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Saturday, June 16, 2007

BlueBird Servos Comparison with Hitec & Futaba

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See how our BlueBird Servos compare to other brands in performance. Most importantly, check out it attractive price at www.zhobbyshop.com.

Saturday, June 9, 2007

Some Beginner Tips

The following list of quick tips should help newcomers to our hobby eliminate some of the problems that beset their first attempts.

• Roll test steering in a driveway or car park. If it doesn't roll straight at home, it won't roll straight on a runway. Set steering control to the least sensitive position.

• Put small marks at the CoG. (Centre of gravity) on the wing to indicate balance location. Makes it easy to check at the field

• Balancing laterally (side to side) will help aircraft track better in manoeuvres. Hold at spinner and tail with glow plug removed. Add wing tip weight as necessary.

• Check receiver battery every 2-3 flights. Make a chart of how long you have flown vs. Voltage drop. Do not operate below recommended voltage level.

• Always turn on transmitter 1st, receiver 2nd. Always turn off receiver 1st, transmitter 2nd.

• Range check your system before 1st flight every time out. This should be performed with engine running at both idle and full throttle.

• When using the buddy box system, make sure both boxes are set identical. Never turn buddy box power "on"!

• Remove transmitter neck straps when starting engines.

• If you don't have a starter, at least use a "chicken stick". Do not hit it against the propeller; start your flick with the stick touching the propeller.

• Never jam a running starter onto the spinner. Back up the propeller, and place the starter cone against spinner before turning on.

• When you start your engine, look at your watch and keep track of time. After flight, check fuel level to assess maximum available flight time.

• Do not reach over propeller to adjust needle valve do it from the rear of the propeller. Do not position yourself (or others) to the side of a rotating blade. It could fail on run-up or kick up debris.

• Taxi while holding "up elevator".

• Always fly with a co-pilot/spotter.

• Never practice manoeuvres at low altitude. Fly 2-3 mistakes above the ground.

• When trimming an aircraft in flight, trim only until it stops the incorrect movement.

• Most trainer aircraft will recover from unusual attitudes (mistakes) by killing the power and pulling up elevator (depending on altitude). Be ready to level out and apply power.

• Remember, unless you are "dead stick", you do not have to land. If it's not right, go around. It's much easier, and safer, to try again rather than try to salvage a bad approach.

• If you get nervous for any reason, climb out and do some simple circuits over the field. When you calm down, try again. Don't' push yourself to try again too soon. Take your time.

• Do not fly too far away as it is easy to get disorientated. This is especially true when the sun is low on the horizon and the aircraft becomes a silhouette.

• Installing larger wheels on your trainer will :
1) Make taxiing in grass easier.
2) Improve your visual orientation in the air.
3) Improve your landings as gear won't bend as easily.

• Maintain your flight path. Do not make any erratic manoeuvres to avoid faster, more manoeuvreable overtaking aircraft (experienced pilots etc.). It is their responsibility to avoid you. However, make a conscientious effort to not be a hazard either.

• If it is obvious that you are going to crash, kill the power to minimize damage.

• If for any reason your aircraft is in trouble and headed for the pit area or spectators: Do your best to kill the power and ditch it. Don't try to save it. Planes are cheaper than people. It's a small sacrifice to make.

• If your aircraft does go down in the field or trees-Don't move! Note where you are standing, and pick a far distance reference point or object. Follow a straight line in your search and rescue effort.

• If you are searching in the trees, listen to glow powered aircraft overhead to orient yourself to the flight line and runway.

• When you do recover a crashed aircraft, be sure to pick up every last part, piece and splinter. You'll be glad you did when you decide to rebuild it after the shock wears off. All those little pieces can be glued together to make templates to create replacement parts.

• If you have adjusted the elevator trim to compensate for lower fuel weight during the later part of the flight, immediately reset the elevator trim to the "full fuel tank" position when you have landed. You probably won't remember until you are about 10 feet off the ground on the next take-off and struggling to maintain climb out.

