|
RE: Regear with Dirt Hawgs on Rustler?
The Dirt Hawgs are physically larger than the stock tires on your Rustler. That increase in size is going to raise the strain on your motor. Unless you reduce that strain,you will eventually damage the motor. Please use the gear-wizard calculator to determine the route that you need to go. Most likely, you need to drop to a smaller pinion.
Posted on: 10/4/2006 8:14 AM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4826404
RE: overheating problems
Please take 5 minutes and read this article: http://www.rcuniverse.com/forum/m_3255405/tm.htm I wrote it specifically to solve problems like the ones that you are describing and to help educate newcommers to the hobby. Without knowing what pinion/spur you were running, I think Duneslider is on the money. If you put in the 'optional' larger pinion gear and ran that for a week, its no suprise that you burned up the motor.
Posted on: 9/28/2006 8:07 AM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4802469
RE: overheating problems
Please take 5 minutes and read this article: http://www.rcuniverse.com/forum/m_3255405/tm.htm I wrote it specifically to solve problems like the ones that you are describing and to help educate newcommers to the hobby. Without knowing what pinion/spur you were running, I think Duneslider is on the money. If you put in the 'optional' larger pinion gear and ran that for a week, its no suprise that you burned up the motor.
Posted on: 9/28/2006 8:02 AM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4802462
RE: Traxxas blues
Gripe all you want. You bought a TRAXXAS. They are the Toyota Corolla of the RC world. Nothing flashy, inexpensive and reliable. As long as you guys keep buying things based entirely on PRICE, Traxxas will continue to churn out entry level STUFF. I mean, what are you expecting from a freaking $160.00 RTR model??? If you wanted bearings, a better motor, better performance, etc, you should have bought a different (and better) model!
Posted on: 9/28/2006 7:55 AM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4802450
RE: mamba powered tc3 58 mph !!
It's pretty easy to check whether someones making things up or not..... Input voltage * Kv Rating of the motor = terminal velocity in RPM. Distance traveled is RPM / 12 (inches) * 60 (minutes in an hour) / 5280 (feet in a mile)= speed in MPH. At 11.1v, a 5700 kv motor will top out at 63270 rpm. Using the rest of the formula, 63270/12*60/5280= 59.914mph
Posted on: 9/26/2006 5:29 PM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4795866
RE: Team Associated (only) powered by brushless Thread
RC10T3 FT (conversion) Batteries: Intellect IB3800 and IB4300 6 cell packs Novak GTB Speed controller Novak SS4300 Gearing: 87/18 Top speed 31mph. Runtime 18+ minutes Motor Temp 138*(max) ESC Temp 118*(max) Novak SS5800 Gearing: 87/17 Top speed 35mph. Runtime 15+ minutes Motor Temp 143*(max) ESC temp 115*(max) Novak 6.5 Gearing 85/17 Top speed 39mph. Runtime 13+ minutes Motor Temp 146*(max) ESC temp 119*(max)
Posted on: 9/22/2006 4:01 PM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4780089
RE: nevermind, i am apologizing to the group for dropping down to a kids level.
Ebald, That's exactly the point that I was trying to get across to specracer. It's a case of he wants to believe what he's posted so much, that anyone who questions him is an idiot. If getting a car up to the speeds that he claims were as easy as he said, we'd all be doing it.
Posted on: 9/22/2006 8:06 AM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4778637
RE: Nitro or Electric
The Ti Pivot pins were a good upgrade. No problems with them. Infact, I had the plastic on the front strut tower fail before the pivot-pin gave way.
