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Elevator Rub

Breezy

Well Known Member
Mounted Elevator to Stab. Very closely measured the eye bearing distance from stab spar. When moving elevators to travel limits there is rubbing at the HS 912 mount flange and the leading edge of the elevator. Center of leading edge has clearance the contact occurs in the last degrees of the travel limits. Tried backing out the eye bearing a turn to gain additional clearance but not enough.

Any others encounter this?
 
I experienced this as well using the exact specs from the book. Its close tho, it doesn't rub until the last degree or two publish in the book. I am not going to mess with it until I set the travel limit later in the build. If I need to back out the bearing a turn or two or even shim the torque arm bearing out .32 I will do that later. After checking out a completed -14 I still have hope that there won't be any rubbing at all once I set the travel limits.

-Jason
 
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Funny, I ran into this exact problem yesterday! I tried messing with the shape of the leading edge yesterday without much success, but the thought occurred to me this morning that I may be able to back out the rod end bearings a half turn or two. Also interested in how people have dealt with this in the past.
 
I had to back out rod ends a couple of turns. Discussed with EAA tech counselor. Most critical is to be sure you don't have too many threads exposed on the rod end AND properly torquing the jam nut.
 
Different rod end bearings?

I thought I saw Vans will send a set longer rod end bearing to RV14 guys as this is a known problem. I?ll check the reference when I have more time. Joe (RV14)
 
Spoke with Vans. Was told there could be up to 4 threads beyond the jamb nut and still have engagement in the nut plate. Discussed the use of a different eye bearing (MD3616M), however the ball width is greater and would not fit in existing brackets.
 
Elevator rubbing

I had the same problem. Van?s has a longer resend that will fit in existing brackets. It solved my problem but created other issues I had to compensate for.
 
Thanks

Thanks Larry! I think I asked you a million questions at Oshkosh and drooled a little on your 14... Lol - Joe
 
I had the same problem. Van’s has a longer resend that will fit in existing brackets. It solved my problem but created other issues I had to compensate for.

Hi Larry,
I just ordered the longer rod end bearings Sterling recommended (BEARING MM-3M-42).
Did you all get them for free?
What other issues does this create? I had to pull mine out from 20.6mm to 23.11mm (2.5 turns from 20.6mm).

snv

624855e5-4440-47ad-9009-bfa68c0d05c4
 
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I had rub on the leading edge of my elevators where they met most (maybe all, I can't remember) of the AN470 rivet heads that attach the hinge brackets to the HS rear spar. I was able to massage the leading edges enough to eliminate the rub through the entire range of travel. Just posting this as a data point for posterity.
 
I'm resurrecting this thread because I have the same issue with the elevators rubbing on the rear spar of the horizontal stabilizer and I'm not clear on how to proceed. For reference, I'm at section 11-2 of the plans.

The plans call for 13/16" for the rod end bearing engagement distance. The distance for mine is now at 15/16" because I've backed out the rod end bearings to improve clearance. I still have part of the rod end bearing protruding from the back side of the nut plates as shown below. I think I still have full thread engagement.

There is no rubbing on the down travel. The plans call for 30 degrees of UP travel. The rubbing occurs at about 32 degrees on the UP travel. Is this "good enough"??? The reason I'm asking is because I'm not sure how all this plays out when it comes time to drill the elevator horns and set travel limits or whatever is done later in the plans. I'd feel better if I had a larger margin (like 35 degrees) but I don't want to back the rod end bearings out any further nor do any further "massaging" of the leading edges of the elevators.

It's very frustrating because unlike the rudder, there were no templates to form the leading edge of the elevators. If those rod end bearings were just 1/4" longer....
 

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You should have no rubbing. I found this part of the build one of the most frustrating, so you are not alone. I farted around with the l.e rubbing, gap between the horns and h.s. and gap between the l.e. of elevators and h.s. for a couple days. Almost as much fun as bending the wire for the fuel sensor. I used a piece of cedar that was 2’x2” wide and tapered at the end. I used it to “massage” the l.e. while prying against the h.s. and rotating the elev a bit at a time. I would then slide a piece of note pad paper into the gap and rotate the elevator full travel to find the areas needing more adjustment. This worked for me. I went to the max adjustment on the rod end bearings but not past it.
Edit: sorry, I misread the travel you have. You may be ok, but you might want to check with support.
Page 2, section 15 max elev up down 30/25, min up down 25/20
One more thing to consider is once your plane is painted will that area get scuffed/scratched when doing your walk around and moving the elevators through full range.
 
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