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Elevator counterweight

wirejock

Well Known Member
I have another elevator question.
E-714 Elevator Counterweight
The right side plans show an area to cut away. The isometric view shows it removed.
The left isometric view show it uncut. :eek:
The book does not mention it till it talks about balancing and drilling small holes.
I've learned the plans are almost always right but in this case the two plans do not agree.
So should I cut or leave it and cut it later when balancing?
 
on mine I did not remove any, with paint and electric trim, I only had to drill a few holes in each one to balance it, with them tied together.
 
DOH!

Only the right gets trimmed. DWG 5, E-714 Trim Detail says, "...Right Elevator Only!"

I must have read that 50 times and still missed the note. That makes sense. I was wondering if balance would be different between the two sides due to trim hardware.
Thanks Larry.
I think I will cut away the area shown.
I wonder what else I missed. :eek:
 
Electric trim

on mine I did not remove any, with paint and electric trim, I only had to drill a few holes in each one to balance it, with them tied together.

I'm using electric trim also. Hmmmm. Oh bother!
Maybe I should leave it as is. It can be cut away anytime.
Thanks Bret.
 
Hi Larry-

7s and 8s tail sections are pretty similary, if not identical. I trimmed as indicated per my 8 plans (or so I thought) and later had to add weight. I too used electric trim and found more weight needed for proper balance. This may vary from one to another depending on how much RTV or proseal used on trailing elevator edge, process used for fiberglass tips, prime/no prime, etc. Suggest you don't trim any until all is complete and you are ready to balance. My 2 cents worth.
 
Yip, RTV, paint, glass work, servo, all adds weight, you will need those counter weights.
 
hey Larry I know this thread is a few years old. but i am asking the same thing now. how did it turn out? was leaving it as is the right move?
 
I had asked Van's what to do and was told it doesn't hurt anything to leave them full weight until painted, then drill holes to balance, if you want to. Extra weight doesn't hurt, too little weight very well could. I just finished the painting and can trim a little from the right side when I feel like doing so and touching up the paint to cover the removal hole(s).
 
Last edited:
Wait

hey Larry I know this thread is a few years old. but i am asking the same thing now. how did it turn out? was leaving it as is the right move?

I can't speak for Larry, but I went through the same decision finishing my 8A empennage a couple years ago. I elected to wait until final paint. It's easier to trim/drill out than add back and paint can add quite a bit of weight to those elevators.

Also, if you are planning (like me) to fly the plane for awhile before painting it, there is no harm in having control surfaces that are a bit over-balanced.
 
Weight

hey Larry I know this thread is a few years old. but i am asking the same thing now. how did it turn out? was leaving it as is the right move?

I'm not flying yet but have had the tail together and right was just about balanced. Left will need a tad due to the trim but she's not finished yet. I plan vinyl wrap. I will add nut plates to the tooling holes for weight adjustment later.
 
Elevator balancing

I also called Van's about this (twice actually, haha). I was paranoid because the RV-4 manual dedicates quite a bit of info to balancing the elevator. They said it wasn't that big of a deal on the -7/8. Balancing the elevator is pretty much optional, but be sure wait until everything is installed and painted if you are going to do it.

I'm still a little wary about this as flutter is one of those things you don't want to mess with. It can kill you very quickly. But, I'm taking Van's word for it right now (might call again before I fly it just for good measure).
 
Getting ahead of the plans

Its a good thing I took a look at this thread. I was not reading ahead and cut both weights the same as shown in the picture of the right elevator. I ended up milling them and it was easier to do them at once.

I have not finished the left elevator yet but the weight has already been match drilled. What is my best course of action at this point? Drilling another weight and getting the holes to match up will be pretty hard (lead is not fun to drill).

Thanks,

Eric


 
This is my weight for the left elevator. As you can see I cut it the same way the right side is. I have already match drilled it to the elevator, what would be the best way of fixing the mistake. I am assuming that it is going to be difficult to drill a new one and gets the holes to line up perfectly with the rib on the inside.

I was considering using some aluminum sheet metal to create a "mold" so I can heat that end up enough to melt it and add more lead to bring it back to its original shape.

Thanks for the suggestions in advance.

weight_zpsak0rtqjc.jpg
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