Posted on: 9/21/2006 2:53 PM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4775907
RE: Nitro or Electric
I have the Lundsford Ti turnbuckles on my T3, B4 and T4. The problem with the Ti is, once it bends (and it will bend if you hit hard enough) it's done for It cannot be reshaped. It has to be replaced and that is not covered by the warranty. Breakage is, but not bending. I've argued down that path before. Originally, I put RPM ball-cups on each of my pivot points (and TI ball-studs as well) becasue I kept having the factory ball-cups popping off when I took a hard hit at the track. Instead of popping off, they transferred the energy of the hit to the turnbuckles. I ended up bending the aluminum ones almost every race. So I upgraded to the Lundsford turnbuckles, expecting them to work better. They did. Actually too well. Instead of failing at the pivot-ball, or at the turnbuckle, the servo saver now became the failure point. It wasn't that the servo saver wasn't set right. It was and it did it's job. The pivot-arm on the servo saver became the sacrificial part. The problem was that it is such a pain to change, it becomes a choice of what you are willing to fix more often. I ended up pulling the RPM ball-cups and replaced them with the OEM associated. I still have the occasional popped ball-cup, but haven't replaced a servo-saver since. I am still running the TI turnbuckles, but like I said before, they'll still bend if you hit hard enough.
Posted on: 9/21/2006 9:53 AM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4774992
RE: Want to go brushless but still confused
A single speed transmission, in something that heavy? I can see it causing problems like you described.. Any idea what the transmission ratio is for that truck?
Posted on: 9/20/2006 6:58 PM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4772667
RE: nevermind, i am apologizing to the group for dropping down to a kids level.
Holy Cow. 15 years as an Engineer, 5 1/2 years of College and some snot nosed kid who can't spell to save his life tries to imply that I don't know what i'm talking about? Ok, Braniac. From the Public Domain called the internet: "THE VERDICT The D5 brings enhancements such as a wider power band than previous D motors, and it feels smoother and more linear under braking than they do. TEST SETUP SPECS WIND: 27 turns of 22-guage wire BRUSHES: Trinity no. 4499 laydown serrated SPRINGS: polarized; red-positive; green-negative COMM DIAMETER: 0.295 in. (7.5mm) TIMING: 24 deg. (fixed) DYNO DATA TEST RESULTS PEAK RPM: 33,299 PEAK POWER (WATTS): 129.2 PEAK TORQUE (NMM): 81.7 PEAK EFFICIENCY: 69.7% " That was excerpted from the following article: http://www.findarticles.com/p/articles/mi_qa3825/is_200302/ai_n9221446 Originally published in RC Car action in Feb, 2003. Lets see, the peak velocity, measured on an unencumbered motor, as in no load, was 33,299rpm. Remember, that it's an unencumbered measurement. You'll never see that kind of performance out of the motor once it's in the car.... What did we measure for the Monster HP Pro? 29.5mph..... That equates to about 16% below the peak RPM potential for the motor. I don't care if you ran it down a 10,000 foot runway, you're not going to see 40mph out of it (even when it was geared with a 2.0:1 ratio!) It does not have the torque or output power to do the job!
Posted on: 9/20/2006 6:49 PM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4772605
RE: nevermind, i am apologizing to the group for dropping down to a kids level.
Oh, Gawd! Heeeeee's Baaaaaaack![:D] So, um, Specracer.... Have you even bothered to try any of the suggestions that I gave you last time to try to accurately measure just how fast you're going, or are you still flapping your gums about doing 40mph with a stock motor???? I was inspired by our last tet-a-tet. I put your words to my resources..... I convinced a friend to donate his RC10l2 for an experiment, a a week ago, Saturday. We did some speed runs at the indoor track using a Monster HP Pro, A P2K2, Reedy MVP, Green Machine and an Orion Core, all 27 turn stock motors. The electronic timing at the track registered the fastest speed of 31.3mph from the Green Machine 3 and slowest speed of 24.6mph from the Reedy Mvp. The 10l2 was geared 48/24, using a Protoform Saleen racing body and Jaco Blue tires. At no time, did any of these motors that we tried get any where NEAR 40mph let alone 34mph. The fastest of the bunch was 31.3mph. Instead of guessing how fast you were going (and boasting about it like its a fact) get a stopwatch and time the silly car like I told you to a few weeks ago. You'll be a bit disappointed when you learn that you're really not going anywhere near as fast as you think you are...
