14T @ 15T

[cpmboy]

I bought a new align 450mx motor to replace my 450m. Im using 35a ESC, 150T gear & 2200mah batt. Still hovering & FF. I have the stock 14T and and 15T pinions. Should I stick to 14T or move to 15T (dunno whether the ESC can handle this combo)?

[SeanM]

It will work fine. I personally like higher headspeeds because it increases the gyroscopic effect, making it more stable. It does make it more responsive also, but that can be adjusted to preference. I used the 15T only before I switched to the helical 12T w/ 121T slant gear... Which I really like. It's a lot quieter...

[snjbird]

10:1 is pretty high for a 3600KV motor, I use one but I run the governor on the Castle ESC... I think a 13 would be pretty good on a flat line.

[cpmboy]

last time I too was thinking of moving to slant gears but I heard that it will put stress the motor.....myb in the next upgrade...

[SeanM]

The 450MX comes in two versions, 3400kV and 1700kV.

[SeanM]

The helical setup definitely doesn't put any more stress on the motor. If anything, it makes everything more efficient.

[cpmboy]

Originally Posted by SeanM

The 450MX comes in two versions, 3400kV and 1700kV.

mine is 3400kV

[cpmboy]

Originally Posted by snjbird

10:1 is pretty high for a 3600KV motor, I use one but I run the governor on the Castle ESC... I think a 13 would be pretty good on a flat line.

Im using the 3400kV version.

[cpmboy]

Originally Posted by SeanM

The helical setup definitely doesn't put any more stress on the motor. If anything, it makes everything more efficient.

ic....thats nice.....how abt HS?....can we calculated hs wt the helical setup as in the normal setup?

[snjbird]

3400 x 12.6 = 42,840 / 10 = 4284 RPM

That's flat out on a fresh pack... Kinda high eh?

stock ratio is 1:11.53 13 tooth with 150 gear....

121/12 = 10.08

3400 x 12.6 = 42840 /10.08 = 4250

[SeanM]

I can't get anywhere close to that headspeed, even ungoverned. On my 6S setup, 3400 RPM was about as high as I could go with the 1700kV motor and 12t helical. I would need the 2221-2010 to get up to the 4000's based on what I've experienced.

My point is that I don't think the math behind headspeed is really all that accurate. It does not take load (pitch/cyclic demand) into account. The calculated headspeed is assuming a no load situation, which to me would be like taking the blades off. As soon as you start taking pitch into consideration, the max headspeed is more realistic. That's why my 450MX came with a chart to show what to expect for headspeed with a 15T pinion at different degrees of pitch. Even at zero pitch, the chart showed only 3900 RPM. I'll check it again when I get back home..

[squibcakes]

I found the 3400KV with 14T a better setup than with the 15T and sounds a lot better too.

[SeanM]

It all just depends on what your goals are... Flight times or performance. The 15T will drain a 2200mah pack in about 3:30 min. I can get about 5 min on 6S at the same headspeed, with 1300mah packs.

[SeanM]

According to this spec sheet, my motor reaches 3900 RPM @ 0 pitch, not 4250. Even the numbers on this sheet I think are a little too generous, but that's pretty hard to know for sure.