I cannot tell you how many PVC holders I have made. Seems like once i made one, It always needed improvement or a I saw someone elses that I liked better. Good thing about PVC is that its cheap. You can cut it with a regular wood saw. I then decided to make one that is more universal. Thing is I found something that I also use with the pipe insulation. Pipe insulatin only comes in so thick. Some stores like Walmart or somthing have those thick long foam style tubes that kids use for swimming. They have a hole in them just like the pipe insulation. So, one day you could put a wide plane in your holder using the thin insulation and another day you can use a skinny plan and put the thick type on to keep the plane more secure.

You may go through several versions before you end up with one that works.