Questions and Answers 1
Over the years, I have answered numerous questions about the Quicksilver planes. I don't remember all of them but the ones I can , I will write down in this column.
The Quicksilver designs have been very well done, and produced in an almost perfect manner. But problems will occur due to errors, damage due to wear and tear and more so during hard landings. Natural causes can also affect our planes such as sun fading of sail material, wind damage when tied outside, and even mice can eat away at the sail.
Since the answers will range all over the place, I won't even try to organize this section just yet.
Q,,,,,,,,,I just bought a plane and the wing wires are all rolled up. How do I separate them into a set of wires that I can use?
A,,,,,,,,,When disassembling a plane, I suggest reinstalling the bolts in the shackles for the four sets of wires. This makes it easier for subsequent assemblers to properly place the wires.
The stock MX has one lower wire, the leading edge outboard wire, larger than all the other wing wires. This would then decide the lower sets making re-assembly pretty easy.
But starting with a pile is much harder.
The first thing I do, is to separate the wires into matching lengths. Wires opposite each other are the same. This should reduce the pile to 8 or 9 sets of two wires.
I then separate the longest of the wires, two of the paired sets. These will be the upper wing outboard wires.
Reaize that the upper wires will always be longer than the lower wires since they go from the same point on the wing all the way to the center of the plane, ie, the kingpost. Lower wires attach at similar points on the wing but only go the the ends of the tribar crosstube.
The next longest set of two pairs will be the lower outboard wires, leading edge and trailing edge.
The next longest two pair will be the upper inboard wires, and the remaining pairs will be the lower inboard pais, front and back.
So the upper wire at a given wing location is longer than the matching lower wire. And the front and rear wires have similar differences.
The upper front wires are longer by a SMALL amount than the comparable rear upper wing wire. The reason is that the kingpost upper end is just a bit behind the midpint of the root tube spar attach points. Thus the front wires must go a bit further to the kingpost, the rear wires not as far. This applies to the inboard and outboard UPPER wires.
Standing out from the end of the wing, you may or may not be able to see this small front to back location. But the tribar crosstube, The lower attach point, is surely way ahead of the midpoint, so all the trailing edge lower wires will be much longer than the comparable front wire.
So, by using the inboard and outboard, the front and back and the upper and lower length requirements, a messed up set of wires may be separated very easily.
Other wires may be identified by the way they are made. For instance, the long upper tail wires are a long Y wire, the wire goes through a thimble and returns as does the lower nose wire. Lower tail wires are single wires too.
Q,,,,,,,,,,,How tight should I tighten the kingpost ?
A,,,,,,,,,,,The kingpost needs to tension the wires to prevent motion of the tail up and down. Also, the wing wires should be tight to maintain the aerodynamics of the plane in flight.
Since the loading on the cables when sitting on the ground is quite different than in the air, the kingpost needs to have a bit more tension than needed to get the wires straight.
The upper tail wires need to be snug since that controls the position of the tail, the incidence of the stabilizer to be specific. To have the tail floating up and down a bit during flight will create varying pitch and require some expert control inputs to avoid a crash. the plane may fly well, albut loose, during straight and level flight, and then porpoise on landing.
If the wing wires are loose, the wings will lift as the plane attains airspeed, and pull back against the trailinjg edge wires due to drag of the air. This will tend to decrease the washout and increase the drag slowing the plane.
During turbulence, the plane will feel loose and likely uncomfortable to the pilot.
But to have the kingpost too tight actually reduces the strength of the plane as continued increases in kingpost tension could actually break the wires without leaving the ground.
There is no way to measure the tension, but the kingpost should turn with some resistance as the wires start tightening. There should be no reason to use any tools such as a pipe wrench to do it. Standing in the seat, reaching over the tank, and turn until resistance is felt. then check the upper tail wires for straightness. With the plane on the tailskid, they should be tight with no obvious slack.
Q,,,,,,,,,,,,,,I tightened the kingpost, but still have some loose wires. What should I do now ?
A,,,,,,,,,,,,,, The wires from the wing to the landing axle should have some slack to allow the axle to move from side to side a bit. This allows the axle to get both wheels on the ground to cut landing loads by two. One wheel landings with tight wing/axle wires would put all the load on one wheel until the plane slowed and got level with the ground.
