Question: The ailerons on my VMAR ARF are activated by torque rods running from the center of the wing. The torque rods are a bit sloppy where they enter the aileron. I am not sure if they were like this from the get go or if this arose after flying for a while. How can I fix this?

Answer: Fill the slack space around the torque rods where they enter the ailerons using Medium or Thick CA.

Better Answer: Hold the wing so that the ailerons are pointing with their leading edge facing upwards and deflect the ailerons one at a time so that the hinge line is clearly visible. Apply ZAP-A-GAP Medium CA or SLO-ZAP thick CA down into the torque rod holes in the aileron leading edge. Apply a small amount of ZIP KICKER accelerator and then more CA until the hole is solidly filled with CA. Let cure thoroughly. Test to ensure there is no remaining slop before flying.

Question: I have noticed that the aileron torque rods to which the control horns are attached protrude from the left and right wings at different angles when the ailerons are neutral. Is this a problem? If so, how do I fix it?

Answer: Ideally the aileron torque rods should be in-sync angle wise when the ailerons are at a neutral position. In practise they may be at slightly different angles and in all but the most exacting requirements (FAI pattern flying for example), a slight variation in angle will not have any noticeable effect.

If however, the angle of the aileron torque rod does not allow for full deflection of the aileron both up and down as per the maximum allowable deflection stated in the operations manual for your model then this should be fixed before flying.

How does this happen? The aileron torque rods are bent and installed at the factory and they have the same angle at that point. The most common cause is compression and bending during shipping. The aileron torque rods are shipped with covers holding the ailerons and aileron torque rods in place but if a large heavy object is placed on the box so that it compresses the wing, the aileron torque rod maybend with no other damage to the wing or the rod will not bend but will compress the wood surrounding the rod in the aileron resulting in a sloppy and off-angle fit. The rods are also subject to bending or otherwise acquiring unequal angles when in a crash or if they are impacted or snagged during transport of the wing.

How do I fix it? There are a number of ways to resolve this... none of them are difficult... if you don't feel comfortable on your own, talk to an experienced modeler and ask them to give you a hand. An experienced modeler will be able to resolve this in minutes. Here are two recommended approaches.

Do either a) or b) and then c) or do a) and b) and then c). In all cases do a) and c). In extreme cases do b).

a) Bend the aileron torque rod without removing the aileron: This should be tried first and will work most of the time. Take two wooden rulers or paint stir sticks and clamp the aileron in its neutral position. Place one ruler on each side of the aileron (above and below) with about three inches (75mm) overlapping the center section of the wing in the wing saddle area. Clamp these retainers in place with a couple of C clamps or other suitable clamping device. Apply one C clamp directly over the location where the torque rod enters the aileron. The main thing is that the aileron be at it's neutral position. Now bend the aileron torque rod that protrudes from the wing so that the angle of the aileron torque rod is similar to the aileron torque rod in the other wing presuming that the other wing is a good reference. If both wings require work, then bend the aileron torque rods in both wings until they are approximately perpendicular (90 degrees) with respect to their respective wing surface. Don't sweat it if the angle is not 90 degrees...  focus on getting the angles similar for both wings and ensuring that the ailerons can be moved fully to their maximum recommended deflection. 

OR

b) Bend the aileron torque rod after removing the aileron. Removing an aileron is not a big deal but why bother if you can fix the problem using method a) outlined above. However, assuming that you have tried method a) and it did not work for you, then here is the ultimate solution. Use a sharp #11 blade and cut the hinges holding the aileron in place. Cut the hinges... do not remove them! Now wiggle the aileron up and down at the wing tip end while gently pulling it back and away from the wing trailing edge. When the aileron has been removed you will have both ends of the aileron torque rod exposed. Bend the rod to align properly with the other wing or so that the aileron will at neutral when the other end of the rod is approximatley perpendicular (90 degrees) with respect to the wing surface. Use the #11 blade to trim the old hinge stubs down flush. Do NOT pull the old hinges out. Re-hinge the aileron by placing new hinges beside the old hinges and re-install the aileron.

