P

plumbflyer

Member
Does any one know how to position and anchor the aileron stop bracket as shown on the plans? there isn't any room to get in behind the aileron to work. Any ideas would be greatly appreciated.
 
Scott Chastain said:
I wouldn't even THINK about using the delrin sleeve method that many others think is some "brilliant idea." That aileron pushrod bolt was never designed to serve as a stop, and I hate the idea of repeatedly applying unnecessary side loads to the bolt, the bearing, and risking eventual failure. Call me conservative or just a stick in the mud, but I think you'll be much happier with what the actual engineers have come up with in this case.;)
Click to expand...

To be completely fair Scott, you should know that the folks at Van's have seen the Delrin sleeve mod, and at least when I asked them about it thought that it was a pretty neat idea, and approved of it.

Of course, the original design works fine, as evidenced by how many are out there flying - but on SOME models of RV (not all - the geometry differs) the Delrin sleeve works fine as well. There are freqently many acceptable solutions to an engineering puzzle.

Paul
 
Let's check the loading via "scaling"

Scott Chastain said:
That aileron pushrod bolt was never designed to serve as a stop, and I hate the idea of repeatedly applying unnecessary side loads to the bolt, the bearing, and risking eventual failure. I think you'll be much happier with what the actual engineers have come up with in this case.;)
Click to expand...

Scott,
I understand scepticizm and you are certianly guaranteed to be "safe" by not altering the design. As an engineer myself, I can assure you that engineers don't always find the most elegant solution right out of the box. Functional yes, but maybe not the "best". I like the simplicity of the plastic bushing, but the stock system is good too.

Anyway, a quick look that the difference between the two systems will show that the AN3 bolt has 10% more cross sectional area than the 2 AD4 rivets, The shear strength of the single bolt is 2.5 times the strength of the combined 2 rivets, and the load impressed on the bolt will be 20% less because of the longer moment arm from the aileron hinge. The only place in my view that is down to similar safety factor as the original system is the bearing area of the 3/16" hole in the aileron bracket A-407 and even then, the loads would be 20% less as stated above. I will use a bushing and not have any worries while in the left seat.
 
Scott, The only time the ailerons are going to hit the stop with any force is on the ground in a wind gust or some doughhead running into one. The stops get little if any stress on them and actually the delrin gives a nice cushioning effect. Don
 
I just cut down a piece of .063 3/4 in. angle and put the stop on the outboard aileron mount where there's room to work. I suppose there might be a potential for a twisting force to be applied to the aileron when at the stop if you're a "Bubba" doing hard rolls.
 
You must log in or register to reply here.