here's a big pile of questions: need setup advice
 

OK, so just a quick refresh: I'm COMPLETELY new to BL; I'm coming from the 1/8 nitro world. I NEVER race, I just kinda bash a little, jump a little, drive on grass, parking lots, and sometimes go to a bmx trail and ride with my buddie's jato. NO racing, just messin around (not really bashing - I don't beat on my cars). I DO NEED to be able to at least go as fast as my italian big block nitro buggy, but I really want to be able to hit warp speed when I find an empty parking lot! :whistle: HOWEVER, I also want something that runs reliably, every time I use it, as in MINIMAL maintenance. Like a Toyota or a Honda :) I don't want to be monitoring/ worrying about temps all day long, hence, the Neu motor.

The vehicle is a Muggy. Yes, I know, not the best choice for high speed runs. That's ok!

I'm thinking something like this:
Muggy/ mech. brakes/ MMM/ 6S Zippy H 5000 mah/ Neu 15XX/ and a XXT pinion! I know, it's vague, but I made some progress.

Soooo, here's my questions:
1) will 6S get me to warp speed?? (~60mph?) Do I need more than 6S?? Is 6S a dumb idea, or am I on the right track?
2) any idea how much runtime I can expect from a 5000mah 6S??
3) which neu motor? I'm thinking 1521/1D (2900kv), but I'm not sure why. Maybe a 1527/1D (2300kv)? Or a 1515/1.5D (2700kv)?
4) is the MMM going to be enough?
5) what size pinion??
6) where do you buy these hyperion chargers? I can't find em, and RCM only has like 1 or 2. Where can I find the whole line?


Sorry for all the questions and hella long post, but I swear I'm making progress! :intello:

with a 6s pack I would go with a 1515/2.5d (1700kv) and the MMM will be plenty, expect upwards of 30mins of run time depending on your spur/pinion setup

1) 6s should be plenty. Its perfect for bashing.
2) It all depends on how you drive, but you can get about 40 - 45 minutes probably.
3) A 1527 will be way to powerful... you won't even be able to go full throttle, you'll just be wheeling all the time or break parts in the diffs/tranny. :lol: The 1521 and 1515 motors you mentioned has too high a KV in my opinion for that voltage. If you want speed but still be reliable, the 1515/2d would work well, or the 1521/1.5d. And they would both give you incredible speed.
4) The MMM will be perfect for this application. :yes:
5) Use this calculator to find the gearing you want: http://www.scriptasylum.com/rc_speed/_top_speed.html
6) Mike can sometimes special order them, but you can also buy them at maxamps.com or I am pretty sure amainhobbies.com also sells them.

Edit: He beat me to it.

The MMM is unproven, but going by stats it should be nough. personally if I were you I would get a lower k/v 1521. somewhere around 2000k/v(I dont know the names).

60mph is fast and i think 55mph would be a better goal, but 6s is a good idea.

What is warp speed to you??? Some people are happy with 50mph, some aren't. The suggestions so far are solid and you can't go wrong with a MMM.

lol i typed this up and got booted, always a dollar short and day late but seems alot of my opinions are close so Im not a total tard :mdr:

1. yes 60+ geared right, 6s will rip and is the MMM max., No, yeah
2. 25-35min depending on driving
3. All great motors but more 5s lipo motors IMO, id go with a slightly lower KV motor for 6s, since you have a muggy you will most likely be using 1 lipo brick ? you want the rpm to not be over 60k max and more around 50k for speed + reliability, multiply the volts x kv = rpm
4. more than
5. use the calculator to see the speed you want http://www.scriptasylum.com/rc_speed/_top_speed.html
5. maxamps.com has them for pretty good prices, but easily found by typing hyperion into a search engine or checking airplane/heli sites

I figured id throw in my 2 cents these are my opinions, this place is full of dudes who totally know what they're doing so I figured I'd start and they can tell me what a cretin I am

ok, so my motor choice may be off, but what I don't understand is WHY? As in WHY do you choose one particular motor over another? ESPECIALLY with a Neu - I mean, you've got 15xx series, and there's say, 50 of them. Many have kv ratings very close, but they're different sizes, so WHY do you guys choose one over another???? I just don't get it! :cry:

Also, why don't I want those higher kv motors? they're gonna be faster, no? :mdr:

Why is picking out a motor proving to be so difficult for me??? It REALLY shouldn't be, should it?

AHHH jzemaxx! I hoped you'd chime in! Your project is SICK (in a good way) with that there MMT truck!!!!!!!!!! But aren't you spinning your Neu motor past 60k?? and getting away with it?

This thread could be relevant to you. http://www.rc-monster.com/forum/showthread.php?t=10316
This is the vid from that thread. http://www.youtube.com/watch?v=bo7GdkNpKAY

Yes higher KV = faster. But it also = more heat = and depending on how high the KV is, it could also = way to high RPMs.

Plug in all the values I linked you in my previous post. It will help you understand the differences in each motor.

I'm spinning a 1521 to right at 71K. Not something I suggest doing, and neither does Steve over at Neu, but I don't care if they blow up.....lol. For someone that doesn't want to replace them often, run them 60K or under :yes:. Still will make TONS of power. Also the higher KV motors draw big time amps and will make less torque then a lower KV motor.