AND THEN

c) Toughen up the wood in the aileron around the aileron torque rod and fill in any voids. Now that the aileron torque rod(s) has been bent to the correct angle and the ailerons can be moved to their maximum recommended deflection, it is time to wick some thin CA such as ZAP/CA and then some medium CA+ such as ZAP-A-GAP down into the hole in the aileron that surrounds the aileron torque rod. Hold the aileron so that the hinge line is above the aileron. Deflect the wing about 20-30 degrees so that the aileron remains upright with the hinge line up and you can see the aileron torque rod entering the aileron. Wick thin CA into the hole in the aileron that surrounds the aileron torque rod. Do this several times. The thin CA will wick into the soft wood around the rod and make the wood much harder and durable. After the thin CA has cured, apply medium CA+ into the hole in the aileron. Whereas the thin CA was intended to toughen up the surrounding wood, the medium CA+ is intended to fill any voids left over in the hole between the aileron torque rod and the aileron itself. Let the CA+ cure or accelerate with ZIP KICKER. When dry, try flexing the aileron via the control rod. There should be no slop in the movement.

That's it! A bit difficult to describe but easy to do!

Question: Can I adjust the position of the alignment dowel holes in the wing roots? I find that the dowels are a bit tight or out of position when trying to join the wing halves together.

Answer: Yes.

Better Answer: Yes. Here is some information and a procedure that you may find helpful to review first.

The alignment dowels are the short (approx 1/4 x 1 inch) wooden dowels used with the wing spar joiner when joining the wing halves.

Taper the alignment dowel ends with a knife or sandpaper. Do NOT modify the dowel center section, just taper the ends. Insert the wing spar joiner. Now try fitting the wing together again. If the wings now fit together well then separate the wings and spar joiner and continue with the wing joining procedure outlined in your instruction book using plenty of 30 Minute Epoxy on all of the components.  

If you find that the fit is still tight then try the following: Separate the wing halves. Remove the alignment dowels. Insert the spar joiner and join the wing halves. If the joiner fits and the wings line up well, then you can adjust the location or size or shape of the alignment dowel holes slightly. Separate the wings again. Remove the dowels and taper the ends but not the main center section of each dowel. Insert one alignment dowel in the forward hole of the left wing. Glue the dowel into the forward hole of the left wing with CA glue. Join the wings and check where the dowel contacts the opposite right wing root. Separate the wings, elongate the forward hole in the right wing root to better line up with the dowel. Work in small steps. Elongate the hole slightly and then check again. Repeat this process in small steps. At some point the hole will accomodate the dowel. Make sure the wing roots can now be joined.

Separate the wing halves again. Insert the second dowel in the aft hole of the right wing. Glue the dowel into the aft hole of the right wing with CA glue. Join the wings and check where the dowel contacts the opposite left wing root. Separate the wings, elongate the aft hole in the left wing root to better line up with the dowel. Work in small steps. Elongate the hole slightly and then check again. Repeat this process in small steps. At some point the hole will accomodate the dowel. Make sure the wing roots can now be joined.

Separate the wing halves and spar joiner and then follow the wing joining procedure outlined in your instruction book using plenty of 30 Minute Epoxy on all of the components.

We have had several questions about wing bolts, do they break, what happens if they break etc.

The wing bolts are extremely strong. Longitudinal load such as that induced by a wing in flight (lift or descent) will not break the wing bolts. Only shear either horizontally (crash damage) or by twisting the bolts under high load will break or weaken the bolts. In order to break the bolts they must be excessively overtightend using either a nut driver, electric drill with socket or a battery operated electric screw driver. Cross threading the bolts into the wing bolt block inserts will strip the bolts and or the wing bolt block inserts.

Our strong recommendation is to tighten snugly only using hand tools. Do not overtighten. Do not use a power tool of any sort. When using a hand tool, tighten until the wing is seated in the wing saddle of the fuselage and then snug down about 1/8 turn more. That is all that is required. If you hold the fuselage in your hand near where the bolts engage the wing bolt blocks in the fuselage you will feel the fuselage sides between to warp inwards just inboard from the wing bolt blocks if you overtighten the bolts. If you feel the fuselage sides begin to warp or see the wing bolt heads beginning to sink into the bottom of the recesses in the wing, you are too tight. Back off on the tension on the bolts. If you persist in overtightening the bolts, you will strip or shear them off or pull out the mounting blocks or in some cases pull the head of the bolt right through the wing! All of these situations can lead to wing damage, fuselage damage and/or wing separation from the fuselage in flight.

Cross threading the bolts into the wing bolt block inserts will damage both the bolts and the inserts. If you persist in forcing the wing bolt in spite of the cross threading, you can damage the threads beyond repair and/or over stress the wing bolt.

