General Notes: As in any other type of aircraft if you pay attention to details a better airframe results. EPP planes are no exception. For all my EPP gliders I try to minimize weight and strengthen only high stress areas. This is a different perspective than those who build for combat but helps a lot when you have to fly in mixed thermal and slope conditions.

EPP foam is actually quite light compared to the other components in the construction process. For instance the strapping tape is quite heavy and quickly adds to the weight of the airframe often without much benefit to strength. The next weight adding element is the wood. I usually replace several pieces after weighing them since they are significantly heavier tan they need to be. The third most significant contributor to weight is the covering. On HLGs I use Ultracote light transparent. On slope planes use regular Ultracote. The 3M77 spray also adds weight and you don’t need much so use it sparingly, a light misting does fine.

Replace the Coroplast with 3/32 medium to soft balsa. This is plenty for a HLG. Cover with film and use film hinges. I usually trim the small plastic control horns with an Exacto knife and then glue them on 1/32" ply horns also are fine. I found that I got better turn authority after increasing the width of the rudder to 2 inches.

First check the decalage between the wing and stab. Use a ruler to draw a line from the stab to the wing root and check the angle. Mine had negative incidence. Sand the flat area that holds the stab so that you have 1-1.5^o.

Next sand some of the canopy away. It still looks scale like with less height and will reduce the drag.

Use Sullivan 507 pushrod tubes and either the supplied cables or 0.025" diameter piano wire for the control rods. Use a z-bend at the tail and I usually like to epoxy on a small piece of tapped tubing at the servo end so that I can use a clevise and make adjustments later if necessary. Trace a line from the servo output arm to the tail wit a pen and sand a slot using a small piece of the pushrod tubing. Tack the tubing in with a small amount of Zap-a-dap glue at severa points along the fuse. Fill in the pushrod grooves with light spackle. On the fuse I would recommend using regular transparent ultracote as the lite variety is not as durable. I also used only half the dowel for a throw stick. This work a lot like a finger hole and produces less drag.

I built two wings. The first came out at 7 oz and I knew I could do better. The second one came out at 6 oz. That brought the total weight of the plane to just under 13 oz. To keep the wing light replace the bass wood spar sections at the tip with balsa. I also tried using balsa with carbon reinforcement but I think that using basswood at the center is best. Replace the bass wood wing joiner with two 1/16" ply strips of different lengths in the front and back of the spar. Use Zap-a-dap for fixing the spar in the foam cores. You only need to use a few drops placed every inch or so on the bottom of the spar. The FG tape will keep it in place. Follow the recommended tapping for the wing which is only two strips. I like to use one inch wide tape on all my EPP planes. I did not use the sub trailing edge. Instead I used wider TE stock (light and true balsa). Cover the wing with Ultractote light transparent.

I’m using an old Futaba AM Rx, one S133 servo and one S80 with a 110mAH pack. It balances fine. A better set up would be a 555 or the new Hitec AM Rx with two HS-55 servos and a larger battery pack.

In my next S-126 I will go with an aileron setup for more fun. I think that I will also try a kite type carbon rod for the spar. My Javelin came out at 11.25 oz with 4 servos so I think that this will help.

This is one of the best all round type gliders. It thermals pretty well and I threw it in a speed trap at Phoenix last year and clock 55 MPH. Joe Wurts even commented that it was pretty good for a foamie. I also like flying it at our slope when there is’nt any wind and no one else can stay up.