RC-Monster Forums - Gearing for 4s and 5s question

RC-Monster Forums (https://www.rc-monster.com/forum/index.php)

- Brushless (https://www.rc-monster.com/forum/forumdisplay.php?f=12)

- - Gearing for 4s and 5s question (https://www.rc-monster.com/forum/showthread.php?t=11043)

Gearing for 4s and 5s question

If i run a 4s setup in my truggy for racing, and i'am gear 16/46 for an exemple, and i want to switch for 5s for bashing, should i change the pinion or i can keep the 16T without overheat the componant.

If i must go down on pinion, so what's the advantage to run higer voltage????? Just to drop curent??

Because if i go down on pinion when i switch for a 5s setup, the speed and acceleration should be the same, no?????

Need help please on this departement.

Thank you!

David

Hey David,

If you increase the voltage and do not change the gearing you will go faster. You can lower the gearing to maintain the same top speed, and enjoy a cooler running system and increased effecientcy. Now this depends if the motor you have will operate properly on both voltages. I think you have a neu, whiich will be fine with this.

You will also find that if you gear both voltages for the same speed you can run the 5s pack with a lower mah capicity, like a 5s 4000mah versus a 4s 5000mah, or something like that. The higher voltage will be more effecient, and thus you will have longer runtimes than expected. This way you can keep the battery weight the same and have some benifit. Plus the battery cost should be similar.

i have a similar question... i don't mean to hijack the thread but i thought it would be better to have all the answers in one place...

i'm in the middle of putting together a 8ight buggy conversion together and i'm trying to choose between 4s and 5s... my application will be strictly racing... the difference between a 4s and 5s packs (thunder power 5000's) as far as weight is concerned is 123g... the combo's i'm looking at are to get around 40,000rpm and are as follows

1512/1Y 2750kv on 4s for 40,700 rpm
1512/2.5D 2050kv on 5s for 37,925 rpm

an rtr buggy comes in at bout 3900g and the 123g is less than a 4% increase in the total weight of setup... my question is how much more runtime can i expect out of the 5s setup... the 4s fits better because of its reduced thickness and i'm just wondering if its worth my while to go to 5s...

another question is, given that this is a race setup with runtime and reliability are the goals of the setup, will there be any advantage going to 1515 over the 1512 size motor... the weight difference is only 70g which is less than 2% increase in weight...

Less weight is better, but you can use a lower mah battery when going to 5s and get the same runtime, so the battery weight should be almost the same.

There are most likely others here that have more experience with the neu motors than I do, but it appears that many use them on 4s in buggys and like them alot.

1515 seems to be overkill in a buggy, so the reduced weight should be fine. I would like to see someone use a 1509 turning about 50k rpm and geared for track usage. On 5s or 6s so a low kv motor would be required. I have some smaller motors that I will try in my hyper8 on 6s and see how they perform.

I recommend NEU 1515 1y with 4s lipo at least with 20c or more rating

A 1515 has too much power to be usable on a track in a buggy. A 1512 will have plenty of power and longer runtime.

i have a mugen truggy, opional 48 t spur and 13 t with 5s lipos.

Quote:

Originally Posted by cart213 (Post 158904)

A 1515 has too much power to be usable on a track in a buggy. A 1512 will have plenty of power and longer runtime.

If you use an esc like the mamba where you can adjust the settings,it is controllable on the track and there is that extra power when you need it.The 1515 is more efficient than the 1512 for it has more torque
Mike Cronin the owner of this website uses that setting as well

Quote:

Originally Posted by super dave (Post 158908)

i have a mugen truggy, opional 48 t spur and 13 t with 5s lipos.

Which optional 48T? The mugen stees 48T or a Kyosho plastic one?

And can we put the Kyosho plastic 46T on the mugen diff?

Quote:

Originally Posted by luvsrc (Post 158916)

My point is that you don't need the extra power for racing. Now if abiye is going to use the buggy for bashing and wants overkill, then the 1515 would be fine for him.

The 1515 is not more efficient because it has more torque. Motor efficiency has more to do with the design than the size. Between a 1515 and 1512 with similar kv, I think the 1515 will pull more amps and will therefore have a shorter runtime than the 1512.

i used mugen spur gear #E0218 metal gear 48T with mod 1 hardened pinion 13t, 1515/1y/f NEU motor and 5s lipos, yes a little noisey but no problems good low end and top speed

Quote:

Originally Posted by abiye (Post 158791)

I use the 1512/2.5d in a buggy setup. On the track I run it on 4s and for bashing (or a huge track) I can just drop 5s into it. Without changing gearing runtime is about the same, maybe a little less with 5s due to the increased amp draw of the additional motor rpm, but with 5s I am easier on the throttle to keep control so it kinda evens out. But, if you geared it down to run the same top speed, you should theoretically get around 20% more run time since you are using the same amount of energy to accelerate and top speed and there is 20% more potential energy in the same mah 5s pack vs a 4s pack.

The 1512/1y will work fine on 4s, and will probbly feel a little more powerfull than the 1512/2.5d, but it will produce shorter run time as well. I found the 2.5d is more than enough for me. Plus the 2.5d will allow the whole system to run cooler as well.

As far as 1515 vs 1512, I found the 1512 is plenty of motor for a buggy on the track. 1515 isnt necessary and tends to give slighty shorter run times from my experience.

thanks jhautz.... that helps a lot... my only problem now is getting 1512... it seems to be out of stock everywhere... so i ordered a 2200kv 1515 to run on 4s...