anyone have one of those 1/18th scale rc buggies?

[audiolife 5,000+ posts]

here ya go

 

[audiolife 5,000+ posts]

also anyone interested in some hand made sport battery packs?

 

[Rattlebrain 10+ year member]

here ya go

Those are so cool. I want one.

 

[audiolife 5,000+ posts]

they are smaller than they look in the picture almost half as big as a 1/10th scale.

 

[audiolife 5,000+ posts]

its not pokey thats for sure go reverse to full throtle forward it will pop a wheelie lol. it doesnt jump too well as far as balanced but thats up a curb (my 10th scales did this easy) when it gets a good launch look out lol this thing sails.

 

[squeak9798 5,000+ posts]

Man......we've gotta get together and play sometime soon !! //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[audiolife 5,000+ posts]

lol as of right now it takes 10 hours to charge it im getting stuff for it soon cant wait to get it in daytona lmao

 

[audiolife 5,000+ posts]

mamba 6800 or mamba 8000? or is the mamba 8000 still too hot on a big spur little pinion?

 

[HiAmplidude 10+ year member]

mamba 6800 or mamba 8000? or is the mamba 8000 still too hot on a big spur little pinion?

Depends completely on the weight of the ride and how many volts you can afford to feed it. Personally, I've found that (within reason) sticking with the lower rpm/v motor and running a taller gear ratio is the way to go.

I have a link to a really decent motor estimation page on http://www.rcnuts.com (links). It may give you a better picture of what kind of end rpm you'll be seeing.

 

[audiolife 5,000+ posts]

im going with 8.4 volts not going to do the lipo. the car isnt much heavier than a 12th scale 4 cell car if not lighter

 

[kotec123 10+ year member]

i have a tmaxx and its nuts

 

[HiAmplidude 10+ year member]

im going with 8.4 volts not going to do the lipo. the car isnt much heavier than a 12th scale 4 cell car if not lighter

Way too hot for that kind of voltage. Even 6800 rpm/v is teetering on too high with that kind of voltage. You could easily run the 6800 with fewer cells to lighten the car and make it snappier. 8krpm/v is out of the question in my mind.

I can't even think of a decent application for an 8krpm/v motor -- maybe a light airplane with just a few cells? I'll say, though, that you could probably get some pretty impressive results in a very light 12th or 18th scale car with just 4 cells on an 8k BL motor. That'll push it to around 40k RPM, which is a sweet-spot for efficiency, even though most BL motors can hit well over 50kRPM.

 

[HiAmplidude 10+ year member]

oh... also take into consideration that voltage drops under a load. When you are calc'ing rpm based on voltage, you should generally use 1.1 volts per cell, even for good matched ones. 1.0 v/c for junk cells. You'll get a closer real-world result on paper.

 

[audiolife 5,000+ posts]

i already drove a mamba 8k on 2 lipos it was mean

 

[HiAmplidude 10+ year member]

I'm sure it was. You'll find, though, that with the torquier motors (lower rpm/v) tuned to deliver around 40krpm under load, geared appropriately, things run cooler, you get outstanding results, and there's a lot less strain on the speed controller. You'll get better run-times too -- not that it's much of a problem with lipos though. I've been through probably hundreds of brushless setups (mostly on heavier vehicles though) and found that 40kRPM is where you want it to be -- 50k tops. Anything higher will never hit it and will constantly be a strain on the electrical system trying to do it. Check out the speed results on rcNuts for an example of that. 14 cells on a very hot Hacker B50 8S was crazy powerful, but was straining the whole way -- blew some expensive controllers that way too.