Logo 600SE and 750MX 450kV Motor

[TommyBear]

Hi, I am currently running 12S setup using HK 4035 560kV with 11 tooth Mode 1 pinion and CC80HV on Governor mode to attain 1850 rpm HS.

I have ordered a 750MX 450kV motor and I intend to use 12 tooth Mode 1 pinion.
Has anyone use this motor on their 600SE and would it be any difference to say a Pyro 700 - 45?

Cheers

[beans07]

You will be very lucky to not strip the main gear. They are a powerful motor for a true 700 sized heli.

[Kiba]

A 750MX on 12S in a 600SE will strip the main gear for sure-- that combo is very stout in my Goblin. I can strip the main gear in my 600SE with a much less powerful Xera 4035, I can only imagine how quickly I could strip the main gear with a 750MX!

Even the lighter (and weaker) 470kv 700MX on 12S will probably easily strip a 600SE main gear. The 700MX would be more suited to the 600SE than the 750MX but at 4000 watts continuous / 6600 peak the 700MX is much more than the 600SE was designed for and you're asking for gear and one way bearing trouble.

Given the headspeed limits on the 600SE and your 1850rpm headspeed a 12T pinion on either the 470kv 700MX or 450kv 750MX puts your CC80 deep into part throttle. An 11T would be more appropriate but will exacerbate the main gear stripping issues because of less tooth contact.

You mentioned the Pyro 700-45; this motor is much better suited to the 600SE and one of my favorites. I previously flew a Pyro 700-45 in my 600SE on 12S with an 11T pinion; plenty of power for the lightweight 600SE. I never had main gear or one way bearing issues with the Pyro but it still has the power to strip the main gear if you bang the heli around hard and the mesh is just slightly too loose. I've only had main gear issues with motors in the same power class (Xera 4035, Pyro 700-45) on very hot days (100F+) when the mesh was just slightly too loose.

[TommyBear]

Thank you Kiba for the heads up. What are your thoughts on using a 4035 400kV with a 12 tooth Mode 1 Pinion also on 12S.

[Roadracerr]

Not an answer to your question but I have been running a 600 SE on 690's with a 4035-330kv and a 15T pinion on 12S for a long time now and have never stripped anything.

The advantage I see to this setup is the gear mesh, there is alot of contact surface and I can run the ESC at 98% and see 1850 head speed.

Flights are 6 mins at 1850 and over 8 minutes at 1650.

[3D Dave]

That's exactly what I'm running (Xera 4035-3y/400, 12t mod 1, 12s) I stripped a gear on the 5th flight. I had just a "hair" of backlash almost all the way around. That was apparently too much. I've now adjusted it to NO backlash except a hair at the lowest spot (about 10 teeth) on the gear. So far, so good but I'm also taking it a little easier than before.

I'm running the HeliJive 120 v11 with V-Bar gov. so I don't know if I can run my throttle curve as low as I can if running on the HeliJive gov.

If I'm able to, I might end up trying a 13 or 14t if I strip another gear.

[Kiba]

Originally Posted by TommyBear

Thank you Kiba for the heads up. What are your thoughts on using a 4035 400kV with a 12 tooth Mode 1 Pinion also on 12S.

A 400kv motor with a 12T pinon on 12S is much better in terms of ESC throttle % and should work fine all the way up to about 1900 rpm governed with a CC. I fly my Xera 4035-400 with a 12T pinion at 1600 / 1770 / 1875 and it works very well with 90% of my flying time done at 1770 rpm.

Roadracerr's suggestion of a 4035-330 is a very good one for 12S; it allows you to run a larger pinion and get more tooth contact. Keep in mind that lower kv motors don't have the peak power "grunt" in reserve that higher kv motors have. The 4035-330 is rated at 2650 watts continuous / 3500 peak which should get a 600SE around plenty quick but the 330kv motor won't have as much "grunt" in reserve as a 400 or 450 kv motor would.

With the 600SE on 12S there's a pretty small window of motor kv and pinion size that works well; 330-400kv is about the sweet spot. Much more than 400kv and you have to drop down to an 11T pinion to keep your ESC throttle percentage in an efficient range and then the main gear is more at risk of stripping with the small 11T pinion.

[TommyBear]

Thanks again Kiba, will give the 400kV and 12T combo a go. I'll just won't use the 450kV 750MX.