Hints & Tips for Happy Flying

Seal down loose covering
This should be the first step in the assembly of any ARTF model that uses heat-shrink covering. Use an iron or heat gun to remove wrinkles that may have appeared during shipping, and then turn the heat up and go over all the surfaces where the covering overlaps or ends on bare wood. Be sure you don’t melt or shrink the covering too much, and pay particular attention to the engine compartment and wing seating areas. After you’ve sealed the covering where it ends on bare wood, apply Superglue (Cyano) along the edges to ensure that it stays that way.

Fuel proof the engine compartment
After a few flights, the firewall or engine compartment of diesel and glow powered planes can incur damage if left unprotected. Check these areas, and if needed, paint, epoxy and even cyano can provide the necessary protection. (Heat-shrink covering material will not sufficiently protect these areas from repeated exposures to fuel and oil residue.) The paint can be sprayed or brushed on. Epoxy should be thinned with a little rubbing alcohol and applied with a brush. Thin Cyano can be dripped on the surface and allowed to soak in, but thick Cyano should be rubbed in with your finger. It’s a good idea to wrap your finger in thin kitchen film.

Check high-stress glue joints
All visible glue joints should be checked for cracks or stress breaks when you unpack a new kit. Damage can easily occur during shipping; changes in humidity levels from one part of the country, or even the world, to another can warp parts and cause cracks or other damage tojoints. When checking the joints, pay particular attention to high-stress areas such as the wings, stabilizer, rudder, firewall, landing-gear attachments and servo trays. Repair the damage with Cyano or epoxy, and reinforce the area with balsa triangle stock, plywood, or fiberglass cloth.

Protect your antenna
If you have a high wing trainer, run your receiver aerial through a small hole behind the wing. Take a small screw and carefully screw it into the top of the vertical fin. Next take an old servo arm with three holes and weave your aerial through two holes and adjust it up to the little hole behind your wing inside the fuselage. Take a small rubber band and a small piece of fuel tubing and feed the rubber band through the fuel tubing. Push the end of the aerial through the loop of the rubber band protruding from the fuel tubing then slide your tubing up the rubber band till the loop holding your antenna is in the middle of the tubing also hook the other end of the band to the screw on the vertical fin. Your aerial is now held firm and should your model crash, the rubber band will pop off the screw and your aerial will be safe.

A good cleaner
In an empty spray bottle, add a tablespoon of dish washing detergent, then fill the bottle half way with surgical or rubbing alcohol, and top up with hot water. This recipe works really well for cleaning the oil off of the wings and fuselage after a flying session. It is a strong cleaner but will not hurt the covering or remove colours.

Simple propeller blade balancing
Here is a simple way to balance props. You will need to obtain or borrow a decent prop balancer. Once you have determined which blade is heavier, apply clear nail polish or clear dope to the LIGHT blade. Add thin coats until they are balanced. It should stand up to fuel and cleaners as long as the prop is cleaned thoroughly before applying the fluid. If not simply remove it and rebalance it.

Receiver battery pack precautions
Most radio control systems come with a 600 - 1100mAh battery pack. The latter is fine for a few good flights but if you are using digital servos, there are times when the current drain from the airborne system can reach several amps. An 1800mAH pack should give up to two hours of continuous flying for just a little extra weight penalty. So if you want more safe flight time, get a bigger battery pack..... JUST A SUGGESTION!

New life for old landing gear legs
It is not uncommon for your wire landing gear legs to get gradually weaker and weaker. A possible solution is to remove the gear from the airframe and remove all the hardware from the legs (i.e. - the wheels, collars, spats, etc). Preheat your kitchen oven to 235ºC (450ºF). Place the wire on a baking tray in the oven for one hour. Turn off the oven and toss the wire into cold water to cool it off quickly. What you have just done is to re-temper the piano wire and you should have put new life into that old gear. Note that soldered joints should not be harmed as solder doesn't melt until about 700ºF.