Q,,,,,,,,,,,,,,,,OK, but the outboard wing wires are loose when all the other wing wires are tight.What now ?
A,,,,,,,,,,,,,,,,From here on, it may require some detective work.
But consider that the only wires that are loose are in line with the tribar crosstube. If this tube has bent a bit such tht the distance from shackle attach points has increased, no amount of kingpost tightening can pull on these before other wires stop you from turning the kingpost further.
The dimension for the shackle attach holes is 40 1/4 inches from hole centerlines. As this dimension increases, the lower inner end isn't pulled in to a proper tension when the kingpost is tight. Since the inboard wire is more vertical than the outboard wire, it is much less affected by a wide tribar crosstube.
The rear lower wires have a lot of reaward angle and also don't get affected as directly as the leading edge outer wires.
Often a new set of wires may have the same problems as the older wires being replaced due to bent parts or even mis-assembly.
To this I suggest getting a manual for your plane. An example might be the leading edge outboard wires attach differently than the other three wing wire attach points They attach to a vertical bolt rather than the compression strut bolt. To attachthem to the nearby compression strut bolt places them in on the wing spar about two inches with a serious effect on their ability to ever tighten up.
Another area where a bent tube can affect wire tension is the axle. Hard landings take a toll on axles and wheels, but when the axle bends up at the ends, the lower tail wire attach point moves futher away from the root tube, since it is inside the landing gear downtube attach point. Should this be significant, the lower tail wires will tighten and before the wing wires.
If you have an overall looseness of wires, possibly the thimbles have become elongated due to overloading. The thimble is the small teardrop shaped stainless steel insert where the wires connect to the tangs. If the elongation is significant, the teardrop shape will be more flat sided like a paperclip rather than the full rounded shape it should be. This makes the wire a bit longer than it should be, with a resulting looseness.
Q,,,,,,,,,,,,,,I ran my finger over the wire as it wraps around the thimbles and found some broken strands. Why and what is the fix ?
A,,,,,,,,,,,,,,,Well, the fix is to replace the wire. The thimbles are not replaceable since they are locked in tightly by the swaging of the nico sleeve.
Since the wires are formed of a multi strand wire, twisted along the length, when the wire is formed into a small loop, all the separate strands must have the same length path around the loop or one will carry all the laod being the tightest. It will quickly fail and the next tightest one will have most of the load, and so on.
To distribute the load, the thimble must have sufficient length around the end of the loop such that each separate strand can go from inside to outside and balance the length and load with each other wire. As the thimble gets overloaded and flatens, the path for the wires can't achieve this distance, one strand of wires gets overloaded and few strands of that strand break. This can progress until the cable actually fails. It can occur slowly or quite fast depending on the loadings and such.
Don't mess around, get the wire replaced if any strands are broken
Q,,,,,,,,,,,,,,,,,A friend has a newer plane and it has small rubber pieces inside the thimbles. What are they for and do I need them ?
A,,,,,,,,,,,,,,,,,The purpose of these small hard rubber pieces is to prevent the thimble from collapsing and allowing the wire to fail strand by strand as mentioned above. They also keep the wires from twisting around the tang during assembly, hense the name neverkinks. The more important function is helping the thimble suuport he loads on the loop of wire. They can't be installed after the nicos are swedged since they are pretty tight inside the thimble so only replacement wires will have them. I wouldn't replace a wire just to get neverkinks in the thimbles, but I would make sure any new wires bought have them.
Q,,,,,,,,,,,,,,,,,My friends plane has wires from the root tube to the axle. What do they do and do I need them ?
A,,,,,,,,,,,,,,,,,These wires are called trike wires. They support the trike portion of the plane when the wings and tail are removed. They surely do a good job and they also keep the lower nose wires tight. They may be twisted a few turns during installation to get the lower nose wire tight. This will bow the root tube just a bit. Any time the trike portion is stored and especially during any hauling, these wires should be installed. If not the whole trike will fall back until something hits something to stop it. The first thing may be the lower rear edge of the engine hitting the seat support tueb, not a good thing.