Posted on: 9/20/2006 5:31 PM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4772339
RE: Want to go brushless but still confused
RURC, Are you still running the multi-speed transmission, or did you lock out all but one gear? If you're not starting out in first gear, you're probably experienceing a condition called torque cogging. Starting in anything but first would put sufficient stall torque on almost any motor and would cause the problems you are describing.
Posted on: 9/20/2006 3:19 PM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4771926
RE: Want to go brushless but still confused
What RURC posted is correct, but I wanted to expand on the sensor based vs sensorless DC brushless motors a bit. The biggest advantage a sensor based motor has is it's near elimination of Cogging. Cogging is the result of a combination of supplied voltage fluctuations and an imperfect geometry between the rotor and stator as the winding is energized. It prevents smooth rotor operation and generates unwanted electrical 'noise'. A sensor based brushless motor employs either a Hall-Effect or optical sensor along with support electronics (based in the ESC). Sensor based motors have, as RURC stated, a smoother feel as you accelerate. This is accomplished using the resident sensors determine the exact position of the rotor inside the stator and allow for the controller to energize the appropriate windings with optimal timing. Sensorless brushless motors generally control the energization of the stator based on back-emf zero-crossing. The motor's back-emf is generated and determined by the rotors position and speed. Simple resistor based circuitry is used to determine the rotors position based on instances when the back-emf reaches an inactive zero phase. Newer controls take this determination one step further not only by monitoring the back-emf, but also by calculating the rotors exact position with additional current feedback circuitry using the controllers sampling rate. The motor efficiency then becomes a product of the quality of suplied voltage. Inconsistent voltages are amplified by the impercise nature of the motor timing when using a sensorless-system. It is therefore crucial that the motor is supplied with the best current possible. This is achieved using high-quality batteries, low resistance (or zero-loss) connectors and good solder joints. In application, a sensorless motor can reach higher rotational velocities than sensor-based motors. This limitation is due the the processing time required by the sensor an its support circuitry. I hope I didn't confuse you too much.....
Posted on: 9/20/2006 11:00 AM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4771129
RE: nevermind, i am apologizing to the group for dropping down to a kids level.
Ok, What'd I miss? It takes a whole lot to get Sleepy up in arms so whatever it was must've been worth the price of admission! What? Was Specracer back with his fantasy claims? Darn me for sleeping....
Posted on: 9/20/2006 10:07 AM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4770980
RE: Charging time for NIMH 3300MAH with Mega 2
Your advice is good, for a flat-dead pack only. If the pack has any juice left in it and he does as you posted, he'll cook the pack in no time. Charging any battery with a timed charger will require him to sit and monitor the pack at all times. As soon as the temps begin to rise, he needs to pull the pack. How many cycles that takes will depend entirely on how much of a charge is left in the pack. For his safety and peace of mind, I do not EVER recommend anyone using a timed charger for charging niMh cells.
Posted on: 9/14/2006 5:04 PM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4748431
RE: Charging time for NIMH 3300MAH with Mega 2
DO not, Do not, Do not ever attempt to charge a Nimh battery pack on a TIMED charger. You should ALWAYS use a peak detection charger when attemtpting to charge your Nimh batteries. Attemtpting to charge an NiMh pack on a timed charger can result in an overcharge which will ruin the battery. A peak detection charger shuts off when it detects a voltage drop in the battery. A timed charger does not. It is dangerous for both you and your batteries to use the timed charger. Throw it away and buy a proper charger!
Posted on: 9/14/2006 3:58 PM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4748165
RE: .
Hey! free thread! Lets hijack it! "Honest office, I just found it laying here abandoned!" New topic. Why do dogs insist on rolling in the stinkiest stuff they can find, then try to cuddle up next to you on the couch?
Posted on: 9/14/2006 3:52 PM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4748133
RE: Electric vs. Nitro?