Clear Canopy polish
Toothpaste makes an excellent polish for the canopy. Smear a liberal amount of toothpaste on the canopy and use toilet tissue to buff it to a glossy finish. The process will not scratch the clear plastic at all. Then use an alcohol cleaner to remove any residue left by the toothpaste.

Covering trick
Have you ever had trouble peeling the backing from polyester covering materials when you have cut away all the edging paper? The easiest way to peel the backing off is to use two pieces of masking tape. At a corner of the sheet, stick a piece of masking tape on the front and back of the covering, with about half hanging over the edge so that the pieces of tape stick together past the edge of the covering material. Then peel the two pieces of tape apart. As the two pieces of tape come apart, the backing sheet will come away also.

A flying tip for new pilots
Control reversal is when the inputs on the transmitter sticks must be reversed when your plane is flying toward you. When flying away from you, there is no problem, just move the stick in the direction you want to turn. Many new pilots become disoriented when their plane is approaching them. To help with this, remember to always move the stick towards the low wingtip. This will level the wing when your plane is coming toward you, avoiding a sharp bank, and possibly a crash.

If you want to make a turn when flying toward yourself, then you must push the aileron control stick in the opposite direction to which you want the plane to turn. E.g. If you want the plane to turn to your right, you must push the stick to your left.

Propeller Selection ChartHOW TO USE THIS CHART
1. Find your engine along the bottom axis.
2. Follow the line up to where it intersects with the shaded area.
3. Each point within the shaded area corresponds to the appropriate prop size range on the left axis.

Note: Four Stroke engines are typically higher torque engines and should use the larger props indicated in the range. Recommended prop ranges will vary depending on your particular engine and airplane. This chart represents average prop usage and should be used only as a general guideline. Always refer to the manufacturer's instructions included with your engine.


Temperature sensitive items
In warm summer months, bear in mind several RC items that deserve a temperaturecontrolled environment. Batteries left in airplanes that are hung in the garage can get too hot. Fuel can evaporate quicker. Some covering films can separate from their backing. Cyano glues can age quicker. Try to keep these things cool so they’ll be ready to use in good condition when you need them.

Rubber band storage
Put your rubber bands in a Ziploc bag and cover them with Talcum Powder or Corn Starch. This will soak up the any fuel or oil residue, condition the rubber and help them last longer.

Cyano or Superglue storage
One popular method is to store the Cyano in the refrigerator. Another possible answer may be to simply keep moisture away from the opened container. This can be done by storing the opened Cyano bottles in a polythene bag with a silica gel desiccant bag. The silica gel keeps the moisture out and the CA flowing. The silica gel can be revitalized by baking in your oven.

Bearing removal
The best way to remove bearings from your motor is to heat up the case. This can be accomplished by using a propane torch, a small butane pencil torch, or in an oven @ 235 - 260ºC (450-500º F) for only a few minutes. Be sure to remove EVERYTHING that can come off the motor. i.e. Carburetor, cylinder head, back plate, everything up front and all paper gaskets. Just give no more than 7 minutes at these settings or it may warp the case. Be sure to use an oven mitt to remove it from the oven. Once out, have a piece of wood handy and while the engine is still hot, just firmly tap the back of the motor on the wood and the bearing should fall out. The bearings will be hot also so take care.

Tip for cleaning bolts
Place the bolts in a fine strainer (stainless) and immerse it in a pot of boiling water with a strong liquid detergent for about 10 minutes. Rinse thoroughly and dry when complete. The parts are VERY, VERY clean when done. No further prep work is needed. This leaves the bolts clean enough for the application of Loctite.

Cleaning fuel soaked balsa
Remove the fuel tank and try to dry as much as possible from the affected area. Take some corn starch and fill the compartment. Also coat external affected areas and leave for 24 to 48 hrs. After that, tip out the excess or use the vacuum cleaner. You will probably have corn starch stuck to the balsa where the fuel was. Push the tank in and then remove it again and use the vacuum to get the rest out. If it is still damp reapply fresh corn starch for another 24 hrs. Repeat as you feel necessary.

