800MX VS 850 MX

[Delljr]

Is it worth upgrading the motor right away this is my first TREX 700 HV DFC helicopter? I'm wondering if I'll be pleased with the 800MX motor? I'm still in the building process.

[waxman]

It depends on flying style, I find the 800 to be more than enough. Depending on headspeed you can still bog it if you push to hard this is more a result of not enough headroom than a lack of power though. If you want to run high headspeeds and push hard either motor will benefit from a gearing change.

[waxman]

I should add that the esc would need upgrading to change the motor.

Just build it and fly it stock.

[charles.frank]

I have the 800mx and it works very well for me. .I was running a HS of 2200 with the 12 tooth but recently installed the kde adjustable motor Mount and installed the 11tooth and dropped head speed to about 1990 and love it. . It was fine at the 2200 just not necessary. .I upped my pitch to 13 from 12 and really enjoying the way it flies at 1990.. it also added a minute of flight time. I'm at 4:50 flying 3d.. using the cc 120hv esc.

Sent from my Goblin while pirouetting inverted.

[Dino Spadaccini]

if you can bog a motor you are running to much of everything. you need to find a balance in the pitch length of blades and cyclic and what FBL you are using, Sounds like you are getting it there. The 800 will run hot just the way that motor is the 850 need a 160 esc the 800 you can get away with a 120 its all in the setup and style of flying



Dino

[Delljr]

Thank you Dino, I made the decision to upgrade to a 850MX which KV 490 or 540? Thanks

Sent from my SGH-T889 using Tapatalk

[Dino Spadaccini]

490

[charles.frank]

Ive only been flying for about 2 years so nothing to fancy. . Collective management not the best. . But heres a vid with the 800mx @ rpm 2000 13°collective

Watch "Trex 700e v3" on YouTube

Trex 700e v3 (4 min 42 sec)

Sent from my Goblin while pirouetting inverted.

[Delljr]

Nice flying..

[Delljr]

Could anyone explain the difference in kv? The 540kv 120A/250A
5330W/ 11000W (2sec)
The 490
115A/250A
5100W/11000W (2 sec)
If I did the conversion right the HP 490kv would be 6.8 HP/14.7HP
And 540kv 7.1HP/14.7HP
Also why would the 540 have more horsepower on the low end...
So basically why is the 490 the better motor?


Sent from my SGH-T889 using Tapatalk

[willy000]

Originally Posted by Delljr

Is it worth upgrading the motor right away this is my first TREX 700 HV DFC helicopter?

Is this your first 700 electric helicopter? or just first Trex 700?

[Delljr]

Yes, its my first 700... Have a 550 DFC...

Sent from my SGH-T889 using Tapatalk

[willy000]

Originally Posted by Delljr

Yes, its my first 700... Have a 550 DFC...

Sent from my SGH-T889 using Tapatalk

And you are wondering if you will be pleased with the 800MX?
You have to be joking! Im sure you would of been pleased with the 750MX.
There is a huge difference from your 550 to a 700.

[K2Freak]

Yup. Fly it stock and get back to us...

[Delljr]

Thanks for all your suggestions....

Sent from my SGH-T889 using Tapatalk

[ddj74]

Originally Posted by Delljr

Could anyone explain the difference in kv? The 540kv 120A/250A
5330W/ 11000W (2sec)
The 490
115A/250A
5100W/11000W (2 sec)
If I did the conversion right the HP 490kv would be 6.8 HP/14.7HP
And 540kv 7.1HP/14.7HP
Also why would the 540 have more horsepower on the low end...
So basically why is the 490 the better motor?


Sent from my SGH-T889 using Tapatalk

Kv is how many times the motor spins for every volt applied. So the higher the Kv the higher the motors rpms are. Now how it applies to you is your style of flying really. All around the 490 is ideal because it's still spins fast but has more torque. More ideal in my opinion for smack flying. Now if your the every day flier i doubt you will notice the difference. Also gearing may become a factor for running one or the other to suit your flying style.

I can guarantee you thou even if you had a 750mx...it has tons of power for most mortals. Also need to remember the bigger the motor the shorter your flights will be.

Lower Kv = slower, more torque
Higher Kv = faster, but less torque

[Delljr]

Great answer, thank you so much for the explanation... Good advice... Thanks

Sent from my SGH-T889 using Tapatalk

[OnTheSnap]

What's your target headspeed? If it's 2200 (hard 3d) with the stock gearing you need the 540kV. If you are targeting sub 2000 you can look at the lower kV.

I run the 800mx and it's truly awesome and ballistic. It's the same motor used by some of the Align pro's in XFC. It has equivalent power to the 4525 Scorp. IMO the 850mx is extreme overkill, and doesn't strike the best performance/flight time balance.

[Delljr]

Thanks, I have the stock 800MX with 520 Kv, so if I don't get the 2200 head speed that's okay, sounds like it will be awesome, Just got my Castle Creation 160 HVF so I will be installing that tonight. Can't wait coming from a T-rex 550 DFC..

Sent from my SGH-T889 using Tapatalk

[Excalibur3]

I have both 550pro with 730mc and 700pro with 800mx both are awesome but my favorite is still the 700.


TS3D#1
NanoCPX, TREX550 PRO DFC,
TREX700 PRO DFC HV, DX8