HS-405 to HS-602 problem?

JulietGolf · #1 11-28-2009, 07:24 AM

I've been getting ready to drill my HS-404/405 holes to the front spar assembly. One thing I have noticed when I put things together is there seems to be not enough room to maintain hole/edge clearance on the HS-405 to HS-602 hole. From searching the forums it seems like this is not an unsual problem. I plan to email Vans on Monday but I wanted to post here as well for opinions on how to proceed if you've been through this before.

JulietGolf · #2 11-28-2009, 05:20 PM

Thanks. Though that drilling is a concern my question is more about the edge distance for the hole that goes through the skin to 405 and the front spar. If I match drill the pre punched skin hole I will not have an edge clearance in 405 or 6/702. I'm having a hard time explaining this well - sorry.

JulietGolf · #3 11-29-2009, 11:33 AM

I drilled it out and what is now obvious to me is that I over trimmed the HS-602 flange when I trimmed it back to get the proper bend. Neither the HS-602or HS-405 will have the proper hole/edge clearance with the HS-602 being particularly bad. Looks like I'll be ordering some parts from Vans...

DaAV8R · #4 11-29-2009, 11:19 PM

Jamie,

I have just completed this drilling and encountered the same problem. The HS-405 does not have enough edge distance at the front flange holes. The edge distance is established by the dimension of the prepunched skin and the length of the 405. The only way to increase the edge distance at the front 405 flange hole would be cheat the 405 forward. This is not possible because cheating the 405 forward pushes the 702 spar forward, decreasing the edge distance at the toe of the 702 flange. I called Vans and they said that this minor dimensional issue has existed since the introduction of the -4. They said the edge distance on the 405 is no problem and to continue on.

I suggest placing a center line on the 702 flanges before assembly to verify that the 702 flange is at an acceptable location before match drilling to the skin. Vans documents states that the 404, 405 and 702 should be pulled tight before drilling. This is an important note considering the minimum edge distance on the 405 and the tendency for the 702 to push forward if not clamped.

Good luck.

Robert

RVG8tor · #5 11-30-2009, 09:28 AM

I had the same question with my kit, I believe this is a known issue. As you say you can't change anything since the hole is established from the skin and the rib is precut and formed. This is Van's replay to me two years ago.

"The HS-405 rib flange has been slightly short ever since the first kit RV-4.
Engineering is OK with that rib and the less than perfect edge distance.
Ignore the edge distance in this case and move on."

I am not sure why they don't publish these known issues, we just have to find them on our own. I am trying to track down own the rudder pedal hardware now.

Cheers