Another method is to blow a heat gun on the affected area to bring the fuel to the surface. Then you can easily wipe the fuel away. A covering iron works as well.

Avoiding screwdriver damage when installing control horns
There is a simple tool that you can make that will eliminate this damage. Take a small piece of thin plywood and cut a rectangular opening in it just slightly larger than the base of the control horn. Place this opening around the control horn base before tightening the mounting screws. Now when the screwdriver slips there will be no damage to your new model.

Firewall fuel proofing
Firewalls are normally coated with epoxy to help prevent fuel and oil damage to the wood. Apply a coat of epoxy on the firewall after you have covered the plane with film covering. Ensure the film overlaps a little onto the firewall. The epoxy seals the edges of the film covering.

Mixing epoxy resins
If you use an old coffee can lid, when the residue of epoxy hardens, flex the lid and the epoxy will pop off.

Marking hinge positions
Use a marker to draw a black line across the middle of Mylar strip hinges. This will indicate whether the hinge is being pushed into the wing when you push on the control surface. If you can't keep the hinge from being pushed into the wing stick a pin through the middle of the hinge. This will not weaken the hinge in any way.

Correct fin alignment
To get a fin in correct alignment with a fuselage, try using thread. Make sure you have an accurate centre mark near the top-front of the fuselage, and tack-glue a long piece of thread to the top near the nose half the thickness of the fin away from the centre-line. Run the thread back to the tail, and hold it against the side of the fin. The thread should touch the side of the fin evenly overall. If it doesn't, then rotate the fin until it does, then tack glue the fin into place, reinforcing it later. Finally remove the thread you tack-glued in place.

Fiberglass Wing Joints
Give the cloth a light spraying of 3M Spray Adhesive, then apply it to the wing. Now you can apply the epoxy resin without wrinkles appearing. This method works extremely well, and it's safe for foam.

Installing triangular stock
Triangular reinforcements can been difficult to handle due to their shape, especially when they're coated with epoxy.

Try sticking your modeling knife loosely into one end of the triangular stock. Lay it on the bench so that the wide part of the triangle (the hypotenuse) is against the bench surface. Now apply the epoxy or other adhesive to the sides that will glued to the airframe.

Using the knife handle to insert the triangle into position in the airframe, press down with your finger onto the wide side that has no glue, and carefully slide the knife out of the piece. This way you can cleanly install triangular stock, and not get any glue on your fingers.

Rib maker
Cut two ribs from thick litho plate or a similar hard material. Drill two holes along the center line for 1/4-inch bolts to pass through, one near the leading edge and one near the trailing edge. Make sure both ribs are identical.

Use one of these ribs as a template to draw ribs onto balsa sheet leaving a small margin of waste wood around each rib. Cut each rib "block" out of the sheeting, and drill the holes in each.

Assemble all ribs on the correct length bolts, and sandwich all between the template ribs. Using nuts, tighten the assembly down, making sure it's straight.

Using a belt sander (a disk sander will work too) or hand sanding block, remove the extra wood around the ribs down to when the templates begin touching the sander. Cut out the spar notches with a hand saw, and clean them out with a file.

This will make all the ribs for a wing in one go, and they'll all be identical. This results in a straight, uniform wing. This method can also be used for a tapered wing (with all the ribs of different size). Multiple bulkheads and formers can be made using this method too.

Making holes in polyester covering
Holes for wing bolts, switches, hatch screw holes, pushrod openings, etc. can be difficult to finish neatly. You could cut the hole/opening with a modeling knife, or razor blade, but then you have to seal the fresh cut covering to the surrounding wood. Take an old soldering iron tip (pointed preferably) in a 25 watt soldering iron and cut the hole/opening with it.

Be sure to clean the tip after each cut. A wet sponge similar to that used for soldering is fine. Do not use the same sponge that you use for cleaning your soldering tips. If you don't clean the tip regularly the burned covering will cake on. It will not only smell badly but will inhibit the cut, as you will not have maximum heat. Thoroughly clean the tip with a wire wheel or wirewool after each use once it completely cools down.

