elevator's

I have a question, when setting up my elevators to drill the center section bolt to the horns, looking over the ends of the elevators they don't exactly match up on the ends with the horz stab ends. the rigth one is up 1/2 inch maybe.. . has anyone dealt with this.. Ie : I didn't build them perfect.. or has anyone one.. fixed one of these.. after looking close I figured I didn't flute
the end proper or maybe some bend. but everthing else looks straight..any
ideas.. I put the straght edge on it and they match and not too much offset on the horns.. but Ididn't want to drill anything till I found this out.. is it time to order a new emp ?


Danny..

Danny

If you are saying that the horns are not aligned when the elevators are then this is usual. You need to align the elevators to the HS and then drill the horns - it doesn't matter if the horns are not quite aligned to each other.

Peter

no what I meant to say was , the ends of the elevators are not aligned to the horz stab were the fiberglass ends go when the rest of the elevator is centered.. the part were the lead is sticks up when everything else is flush..

Danny..

elevators

What you describe is difficult to visualize. Maybe show a picture or better yet, try Vans tech support. They have heard and seen most everything. When I have called, my concerns were very fixable (usually) without having to buy new parts. Jack

Danny,

I think I understand what you are saying (a picture would be great)....are you saying that the trailing edges, when in a perfect neutral position, are equal with each other, but the counterweight balance arm on one of the elevators is pointing up about a 1/2"? The other question is, is that elevator straight and maybe the HS is twisted?...probably a little more costly fix.

Either way, I would definately call Van's as I see no way to let that slide...it may be as easy as pulling the skin off and doing some massage of the skeleton, but I would suspect it is probably more and may require a new elevator, not a new emp.

I had this problem. I got everything in trail fine, but where one side had the HS and the elevator counterbalance relatively flush, the other side -- I think it was the right side -- was off about a half inch.

Basically, there's a twist in the elevator...or at least there was in mine. It was caused in my case by the jig I was using coming unclamped while I was doing some riveting. It was sitting in a little cradle and when it hit the floor (unbeknownst to me) it put a little crease in the trailing edge. I was basically "fluting" the darned thing and it was enough to add the twist.

I started taking it apart and then said "screw it" and ordered new parts and rebuilt the elevator.

I doubt that's what you want to hear but I'd spend some time investigating whether there's a twist in one of the elevators.

that sounds about right, it must be twisted.. not so bad building the elevator but the horz stablizer looks straight.. I looks straight though.. I will call them in the morning.. thanks everyone..

Danny..

What I would do is take both elevators and put them on a flat surface and see if the trailing edge distance to the worktable is consistent across the length of it. See if one has a substantially different distance to the worktable than the other.

What I've seen folks who've had this problem do, then is drill out the rivets on the outboard end (around the counterweight too) and reposition the outboard rib a bit and then re-rivet.

elevator travel

I am getting about 24 degree's up and 14 down, the up is the horn hitting
the back of the tail cone, but the down has be a little confused, its hitting
the stop , do I adjust the elevator stop ? or is 14 enough ? book shows
25 up min and 20 down min.. what did yall do ?

Danny..

elevator stop

you can just trim the down stop. I had the same experience as you, called Vans and was told that it is expected that you will need to trim the down stop. Also, if you are hitting the rear bulkhead on the up position, you should use a wider up stop. The bulkhead is not made to be hit over and over again. Per Vans also. I had that issue as well. Jack RV9a flying 2.3 hrs.

wider upstop

I have read about the horns hitting, I think If I trim a little on the bottom
outboard corner of the horn it would hit the stop pretty close to the
25 degree's I think maybe 1/4 inch would clear the back, and allow it
to hit the up stop angle.. what do you think about that instead of a new
angle.. ?

wider up stop

Sounds OK to me. I would send a short email to [email protected] and ask that question. You will get an answer the next day and you will feel better about any alteration that you might come up with. Jack RV9A

Careful...

If you go grinding away part of that control horn or the stop, you could be compromising structural strength where you might not want to. Like the man said, talk with the experts at Van's. I think you will ultimately find that you will never need +/-25 degrees of elevator travel for sufficient pitch authority, even at stall/flare speeds.

Jerry K. Thorne
RV-9A N2PZ

elevators

Yeah I hear ya.. I know kathleen had simular problems with the horns hitting
the back of the cone, and they told her to trim some of the back off the
horns.. she posted this here I think.. as for the down elevators, I am going
to have to cut something to get more than 14 degree's the min in the book
says 25 up and 20 down, 23 up would be fine but its hitting the wrong
item, 14 down is prob plenty but I want to make sure.. mostly I was just
asking what others have done to resolve this issue.. the more info the better



Danny..