Ok, keep in mind that the longer can motors make more torque. It seems like mosty use a 1515 for a mt or truggy. Your muggy will most likely be heavier than a std truggy, so the 1521 may be a good choice for you. I would say that around 45k rpm is good for the motor, so at 6s lipo=22.2v you will want a 2000kv motor. 2000kv x 22.2 = 45k rpm (or so)

You battery choice sounds good, I would think that you will get somewhere between 25-30min with that pack, considering vehicle weight and gearing. Having the truck geared for 60mph may cause some issues during regular driving. I would say to have gearing setup for about 45mph regular, and have a larger pinion you can put in for speed runs. The lower gearing will cause less heat, and offer better runtimes.

lol jze, he not for racing, reliable just for goofing around... not drive it on an abandoned airstrip !! :rofl:

Hehe, I'm all about flat out stupid speed. If its not faster then the speed limit, its boring....haha.

In all seriousness, a 1515 is probably more then enough. Most emaxx's are 12-14lbs depending on setup and the guys running the 1515's are flying and with the right gearing you can bash all day with no problems with heat.

Here is a video of a 1515 Emaxx on 6S......thats is sick fast across the grass.

http://www.youtube.com/watch?v=EoOlsYrUF5s

Yes, i agree... I have a my setup which is running 7s2p A123 on a 1512 Neu 3D(1700kv.), so thats 23volts @ a hair under 40k rpm; and I was able to achieve 50mph no problem. The motor was still only 160F after a full run.

my quest for understanding continues............

so if a neu can safely spin to 60k, and I'm spending $255+ on it, then don't I want to be able to hit 60k rpm with it if i want? Not that I'm gonna run that speed all day long, but shouldn't I be able to hit that number or close to it sometimes? If not, why? If heat is the issue, will it really be? I can make some type of air intake, and it will be the finned can anyway. If so, then wouldn't a 1515 1.5D (2700kv) be the ticket on 6S?? Or the next 1515 down (2200kv)??

Reason is, I saw the 6s savage video (found that a while ago actually), and THAT was what made me decide to go BL! FAST on grass!! Also, I saw satheman's video, and while it was nice, it was geared real high (22T pinion) and STILL flipped like crazy (WAY too much for me) with a 1521 Neu 1577kv. That's why I'm thinking maybe I don't want a 1521; too much torque, AND it looks like the don't come with a finned can.

Feel free to correct all my mistakes! :oops:

Well, the faster you spin the motor, the less life you will get out of the bearings. Plus you do place more load on the rotor and the case. Power is not really an issue with a neu 1515. I would say that a 2000kv neu motor would be fine on 6s. Plus, you run into issues gearing a motor turning more than 40k rpm low enough to keep speeds around 40-45mph. I have a buggy that has a hacker c50 8l on 4s lipo. It spins around 45k rpm. I have to run an 11t pinion to get speeds around 40-43mph. That is the smallest pinion I can fit before the motor hits the center diff outdrive.

If only Toyota and Honda made RC cars.

ok, but why do I want to limit top speed with low gearing? Wouldn't I just limit throttle on my radio? Or just not pull the trigger as much? OR is there something weird that happens with BL that I'm missing?? :neutral: I hope not, my auctions for all my nitro stuff end tomorrow afternoon!!!!

Or is this in the name of heat and keepin it cool?

As for motor bearings, I kinda hope they die soon, so I can put ceramics in there. I can change them myself on a Neu right?

Partial throttle causes more heat in the esc, as the fets are switching on/off very quickly to limit output voltage (simplified description). I gear my stuff so I am WOT most of the time, and do not have heat issues. Plus you will find that over 45mph a big truck it very difficult to control on anything other than a very smooth surface.

ooooooooooohh. OK. SO, let's say I gear for 60mph with a 1515 neu. I run on a parking lot wot most of the time, and all is well. THEN, I leave everything except the wheels alone, I go to a track, and I'm not running wot, but on and off for a smallish track. Am I asking for problems here??

PS - thanx for all your help linpimp, and thanks for helping me find those pinions. Do you know what grade of steel is strongest there?

By pinions you mean the 8mm ones on spi huh? The only real choice is the carbon steel ISO8 , as the commercial quality do not have a hub. These are still not hardened so you will want to use them with a plastic spur. If you want to use a metal spur, the hardened gears that mike sells are the only option that will last.

Not sure if a 1515 will get that truck to 60 without getting hot. Someone with more experience than I will have to advise you on that. I would just gear the truck down to track/offroad speeds. Your runtime will be better and everything will run cooler that way. Plus you will have more throttle control.

Don't know what savage your talking about, but the e-maxx on 6s that jzemaxx linked to is mine. It's only a 1700kv 1515 2.5d (no more than 37 000rpm on 6s) geared 51/20 with e-maxx diffs and old 2 speed trans (12.5:1 fdr). Theoretical top speed of ~50 mph, but the amount of tire ballooning I had can throw the calculator out a bit, and I don't have anything to test the actual speed, but it was fast enough for those old bow ties. Very hard to get to top speed without it trying to wheel stand. I don't know how it would go being geared for 60, but I'd be more worried about my esc and batteries
That setup has worked well for me with that type of driving, but in smaller areas where you can't get to top speed and your doing lots of stop starting (racing) I don't use that gearing, it just puts more load on everything.
Your real car will drive well on a highway in top gear, but you don't drive around the city in top gear.

yeah, I figured out it was an emaxx after I posted. Not sure why I thought it was a savage, but it was fast nonetheless! Thanx for that info! :smile: