Also check this out we can buy a professional device for like $10

https://www.alibaba.com/product-detail/Pull-Headgear-Face-Mask-Polo-Type_60698433897.html

I think the direction is not necessarily that relevant. The face will not just be freely pulled downward. Instead, the sutures will give in to the pressure (because the solid bone will not), and sutural growth tends to happen in a way that is predetermined by the rest of the structure the bones of the skull create. The skull seeks to maintain a certain level of balanced tension throughout its bones. As with any kind of palatal expansion, the molars will move down nevertheless as the smile widens.

Posted by: Progress

I think the direction is not necessarily that relevant. The face will not just be freely pulled downward. Instead, the sutures will give in to the pressure (because the solid bone will not), and sutural growth tends to happen in a way that is predetermined by the rest of the structure the bones of the skull create. The skull seeks to maintain a certain level of balanced tension throughout its bones. As with any kind of palatal expansion, the molars will move down nevertheless as the smile widens.

If you're saying to feel it out, I think you're right. I'm feeling mine out and I think I need a forward and slightly down pull. My face resists other angles, but seems to want to pull down and forward.

But looking at everything I can find, it seems like pulling up more than a few degrees is never the direction that is used. Which makes sense, you'd be pulling the maxilla into the other face bones instead of out from them. Platos 45 degree angle (and even Mews) seems incorrect.

In children the pull is always mostly forward and down to correct growth. Why should this be any different in an adult?

In short, no I don't think you want any component of the pulling force to be directed downward. We are trying to mimic the force of the tongue pushing up and forward on the maxilla. The type of headgear you mentioned is conventionally used to treat an underbite in children. I don't plan to use this rig because it has a negative reciprocal force pushing in on the mandible while it pulls out on the maxilla. In this rather long video (  https://youtu.be/-pzL3ETuiKc ) of a lecture by Dr. Mew, you can see a few different types of extra-oral anchorage pulling up and forward including the MewVector and a couple similar systems developed by others.

I don't think they are incorrect, just insignificant (unless left on for 10+ hours). The reason for this is that I suspect that the genius in Plato's helmet design is an unexpected quirk. It requires you to keep the helmet in place with your hands and your head in place with the posterior tongue and anterior neck. So you got the tongue/neck complex resisting the rotational pull of head resisting the rotational pull of helmet resisting the hands that eventually glue this force back to the skull. 

What this means is that the design seems to automatically encourage proper hard mewing through the facepulling session (and after), and that you chould probably achieve similar results by taking half an hour to intentionally mew hard and deep as if you were trying to prevent an imaginary helmet pulling your head up, . Done right, the tongue and anterior neck should start to feel inseparable. This may be easier to get a feel for when the head is turned up. I never achieved results from facepulling, probably because I didn't engage the posterior tongue while I was doing it.

So it's not necessarily even about pulling, it's about resisting the pull by mewing and relaxing everything else. Plato's design seems to encourage this, and I think that Asian belt puller did this intuitively too.

You're correct to pull in the direction that you feel your skull is responding to. Lots of skulls only look downward grown because they are not grown forward enough. The look of a straight forward growth is mostly caused by a long ramus, but there is also a downward dimension to proper growth - it's not just 90 degrees from the neck. 

Don't pull more than a few degrees down, though. The downward movement may be part of the forward movement, not the other way around