| Author | Message | ||
     Anonymous |
Rob, Considering the price that will be paid if an elevator goes into flutter, I would balance both of them. Like Eric pointed out, you are going to depend on the torsional stiffness of the connection between the two halves of the elevator, which will have some ability to deform plastically, which, under some high stress circumstances, could allow one control surface to move slightly with respect to the other. Having one of your elevator halves go into flutter would definitely classify as a high stress circumstance. However, you probably wouldn't know your elevator fluttered, it probably would seem more like an explosion. Jim Butler | ||
| Jerry Sjostrand |
Fellow builders, In light of the dilemema you are having with the elevator balance problem, not being the engineer that Reinhard is, I have to agree that both surfaces should be balanced. I suspect that most of the builders end up with a similar problem and do not do the final balance necessary. I was informed that the balance should be in the favor of slightly "over balance" rather that the reverse. Any other comments on that situation would be appreciated. I had the problem and solved it by adding a "weight capsule" to each elevator. It involves a fiberglass cap attached to the inner end of the elevator horn to allow the addition of the lead to balance. I made the lead weight to fit inside the glass cover and then reduced the length (weight) of the lead to make the balance. One side took an additional 1 ounce (the side with the trim tab), the other 1/2 ounce. I am going out to the airport today to re-calibrate the VMS fuel system and will take pictures of the stabilizer and elevator to post before the end of the day. If you are already painted, this system means you will only have to do a spot paint on the stablizer, non on the elevator. I will explain the method of attachment and hope to find some earlier pictures that I took while making the change. I documented everything by photo while building. I hope all of you are doing the same as the FAA loves pictures and they are great when it comes time to "show off" your construction. 'Till later. Jerry Sjostrand | ||
| Rob Jordan |
Thanks for all the input. I was trying to call express today to ask them about it. I'm not one to skimp but I would rather ask first before destroying an elevator and having to rebuild it over 2 ounces. If the outcome would be the same. but as you all have pointed out there might be problems with this and I do not care to take risk of that type. I was going under the assumption that a chrome moly tube would be the most ridged part of the elevator. | ||
| robert jordan |
Thanks Jerry I wrote the last post as you were entering yours I app the help. | ||
| Jerry Sjostrand |
Pictures as promised regarding added weight on the elevator.     | ||
| Eric Holmberg (Erich) |
Nice work, Jerry. What did you use for paint? It looks great! | ||
| Anonymous |
Check out the following link to see a quick little movie of actual in-flight flutter. Then ask yourself if you think it's really worth balancing your control surfaces accurately. http://209.41.125.134/Sightings/QT/TCFlutter.mov | ||
| Kevin Dennes (Kdennes) |
Anonymous. I was disappointed to find that my computer would not open the movie to which you refer. What do I need to load in order to view it? Perhaps the first thing I should buy is a book called "Instant Help For Computer Dummies". Regards. Kevin (from Downunder) | ||
| Chris M |
Hi Kevin, Try downloading Apple's QuickTime Player 6.0 (www.quicktime.com). It works on both PC and Mac platforms. That should let you view the video 'annon' referred to right in your web browser. - Chris | ||
| Rob Jordan |
//Anonymous //Then ask yourself if you think it's //really worth balancing your control surfaces //accurately. You've missed the point! I dont need to ask myself this as if I didn't want to balance them accurately I wouldn't have asked the original question. I would have left it the tiny amount lite that it is and not worried about it. But instead I started looking into the possible solutions to the problem. I do thank those who have help me with all the emails and post and I have chosen my course of action after recieveing all the input that has been giving me. I hope with out to many additional delays to make Sun and Fun. |