Total length should be about 18'.
Total length should be about 18'.
Setting up the Bogert Wing Rotators
Now that I have started covering the wings, I really like using the Rotator. But getting it set up proved to be a bit of a challenge. There were two issues. Both have been resolved.
The basic assembly is well covered in the manual. The trick is mounting the wing to the rotator, which is not well documented. So we did some experimenting. I mean a lot of experimenting. Virtually every possible combination of connection locations was tried.
1. Washout. The washout as measured between the third rib and twelfth rib should be ¾”. Getting there was a challenge. Here is why:
a. The wing root is held in place with two brackets. The information indicates that the single hole bracket goes on the aft side and two hole bracket goes forward. Wrong. It won’t work that way. It is just the opposite.
b. The aft bracket has two holes. If the lower hole is used it fits nicely and the wing sits parallel to the rotator arm. But there is a problem. More on that in a minute.
c. There are two supports for the strut connection. The information indicates that the long support goes forward and the short support goes aft. Wrong. It is just the opposites. But there is another problem. The supports are not adjustable, and the aft one needs to be about a half inch shorter or the forward about a half inch longer to get the washout right. But who wants to modify the tubes? So here is the simple solution:
First, use the upper hole on the aft root bracket. This will require several washers to clear the bolt on the wing bracket. Yes, the wing will no longer be parallel to the rotator support arm, but so what? At least the washout will be close to ¾” or two degrees measured with a digital level. Simple solution and no cutting, welding, or fabrication is needed.
DSC_0566.jpg
DSC_0567.jpg
The washer sticking out is to avoid compressing the two halves of the wing bracket.
Second, make sure the center supports are placed in the correct location where they attach to the wing. They need to be within the slots so the interfere less with the fabric.
DSC_0554.jpg
DSC_0553.jpg
Third, support the wing on all four corners with the appropriate washout, then tighten all the nuts and bolts connected to the wing, including the root brackets. There is a bit of play in the connections and it can make some difference in the washout.
Washout problem solved.
2. Height. The manual makes clear that the 17 foot long "get – it – yourself" steel tube must be parallel to the floor to assure that it will rotate properly. The problem is that the wing sets much closer to that same tube at the tip than at the root. This means that when working on the top of the wing the tip is down and when working on the bottom of the wing the tip is up. Way up.
The reason is simple: the two center support braces, mentioned above, are not only either a half inch too long or too short (take your pick) to get the washout right, they are both collectively two or three inches too short to level the wing.
This problem was also easily solved, but required a bit of fabrication.
The solution is a plate drilled with holes that raise the center supports. The plans I drew up are attached. You don’t need to drill all the holes, unless you really enjoy drilling. Just drill the top and bottom holes 2 ½ inches apart. That is just about right.
Wing_Rotator_Adapter.pdf
DSC_0555.jpg
Now someone may tell me that I did it all wrong. If there is a better way I am all ears
I suspect that Bogert may make some modifications once it learns of these issues. The solution is easy: simply make the length of the two center supports adjustable and make the minimum length of each a couple of inches longer. In the meantime we are delighted with the rotator and with these two simple modifications it works just great.
DSC_0572.jpg
Last edited by ceslaw; 02-23-2015 at 07:27 PM.
Chuck,
I don't think it is that critical to have it "perfect" in the rotator. I have used two different wing rotators that didn't account for the washout. After the wing was covered, stitched and finished it still sat on the saw horses with 3/4" washout. It is hard to get that twist out once it is built in.
However, I agree with you, if the holes are there it is best to have them in the right places!!
MR
Last edited by Cubrath; 02-23-2015 at 07:48 PM.
MR
i am probably a bit over the top on this, but the rotator was giving a pretty consistent washout of 1 1/2", double what it should be. The idea of covering and shrinking with that much, and then having to bring it back to 3/4 caused me concern that the fabric might wrinkle or distort. With this simple set up I know the fabric will be shrunk with the right washout and hopefully there won't be any issues with the fabric when the wings are adjusted on the plane.
i have no prior experience in this area so I tend to err on the side of caution.
Chuck
Hello,
I'm Richard Bogert of Bogert Aviation. I am new to the forum. Another Carbon Cub builder called me today to tell me about the forum and some of the discussion going on here regarding the wing and fuselage rotators. I would like to discuss your ideas. It makes since that we would want to build the best tool available and if we can improve it we will. Please call me at the office (509) 736-1513 so that we can discuss. Regards, Richard Bogert
Do you mean for the wing rotator adaptors? I have that file. Send me an email. Unfortunately I can't (or don't know how) to attach it.
Gregg
Carbon Cub EX CCK-1865-0092
Steve, Chuck, Pete, Paul and others,
We are about a month away from needing to mount our wings on rotators for covering. I read all the entries in this thread and now know enough to be dangerous :- )
My questions are as follows:
1) how do I find the drawings under Mitch's drop box if I want to fabricate my own rotators? I was unable to find the link anywhere on this forum
2) Does anyone know of a builder near Southern California with a set of rotators that might have served their purpose so I can borrow or steal them?
3) Looks like the option of buying the Bogert Rotators is also a good one. Does anyone know if the improvements Chuck described in his thread have been made to the Bogert rotators?
Thanks for the help
Greg Geiger
Torrance, CA
Last edited by Redbruin; 02-02-2017 at 08:53 AM.
Greg
i am not aware of whether Bogart made the modifications I suggested.
the main mod was the plate that extended the wing supports. That is easily accomplished and once in place Bogert rotator worked fine.
by the way, if you make that extension plate you need only drill the top and bottom holes. The others won't be needed.
chuck