Ch. 14 – Main Wing Spar
This chapter deals with fabricating the main carry through spar that mounts to the fuselage and provides the mounting surface for the wings to the fuselage. This was easier than I thought it would be. Just some long layup schedules for the spar caps……like 9+ hours.
9/24/02 - Cut out main spar jig pieces. 1.5 hrs.
9/26/02 - Cut out jig support pieces and started to assemble spar jig onto work bench. 2.5 hrs.Here, the jig is in the process of assembly.
9/27/02 - Finished assembling spar jig. Started cutting and fitting CS-1 foam for jig. 3 hrs.
9/28/02 - Finished cutting CS-1 foam and microed together. Cut and fitted foam for CS-2 & 3. 5 hrs.
9/29/02 - Cut and glued 10 pine sticks for CS-3 support on main spar jig. Microed CS-2 & 3 foam pieces in place. 3.5 hrs.The foam is cut and placed in the jig. The pine sticks support the outside foam. The spar is actually built with the forward face of the spar (as it sits in the fuselage) facing upwards. This makes it easier to get the proper sweep to the spar so it will match the swept wings once assembled. The only problem with this is all the instructions are shown as the spar is installed in the plane. I always had to stop and make sure I was working on the proper side of the spar....ie top=face, bottom=back, etc.
10/4/02 - Fabricated all LW hardware for wing attach points. Microed end bulkheads CS 5 & 8 into position. Cut and fitted CS 4 foam. 3 hrs.
10/6/02 - Cut glass and laid up left and center portions for inside of wing spar. Installed LWA-1's with reinforcing layups per plans. 6 hrs.
10/7/02 - Cut glass for right side of spar inside layup. .5 hrs
10/12/02 - Completed inside layup of main spar. Knife trimmed layup. 4.5 hrs.The picture on the left shows the center bulkheads in place. The holes in the middle will be used to route wiring harnesses from the engine compartment forward. The picture on the right shows the outside wing attachment pieces floxed and glassed over. I alodined the aluminum pieces before install for further corrosion protection.
10/13/02 - Trimmed all inside spar layup so CS 4 foam will lay flat on spar. Cut glass, microed, glassed and peelplied inside of CS4. Cleaned garage. 3.5 hrs.
10/14/02 - Removed peelply from CS4 layup. Sanded CS4 layup and microed CS4 in place on spar. 2 hrs.The left pic shows the inside of the top (er front face...I told you this is confusing) being glassed. It was then flopped over and floxed in place as shown with the picture on the right.
10/18/02 - Marked top and bottom spar cap trough dimensions on main spar. Started sanding and shaping spar cap troughs. 3 hrs.These are the templates that are used to make the spar troughs in the spar. Thick heavy fiberglass roving is used to fill these troughs to give the spar the needed strength to carry the load of the wings.
10/19/02 - Finished sanding top and bottom spar cap troughs. Routed out foam and floxed LWA4&5 outside wing attach points. 5.5 hrs.The picture on the right shows the trough sanded to the proper depth by using the templates at the proper locations from center. The trough gets "shallower" towards the ends because it doesn't need to carry as much weight out there. The picture on the left shows the tool I fabricated from other builder's suggestions. The spar troughs need to be exactly 3" wide. The tool is just some sandpaper glued to a 3" board with another board attached at a right angle to act as a fence so I didn't sand more than 3" into the spar.
These wing attachments are placed directly over the top of the ones that were installed inside the spar earlier. The wing attach bolts will end up going through a 1/4" of aluminum plus the layers of fiberglass.
10/21/02 - Rounded edges on wing spar. Cut glass, microed, laid up 4 ply uni shear web and peel plied. 9 hrs.Here I am doing the "9 hour haul" The plans give you the layup schedule based on how many "full length" layups there are. Each subsequent layup is made shorter so you end up with a tapered sparcap. This taper is achieved by marking the spar for each layup as shown by the picture on the right.
10/22/02 - Removed peel ply from shear web layup. Sanded spar. Built dams. Taped off spar troughs. Replenished epoxy and hardener. 2 hrs.
10/24/02 - Laid up and peel plied top sparcap. 9.3 hrs.
10/25/02 - Sanded bottom spar trough. Taped off spar. Fabricated dam for spar trough. Microed between dam and spar trough to prevent epoxy drips. 2.5 hrs.
10/26/02 - Laid up bottom spar cap and peel plied. 6.5 hrs.
10/27/02 - Removed peelply and dams from top and bottom spar caps. 1 hr
10/28/02 - Sanded and shaped top and bottom spar caps. Cleaned garage. 3.5 hrs.
