ESC, Motor, LiPo help. - Page 2 - RC-Monster Forums

rustnpede · **One last look at my shopping cart -** 12.15.2006, 03:40 PM

Well the 7xl are out of stock currently so Im going with an 8xl for the 9920 and power them with 5s.

Does the Li-Saver work with both 5 and 6s?

I have a reciever pack but do I need it for the 9920? It has "3Amp.BEC on/off Function". I dont know what that means. Will that alone provide 6.0v for my servo?

What gearing for a single speed tranny should I start with? Is 16 or 18/66 32p a good start?

BrianG · 12.15.2006, 03:52 PM

You definitely need a receiver pack or UBEC for that cell count. You should be using one for anything over ~9v.

"3Amp.BEC on/off Function" means it has a built-in BEC, but it can be disabled via a jumper (the black one).

I'm sure others will answer your other questions...

riceman · 12.15.2006, 03:52 PM

The Li-Saver is supposed to auto sense between 2-12 cells. Most everyone on this forum recommends the use of BEC or receiver pack to help keep the ESC cool. As for gearing I again recommend using Brian G.'s calculator (the same link as the wiring diagram in my previous post) to start and see what speeds you are after. Hope that helps.

rustnpede · 12.15.2006, 05:10 PM

Ok, Li saver in combination with rx pack it is.

I diddnt understand the "gear calc" but I tinkerd with the "motor selector" and "Random Parameter Solver". Found that an 8xl with 5s and 18/54 gearing is "good" for a for a top speed of +/- 40mph, 20/54 for 45mph and 22/54 for 50mph without any overheating warnings.

mtucker · 12.15.2006, 06:21 PM

Is it OK to use the Li-Saver with a car that is using reverse?
I ran into a problem with another brand of Li-Po cutoff device. Most are made for airplanes so when they do their "pulsing" they pulse down to near 0% throttle. 0% throttle on a car controller is full brake or full reverse if reverse is engaged. After coming to a complete stop it then went to full speed reverse. I really should have known better, but I guess the excitement of a new toy got to me.

Seeing a 8 pound buggy flying backwards down your driveway and into the iceplant at near 40MPH is quite alarming :026:
Perhaps the Li-Saver doesn't pulse below mid throttle (neutral for cars)?
Just thought I would bring this up.

Matt

neweuser · 12.15.2006, 06:22 PM

Quote:

Originally Posted by mtucker

Is it OK to use the Li-Saver with a car that is using reverse?
I ran into a problem with another brand of Li-Po cutoff device. Most are made for airplanes so when they do their "pulsing" they pulse down to near 0% throttle. 0% throttle on a car controller is full brake or full reverse if reverse is engaged. After coming to a complete stop it then went to full speed reverse. I really should have known better, but I guess the excitement of a new toy got to me.

Seeing a 8 pound buggy flying backwards down your driveway and into the iceplant at near 40MPH is quite alarming :026:
Perhaps the Li-Saver doesn't pulse below mid throttle (neutral for cars)?
Just thought I would bring this up.

Matt

the one that Mike sells will work good for you.

coolhandcountry · 12.15.2006, 06:26 PM

Quote:

Originally Posted by mtucker

Is it OK to use the Li-Saver with a car that is using reverse?
I ran into a problem with another brand of Li-Po cutoff device. Most are made for airplanes so when they do their "pulsing" they pulse down to near 0% throttle. 0% throttle on a car controller is full brake or full reverse if reverse is engaged. After coming to a complete stop it then went to full speed reverse. I really should have known better, but I guess the excitement of a new toy got to me.

Seeing a 8 pound buggy flying backwards down your driveway and into the iceplant at near 40MPH is quite alarming :026:
Perhaps the Li-Saver doesn't pulse below mid throttle (neutral for cars)?
Just thought I would bring this up.

Matt

They have more than one version of the li saver.
It has a plane and car mode.
Mike sells the car mode one.
No worries on wide open reverse.

mtucker · 12.15.2006, 06:33 PM

Quote:

They have more than one version of the li saver.
It has a plane and car mode.

That is good to know. Since I switched to the Mamba Max, I don't need a LVC any more (I run 4S).

I just wanted to make sure the same thing didn't happen to rustnpede in case the Li-saver did the same thing. He might not have as much iceplant as me :005:

Sounds like he is good to go.

Thanks,
Matt

neweuser · 12.15.2006, 06:36 PM

Like this one http://www.rc-monster.com/proddetail...avercar&cat=22

rustnpede · 12.16.2006, 04:55 AM

Quote:

Originally Posted by mtucker

. . .I just wanted to make sure the same thing didn't happen to rustnpede in case the Li-saver did the same thing. He might not have as much iceplant as me :005: . . .

Thanks for looking out. No ice plant here just rocks, not so r/c friendly. Unless its a crawler:025: