Trammeling- How to adjust drag wires to make spar straight

[Daveembry]

Garrick, I really don’t understand how that could happen. Once the 2 wires in the first (fuel) bay are tightened, I can pick the wing up and move it all around (as I get front and rear spars on the stringlines) and no way that bay changes. The 2 wires on the front and rear spars lock that section in. If the wire going from the rear spar on the inboard end and going to the outboard end of the front spar is tight and the same same for the one from the inboard front spar to the outboard side of the rear spar…..it just can’t move. Maybe just check and make sure the wires on each end are fully seated on the threaded ends……up against the attach fittings and are not catching on the threads and maybe seating more after you tension?

in any case, something is wrong because that bay can not move once both wires are properly tensioned.

I am a new EX-3 builder and have watched the Dave E. video, the forums, and read the instructions. I have spent a couple of hours the past few weeknights and still can't figure out trammeling. I can square the #2 tube and then I move to the next bay. As I adjust the next set of drag wires tube #2 comes out of square. I tried going down the line in the case of a miracle and adjusting the drag wires bay by bay from inward to outboard but the #2 tube ends up out of square. Any ideas why this is happening?

[garick]

Garrick, I really don’t understand how that could happen. Once the 2 wires in the first (fuel) bay are tightened, I can pick the wing up and move it all around (as I get front and rear spars on the stringlines) and no way that bay changes. The 2 wires on the front and rear spars lock that section in. If the wire going from the rear spar on the inboard end and going to the outboard end of the front spar is tight and the same same for the one from the inboard front spar to the outboard side of the rear spar…..it just can’t move. Maybe just check and make sure the wires on each end are fully seated on the threaded ends……up against the attach fittings and are not catching on the threads and maybe seating more after you tension?

in any case, something is wrong because that bay can not move once both wires are properly tensioned.

Thanks. I am going to start from scratch on trammeling today and will look over the drag wire setup and hardware before I start again. The other bays did seem to hold the sringline so maybe you are onto something with my hardware setup.

[garick]

Thanks. I am going to start from scratch on trammeling today and will look over the drag wire setup and hardware before I start again. The other bays did seem to hold the sringline so maybe you are onto something with my hardware setup.

I think I figured out why the tube was "coming out of square." When I first tighten to square the #2 there is a little bowing of the tube. When I move to the next outboard bay, as I tighten it - the bow changes. The tube becomes straighter. I continued trammeling and was able to fit the aileron. However, I was still concerned that the wing root fittings would be off. I tried to see if my rifle laser boresight would work to tell if the fittings are aligned but that does not work because the fittings our at different level. So, I decided I would just try to fit it on the fuselage (parents were in town and had extra hands available)IMG_5398 copy.jpgIMG_5412 copy.jpg.

So, if the airelon fits well and the wing root fittings attach to the fuselage, does this mean that it is a well trammeled wing?

[garick]

Thanks. I am going to start from scratch on trammeling today and will look over the drag wire setup and hardware before I start again. The other bays did seem to hold the sringline so maybe you are onto something with my hardware setup.

My picture version of this post is taking a while to get approved by the moderator so I will just go with words right now.

I went back and trammeled the wings. When I did the first bay with the compression tube, the tube definitely bows a bit but I was able to get it square to the front and rear spar with the realization that there are parts not lined up with the modified squaring tool. When I moved to the second bay, the bow starts to straighten out as I tension the wires and that is making the spar look not square with the tube anymore. I continued trammeling the wing with the string line and confirmed that the aileron fit when I was done. It was a perfect fit. However, I am/was still concerned with the compression tube since that is for the wing root fittings. First, I tried to use my rifle laser boresight at the wing roots to check the hole alignment. That method did not work as I held a level and realized one hole is higher than the other. So, I decided to try and attach the wing to the fuselage. It fit - so does this mean I have a properly trammeled wing?

[Daveembry]

Sounds good to me. You are correct that that 2nd tube (where you square the first bay) will bow a little as you tighten the drag wires up to the correct tension. I just get it as equal as possible as I tighten the drag wires. The most important area is the straightness of that rear spar since the ailerons and flaps will be up next to it. Of course the front spar will be straight as well.

On my first build, my biggest apprehension the entire build was …. “Is this wing gonna really fit up onto the fuselage right?” Amazing how perfect they all have and with the exact washers called out for in the manual for spacers in the fuse attach fitting. Excellent engineering!

My picture version of this post is taking a while to get approved by the moderator so I will just go with words right now.

I went back and trammeled the wings. When I did the first bay with the compression tube, the tube definitely bows a bit but I was able to get it square to the front and rear spar with the realization that there are parts not lined up with the modified squaring tool. When I moved to the second bay, the bow starts to straighten out as I tension the wires and that is making the spar look not square with the tube anymore. I continued trammeling the wing with the string line and confirmed that the aileron fit when I was done. It was a perfect fit. However, I am/was still concerned with the compression tube since that is for the wing root fittings. First, I tried to use my rifle laser boresight at the wing roots to check the hole alignment. That method did not work as I held a level and realized one hole is higher than the other. So, I decided to try and attach the wing to the fuselage. It fit - so does this mean I have a properly trammeled wing?