Sirui VA-5 head & Arca plate question

[Stein]

I recently upgraded to the VA-5 head on the advice of many here and other places and the pan is really great.  The one thing I am having trouble wrapping my head around are the Sirui arca plates.  It came with a TY-70 plate and I bought a second Sirui plate, TY-C10.  I figured if I stick with Sirui I should be set.  Nope.

The TY-70 plate is larger and the cutout for the Arca clamp is a different shape altogether.  If I adjust the head to be able to clamp the smaller plate (C10), then the larger plate falls out.  If I adjust the head to fit the larger plate, the smaller plate won't fit into the head.

So, I figured it was something funky with they TY-70.  I wanted a larger plate for my spotter than the C10 that I bought for my bino adapter, so I bought the Sirui TY-50E.

I received that today and figured it would either match the 10 or the 70 and I would simply go with whatever two were the same.  Nope, it's slots are bigger than the 10 but smaller than the 70.

Any Sirui gurus out here that can explain what I'm missing?  I assumed Arca swiss plates were supposed to be the same size or at least pretty dang close from manufacturer to manufacturer.  Going with plates all made by the same company as the head should guarantee they will work together, but apparently not.

I simply don't understand the value of quick disconnect plates if they are all different sized.

I upgraded from Vortex and had multiple different plates and two heads and they all fit perfectly, so by "upgrading", this has me a bit baffled.

The only solution I have is to go with the exact same model plates which means one too small for my spotter and too big for my bino adapter.

[Wanttohuntmore]

Tagging along.   I just bought a VA-5 head as well,  and bought an additional plate for the bino.  I did get the same plate that came with the head,  TY-70, but am curious on the compatibility.

[Stein]

The TY 70 plate is different sized as well as the grove has a different shape.  I Googled it and seems to be an issue but most people only have a spotter (bird watching world).

The clamp on the VA-5 contributes to the problem since there are limits on opening and closing.  Other designs have a knob with no limits and you can open or close a much further range so you wouldn't notice if a plate was slightly different sized.  You can pull the lever on the VA-5 and re-index it for the particular plate and get them all to work, but it kind of defeats the purpose of quick change plates when you have to adjust the head every time you switch them.