Tired of going out to the slope or flying field and having your EPP delta wing break on a hard landing? Know of a really cool place to slope fly but don’t fly there because of a rough or really small landing area? Are you like me? A really good flyer but can’t do a decent landing to save your life??? I just might have the wing build for you!!!
I have been building planes a very long time and was looking for a plane design that was a little more durable to accommodate my crappy landing skills LOL. A good friend of mine John Peters told me about a method of building an EPP style wing that would withstand some pretty strong punishment. The technique was originally developed by the Dynamic Soaring slope flyers to practice and so they could fly in areas where the landing zones were a little less forgiving. He gave me a couple sets of Wing Warrior Ridge Runner cores and taught me the entire process. I am sure there are a few ways to do this technique but this is the way I was taught and it has been working out pretty killer so far. If it ain’t broke, don’t fix it!
I have built several of these planes and they really fly great and are strong enough for some really aggressive combat flying. The technique makes for a heavier plane so if you are looking for a light wind flyer, stick to the model tape method. Most of the models I have done in this way need at least a 15-18 mph wind to fly decently. If you use the really heavy duty X-Ray film you are looking at least a 24+ mph wind. If you are building a power wing, it just means you will need a bigger motor and battery to get it moving. Here is the build in a step by step process!
|You can buy your model here or the brand and place of your choice. At this point in the game you are basically glueing the 2 halves of the model together. I use Goop. This is a killer glue product that remains a little flexible while gluing stuff tight! Perfect for an EPP foam application. Make sure you get a decent amount of glue on the center spar and between the 2 sides.|
Be sure to take extra care to make sure the wing dries straight and pressed together. I use tape to secure mine.
After the glue has dried on the wing. You will need to attach 2 carbon strips to the trailing edge of the wing with Goop on both sides of the wing. Use tape to hold them in place while they dry.
|The Carbon fiber strips will need to be bought separately at your local hobby store or online. You do not have to use these strips but it is highly recommended, seeing as it provides quite a bit of rigidity to the wing. It also gives a more sturdy platform to mount the elevons to.|
|Next in the process is to cut or burn the areas for the servos and battery. I always use a torch and an old chunk of iron to burn mine in because it is easier to do and the melted EPP creates a really stiff bottom for the servo to mount to. If the servo holes are cut in, it doesn't leave much foam in the base to keep the servo from flexing in the slot. So burning is highly advised. Just make sure you do it in a well ventilated area because EPP stinks when it burns!|
|Verifty the spaces are big enough for the items before you put the torch away. After the slots are complete you will need to cut paths to push the wires into for the servos and battery to the center receiver compartment. You will also need to cut a piece of 1/8th inch plywood to cover the receiver compartment area. Make sure the fit is tight, it will need to stay closed in flight.|
|Servos should be completely covered with masking tape prior to putting in place to prevent glue from getting in the servo!|
|You will also need to test and center the servo prior to glueing it in place. I buy the HiTec HS-485HB servos with the karbonite gears. They will be better at withstanding the shock of plane strikes and hitting the ground at 40+ MPH. Metal gears are not better, they have been tried.|
Metal gears bend and Karbonite gears have a little flex to them. Either are better then a standard gear servo!
I use a 5 cell, 6.0 Volt 2000mAh NiMH pack in my wings. Although you can use any size you like. You need a bit of weight in the front of these to CG them properly. Might as well make it useful weight instead of lead weight!
Don't be a fool! Check your battery and servos prior to glueing them in! Also once this stuff is glued in it is semi-permanent. If you put cheap crap in your model you are going to be cutting into your cool paint job and covering later to replace the stuff when it breaks! Better safe then SORRY!