Check the bolts before and after each time you install the wing. If the bolts look stripped, replace them. If the bolts appear to bind or require a great deal of torque to tighten them, lubricate the bolts with light oil and make sure they are not cross threaded. If you have any concerns that the bolts may have been damaged due to overtightening, cross threading or crash damage, change the bolts and check the wing bolt mounting blocks and inserts in the fuselage to make sure the blocks are secure and the inserts have a good thread. Do NOT fly without checking the wing bolts, handtightening them and making sure the wing is secure. Mounting blocks and bolts can be damaged by overtightening or crashes and may not be obviously loose upon cursory inspection. Check carefully and remove the wing after any crash so that you may examine the wing bolts and the mounting blocks carefully.

Question: I am having trouble threading my wing bolts through the wing into the T-nuts installed in the fuselage. I think there might be some epoxy in the T-nut threads. What should I do?

Answer: Try to thread the wing bolts into the T-nuts without the wing.

If the wing bolts thread into the T-nuts OK without the wing them the T-nuts are fine and you probably are not seating the wing firmly against the former before trying to thread the bolts into the T-nuts.

If the wing bolts will NOT thread into the T-nuts without the wing, the T-nut threads are either plugged with something like epoxy or have been stripped out. They will need to be replaced.

Question: What is Wing Dihedral? Is it Adjustable on a VMAR ARF aircraft?

Answer: Dihedral is the bend upwards at the center of the wing. When you look at a wing with dihedral when it is top side up, the wing tips will be higher than the center. The more dihedral the higher the tips. Dihedral provides stability so trainers usually have more than sport airplanes and pattern or aerobatic airplanes often have none at all.

The dihedral on VMAR models is set at the factory. There is nothing to adjust. The angle of the wing roots and the angle of the wing spar joiner ensure that when the wing is assembled properly using 30 minute epoxy, the wing roots will be flush to each other and the correct amount of dihedral will be built into the wing.

Question: I have found what looks like a foam sheet in the shape of a wing rib in my kit. My friend has another VMAR ARF and it has a black plactic component that also looks like a wing rib. What are these for?

Answer: These parts help seal and fit the wing root to the side of the fuselage.

Better Answer: The pre-cut foam is a gasket that can be attached to the wing root of your wing and serves as a sealing and protective gasket between the wing root and the side of the fuselage. Use silicone or latex contact cement to attach the gasket to the wing root.

The pre-molded plastic piece is a fairing that can be cut and attached to the wing root to serve as a finishing piece to enhance the appearance of the wing root to fuselage fit. This is used on fuselages that have a considerable taper or curve to them.

Question: A friend of mind had his wings break in half during flight. I don't want this to happen to me. How do I make sure that I do a good job when joining the wing halves of my ARF?

Answer: Use 30 Minute Epoxy and don't overpower your model.

Better Answer: Wing strength is critical to the integrity of an aircraft and we do extensive testing to make sure that the design is strong and solid. Wing failure is not something that we see or hear a lot of . We have analysed a few wing failures  sent to us for review by consumers and in all cases we found that improper assembly and use of adhesives was the cause of the failure. Do a dry assembly first with no adhesive while following the procedures listed in the instruction manual. This will ensure that the parts fit well and that you are familiar with what goes where and how to install it. When you are ready for the final assembly with adhesive, use 30 Minute Epoxy only and use plenty of it. Secondly do not overpower your model. See below for some more information that you may find helpful.

Question: Epoxy is available in different cure speeds. Should I use a Slow Cure (30 Minute) or a Fast Cure (5 Minute) Epoxy?

Short Answer: Use 30 Minute Epoxy where strength and structural integrity is important such as when joining wings or mounting stabilizers, engine firewalls etc. Use Fast Cure for quick repairs of small non-critical components or joints. If in doubt, always use 30 Minute Epoxy.

Better Answer: There are two general factors to consider,  Bond Strength and Working Time. 30 Minute Epoxy creates a stronger bond and it gives you more time to work. 5 Minute Epoxy gives a good bond but it is not as strong as 30 Minute Epoxy and it must be used very quickly, particulary in warm conditions.

The Bond Strength is pretty straighforward... 30 Minute simply gives stronger bonds. Use 30 Minute when joining wings, installing stabilizers, engine firewalls or other load bearing critical structural components that you simply cannot afford to have come off or fail. Use 5 Minute Epoxy for quick minor repairs of non-load bearing or light load bearing less critical components.