10/29/02 - Cut bevel along top and bottom front face of spar. Fabricated and installed 4 wood shoulder support blocks. 3hrs.The left picture shows the front face of the spar being rough cut for the bevel. The picture on the right shows the hardwood blocks installed for the rear seat passenger shoulder harnesses.
11/1/02 - Cut uni glass and sanded spar for main spar layup #6. 1.5 hrs.
11/2/02 - Did layup 6, 4 ply Uni @ 45 degrees around three sides of spar. Floxed LWA2's and 3's in place. Peelplied entire spar per plans. 7.5 hrs.
11/3/02 - Removed peelply and trimmed previous layup. Measured, cut out, and beveled foam for center access holes in front of spar. 3.5 hrs.
11/8/02 - Sanded, cut fiberglass and laid up 3 uni ply reinforcement plies over all 4 external attach points on spar per plans. 3.5 hrs.
11/9/02 - Radiused corners, cut fiberglass, laid up, peel plied and knife trimmed 2 uni ply on forward face of spar. 4 hrs.These two pictures show the access holes for wiring and inboard attachment bolts. This is the portion of the spar that will face into the fuselage directly behind the rear seat backs.
11/10/02 - Made flox corners, cut glass, and laid up 1 ply bid on spar ends. Sanded, cut glass, laid up and peel plied 1 ply bid over external hard points per plans. 3 hrs.
11/11/02 - Cut out outside attachment access holes in bottom of spar. Removed foam and dry microed edges. 1 hr.The picture on the left shows the final layup for the end of the spar. I will make a hole for wiring once I see how the wing will attach and where the wiring needs to go. The picture on the right shows the access hole for the outside wing attachment bolts.
The remainder of this chapter deals with mounting the spar into the fuselage. Since I have a rather narrow workspace, I will mount the spar at a later date once the wings are completed.
In anticipation of warmer weather
and starting construction of the fuel strakes, (
As I have mentioned in other chapters, I am amazed at how well everything fits into place. The spar was no exception. Earlier in the chapter, the plans have you match drill the wings to the spar for the proper incidence. Once that was achieved, you bondo leveling boards to the wings and spar so once they are mounted to the fuselage, the proper incidence is maintained. I trial fitted the spar into the fuselage and had to trim a small amount of foam so the spar could slide in all the way. Once this is accomplished, many measurements have to be done so the spar is level side to side, for and aft in relation to the fuselage, and that both ends of the spar are equidistant from the centerline of the fuselage. I was dreading all of these because when you change one measurement, the others all change. You end up chasing around trying to get everything just right.
Well, it must be clean living or just dumb luck, but all I had to do was place a single stir stick under the right side portion of the spar to get everything level!
Here are the shots of the various locations of the level……..
Fuselage side-to-side fuselage longeron (lengthwise)
Center spar level side-to-side in fuselage right side incidence angle
Left side incidence angle
And, as I mentioned at the
beginning of this update…….the plane now takes up a lot more of the garage!
This lead to a series of events that happened in the matter of two days.
The big move!
I was planning on putting the fuselage sideways in the garage and build each strake one at a time. I started hearing from other builders that you should build each strake with the wing attached so the leading edge of the strake will line up properly with the wing. Well, there was no way this would work. The hanger situation here is much like everywhere else in the country. You basically have to inherit one. I called around for about a week and couldn’t even get anyone to return my calls. Finally, one company called and said they didn’t have any available but they would put me on their list. The wait is averaging about 15 months. I said that I was still in the building stage and asked if they had any that someone was willing to share. She said, “if you don’t need a full hanger I have half of a T hanger available right now. I grabbed it immediately. The T-hanger setups are a series of T’s that are arranged front to back and overlapping eachother. This is fine until you get to the end of the row and you have a weird shaped corner of the building. So the builder finished off the side of the building by adding half of a T (basically an L shape) to the end of the building. It ended up being very cheap rent because it will not house a completed plane, but it is ideal for my situation. Hopefully, by the time I have the fuselage complete in a year or so, they will have a full size hanger available.
Anyway, this all came about on Friday, March 18th and I wanted to get in before she gave it to someone else. Fortunately, Ron Springer, a new builder in nearby Folsom was foolish enough to offer his assistance in moving the fuselage, wings, canard, and worktable to the hanger. Of course, we hadn’t seen any rain in over a month and you guessed it, it poured on Saturday. Worse yet, as soon as we had everything safely moved to the hanger and I was putting the lock on the door, it stopped. Well anyway, Ron and I grabbed some lunch and did some hanger flying. A public thanks to Ron for all his help and I highly suggest you get to know any other builders in your area because this project is plenty big enough even with their help!
Here are a couple of hasty shots of the fuselage just before leaving for the hanger.
Fortunately, we didn’t have any “unintended” first flights! Doesn’t that sky look inviting?!
I’ll add some pictures of the hanger once I get it setup.