HORIZONTAL STABILIZER INSTALLATION
Stab installation is by far the most critical part of assembling an ARF airplane. Fortunately, it’s a relatively simple procedure compared to building a kit, but errors in trammeling can cause a good design to fly very poorly. I normally do this next so that I can go ahead and get it out of the way before I get too worked up in other details of the project that may have gotten me frustrated and make me want to rush. This is something that you want to take your time with. If you’ve had a bad day at the office, crack open a cold one and watch some TV instead. If you’ve partaken in one too many cold ones in your cool down process, perhaps you’d still better wait until you’ve got a clear head and calm nerves. It never hurts to have a modeling buddy over to put a second set of eyes on this as well.
One thing is for certain, there is no race to get an airplane in the air the quickest. You can become fast through experience, but the only reward you get is with a good flying airplane.
The Axiome 70 stab is one-piece, airfoiled construction. It is remarkably well built and straight, so the installation process is very easy. Start by sliding the wings onto the wingtube and bolting them into place. Even though you’re not setting any incidence angles, I find it easier to block the airplane up as though you were. Like mounting the wheelpants, use the canopy frame as your zero line reference. Block the tail up and chock the tires so that the airplane can’t roll.
Slide the horizontal stabilizer in place, firmly ensure that it’s seated as far forward as it can go and center up the best you can. Do not rely on the covering layout to center the stab as it will be wrong. Measure the span of the stab outside of the fuselage using the same reference points on the left and right sides. This will ensure that the stab is centered in the fuselage perfectly.
Now, triangulate the stab to the wings. One note of caution here…ensure that you are using reference points that are made by laser interlocking of parts and not places that are sanded to size. Wingtip outer corners are horrible places from which to measure because they can be off a few millimeters and while the rest of the wing will be square, your stab will be misaligned; measure from the outside corner of the aileron cutout in the wing to the outside corner of the elevator cutout in the stab. These are your most accurate reference points on this type of model.
Once the stab has been triangulated to the wing, mark the outline of the fuselage on the stab, left and right, top and bottom, with a fine point marker and pull the stab out. Using a very sharp blade, cut 1/16-1/8” inside this line, leaving about ¼” covering intact along the trailing edge as this will be visible once the stab is installed since there is an elevator joiner that passes through the fuselage. Use light pressure, just enough to cut the covering. Many people recommend using a soldering iron; your mileage may vary, but again, I do not like using a soldering iron to remove covering like this. I find it messier and no easier to do than with a sharp blade. Once the covering is removed, Take your covering iron and give the seams a good once over to ensure that the covering is well adhered. It’s a good idea to touch up the areas around the saddle once more since it will be much more difficult to do so once the stabilizer is in place.
Reinstall the stab, triangulating it again and stand back from the model about ten feet and check to see how level it is with the wing. There may be a small difference that needs to be adjusted out with a shim before you glue it into place. Take note of this at this time and prepare a shim if necessary. A lot of guys use lasers and other sorts of high-tech equipment to level stabilizers to wings, and that may have a place in a two-meter model, but I don’t see a need here. My “workshop” is my dining room table, so I don’t want to drag out a bunch of equipment that my eyeballs can sight just as easily. The Mk 1 eyeball is a very powerful tool…
In my case, the right side of the stab was sitting a little low, so I sanded down a piece of 1/16” balsa sheet into a wedge as best I could and saturated it with thin CA so that it would insert easier in between the saddle and the stabilizer without cracking, bending, or breaking. I anticipate that it was probably 1/64” on one end and 1/32” on the other, so it was pretty thin and quite flexible, particularly cross grain. Insert the shim and adjust until the stab is level with the wing. Verify the trammeling one last time and once completely satisfied that the stab is square, level, and positioned properly, carefully wick thin CA into the joint on the top side only. Wait about a minute and flip the airplane over in a stand. Carefully tack the shim (if applicable) in place with a drop of thin CA on the saddle side, and then take a sharp blade to trim the excess wood protruding outside the fuselage side. Wick thin CA along the seam on the bottom side and let the airplane sit for a few minutes. When wicking CA into the join, ensure full saturation, but don’t wick so much in that it seals the wood and begins to run off as it will make a big mess. If the relative humidity of your building room is high, the CA will more than likely “fog” when it cures, leaving a chalky haze on the covering. This is not a big deal and can be cleaned up very easily with some CA debonder (or simply acetone, though it is less effective) on a Q-tip. Go back and clean the area with some glass cleaner and a clean paper towel to remove any sticky residue that it will leave behind.
Congratulations! You have just done the most difficult task building this airplane. It’s all downhill from here.