Q,,,,,,,,,,,,,,,,Another plane has bigger diameter wires than mine. Should I change mine for safety sakes ?
A................The stock diameter wires are plenty safe. They should be checked regularly for thimble elongation, broken wires and overall tightness and appearance possibly.
Just to replace them to get bigger wire diameter is another matter. The above questions and answers have the words stiffness and strength used a few times. The best answer for changing wires to a laregr diameter is that the larger wires will stretch much less during normal flight. This keeps the aerodynamics of the plane much closer to original than the stock wires.
Should you ever see pictures of an MX flying, or fly above and beside one, you will notice the upper wires are bending back in the airlfow. To do this, they must have some serious slack available.
This slack comes from the lower lift wires stretching, the wings moving up and possibly forward, and the upper trailing edge wires becoming loose.
To install a set of all 1/8 inch wires will reduce this effect by quite a bit, and retain the original wing shape, position and dihedral.
Q..................How can the wings move forward ? Seems that drag would pull them rearward, not forward.
A..................If you stand off to the side of your plane, you will see that the lower leading edge wires are fairly vertical, since the tribar cross tube is forward of the center of the spar attach points, while the trailing edge wires have a much steeper angle from their attach points up the the tribar.
This difference in angle puts most of the load on the leading edge wires, and that is where the majority of the lift is created. But the trailing edge has some lift and this lift creates loads in the trailing edge wires, and their large angle pulls the wings forwardmore than the near vertical wires can resist. Thus the wings move forward under load.
Q...................I have seen a diagonal wire on some planes, mostly the two place planes. It goes the wrong way to hold the wings forward. What gives ?
A....................The previous answer addresses the potential for the wings to move forward under load. These wires keep them from moving too far, and yes, they do angle such that they resist forward movement, not rearward movement. Seems almost the wrong way, but experience an testing show the above scenario to be true. Some thought on the angles of the wires and the loads will also lead to that conclusion.
All the aileron planes and all the two place planes had these wires standard. If you fly very hard or have a heavier than average plane, I suggest they be installed. the original wire on the MX II had small round inserts similar in function to the neverkinks discussed a few questions ago. These inserts are aluminum. They eliminate the thimble since they have a groove for the wire. The two place bolted them to the outboard leading edge wire attach bolt, adn the inner end bolted to a vertical hole 4 inches from the end of the spar. Later models, the MXL and such, had the inboard end attach to a horizontal bolt 2 inches from the end of the spar.
Q.....................I saw a plane that used uncoated cable for the wing wires. Is that better or worse than my coated cables ?
A.....................I prefer coated cable for several reasons. Less drag in the air. It also looks better. Any damage to the coating will be obvious and help locate possible damage to the wire itself. The coated cable will do a lot less damage if you catch on it or trip and fall against it than uncoated cable. Uncoated cable will act as a saw blade and really hurt bad.
Having the coating disallows any direct inspection of the cable wires. I deem this no problem since the cable inside is typically well made from quality products. And the chances to damage the wire is greatly reduced by the coating.The wires on our planes are in my opinon, the least likely to ever give trouble of all the many parts and pieces they are made of.
Q......................But didn't you witness a failure of a wire ? How can I check my wires ?
A.......................Following the wire fiasco, Quicksilver did take some remedial action. First, in my case, they replaced the broken parts and the torn sail half at no expense to me. They also changed the coating from white to black thereby identifyng all the suspect wires as white. they also instituted some QA policies and practises to eliminate such problems in future production. They also started shipping a Nico check gauge with every kit. this allowed and was suggested in the manual, to check every nico on every wire prior to assembly. In the following twenty years, I have ehard of no other wire problems.
Q.........................How can I get such a gauge ?
A.......................... I sell them for 4 dollars. Next time you order something, just ask for one.
Q........................My wires appear to be OK but the vinyl coating is loose, missing and can be slid along the wire. Is this OK ?
A........................Other than appearance, and the protection from abrasion should you rub one, the coating doesn't have to be be intact or even tight. The wire I buy has a more adherent coating that is pressed deeper into the twist of the wire. It doesn't slide at all, and is harder to strip off when making wires. Unless the apperance is worth buying new wires, I wouldn't get new ones.
