Ok I'll ask seeing as I'm getting ready to do something similar. What would you do different? What I see here looks really good. What am I not seeing??
It works pretty well but it is more difficult to get down. My goal was to make it easy to setup and take down with only one person. This might be a bit long winded in order to explain everything.
I used 2" and 2.5" tubing with .125" wall so there is .25" of play to decrease binding. This is reduced to 1/8" because I have a set screw with a flat disc on the inside. There's a good angle of this in one of my drawings from a previous post. This works great for taking out all movement and rattles for driving and in the raised position. These tighten the tubes together from front to back. There are also spring loaded locking pins on each tube across from these set screws.
My tent raises 20" and binding occurs at maybe 8"? Going up, the struts engage and the binding is not an issue. Going down would not be an issue with two people but with only one the tent will teeter totter back and forth because the struts will be pushing the other side up.
The best thing to do would be to put another hole for the spring loaded locking pin to pop into right at the midpoint (10"). I would do this on just the front two tubes or back two, not all of them. This way I would be able to pull one side down to the midpoint, the pins would lock and I could go to the other side and pull it all the way to it's bottom locking position. Then return to the other side that is still locked at midpoint and pull it the rest of the way down.
The problem is that my rack binds before it reaches the midpoint. I suppose I could do more holes for the locking pins, like thirds instead of in half. Or I could use shorter struts. Or I could use a set screw without the disc that reduces the play to 1/8".
But what I wish I would have done is have the top of the rack pivot from side to side instead of front to back. This would give the tubing the full 1/4" of play because the set screw is on the front to back plane. My rack is also narrower (side to side) than it is long (front to back). This would also allow the tubing to telescope for a longer distance without binding.
Hopefully all this makes sense. I haven't decided exactly what I'm going to modify to make the tent/rack easier to get down. It is still very new.
I should also mention that I experimented with many different strut weights to get the best function. Also, strut performance is temperature dependant.
I would have also made the top tent platform out of aluminum to save weight.
And I would suggest bolting the rack through the frame tubing if possible. My trailer is designed for off roading so it will be taking impacts and riding at all angles with a heavy tent and awning on top. I can see this cracking welds after a while. But this really depends on your usage.
That's all I can think of at the moment.
Let me know if you have any questions.