Cutting covering
For laying out sheets of heat shrink covering for cutting intricate shapes or just straight lines, nothing beats glass for a surface to cut on, it will not dull the knife or slow it down when cutting. The covering material will stick to the glass if the backing is removed all by itself for easy cutting. You can also use a little low heat from a hair dryer to make it stick even better for critical cutting. You can use solvent to put together large panels of covering without it sticking to the work surface. An old rectangular glass coffee table top is ideal. Try to get safety glass or plate glass.

Vertical rib supports
Obtain a piece of aluminum 1 or 2 inch right angle that can be found at most hardware stores. Make sure it is really square (90%) then cut off 1/2 inch wide pieces. Drill small holes in each end about the size of a modeling pin. Use the angles to hold ribs perpendicular to the building board by putting one on each side of the rib and then pinning it to the board.

Cutting clean holes in thin balsa & plywood
Do not try to use a common wood drill as it will usually leave a ragged hole that is the wrong size. Purchase a piece of thin wall brass tubing the same outside diameter as the hole you want to drill. Mount the tubing in an electric drill (preferably a drill press) then hold a piece of sand paper or a file against the end at 45º while running the drill to sharpen it. Use this sharpened tube to drill your holes it will cut perfect holes.

After cutting several holes you may have to push out the wood that collects inside the tube with a stiff wire. If you can find a drill that is the same size as the inside of the tube, push it in the top of the tube so that the drill chuck does not crush the tube. Also watch that the tube does not flare out at the bottom and change the size of the hole.

Better Screw Holes
When you have to use screws that will be removed often drill the holes for the screws large enough to allow you to insert a small length of Sullivan Gold-N-Rod and glue the rod in the hole. The screws can then be removed and reinserted with out weakening the wood.

Easier Plastic Bolting
After cutting a plastic wing bolt to shorten it, use a pencil sharpener to give it a beveled tip. This makes it much easier to insert the bolt and cleans up the start threads.

Covering Iron Cleaner
To remove the residue that accumulates on your covering iron, use a Cyano cleaning fluid. Brush on a thin coat on a cool iron and then wipe off with a clean rag.

The following list of quick tips should help newcomers to our hobby eliminate some of the problems that beset their first attempts.

Skeldar V-150 UAV


Based on the Apid 55 from Linköping's Cybaero, Saab took over the rights to the product and development.

Skeldar V-150
Lenght : 4 m
Height : 1,2m
Weight : 150kg
Payload : 25Kg @ 3500 meter altitude @100km range @ 100km/h.

http://www.saabgroup.com/en/MediaRel...ortunities.htm

http://www.corren.se/archive/2006/5/...=1096984640-7&

Saab launched at Eurosatory 2006 the Skeldar V-150 lightweight unmanned helicopter, designed for military and commercial applications. The Skeldar is currently in final testing and is expected to be ready for operational use by mid 2007. The maximum takeoff weight of the Skeldar is 150kg, including 55 kg of fuel and payload. It can fly a 4 - 5 hour mission, up to a range of 100 km, dashing at maximum speed of 100 km/h. The basic system includes two unmanned helicopters, EO/IR payloads and a control station. The platform can accommodate an optronic, stabilized payload, or a SAR or various electronic sensors (ELINT, EW etc.) Saab is working with the Swedish Airworthiness Authorities to establish the necessary procedures and regulations to certify Skeldar UAVs to operate in civilian airspace.

The Skeldar is designed to take off and land vertically, and maneuver precisely even in tight airspace. The system uses a water cooled two cylinder, two stroke fuel injected gasoline engine located in the front of the fuselage. The rotor system uses a Bell-Hiller configuration, with stabilizer bar and paddles. Navigation is performed by redundant GPS and IMU system, air data and magnetic heading indicator enabling autonomous operation while maintaining total radio silence.