 1500 dollar RC motor dyno,I race RC dirt oval cars,and used to run RC pullers at national level...[oh yeah,check out the pic,no funny smells here..Been in dozens of magazines..] I have rare earth cobalt magnet.15 size puller motors,the size of a small soda can,that barely top out that 4 pound number.News flash..The shaft size necessary to even handle that kind of torque is in the 3/16 range,unless,of course,that piece is made of "unobtanium",too...By the way,both of the pullers have automatic weight transfer systems,weight on tracks inside that keep the chassis balanced to just barely keep the front tires on the ground,and the truck has a system that changes from standard to cat steering if the steering is turned to full lock in either direction..
hey lou where can i get some unobtanium for a scale r/c tug the brass props weigh next to nothing:tb-nerd:
Ask Mark Donohue...LOL!!! Anyway,I just remembered something..I have a SOLID LEAD K4!!! Not just the shell,but the entire shell cavity,plus extra,way over what the actual space a loco would occupy would be...Mr. scale? Drumroll please...7.63 ounces..And really,1/4 of that is probably extra..
Pete, Instead of using specific gravity for your calculations, you should just be using density. I know its a minor technicality since we aren't talking about weights and mass in different gravity fields, but desity is the correct term. The density of tungsten is 19.3 g/cc. Four pounds of tungsten would require about 94cc of volume. Realatively speaking ,thats really not alot of space, it would only be a 4.5 cm cube. But I do think that is quite a bit larger than a Mike could fill. Anybody want to dunk their Mike in some water to determine the dispacement?? C'mon...take one for the team. Eric
Eric, you crack me up... Lou, I was just watchign RFDTV this weekend, and some NTPA 4WD trucks competing. man, that's a rush! I didn't know, however, that is was a sport in R/C as well!
I looked up the MR article on Jim FitzGerald's Minitrix U-boat variations in the January 1981 MR. The Cotton Brute was a freelanced "U-60" made by combining 2 U-30s. He machined away most of the alloy frame, and replaced it with pieces of lead. Looking at the picture, it would probably more feasible to machine away as much of the stock frame as possible and fill the resulting voids with stacks of tungsten bar, rather then machining a new frame from tungsten alloy. Jim's engine weighed in at 24 oz, and once pulled 355 cars with no helpers.
Hemi,I was one of the originators of the sport back in '87.I was layed up,nothing to do,[broken achilles tendon..] I spent the time building my first truck,and trains.The local hoby shop guy picked up on it,and we got a bunch of guys together and started doing it.That big truck will haul well over 500 pounds,4 motors,28 batteries,25 pounds.Still have my first truck,it ran undefeated for 2 years..Was at the first NRCTPA world championship in '89,the funny car won best engineered..Here's my first truck..
