How many motor mount bolts?

[Bobkeenan]

This is my first build and I have an iFlight xBird 250 class build kit. I started to mount the motors and there were only 6 screws. I emailed the vendor, Gothelirc, and told them I was 8 screws short. They said itmismonly 2'screws per motor mount and that they would send me 2 more.

Is that correct. The main build video set that I am relying on uses 4 per motor?

 

[Pumpkinguy]

If I had 4 bolt holes available I'd certainly use all of them. I'd rather have 1 of 4 vibrate loose than 1 of 2.

 

[Motopreserve]

+1

 

[SleepyC]

Honestly with some of the racing quads, guys are actually using ziptyes to attach the motors so if there is a crash, the motors break free of the arms. And a lot of the racing guys only use 2 bolts as well.

That being said, I'm with Pumpkin and Moto, as AV guys we will always try to minimize the chance of failure or vibration... I'm building a 250 quad later this week, and I'll be personally using 4 per motor!

 

[cootertwo]

3DR's Iris+ only uses 2 screws per motor.

 

[Motopreserve]

I don't think there's any question that 2 bolts can hold a motor (or even zip ties as @SleepyC mentioned). But if weight and access is not a consideration - seems that 4 bolts will resist rotational forces better than 2.