I always add 4-5 oz. more lead to the battery area prior to spackling it for CG purpose. You can test your model and decide what you need.
|This is where it gets a little tricky. Depending on where you live will depend on what type of thinner you will need to use for the next step. MEK is what is used for thinning the GOOP glue. If you can get it, use it. If you can't you're in the same boat as me. You will need to find an alternate product like the one shown in the picture to the left. This thinner works but takes a little longer to dry then the MEK and feels a little oily when applying it.|
|I know this seems strange but next you are going to squeeze 1 and a half 3.7 oz tubes of GOOP into a pint glass jar almost full of MEK/thinner. I usually start with the jar half full of thinner and then add to it after the GOOP is in. You will next mix the thinner and GOOP until it is completely incorporated into the thinner. The thinner should be the consistency of Milk or a little thicker. Now get yourself a throw away paint brush.|
|You will need to put 3 thick coats of the thinned GOOP on your wing on both sides including over the receiver hatch. If you get a little over the servos it won't matter because you taped them up, so it shouldn't get in. Be sure to save your core sleeves! After each coat of GOOP put your model back in the sleeves on a completely flat surface to finish drying. This will keep the wing from warping. Put the lid on your jar and save your thinned GOOP and brush.|
|This will be the most time consumming and messiest part of this build. You are going to use a lightweight spackling compound to fill the battery compartment and servo holes up to the arms on the model. I usually use a piece of 1/8 inch balsa or ply to make a dam to create a slot to keep the spackling compound away from the servo arms. The stuff shown to the left works great for this process. I can't make any promisses on any other brands because I haven't tried them.|
|You are also going to be using the spackling to fill all of the EPP foam imperfections to create a smooth surface on the model for the film to stick to. It usually takes around 3 passes of spackling and sanding to get a good enough surface to do the process. Do one side at a time! My friend John at this point in time usually cuts the foam sleeves down the middle to create a tray to set the wing in during this process.|
|I have done it both ways and it works either way with John's method being the easiest if you have the space to fit it on your bench. If you only have a small place to work like me, it can be a little more trouble then it is worth. It is up to you. Just make sure the surface is smooth and that you don't damage the finished side when you are working on the other side of the model.|
|After both side are smooth and completely dried you will need to brush 3-4 more thick coats of thinned GOOP over the entire model and let it completely dry for 24 hours.|
|Purchase some 1 inch fiberglass cloth tape. Cut enough off the roll to go across one side of the models trailing edge surface with a little extra to be safe. Dip that strip in the remaining thinned GOOP and squeegee the remaining off with your fingers and let it dry. You will then cut that strip down the middle to make 2 strips the length of the wing, one for each side of the model's trailing edge. Use a mild tack masking tape on your model now or it will pull up your GOOP finish!|
|Take your kits supplied elevons and masking tape them to the bottom of your model into their correct location and then fold them back flat against the bottom of the trailing edge of the model so the flat end of the trailing edge and the inside edge of the elevon are expossed. Then take the fiberglass tape you cut and GOOP it into place like in the picture to the left. Let it completely dry and then trim the excess tape away. You should now have a fully functional elevon when you fold it backward.|
Make sure you only use enough GOOP to hold the fiberglass tape in place. If you use too much it will limit the movement of the elevon.
This is where you decide how you want to paint your model. You will need to use the paint to the left, it is available at most hardware and Walmart stores. It is fairly cheap and comes in a pretty good selection of colors. This paint works, try any other brand at your own risk folks. It is pretty messy if you choose the wrong paint. The film won't stick!
|You will need a Monokote iron, heat gun and a hot glove for the next step. You will also need to pick up some film. You can buy the film by the roll for much cheaper but you will have a lot more then you need for one model if you buy it this way. There is a technique to doing the film but it would be pretty hard to explain on a text based post. You will need to overlap the film in several areas. On my next build I will be filming a video showing some technique on doing the film and post it here.|
|If you look in the picture above I am running the film all the way down the bottom of the wing and accross the entire elevon to provide some extra strength and durability to the flight surface. When installing the film you want to heat it until the frost on it turns clear and then press it against the model|
surface with the hot mit and it should stick into place. I also make sure to run the film overlaping the leading edge of the model. The more the better. I have also been notified by my friend John that the website for Wing Warrior is currently down at the moment. I will change the link when the site is up again.
Thanx for taking the time to read my tutorial
Assembly time: 16 hrs (*1)
Build Difficulty (1-5) 4 (*1)
Kit Quality (1-5) 3 (*2)
(*1)This represents the amount of difficulty and time I spent building this model and in no way reflects how long it will take for someone else to complete the task. These factors will depend on your individual skill in modeling.
(*2) Every Kit or ARF is different and this rating in no way reflects this product as a whole. This rating is just my experience with the individual product I dealt with.