Q........................I removed the shackles from my plane and the whole group of wires twisted into a ball. What happened to cause this ?
A........................ Very likely, one or more wires were loose when the kingpost was tightened, and the previous owner twisted one or more wires to make them tighter. While twisting a couple turns in a wire will shorten it a bit, the fact that the wires didn't tighten evenly should lead you to find the real reason rather than re-twisting them when you re-assemble the plane. Elongated thimbles, bent axles, widened tri=bar cross tubes, improper assembly, can all cause loose wires. these are problems that need addressed, not re-twisting the wires.
Q........................I've seen some small wires supporting the rudder. Should I install these on my plane ?
A........................These wires are called rudder brace wires. The come in a kit with the necessary hardware and instructions. Older planes will need a hole drilled in the rudder leading edge. Installation is simple.
The purpose of these wires is to stabilize the upper end of the rudder which gives more effective rudder output for the same amount of effort at the pedals. The plane flies more crisply and easier. The wires reduce the side to side flexing of the rudder which allows a lot of the air over the rudder to bypass it.
Q........................The tubes on my plane have small white pits on them. How do I remove them and are the tubes safe ?
A......................This piting is from the salt and corrosives in the air attacking the aluminum surface of the tube. They can be removed by light sanding and the tube painted for protection from further corrosion. A coat of paste wax, Johnsons, will slow the corrosion greatly. Unless the tube has actually lost sone significant wallthickness, the pits are more an appearance problem than structural. Planes stored outside or in locations near the oceans are especially subject to this corrosion. Tubes are anodized which offers some initial protection.
Q......................Some of the tubes on my plane are siver colored, and some look like they were a shiny blue at one time. the blue has faded a bit. Can this be repaired and why are some tubes silver ?
A.....................All the tubing in the early days was the shiny blue. Exceptions were the spars, rudder frame and the wing ribs. The tubing has either a shiny surface or gets a light etching done to give it a satin effect. the blue is another process similar to dying cloth. None of the parts were shiny and not dyed, nor were any parts etched and dyed blue. At least on the planes through the mid to late 80's.
For some reason, Quicksilver started etching all the material during the anoidizing process, dying the same parts blue as before. Thus, all the frame parts had a dull matte finish to them. Surely not as pretty as the original shiny blue parts.
Q....................... Does anyone make the priginal parts with the shiny blue anodizing ?
A.......................Yes, I still offer these parts. I liked the color of the parts and have tried to keep an original appearance for replacement parts. Some people replace parts just to get the 'new' look even if they aren't broken or worn out.
Q.....................Some of the ends of my tubes have had the bolts tightened too much and are oval shaped. Can this be safely repaired and how ?
A.....................One problem with the assembly of out tube framed planes is that torquing bolts can flatten tube ends. Out tubes are usually long, have thin walls and many don't have a sleev to strengthen the end.
To repair such flattening, I use a socket from my tool box. With all the different sizes of socket sets, 1/4, 3/8 and 1/2, plus deepe well, metric, etc, there is usually a socket that can be driven into the ovalled end to start rounding it it back out. A couple different sockets may be required and don't attempt to use just one and get it stuck in the tube. Work up tto the final one if the tube is qyuite a bit out of round. It also helps to place the tube on a flat hard surface and tap the widest part with a mallet. This uses the socket for an internl mandrel. A couple tubes and you will find which sockets fit which tube diiameters. The ends of the tube are usually low stressed overall and highly stresses right in the hole itself so restoring tubing to a round end condition is safe to do.
Q.....................How do you keep from smashing the tubes in the first place ?
A......................A typical tube joint is a couple tubes and some saddles that help spread the clamping force and maintaining the tubes in a round condition. I use a wrench and a socket. When I turn the socket, there is some turning effect on the wrench. When the wrench doesn't freely turn its end of the bolt, the nut is prolly close to tight. By seing the required effort to turn the bolt, the nut can be slowly tightened until the wrench feels snug. You can also watch the ends of the tube. If ovalling begins, backoff a half or quarter turn on the nut.
Q.....................I have several sizes of saddles. How do I tell where they go ?
A.....................First, I would encourage you to have the original assembly manual for your plane. I sell them for between 25 and 75 dollars for the really large ones. This price includes postage.