You mentioned , put a bigger stop on the up stop, but like I said I am only
getting 23.5 degree's when the horn hits the back of the tail, I need atleast
25 degree's per the manual so the only idea I can see is cutting the bottom
of the horn a little.. shouldn't take much and its on the other side of the
area where the push tube bolts.. sound good ?
Danny..

might be worth checking the bearings

Don't know if this is relevant but it might be worth checking and or adjusting the bearings before cutting away metal.

I looked at the bearings and how far out they are, but it will not give me
enough 11/32 min, if I screw them out, I think they would hit sooner, if I
screw them in more It looks like it would not have enough clearance..
I will try that today..

thanks for helping..

DAnny..

Its done, drilled , trimmed the stops got 28 degrees up and 20 down, close enough.. just took a very little off the horns and rounded it a little, should not
present a problems.. didn't take much on the stops either.. maybe 1/8 inch
I think thats going to be ok.. my eaa tech is coming tomorrow.. I will let yall
know , its the 1st time I have been able to get anyone over here to check it..


now I am wondering if anyone has done anything with the rudder lead weights..
balance ? anyone trim any or just leave it alone ?

Danny..

I don't think there are any instructions to trim the rudder counterweight (although I know the elevators require it). That said, I had to gouge out a little (very slight) bit of lead on each side where the forward-most skin-to-rib rivets prevented the weight from setting flat on the rib. That should be all that is required.

Steve

Insurance on tail draggers is higher...

Steve,

You know the insurance on the tail draggers is higher than nose-wheel airplanes. The visibility is better on the taxiways in the nose-wheel models. Van's converted one of their airplanes from a tail dragger to a nose-wheel model after it was built.

Just some things to think about.

Jerry K. Thorne
RV-9A N2PZ
www.n2prise.org

godspeed said:

now I am wondering if anyone has done anything with the rudder lead weights..
balance ? anyone trim any or just leave it alone ?

Danny..

Click to expand...

Danny,
The weights on the control surfaces serve to reduce the natural frequency of their vibrational modes. "Imbalance" on the elevators can cause minor gravity influenced control input that must be counteracted by the pilot/trim system.

The Rudder has no equivalence relative to the elevator concept of "balance" since in normal controlled flight, the gravity vector is always pointing straight down. The rudder weight is therefore used primarily to reduce the frequency of the vibrational modes. It will probably also help to reduce odd secondary control input during yawing motions.
Only remove the minimum lead necessary to allow its correct installation. I think on mine, I just formed the clearance for some interfering rivet heads using a round nosed punch and a hammer. I didn't remove any of the lead.

-Mike

n2prise said:

Steve,

You know the insurance on the tail draggers is higher than nose-wheel airplanes. The visibility is better on the taxiways in the nose-wheel models. Van's converted one of their airplanes from a tail dragger to a nose-wheel model after it was built.

Just some things to think about.

Jerry K. Thorne
RV-9A N2PZ
www.n2prise.org

Click to expand...

Yeah, thanks Jerry. I do know that insurance will be more of an expense. I don't plan to have hull insurance (not a big fan of it on homebuilts--if it gets busted up, and I'm still alive, I'll just be happy I lived and part out the old one and build a new one). I'll likely only carry liability and ground not in motion insurance which I would think should reduce my costs significantly.

I'm not of the school that thinks one is better than another or will make me a better pilot or anything like that. Even IF there is a nosegear "issue" re: strength/tendency to flip on off-field landings, with the slower speeds of the 9A, that should be less of an issue than it might be for a 6A/7A/8A. I'm still not yet convinced there even is an issue.

I'm mostly interested in the 9 just because I'd like to fly a taildragger. Having said that though, and having flown in Van's 9A, the one thing I noticed right away, and that bothered me, were the main gear attach points right up next to the seats in the cockpit. I suppose maybe you get used to them, but they bothered me right away (and that was before I was even thinking about a 9).

Anyway, thanks for the thoughts--I've gone back and forth over the past 3-4 years on this issue. Now that I've begun building, I suppos I'll be going back and forth still until I order the fuselage kit (probably this fall).

Steve

P.S. Thanks for your great website. I've used it a few times--it's been very helpful.