can you run 850MX 490KV with 12t pinion 112t Main

[Lee2782]

Hi All,
I'm looking at get a 850MX 490Kv motor but I still have my 12t pinion and 112t main gear will this combo still be powerful?

I know the ultimate setup with the 490Kv is to use 110t main gear with 13t pinion but I have a spare 112 gear and would like to use it first before changing to 13/110

oh and is there much difference between the 800mx and the 850mx (i know one is red)

Cheers

Lee

[BladeScraper]

It will be fine. I'll be using a KDE 495Kv on 12T and 13T with 112.


I think they say that because they want more tooth contact to handle the extra power, but it really doesn't make much of a difference.

[Lee2782]

Cool Thanks,

is there a big difference between the the 750mx 530 and the 850mx 490? I know on paper the 850 has more power but would like to hear from guys who have flown both and what are the flight time difference between the two

Cheers

Lee

[Excalibur3]

Originally Posted by Lee2782

Cool Thanks,

is there a big difference between the the 750mx 530 and the 850mx 490? I know on paper the 850 has more power but would like to hear from guys who have flown both and what are the flight time difference between the two

Cheers

Lee

Huge diff my friend. Huge I think I got 5 minutes with the 750mx and I now get 3:45 with the 850mx. But my skill level has increased since then as well. But I love the 800 and the 850 both great motors

Trex700Pro/Trex700LTop/X3/14sgh T$3D

[Lee2782]

Great Thanks!!

[Solmanbandit]

Originally Posted by BladeScraper

It will be fine. I'll be using a KDE 495Kv on 12T and 13T with 112.


I think they say that because they want more tooth contact to handle the extra power, but it really doesn't make much of a difference.

It doesn't give more tooth contact. Different size pinions changes the gear ratio and affect what head speed you can obtain. a 12T pinion will give you 2098 and a 13T will give you 2273 head speed. Both will work, but depending on what head speed you want will determine what pinion you will use.

[BladeScraper]

It does give more tooth contact. The more teeth you have the more teeth are touching at a given time. This is why the old 450's with the high power scorpion 4400kv were stripping gears. They had to use a small pinion and that made too little contact. They lowered the KV and put a bigger pinion - problem solved.


Sent from my Gaui X3 using Pulse LiPo

[Solmanbandit]

Originally Posted by BladeScraper

It does give more tooth contact. The more teeth you have the more teeth are touching at a given time. This is why the old 450's with the high power scorpion 4400kv were stripping gears. They had to use a small pinion and that made too little contact. They lowered the KV and put a bigger pinion - problem solved.


Sent from my Gaui X3 using Pulse LiPo

If you say so, but still is not correct. Besides, a 3500 KV motor puts out more power than a 4400 kv motor. That is why they went with a lower KV motor. Pinions are changed to adjust head speed, not to have more contact.

Head Speed =
((Motor Kv x Battery Voltage) / (Main Gear Teeth / Pinion Teeth)) x Efficiency Coefficient

[BladeScraper]

I know that pinions change the headspeed. I'm not stupid

But the more teeth there are the more contact there is. Just like the Cell 500. If you have a small pinion on the motor, the belt can slip during high load situations. If you have a lower KV motor that has the same Wattage, but with a bigger pinion, the belt will be less likely to slip because there is more contact. The same is true with geared helis. It's simple physics mate...


Sent from my Gaui X3 using Pulse LiPo

[el guapo]

got to agree with Keith.

in this case, the larger pinion was used to increase gear strength. Some smack pilots can strip the 700E gears if they are not careful. I've witnessed this first hand. many times.

the new gear set increases strength, while fitting in the same chassis. The motor was rewound to make the gear ratio work out.

Mikado did the same thing with the new logo 690.