This is also a good time to make the ribs for the center section. I used 1/16” balsa, and made 2 copies of the regular ribs. Notice however, they only have the notch for the ¼” spar, and not the spar jigs! (The actual ribs are solid, and do not have the lightining cut-outs in them)

Step 3. Before assembling the fuse crutch, I made a balsa plug out of 1/8” balsa to fill in the area where the wing would go,
(reference thread and photo in “John Thompson's Removable Wing E3D”) also. Mark the hole in this piece using the same method as before with one of the ribs.

(This photo courtesy of the John Thompson thread)

Build the crutch and fuselage as normal from here to the point where you sheet the fuse bottom. I started sheeting the bottom normally, except I left the area directly below the spar area open so I could have access to it later for wing and spar alignment.

The wing is built normally up to step 10. For this step, I sheeted the bottom section, and then installed the center section shear web on the FRONT of the spar only! Now is where we modify the wing to accept the swing joiner. At this point the wing is strong enough to hold shape, but everything is still accessible. Please bare with me here, as I zipped through this step without getting any pictures, so I’ll have to explain what I did.
The regular plans call for shear webbing on the rear of the spars, full length of the wing. We also need to add shear web to the FRONT of the spars in the area where the swing joiner will be, (this makes our spar pocket) However, the spar jigs need to be removed from the area where the wing joiner will slide in! First, I installed the shear web to the FRONT of the spar from the first rib to the second half rib. Then I carefully removed (cut away) the spar jigs in these rib bays, and removed the area of the ribs between the spars where the joiner would slide. Then I glued the shear webbing to the rear spar, full length, as normal.

shear web detail

rear shot

Now you need to take a deep breath, measure the center of the wing carefully, and cut it in half! The leading edge, spar and trailing edge jigs all have a center joint which makes it easy to mark the exact center of the wing.
Next, install the center ribs cut out earlier. These need to be cut in half and fit to the spar pocket location. Once these are fit and glued, I sanded the root smooth, and added a wing root cap of 1/16” balsa, then carefully cut the rectangle opening for the wing joiner.
I used a file to clean up the inside of the pocket for the joiner, concentrating on the area of the pocket where the ribs were. I sanded the joiner smooth on all sides, then slightly rounded the corners and test fit it into the wing halves until I had a fit that was snug, but did not bind.

Now we can mount the wing and get all the alignment pieces installed. Slide the wing joiner through the fuselage holes, adding the doublers for the sides as you go. (I used the shorter, cut off joiner for this procedure). Now slide each wing half onto the joiner. The easiest way to make sure that the wing is aligned properly is to simply slide the wing on, and align it with the former opening of the fuse (remember, we glued this opening closed when we started! Once the wing is in position, pin the root rib to the fuselage side. Now, carefully tack glue the spar doublers to the fuse sides, and the crutch center piece. I then removed the wings and joiner and fully glued these doublers in place. Make sure you take your time here, and be sure to remove the wings and joiner before you permanently glue the doublers in place, or you might make your removable wing E3d a one piece project again!

The alignment pin is a 3/16” dowel that passes through the fuse and extends ¾” into each wing. Or if you prefer, it could be glued to the wing root rib, and just pass into the fuse. I marked exact locations on each wing root, and then drilled the hole through the rib, into the fuse. When satisfied with the alignment and position, the doublers for these holes were glued to the inside of fuse, and inside wing root rib.

I am sure it is overkill, and not needed, but I did add one more little item for piece of mind. I made a small music wire loop with a 1/32” ply backing to serve as a means of holding the wings on, in case they wanted to slip apart. I have built many planes over the years that have slip on wings (mostly sailplanes) and some stayed on well, and others slipped apart slightly. So, when able, I have always made some version of this hold-on to keep the wings where they belong. The weight penalty is nil, and I just feel better with it. To each his own. To hold everything in place, I simply used a couple short pieces of tapered 3/16” dowel that I slip into these wires inside the fuse before flight. As I said, overkill, but piece of mind!

back side

wing roots

Now before sheeting the top center section is also a good time to make the holes and openings in the fuselage required for servo wires.

Wing root servo wire holes

The ailerons will need to be extended to accommodate the extra length of the wing. (about an inch each side)

That’s it! Now you can add the wing servo mounts and sheet the top center sections and complete the wing per the instructions. I did add a cap strip at the wing tip on the spar as a little grabbing point. When I want to take the wing off, I use this area as a holding point and pull outward.
The rest of the construction is normal, and the flying so far has been excellent. Once spring rolls around for good, I'm sure I'll have this one out often!

I hope this helps some of you in the decision about what version to build. After reading and researching all the E3d posts, and building my E3d, I think that either version would work for the new builder. However, the one-piece version is probably the only way to go for those E3d’s out there which are already constructed, as I see now way, short of massive destruction and reconstruction to the wing for the slide on mod. However, if you are just starting, or are about to start construction, take heart, the slide on version is relatively simple, and added the flexibility
I needed for storage and transport. Let me say one more thing before I go on. I know there are other
threads on this mod, and I in fact used them for reference. However, I am just trying to add a little info that was not in these threads for those just starting to build. Knowledge is power, and when starting something like this , one needs to have as many of the facts before beginning.
Darryl