In electric RC, speed and endurance are all products of what you want to invest in the model. Don't have alot of cash? Don't want to mow more lawns and otherwise wait? Then buy a nitro. Out of the box a Nitro RTR will always be faster and run longer than its electric RTR counterpart. Nitro is a good way of going fast for real cheap. Nitro's are messy and are a pain to tune and keep running. They also end up costing you more over the long run, since the fuel is not renewable. If you have time and money to invest, you can make an electric that puts most nitro models to shame. A brushless motor and li-poly battery combination can push something like an E-maxx to a top speed in excess of 40mph and do so for almost 20 minutes. But to do so will require a signifigant expense (about $500.00 for the motor and ESC and another $175.00 for a good Li-Poly battery). (contrary to what was calimed earlier, a stock E-maxx tops out at 23mph, not 30mph. The traxxas claim of 30mph was achieved running a pair of specially built 7 cell battery packs (14 total cells). Runtime with 2 7 cell GP3000 packs is around 9 minutes.)
Posted on: 9/14/2006 8:01 AM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4746802
RE: Oh No, Not another Nitro to electric Conversion
Thanks for the encouragement, 125.. I did a Hyper 7 to electric conversion about a year ago, but wan't happy with the strength of the diffs. They just couldn't handle the torque produced by the Brushless motors, so I sold it as a roller on Ebay. The funny thing is, My T-Maxx is still runningl ike a dream! An Traxxas had such a rep for poor engines. The TRX2.5 still starts right up and almost never heeds a screwdriver put to it. Head temps are ~210* and i'm getting about 14 mins a tank from it. The only thing I hate is how fast it wears through clutches.... By the way, what 125 do you have? I got a Yammy XC125v in June and Love it!
Posted on: 9/11/2006 8:48 PM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4737429
RE: Oh No, Not another Nitro to electric Conversion
I ran 4 1/2 gallons of 20% (12% oil) Nitro through the buggy in the 7 months that I've owned it. Most of the guys I race with get about 5-6 gallons out of an engine before it needs a rebuild. I'm not as disappointed in the longevity of the engine as I made it sound. I was pleased when I got it. But I could not keep it running steady, I could not keep the head temps below 275* (without stalling the engine). I really hated the sticky, clumpy mess that the unburnt oil and dust made after every track session. It was a pain to clean! The Roto-start kept dying because I spent so damn much time trying to re-fire the stupid engine. I wanted to use some of my 3300 cells, but the stupid roto-start was built only to accept stick packs. I have all SxS packs for my electric. The battery that I had in the Roto-Start was a Sanyo SC-2400. It wasn't just me. Any of the nitro guys who tried to help me threw their hands up in disgust and said I can't make the damn thing work! All this time, my 2.5 TRX T-maxx is tooling along with no trouble. No, I have plenty of experience with nitro, just no patience for it. Besides, I never had a DNF running my electrics at a race because the battery died. I had 4 DNFs this season with the crappy Nitro because of flame-outs. Nope, I'm done with it.. I'm still not sold on Li-Polys, but I do have a few IB4300's just waiting for a destination....