They will give the original part description, and the part number. They won't show the tube diameters and such so you could decide what saddle on your own though.
Saddles have several parameters,,,,the diameter of tube that fits the 'saddle' part of the saddle, the thicknes of the saddle at the thinnest point of the saddle, and the outer diameter of the saddle. One of the larger saddles goes against the axle at four locations. It is 1 1/2 inches in diameter, has about a 1 1/2 inch diameter tube area, and is about 3/16 at the thinnest spot of the saddle. Most of the other saddles are 1/8 or 1/4 thick, and mate to 7/8 or 1 inch tubes,,,,,,,Use a saddle with a crotch diamtere that matches the tube. This will support the thin walls and prevent crushing and also reduce rocking of the tube. The thickness is usually dependent on the joint. Where tubes are touching except for the saddles, use the thinner ones to reduce the bolt length and stresses in the joint. Some locations need extra distance such as the stabilizer attach bolts and here, use the 1/4 inch ones, againa per the manual.
Q.....................I have some saddles that have cracked the thin part off and a couple broken in two. What happened ?
A.....................This is a problem with the materials of the saddles in some cases, and a problem with the choice of saddle in others. If the crotch diameter of the saddle is too small, ie, smaller than the tube resting in the saddle, the tube will tend to break off the ends of the saddle, or even break it down the middle. the fix is to understand the joint, and buy saddles that work better and fit better. Just ask,,,,,,,I have replacement saddles of better materials, and also have some suggestions on what to use for replacements dimensions.
Q.....................After reading that, I realize the saddles on my axle allow the axle tube to rock since they have a larger diameter thatn the axle. Do you have a fix ?
A......................Sure do. This problem has been with our brand since day one. The early planes had a round root tube and required saddles under all the attached channels. The change to a square root tube left the factory with what must be a lot of 1 3/4 saddles. They used them everywhere on the axle,,,,,,,,,but they don't fit. They allow the axle to rotate in the saddles. When brakes are installed, the problem is much worse, and even without brakes, the axle struts push down on the front of the axle rotating and wearing out/bending parts. The fix was to install the four torque plates that bolt to the axle and gear channels. These hold the axle from rotating. I do have a proper 1 1/2 in saddle should you care to replace them.
Q.......................Some of my tubes have holes that are very loose on the bolts. Can they be fixed ?
Yes they can, in most cases. A plug can be made that fits the inside, driven in and the hole redrilled.A short section of smaller tube can be slid in and the hole redrilled. In some cases, an outer sleeve can be used. But most of these fixes don't help the bolt hold the tube, unless the added piece is securely attached to the bse tube and is carrying the loads through to the bolt as the original tube might do.
For example, an inner sleeve at the aft end of the tension strut may merwely slide along as the original hole gets even longer, more ovalled. This doesn't help much. But if the sleeve were epoxied, bolted or pop riveted to the original tube, it would then actually carry the loas to the atthment bolt without the slop of the original hole/s. This is a good fix. Replacing the tube is the only other option.
Q......................Someone stepped on my tension strut and bowed it a bit. Can it be straightened ?
A.......................Yes, but with some reservations. The tension struts are in tension when the plane is on the ground. But they can see some serious compressive loads when the plane is flown as they are holding up the front end.
To straighten them very much may reduce their ability to support the front end. Add to this, the many planes have heavy steerable nose wheel assmblies, others have fiberglass pods, all of which must be supported by the tension struts while airborne. Should an abrupt manuever place high G loads on these tubes, they may, and have, collapsed allowing the whole front end to drop amking control a problem. Surely small bends can be done, but if there are any kinks or reduction of area after straightening, new ones may be a better option.
Q.....................After installing a steerable nosewheel kit, I see a lot of flexing in my nose struts. Is this normal ?
A......................Yes, with the stock factory nose struts, usually of aluminum. The factory does make some steel ones, fairly expensive for the two place, ie, they have incorrect holes for a single. I make a double walled nose strut with an outer sleeve from the front to a few inches from the back. It fits the channel at the rear, but require an 1/8 inch longer bolt/s at the front. It makes a world of difference in the flexing of the nose struts during taxiing.