The Working Time is something that modelers frequently overlook and tend to err a bit in favor of  "fast is good". In some cases, like a quick repair of a simple small component... fast is really nice! But in cases where the amount of adhesive is considerable, the components are large or complex and/or need to be simultaneously mated with other parts.... you need to allow for plenty of time to work in order to get the parts aligned and properly placed. It is very important that the Epoxy is fully "wet" when being used. If Epoxy starts to thicken at all before the parts are joined, the Epoxy will not produce a good bond.

The worst possible scenario is using 5 Minute Epoxy on a complex multi-piece job like joining a wing. We have had too many calls from people who end up with the Epoxy beginning to cure before the wing halves are properly joined. We have also seen wing joints after in flight failures caused by gummy thick half cured Epoxy not penetrating and filling the joint and component substrates properly.

If you have any doubts about the complexity of a job, need for strength, working time etc, always use 30 Minute Epoxy!

Question: How much engine power is appropriate? Many models give a range of engine sizes... should I use an engine that is at the bottom of the range or go for broke and use the biggest engine recommended?

Answer: If in doubt go with something that is more or less in the middle of the range unless the distributor or your dealer have some specific recommendations.

DO NOT use an engine larger than the maximum size recommended by the model manufacturer. You run the risk of overstressing the airframe which can lead to sudden breakup of the model in the air and may injure someone.

Better Answer: Generally manufacturers specify a range of engine sizes for a model. An engine in the middle usually works well but you might want to consider going with the higher end of the range if you are going to be flying at altitudes above 2000 feet or in very hot weather or flying off of floats. Naturally if you are doing all of these, flying at high altitudes from a lake on a hot day... the bigger engine is the better choice. You might also want to ask around in your area to see what other RC flyers are doing. Be a bit cautious of the "power at all costs" type of recommendations but listen carefully when you get advice from those who have thought it through and tried it out.

Question: I found a small roll of what looks like Covering material. What is this for and how do I use it?

Answer: This is for sealing the joint after the wings have been epoxied and joined together. Peel the backing off and apply it to the joint.

Better Answer: This is a long narrow strip of self adhesive tape with a removeable peel off backing. It may be colored to match the center section of the wing but is generally clear in color to enable it to be used universally with any graphics or color scheme. Some modelers may confuse the clear material for the white of the peel off backing material. The self-adhesive side is applied so that it seals the wing center joint.

Unroll it and plan your work according to your instruction manual. In the absence of specific instructions in your manual, start on the fuselage side of the wing and work from back to front. Peal off about 4-6 inches of the backing at a time and carefully apply the sticky side evenly astride the joint. Work to the trailing edge on the fuselage side of the wing and carefully continue over to the non-fuselage side of the wing and back around to the leading edge and over to the top side of the wing to where you started. Firmly apply pressure to the tape so that it sticks to the wing.

Problem/Question: When mounting the wing to the fuselage of a VMAR model, the wooden dowels in the wing key into the receiving holes in the fuselage former OK but when I try to push the wing onto the wing saddle, there is considerable resistance and back pressure. I can't easily seat the wing at the back edge and it almost appears as if the wing saddle is the wrong shape for this wing. What causes this and what should I do?

Solution/Answer: This is quite easy to put right. In some cases the dowels in the wing or the holes in the fuselage are not lined up quite right or the holes in the fuselage former are a bit too low. The wing saddle will be the correct shape, but some adjusting of the holes in the fuselage former is needed in order to better seat the wing.

First things first... DO NOT modify or reposition the dowels in the wing. Instead, modify the holes in the fuselage former slightly by elongating the holes higher towards the top of the fuselage. Do the adjustments in small steps with frequent tests. Use a small round file. You will gradually elongate the holes into more of an elliptical shape (egg shaped). After each small adjustment, test the the wing fit again. You will find that it will be easier to press the rear of the wing towards the saddle as you make the adjustments. When the wing seats properly in the saddle, you are done. Remember, it is easy to do BUT do it in small steps rather than all at once.

Question: Can I modify the shape of Wing Spar Joiner to provide a better fit in my particular wing?

Answer: Yes with cautions. See Below

Better Answer: The Wing Spar Joiner is a very important component. Looks simple, is simple... but the most vital piece in the entire wing.

Yes you can modify the shape of the wing spar joiner if you really have to provided that you strictly pay attention to the following cautions:

1) Do you really have to? Understand what you are doing and why.

2) By how much? Sanding a corner that binds or reducing the thickness a couple of thousands of an inch at each end to assist with insertion or trimming the overall length by 1/8" or so is one thing... but doing anything more than that requires careful consideration. If you require big changes, make sure that something else is not wrong.

