LANDING GEAR INSTALLATION
The first thing I like to do when assembling a model is to install the landing gear. I don’t really like to work with the airplane on stands just as a personal preference. Also, it’s nice to be able to set the model aside without damaging the finish. For these reasons, all of my ARF assemblies begin with landing gear installation. I will start by installing the axles and tires onto the landing gear legs and then install the finished assemblies onto the model. To install the wheels and tires, you’ll need:
(1) left and right landing gear leg
(2) tires; the tires were missing from the hardware pack in my model, I simply substituted with 2-inch lightweight Du-Bro
(2) M4x30 socket head cap screws
(4) M4 flat washers
(4) M4 lock nuts
For tools and materials, you’ll require:
Light oil
3mm hex head driver
7mm wrench
Needle nose pliers
Begin by generously oiling the M4 bolts near the head. I’m a stickler for wheels that rotate freely and don’t squeak, so this is something that I do on every airplane, regardless of type. Because this airplane isn’t a glow model, there is no concern of the model taxiing away from you on a hard surface at idle. I’ve found that wheels that spin freely will make ground control, particularly at the beginning of the takeoff roll and the end of the landing roll, much easier as you don’t have one wheel grabbing. I find that the model doesn’t roll any appreciably longer on rollout having lubricated axles, and it most certainly doesn’t squeak. If you fly off of grass, this is a little bit less of a concern, but unfortunately 90% of my flying is done off of a hard surface, therefore this has become more or less a necessity.
Slide the wheel onto the bolt, and thread one of the M4 locknuts onto the bolt. Using your 7mm wrench and 3mm hex driver, tighten the nut down until it is tight against the tire. Not so tight that it compresses the wheel, but tight enough that it doesn’t rotate. Now, back the locknut off of the wheel ¼ of a turn or until the tire moves freely, and repeat this process with the other wheel and axle.
Once this is complete, slide an M4 flat washer onto the axle, push the axle through the hole in the landing gear strut, slide another M4 washer on the axle on the back side of the landing gear strut, and then begin to thread the other M4 locknut onto the bolt, threading as far as you can with your fingers. Repeat this process for the other landing gear leg.
Take your 7mm wrench and 3mm hex driver and again tighten the locknut. This operation takes a little finesse so that you don’t start to tighten the first bolt back down, so I find it easy to take a pair of needle nose pliers (as I don’t have a second 7mm wrench) and hold the nut nearest the tire with the same hand that is holding the 3mm wrench to prevent that nut from moving while I snug the retaining M4 nut down. Ensure that the axle is tight against the gear leg and that your wheel still spins freely without having any lateral play. Repeat for the other gear leg.
To install the complete gear leg assemblies, you’ll need:
(1) left and right landing gear assembly
(6) M3x15 socket head cap screws
(6) M3 flat washers
Slide one of the gear legs into the fuselage and verify alignment with the preinstalled blind nuts. I noticed that my outer two holes would not align perfectly, so I had to slot them slightly. The innermost hole (single hole) aligned well, so it did not need to be modified. Carefully slot the holes as necessary, ensuring not to elongate them laterally, only longitudinally. You do not want to introduce any play into the system. Ordinarily this adjustment would be the other way around…on the fuselage and not on the gear leg. Functionally they are the same, but there is a little more room for error on the gear leg. Once satisfied with the alignment, slide the gear leg into place (with the sweep aft!) and put your first bolt in.
Because the gear plate is underneath the battery tray, save yourself some curse words and frustration and install the bolts with a telescoping magnet. The magnet I have has a head that is about 3/16” diameter, so it fit through the slots for the battery straps easily. Also, it’s strong enough that the M3 washer will not fall off, but not so strong that you can’t break the attraction after you have the bolt seated in the hole. Alternatively, you can magnetize a 2.5mm hex driver. Put a generous few drops of blue threadlock on the bolts and tighten them down.
Now that the airplane is sitting on its own two feet, you can go ahead and install the wheelpants. There are many different ways to skin this cat, however I’ll detail the method I used on this build. The process is pretty straightforward as the pants are pre-slotted for the axles. If you care to, ensure that the slots are the same elevation into the pant; on my airplane I found that they were even with one another, so no adjustment was necessary for them to fit properly.
First, put a piece of tape lengthwise down the outside edge of each pant and sit it down on a flat surface. Because these wheelpants have a flat bottom, you can simply measure up some arbitrary amount on the front and rear of the pant and make a dot, then draw a line connecting the two. This will be your level line. Next, block the fuselage up to the angle at which it will fly (I simply used the canopy frame as a zero line, it was close enough) and set one of the wheelpants on the axle. Level the line with your table and mark the screw holes. Take a 1/16” drill bit in a pin vise and drill the screw holes. Thread the included self-tapping screws into the holes, saturate with thin CA and you’re done. I generally leave the wheelpants off until I’m completely finished with the airplane so that they don’t get dinged or damaged during the rest of the building process. Main gear installation is now complete, and you can move on to the tailwheel.
The included tailwheel is a pretty nice unit; identical in design to Oxai airplanes, it uses a machined aluminum main threaded assembly instead of a repurposed nylon bolt. The hole for the tailwheel is already laser cut into the bottom of the fuselage, so two quick slices of the covering 90 degrees to one another to gain access to the hole and the assembly is ready for threading. Thread as far as you can by hand and finish with a 7mm wrench. Back the assembly back out after you have cut the threads, and wick thin CA into the threads to harden them. The CA will wick into the wood quite nicely, so ensure that you are properly saturating the wood, but not so much that you seal off the wood and cause the CA to drip everywhere.
Put a few drops of oil on the top and bottom of the wire as it enters into the threaded housing and rotate around to allow it to wick in. Reinstall the assembly after giving the CA a minute or two to fully cure, and if you’re picky, align the unit with the centerline of the fuselage. The tailwheel and collar can be installed now; lubricate the wire with more oil, put some threadlocker on the setscrew of the wheel collar, and tighten down snug with a 1.5mm hex driver. I always align the setscrew aft because I’ve theorized at some point that it has a lesser chance of being disrupted in that orientation. Realistically, if you are generous with the Loctite and with the torque, you won’t have any problems. Be sure to hang onto the rest of the tailwheel parts, the steering arm, the spring, and the attach screw as you’ll need these after the rudder is installed.