Posted on: 9/11/2006 7:39 PM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4737165
RE: Brushless vs. brushed
[quote]ORIGINAL: specracer and i dont think im a step abouve everyone bro.all i said is my losi hit 34 and if a buggy can hit 34 then i know my 10l will hit 40.then i got thes science masters come up and say im lieing.and other people saying im dumb and i need to get my facts strait.its ok becouse i want a big opoligy when yall do see my 10l hit 40.so can yall stop bustin my balls over some dumb junk like this.we will procede with this conversation when i get a video up ok guys? [/quote] Buddy, you just don't listen when people are talking to you. For the last time, there is no way in heaven or on earth that you got any buggy past 30mph with a STOCK motor and 6 cells unless it was tied to the bumper of the car in front of it! A brushless Novak SS4300 can't do it and neither can a P2K2 pro! Real simple math here. 31000 rpm is the peak, unencumbered velocity of the P2K2 pro. The buggy will travel approximately 1" for every revolution of the motor. There are 12 inches in a foot. There are 60 minutes in an hour and 5280 feet in a mile. Know how fast you can go? 31000/12*60/5280= speed in miles per hour. Want me to do the math for you? That's a MAXIMUM of 29mph PEAK. The reality is you will never see your PEAK speeds. Your ACTUAL speed will be about 10-12% lower than the expected speed. So whats 10% of 29mph? 2.9mph. Your actual speed was probably closer to 26.8mph than 34mph. Like I said before, pacing a 1/10 scale model with a full size car is NOT an accurate way to measure the speed of the model. Don't want to spring for a radar gun or gps? You have a stop watch don't you? Measure off a 100' section of road and mark it with some chalk. Get your car up to speed and use the stopwatch and time how long it takes for it to cover 100'. Divide the number of feet by the number of seconds to give you the velocity in feet per second. Then multiply by 60 (seconds) then again mulitply by 60 (minutes in an hour) and divide that by 5280 (feet in a mile) Viola, a time/distance calculation that can pretty accurately answer just how fast you were going through the time trap ( this is how vascar computers work ). Repeat this course 5 times. Throw out the fastest time and the slowest time then average the remaining results. You'll be a bit suprised ( and humbled) when you finally realize you're not going as fast as you think you are.. You can thank me later......[>:]
Posted on: 9/11/2006 7:27 PM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4737087
Oh No, Not another Nitro to electric Conversion
Well boys and girls, I've had it (again) with Nitro. I bought an RD Logics SHO last February and was thrilled to have another Nitro buggy. After a summer of racing, I remember just how much I hated it. I have had overheating issues since day 2. When the air temps got over 90*, it wouldn't bloody start. So I converted it to Roto-Start to save my nuckles. That worked ok for a while, but the battery kept dying. In early Sept, the engine began to sputter under acceleration. I thought it was another glow plug ( this engine eats them! ), but the plug still looked new and tested fine. A quick compression test later and I knew I was in need of a rebuild. And now, the kick in the teeth. The rebuild kit is $87.00, and its on backorder until November. G(*T^)*&%)*&%! Forget this noise! I'm going back to all electric. I ordered a Plattenberg Big Maxximum and a few mod1 pinions. I'm working with a guy from the fab team in the prototye shop to come up with an adjustable motor mount. My plan is to keep the 4 disc brakes (they rock!) and lock out the reverese on the ESC. ( I'm going to use my MGM80 for now, but plan to get a better one) I hope to have the thing up and running by the end of the month. I'll post pics if I remember to take them!! Long live electric![:D]
Posted on: 9/11/2006 3:23 PM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4736168
RE: Brushless vs. brushed
Actually, I'd lke to see Sleepy23 work his voodoo on a Pancar. I think with some tweaking, his Mamba Maxx 7700 and a custom sadle pack li-pol, he could push 70mph, if not better. Whadda ya say, Sleepy? Are you up for a new challenge? Specracer, I for one, believe that given enough room, you could get a 1/12 scale pan car beyond 30mph with a stock motor. Your problem is you shot your credibility dead when you claimed to have run 40mph with a stock motor: [quote]ORIGINAL: specracer dude i hit 40 with a stock motor with 6 sub-c cells.i can hit over 80 with mod no prob.you never had a real brushed motor huh?get one [/quote] I'd love to see you do it and tell us all how you did just that, since no one else in the RC world can reach those numbers! You got called on that exaggeration, you dropped from 40mph on 6 sub-c's to pacing the model at 34mph sitting on your uncle's Tailgate: [quote]ORIGINAL: specracer if you gear it right you can easly go 40mph.i have no speed recorder or nothing but i hit 34 sitting on a tailgate on the highway wile my uncle drove.so are you saying brushed motors limit is 40?i would like to see proof on that to. that was with a losixx buggy with a old p2k2 pro.now i got a 10l witch is way faster.and a tc4 [/quote] Right there, the BS meter just went off the chart! You have alot of guys that would give their right wing-nut to get performance from their models as you otherwise claim. Hell, Sleepy23 has spent over a year shaving weight off of an RC10t4 trying to get it past 50mph with just 7.4v. If getting speed was as easy as you claim, we'd all be doing it. So you got caught exaggerating again. Now the story has changed to : [quote]ORIGINAL: specracer im talking about a 10l guys not a freaking stampede garbage.if you get a nascar body stick it on a 10lss and gear it right you can hit 40.and if you say a brushed motor only hits 56 then your crazy.i know for a fact a fast brushed motor hits over 56mph.and you dont hav to hav a 4t to do that.you can get a 10t or maby a 12t.i might not know much about science but you got something mixed up dude. [/quote] Like I said before, a Pancar can get beyond 30mph with a stock motor and 6 cells. But your claimed speed is still in doubt. Pacing a 1/12 scale model with a pickup is inaccurate at best. I believe you might have gotten close to 34mph, but without a GPS or radar measurement, I cannot believe you. You've got no credibility left....
