Brushless ESC and Motor - Advice (n00b)

[Allan1875]

Hi lads, raced TC's back in the day of good old nicad and towards the end nimh.

For the last few years i've been racing 1/12th scale oval and we are still on brushed and nimh, however at our latest AGM, brushless has been voted into all classes so i need to learn about this stuff and fast.

Here is what i have to work with:

Speedo:

- Must have reverse
- Must have a blinky mode as no timing to be run on motors
- No price limit

Motor:

13.5T limit, RRP no more than £60

Lipo:

Must be 1s

Now from what i've picked up from reading so far, the higher the C rating, the more punch you have. What i don't understand is the difference between burst C rating and continuous. Can someone explain?

The system that is being pushed on us so far is this:

http://www.apexmodels.com/gbu0-prodshow/CR175.html

My problem with the above system is the limit on the C value.

I like my cars punchy so i am reluctant with that system. Can someone please offer some advice as i feel like i've just jumped in at the deep end big time.

[sosidge]

C ratings are often exaggerated, so take them with a pinch of salt. Basically, multiply the capacity of the battery by the C rating and you should get the current handling ability of the battery. So in the example yo have listed, 25C x 3200mAh = 80000mA = 80A.

Now that ESC is theoretically limited to 45A, and is fine with that motor, so your battery will comfortably cope with anything the motor can throw at it, even if the C rating is optimistic.

Performance (punch) on the track is more subjective - I have yet to have a bad LiPo, although I would add that the one budget LiPo I did own needed a lot more balancing after each run than the more expensive ones. LiPo is a big step forward from NiMH, not only in performance but in lifespan and consistency from pack to pack.

All in all I think the Core combo you've linked to is a bargain and will suit you well. Just be careful with the servo you use, some (Savox especially) are very power-hungry and can cause issues in 1s Mardaves. I always use Futaba.

[Allan1875]

Seen the Core system in action on Tuesday night and it seemed decent, however the battery that came with the system did seem to pack punch.

The guy running it shoved a 4 cell nimh in for a race and it was so much better. I am assuming that upping the C rating of the lipo should match that? If so it seemed a decent system.

Thanks for the reply above, any other contributions much appreciated.

[sosidge]

Originally Posted by Allan1875

Seen the Core system in action on Tuesday night and it seemed decent, however the battery that came with the system did seem to pack punch.

The guy running it shoved a 4 cell nimh in for a race and it was so much better. I am assuming that upping the C rating of the lipo should match that? If so it seemed a decent system.

Thanks for the reply above, any other contributions much appreciated.

4-cell NiMh is 4.8V nominal - 1s LiPo is 3.7V nominal - even the punchiest cells in the universe won't overcome the 25% difference in voltage!

For the change to LiPO/brushless to work, you need everyone to do it. Or you need to put the NiMH cars into a seperate class.

[Allan1875]

Originally Posted by sosidge

4-cell NiMh is 4.8V nominal - 1s LiPo is 3.7V nominal - even the punchiest cells in the universe won't overcome the 25% difference in voltage!

For the change to LiPO/brushless to work, you need everyone to do it. Or you need to put the NiMH cars into a seperate class.

That makes sense, didn't really put much thought into that one before posting.