Motor Mt. screws

[Sundance2015]

What is the thread pitch for the motor mount screws (If it's standard). The frame I am using has a
weird setup and I can't use the screws that the motors came with I need some
just a tad bit longer (not to long of course). I noticed a lot of the motors offered
mention 2212, A2212, X2212, X2212-13............
What is that in reference to?
Where might I find small metric screws?

Also what is the more powerful motor a 950kv or 1000kv?

Thanks

 

[alm865]

I think most motors use standard 5mm hex head bolts. Whatever the standard M5 thread pitch is what they'll use (ref: I have A2212 motors also)

As for which motor is more powerful, the answer is neither. The KV rating roughly refers to how fast in rpm the motor spins per volt of battery voltage. This definition is a bit of an oversimplification, in reality it's way more complex (i.e. the ESC is essentially a VVVF drive and the motor is a three phase AC motor but let's not get into that...).

Power = Voltage x Amps so you'll need the power rating of the motor (i.e. 300W). Really you don't need to know the motors power rating to build a quad, just don't put an oversized prop on it and everything will be okay.

Typically 950kV = 12" x 4.5" props, 1000kV = 10" x 4.5" props from what I've found out recently. The faster kV motor will respond a little bit more quickly to changes in speed, the lower kV motor will be slightly more stable with the bigger props.

 

[Sundance2015]

Thanks for the info. One other question on ESC's. When determining what ESC to use the main consideration
is that the ESC can handle the max. current the motor will draw, is that correct. So if you have a motor that
draws say 14 to 18 Amps peak a ESC rated at 30A will be fine.

Thanks

 

[alm865]

Yes if your motor only draws 14-18Amps you'll want a 30A ESC, I wouldn't go any smaller.

A 30A ESC will only be able to deliver a maximum of 30A continuous. Typically they can peak higher for short durations depending on the ESC.

Typically you'll want to run your ESCs well below their rating, i.e. 20A continuous for a 30A ESC. Why? Because you really don't want your ESCs failing mid flight, the less load they have the less likely they are to fail (most of the time anyway...).

Now remember that it's the Motor's kV rating, battery cells, and the prop size / pitch that determines current draw. Here is a snippit from another Member's post that helped me out in roughly determining how much current a motor will draw:

Here are some relatively cheap motors that are 1100kv.
Too pricy, there are cheaper ones here
Here are the test:

Prop Tests: 8x4 - 14.8v - 251W - 17A

8x4 - 11.1v - 121W - 11A
9x6 - 11.1v - 178W - 16A
9x6 - 14.8v - 355W - 24A
10x5 - 11.1v - 200W - 18A
10x5 - 14.8v - 385W - 26A
11x5.5 - 11.1v - 200w - 20A
12x6 - 11.1v - 266w - 26A
​

 

[holtneil]

Hi mate Lower Kv motors have more torque so can spin a larger prop , high Kv are high speed and like small props , as for the 2212 motors this is the size of the motor in mm so its 22mm x 12mm
once you go over 1200kv the prop size should be small up to 1200kv you can get away with a 10x4.7 prop using an 30 amp esc
under 700kv you can use props upto 14x5.5 depends on frame size
2300kv used on 250 racing quads run 4 to 5 inch props you can some times get away with a 6 inch prop but watch the amp load on the ESC this will load it high so may need a 45amp ESC