Posted on: 9/11/2006 2:09 PM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4735973
RE: Brushless vs. brushed
[quote]ORIGINAL: specracer if you gear it right you can easly go 40mph.i have no speed recorder or nothing but i hit 34 sitting on a tailgate on the highway wile my uncle drove.so are you saying brushed motors limit is 40?i would like to see proof on that to..... ...that was with a losixx buggy with a old p2k2 pro. [/quote] Originally, you claimed that you reached 40mph with a Losi XX and a stock motor. Highly improbable, since the buggy batteries and equipment weigh nearly 4 pounds. Having had an RC10B4 FT that was running a Feigao 6s brushless motor on 6 matched GP3000 cells, it BARELY reached 43mph. (That motor produces around 5900k/v which at 7.112v (actual) gave a velocity of only 41,960rpm ) With a stock motor, a Losi XX will be lucky to see 26mph (at a peak rpm of 31,000) [quote]ORIGINAL: specracer im talking about a 10l guys not a freaking stampede garbage.if you get a nascar body stick it on a 10lss and gear it right you can hit 40.and if you say a brushed motor only hits 56 then your crazy.i know for a fact a fast brushed motor hits over 56mph.and you dont hav to hav a 4t to do that.you can get a 10t or maby a 12t.i might not know much about science but you got something mixed up dude. [/quote] So now it's with an RC10L? In a 1/12 scale pan car such as an RC10L a stock motor would be substantially faster. Since it has a smaller chassis, with a greatly simplified drive train, it does not need to produce the torque for acceleration that the larger vehicles would. That simplified direct drive gearing can allow for a nearly 2:1 FDr/Rollout ratio. It is entirely possible that you did indeed pace 34mph with an RC10l and a stock motor. With a 12t or even a 10t, you could see speeds of 60mph. But you are comparing a 1/12 scale 1.75 pound pan car to a 1/10 scale 4 pound buggy. You cannot acheive the same performance with the same motor in both applications. The larger you go, mass, inertia, friction, torque and drag all become increasing factors.
Posted on: 9/11/2006 8:38 AM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4734984
RE: Brushless vs. brushed
[quote]ORIGINAL: specracer if you gear it right you can easly go 40mph.i have no speed recorder or nothing but i hit 34 sitting on a tailgate on the highway wile my uncle drove.so are you saying brushed motors limit is 40?i would like to see proof on that to. [/quote] Good story. Too bad it's not possible. The best "Stock" motors top out at around 31,000 rpm. That's about 26mph. Those same motors produce about 19 in/oz of torque. To reach 40mph, that motor would require a final drive ratio/ roll-out ratio of 1.508:1. To achieve this, you would have to be running a rediculiously low gear ratio around 6.55:1 (78/26 for a Losi XX). At that point, a stock motor would not produce sufficient starting torque to adequately accelerate against that mass. The result would be an overcurrent and if you're lucky, a popped brush. I have seen a few hand wound 4t brushed motors that turned close to 60,000 rpm @ 7.4v. Thats a healthy 56mph. But those same motors ate brushes at a rate of 1 set for every 3 runs. They had to be broken down and rebuilt every 5 runs. Compared to brushless: A relatively inexpensive Mamba Maxx CM36s 5500kv motor can scoot along at nearly 65,000 rpm @ 11.1v. It can do that speed every day all day. No brushes to replace, no comms to true, no loss in magnetic field as heat builds in the can. Unless you have top dollar maintenance equipment and a sponsored racers budget, trying to keep top tier brushed motors running competitively will break the bank. Most brush-fans hate brushless because it takes away the tweekers voodoo and can give even a novice racer a competitve car.
