The piece that holds the rail can still hinge if is square in cross section. The pipe seems like an awkward connection to a rail. The only advantage I can see is the rail would overhang from the pipe so rockets can slide down further. Anyway this is somewhat academic. All of these designs are pretty study and look great.
Ah, I understand your question. The primary purpose of the pipe is to stiffen the rail itself. There are certainly many clubs that don't stiffen their rails in some manner, but it is my opinion that this is an important thing to do. I do this on 1515 rails, even though most wouldn't, and I never fly off of an unsupported 1010 rail. I had no choice at AirFest a couple of years ago, and sure enough, rod whip cause my two-stage flight to take off at an angle. More times than not, I show up at launches with my own rails. It turns out that the pipe and also serve as the connection to the pad if you just design it that way.
By adding an iron pipe backer to the rail, you make it MUCH stiffer, especially if it's a longer rail. The 1515 rail is pretty stiff, but if you are using a 8' or 10' length, it can flex under the load of a heavy rocket or an extreme motor. And by using a pipe, you distribute the clamping forces along the rail, rather than concentrating them at the bottom. The aluminum is relatively soft and deforms under a lot of clamping pressure. The pipe is relatively inexpensive and makes a big difference in overall safety and longevity of the rail.
Okay that makes sense. How long is the pipe?
I usually arrange for it to go to within a few feet of the top of the rail. It might be supported along the rail by nominally 5 "shoes" that fit the rail slot (getting them lined up is a chore). Maybe I can find a pic in a while.
Okay that is quite substantial! I have seen some pipes at launches and they were only a foot or two. I thought that is what you were talking about. A nearly full length pipe seems very strong.
I was trying to remember if the Spaceport (17') rails were double-wide or had a backing. The picture on the video shows the backing - it's all coming back to me now. Maybe some day I'll touch them again!
Only at Brothers...
I had similar thoughts and most of my experience with hobby rockets was in the 90s and early 2000s when rods were still a popular launch guide. It is worth noting that length is really important and the deflection is not linear with length but rather cubic. A 10 ft rail will flop a lot more than a 6 ft. It is also worth noting that projects have gotten more aggressive since that time.
In our case it was the mount between the rail boom and pad base.
I have a TRI-3 and Biggun. They are great pads and well built.
You can also order rails on Amazon. The price is good and they deliver directly to you.
YUP. They will deliver up to the 8-foot length right to your house. A few years ago, they sold a 14 foot. I have two. Unfortunately, they will not fit in my trailer.