3) Remember LOTS of 30 Minute Epoxy must be used when gluing the wing spar joiner and wing roots together. LOTS, fill up the entire cavity and cover all surfaces and the wing roots thoroughly. Never use 5 minute or 15 minute Epoxy for joining wings... 30 Minute Epoxy only. Lots of it!

4) Never score or mar the surface of the wing spar joiner with a knife, scribe, vice grip teeth, plier teeth or meat tenderizer. Each time you indent the surface of the wing spar joiner you create a risk of a stress fracture later. If you want to roughen up the surface a bit, use 80 grit sand paper and blow away the dust before glueing into place.

5) If you want to make the vertical dimension of your wing spar joiner thicker (i.e. in the dimension that lies from the top to the bottom of the wing) you can use 1-16-3/16 thick balsa or other strip wood if you prefer to eliminate any gap in the fit. Any gap in the fit is normally found only on trainers where we use a wing spar joiner for several different models each with a different degree of dihedral. By making the wing spar joiner a bit narrow, we can vary the dihedral a few degrees between models.  Adding strip material to fill the gap is fine as long as you can flush fit the wing roots of your wing with the spar joiner inserted AND as long as you can still insert plenty of 30 Minute Epoxy into the joiner cavities in the wing.

Question: I have a VMAR ARF model. I notice that the cavity for the Wing Spar Joiner is blocked at the wing root end of one wing panel. It appears to be blocked by wood. Can I fix this?

Answer: Yes. The wings on some of the models are produced in one piece and then cut into two halves. What you are seeing is a very thin skin of balsa covering the wing cavity entrance. Use a sharp #11 blade to carefully cut away the thin skin of balsa from the cavity entrance.

Question: I have an Extra 330L and I find that one of the plug in wing panels is slightly loose on one of the wing tubes. Is this a problem? How can I tighten this up a but.

Answer: Actually this answer applies to pretty much any of our models that have plug in wings and aluminum wing tubes. If you want a tighter fit, we suggest inserting the tubes through the fuselage and then applying a small piece of heat shrink tubing around the end and mid point of the wing tube that is loose. This will increase the diameter of the tube slightly and you can adjust the thickness of tube by adding additional heat shrink layers if you wish. Or if you are short on shrink, vinyl like MacTac or even black vinyl electricians tape works well.

If you want to do this to both sides of the wing tubes to accomodate both plug in wing panels, you will have to consider the following:

a) You can increase the diameter of both ends (but not the middle) of the tube and leave it in place in the fuselage, or

b) You can increase the diameter of the entire tube (shrink works well for this) and ream out the fuselage holes carefully ( a round sanding stick works best for this) to accomodate the bigger tube. This way the tube will be removeable as before, or

c) Remove the tape or shrink from one side of the tube at the end of the day and slide the tube out as per usual. You would then have to re-apply the tape or shrink next time.

Question: I have a VMAR model with plug in wings. Should I glue the aluminum spar joiner tubes into the fuselage or not?

We occasionally (but still too often) get inquiries from modelers who are concerned that their wing tips appear to hang lower than the centre section of the wing when the wing is mounted on the fuselage.

Resolution:

In Brief: Check the instructions, pictures, illustrations, box art and all documentation to ensure that the wing has been assembled right way up. If the wing has been assembled upside down, a new wing will be required.

In Detail: Most real aircraft and most models have wing tips that are slightly higher than the centre section of the wing when the wing is mounted on the fuselage. This is called Dihedral and is a part of the design. Dihedral helps with stabilty and Dihedral is used on most trainers and many scale models of real aircraft. Some models are designed for aerobatics and will have a very small amount of Dihedral or may have none at all... they will have wing tips that are more or less even with the height of the centre section of the wing when the wing is mounted on the fuselage. In rare cases full size aircraft will have the wing tips hanging lower (drooping) than the centre section of the wing when the wing is mounted on the fuselage. This is called Anhedral... it is rare in full size aircraft winds and even rarer in model wings. Anhedral is used on a few horizontal stabilizers such as the F4 Phantom II.

If a wing is intended to have drooping wing tips (Anhedral) then the wing roots will still fit tightly together where they join with no gap in the joint on either the top or bottom of the wing. If a wing has drooping wing tips and has a gap in the top or bottom of the wing where the wing sections join, the wing has been assembled upside down. If the wing has been assembled upside down, a new wing will be required.