iOS Changing SKAction speed in repeating action - ios

Question

I've read in a few placing that changing the speed variable of an SKAction will change the speed; however, that doesn't seem to be working for me.
- (void)startAnimating {
SKAction *moveDown = [SKAction moveByX:0 y:-[CAUtilities screenSize].height duration:self.animationDuration];
[self setMoveDownAction:[SKAction repeatActionForever:moveDown]];
[self runAction:self.moveDownAction];
}
- (void)incAnimationSpeedBy:(CGFloat)aFloat {
self.moveDownAction.speed += 0.5;
NSLog(#"%f", self.moveDownAction.speed);
}
The actual value of self.moveDownAction.speed changes as seen in the NSLog call, but the actual animation doesn't change.
I have incAnimationSpeedBy: being called when the screen is tapped, so using a SKAction sequence with a runBlock won't work for my needs.
I've tried:
Having the initial moveDown as an instance variable.
Having the repeat forever action as an instance variable (seen above).
Changing the duration property rather than speed.
Any help is appreciated, thanks.

Answer 1

The problem was I was trying to change the speed on the different SKAction objects when I should have been changing the speed on the parent SKSpriteNode.
- (void)startAnimating {
SKAction *moveDown = [SKAction moveByX:0 y:-[CAUtilities screenSize].height duration:3.0];
[self runAction:[SKAction repeatActionForever:moveDown]];
}
- (void)incAnimationSpeedBy:(CGFloat)aFloat {
if (self.speed + aFloat < kMaxSpeed)
self.speed += aFloat;
}