Posted on: 9/10/2006 8:35 PM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4733317
RE: STAMPEDE stops when hot...HELP!
The novak reactor does have thermal protection circuitry built into it. However, I don't believe this is the cause of the problem: Jesse, How many runs do you have on that motor? Was it new when you got it, or did it come used with the truck? Because of the nature of the motor, the brushes will wear away with each revolution of the commutator. After a period of time the wear of the brushes contaminates the commutator plates with carbon fouling as well as other garbage. This foulfing reduces the efficiency of the electrical flow and increases the resistance. As the brushes continue to wear and the commutator continues to degrade, the resulting resistance increases the ambient heat of the motor ( a byproduct of resistance to electrical flow is heat ). It is entirely possible that your motor is over-heating not because of the gearing, but by the condition of the brushes and commutator. If the motor was bought used and you don't know just how many runs have been made with it, take it out and have it re-built at your local hobby store. If they do not offer a motor rebuild service, purchase a new motor. Brushed Ferrite-magnet based motors have a finite lifespan. In most cases, they need to be broken down and rebuilt every 20-30 runs. Faster motors, such as a 13 turn, will require service at much shorter intervals. In some cases as little as 15 runs. Continuing to run a spent motor will only damage the motor further eventually resulting in a full-scale endbell melt down or popped brush.
Posted on: 9/10/2006 11:57 AM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4731560
RE: Is a 26T Pinion gear the best for 13T motor??
Guys: Will someone please explain to me why, after nearly 2 years of being posted right at the top of this thread, we keep getting this same question over and over again. Jesse, for the sake of your model, please read the sticky at the top entitled "Understanding gear selections for 1/10 Electric RC!" http://www.rcuniverse.com/forum/m_3255405/tm.htm There are so many variables that go into choosing the right gear ratio for your truck. Thie old wives tale "use a pinion 2 teeth lower than the turns of your motor" is HOGWASH! It does not take into account what type and size tires that you are running, what your transmission ratio is, or what your spur gear is. Following advice like that is a good way to trash your motor in a hurry. (and yes, contrary to opinions, you can damage your motor just as quickly by undergearring it as overgearriing it.) Please, take 5 minutes and read the article. Educate yourself, then use the handy calculator provided by RCU, to determine the best setup for your truck. http://www.rcuniverse.com/community/gearwizard.cfm The calculator changed a bit. Rather than subtracting the two numbers (roll-out and final drive ratio) you divide the two numbers, to get a true ratio.
Posted on: 9/8/2006 7:52 AM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4724178
RE: turn and gear ratio
Zephar, Read this: http://www.rcuniverse.com/forum/m_3255405/tm.htm and then use this: http://www.rcuniverse.com/community/gearwizard.cfm Don't guess. Use the tools provided and you can answer the question yourself. :-)
Posted on: 8/31/2006 8:11 AM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4692781
RE: bad li-po?
LiPol packs have special handling requirements during charge and discharge. They have no tolernace for overcharging or deep discharging. The vendor will not honor any warranty requests for a pack that was improperly charged, discharged or improperly stored. Sorry, you're stuck with it....
Posted on: 8/29/2006 2:21 PM by Author "SkrapIron"
in the forum "RC Electric Off-Road Trucks, Buggies, Truggies and more"
http://www.rcuniverse.com/forum/fb.asp?m=4685055
|
