VT Rib Issue - beware??

[Greg Pixley]

Dan,
Placing a square between the aft spar and the center rib eliminated the gap in the lower rib. Probably need a picture in the builders manual to help dummies like me.
Sorry for the confusion,
Greg

[danweseman]

Greg
First< we have built or had out hands in building 5-6 VTs out of kit parts and they all went well. if builders are having issues like yours they have not contacted us about them, so I think you may have a isolated problem. The rib could have slipped on form or something, who knows. I cannot tell get a good feel from the photos on the entire build as they are zoomed in to close. A "big picture" photo may help.
To other builders. I DO NOT recommend cutting of any flanges if you encounter problems . CALL ME first?? (904 563 4337) we can work through it so that if a there is a issue we can resolve and eliminate the problem. I do not think we have design or part problem as this seems to be a isolated case. Greg you can compare you parts to the plans sheets for the parts and verify the are per plans.
Also I don't see a square of any kind in photos. If the top and center ribs are not perpendicular to the aft spar it will have the effect you are describing. this is due to the different length ribs and the lower one being on the long angle.
I can mock this up and post a photo later today
Dan

[Greg Pixley]

I think I've found a way to say the VT and for those who have yet to start, I offer the following lessons learned:
1. Use the metal yardstick clamped to your hinge every time you drill a hinge! I learned that too late and may have to redo my rudder.
2. For the VT, I'd adjust the center rib until the lower rib fits flush. Cut the end and rivet a plate to adjust to fit or just build a new one.
3. Use -4 hinges on the VT. They offer more edge distance in case you need to make adjustments or drill a hole slightly off center. -4 fits between the stiffener and the star with plenty of room. I also used about 8" of -4 on the tips of the HT.

With the center rib removed the tail still retained some of its original shape but now I'm left with only about 1/16" gap at the bottom and a 1/32" at the top of the aft spar. I plan on taking that gap out by drilling another -4 hinge.

Greg Pixley

[Greg Pixley]

Dan,

I wish it was as simple as putting the stiffener on the wrong side of the spar but they are IAW plans. I was able to save the photos to a smaller format (less than 256K) so they should post here.

Thanks
Greg

[danweseman]

Greg
A 3/16 bow is not acceptable. It sure seems like a stiffener may be on wrong side. Verify the 3/16 stiffener is on aft side of aft spar and forward side of forward. A small amount of tension on the hinge is likley fine but not this much.
Some pics would be great!
Dan

[Greg Pixley]

When building the VT I came across an issue I don't know how to resolve. The bottom rib appears to be about 3/16" short! At first I thought I had a spar on the wrong side but they are correct. So instead of asking the question I pressed on, certainly many tail kits have been built before mine! Thinking the skin would define the straight trailing edge, I added the skin. The result is, as one would expect, a bowed rear spar (off by about 1/8").

Here's the hard question; how do I fix this, or do I fix it? Adding a spacer to the rib would have messed up the trailing edge of the skin and change the dimensions of the attach point at the aircraft. I can attach the rudder currently, it just takes some force and once the hinge pin go in, it's there to stay.

Thanks for your help/opinions in advance!
Greg Pixley
#35