Van's Air Force
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Gear Tower Mod Poll
- Thread starter YvesCH
- Start date
Ok sorry,
here are the two options with Pictures:
Answer 1:
Answer 2:
here are the two options with Pictures:
Answer 1:
This is how I did mine during construction but I think itcould be done to a finished aircraft by being careful not to cut anything besides the web in the gear leg tower .
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Answer 2:
Have to agree with Mel, those square corners look like the source of cracks beginning in a pretty stressed area.
The whole idea is to be able to get into the tower for maintenance. Mainly torquing gear leg hardware. Really only need an opening big enough to get your hand in to make it easier.
Doing an extensive modification to the tower as shown doesn?t seem prudent or necessary for a once a year access.
The whole idea is to be able to get into the tower for maintenance. Mainly torquing gear leg hardware. Really only need an opening big enough to get your hand in to make it easier.
Doing an extensive modification to the tower as shown doesn?t seem prudent or necessary for a once a year access.
I was just wondering how common such a modification is. Personally I have done the first option and I am somewhat glad I did it as my towers are quite full with cables and its even with the modification not really easy to access those nuts..
Habe there once been reported failures due to this modification? I could not find any...
Habe there once been reported failures due to this modification? I could not find any...
Big hands
I just didn't put much in there, only routed a few cables through the towers. Pretty easy to snake things through with a bit of guidance.
Van's said that they have not seen any reported failures. I didn't make the mod, and since I have such big hands,
I just didn't put much in there, only routed a few cables through the towers. Pretty easy to snake things through with a bit of guidance.
N546RV
Well Known Member
There aren't really any square corners there, at least not in the way I think you're suggesting. The procedure is to take the single provided piece for the "face" of the gear tower, and cut it into three pieces instead. The top and bottom pieces are riveted to the inside corner angles as before, and for the center piece, the prepunched rivet holes are enlarged for screws.
See:
https://rv.squawk1200.net/2015/05/04/priming-right-gear-tower-modification/
https://rv.squawk1200.net/2015/05/06/left-gear-tower-modification-and-match-drilling/
Which Mod?
Resurrecting this thread as I'm about a week away from the gear towers.
I'm leaning towards answer 1 since it seems easier, quicker and less structurally invasive. Are there any arguments against doing this or doing answer 2 instead?
My plan is 20 to 25 countersunk #8 screws. I still have to work out spacing and minimum edge distance, all that fun stuff. Is there a recommended hardware AN507 or AN509?
All knowledge welcome
Resurrecting this thread as I'm about a week away from the gear towers.
I'm leaning towards answer 1 since it seems easier, quicker and less structurally invasive. Are there any arguments against doing this or doing answer 2 instead?
My plan is 20 to 25 countersunk #8 screws. I still have to work out spacing and minimum edge distance, all that fun stuff. Is there a recommended hardware AN507 or AN509?
All knowledge welcome
Don Patrick
Well Known Member
1
I did 1....no issues.
Don
I did 1....no issues.
Don
Lot of field experience at this point, many airframes. Personally, I've probably landed as hard as anyone.
Well, maybe not. IIRC Mike Stewart did the "whole panel" mod, and he was slamming a 540 powered -8 into a small grass strip.
The "oval access" mod is way less invasive. It removes a connecting strip 2.625" wide and replaces it with a solid panel.
Matt Dralle suffered what may be the best documented groundloop:
http://www.matronics.com/forums/viewtopic.php?t=97483&sid=137bd43fdb569e8ae0d19279e8047f21
The failure appears be in compression, originating at the outer skin. The oval mod would not affect this failure (fourth photo). Not that it matters, as the entire fuselage is shot.
From the wayback machine, original thread:
https://vansairforce.net/community/showthread.php?t=13079&highlight=tower
Well, maybe not. IIRC Mike Stewart did the "whole panel" mod, and he was slamming a 540 powered -8 into a small grass strip.
The "oval access" mod is way less invasive. It removes a connecting strip 2.625" wide and replaces it with a solid panel.
Matt Dralle suffered what may be the best documented groundloop:
http://www.matronics.com/forums/viewtopic.php?t=97483&sid=137bd43fdb569e8ae0d19279e8047f21
The failure appears be in compression, originating at the outer skin. The oval mod would not affect this failure (fourth photo). Not that it matters, as the entire fuselage is shot.
From the wayback machine, original thread:
https://vansairforce.net/community/showthread.php?t=13079&highlight=tower
As an update, I've decided against countersunk screws. Too afraid of the #8 screw head dimples stretching the material with on the gear tower and messing up the pre-punched rivet hole locations. It also seems like unnecessary work for little gain.
AN 525 at 1/2" long are "washer head" structural screws with a smooth grip that's just the right length using a standard washer.
How about using .063 for the cover plate, and you can machine countersink the holes for the screws?
I thought about going that route too, but I already had the 0.040" by the time that thought occurred. Pan head screws really aren't that big a deal. My biggest concern was catching my legs on the screw heads. Decided I was making a mountain out of a mole hill and to just get on with building the airplane. I already had the 0.040", and wanted to just get on with it.
Dan, thank you for taking the time to post. Those pictures along with that #4 pic reinforce what I thought - that the tower is strong enough with whatever mod you chose. I don't need my airplane to to withstand more G-forces than I can handle.....
