Post by Webmaster on Nov 24, 2018 21:24:27 GMT -5
I get asked a lot of questions about the DF 95 so here is my experience with this class so far. This is a lengthy report so read at your leisure.
Design
The DF95 kit comes with a one piece plastic hull painted white with a full height rubber bow bumper, a carbon fiber keel fin, a bulb keel painted black, a plastic rudder with a steel shaft, A rig Mylar sails, a spool of Dyneema line, installed servos, a build stand and a partially assembled rig. It took me about 5 hours to complete assembly. Since it is an international class, all dimensions in the manual are metric. There are two upgrades to the kit. One addresses the need for more sealant around the keel fin box and mast support and has its own how to YouTube video . The other allows you to re-sleeve the rudder post insert fitting with a closer tolerance aluminum tube to address a wobbly rudder shaft problem. The kit is available with or without the FlySky FS-i6 transmitter and receiver from the Dragon Sailing North America ( DSNA ) website.
Unlike the Soling One Meter or EC-12 which are fractional rigs, the DF95 is a masthead rig. The jib sail is almost the same height as the main sail and the forestay attaches to the top of the mast. There is a topping lift to adjust jib leech twist and leech tension. The main has an adjustable compression strut vang to set main twist and leech tension. Both sails camber and downhaul tension are adjustable. It does not have upper or lower shrouds. It has a sliding deck plate and mast socket which supports the mast and keeps it centered. The sliding deck plate is attached to the deck with an Allen head cap screw. In order to adjust helm, loosen the screw, slide the mast forward or back and retighten. The keel assembly is attached to the hull by another Allen head cap screw. The kit comes with three Allen head wrenches for various screw sizes to assemble and adjust features on the boat. The sails are moved by a sail winch servo that keeps the line tensioned with an elastic shock cord which lies on the deck. The rudder has an arm servo. The boat has an external on/off switch and a drain plug. The hatch cover is a simple clear plastic piece which has no retention feature on its own. The hatch cover has to be taped to the boat to keep it on. The servo tray is attached up high beneath the hatch opening. The servo tray contains the sail winch and rudder servo on the port side and spaces for the battery and receiver on the starboard side. The boat is designed around the FlySky FS-i6 transmitter and receiver.
Once the rig is assembled, putting it on the boat at the lake is easy. Slide the mast into the mast socket. The mast socket will hold the rig in place without any other attachment. Hook up the jib line, attach the back stay, attach the jib sheet and the main sheet to the winch line, put in a battery, tape the hatch shut, make sure the drain plug is seated and you are ready to go.
Additional Info
I use a Spektrum DX6 transmitter with a AR610 receiver. The AR610 receiver has a small body but a long whip antenna and amplifier which would not fit in the servo tray. I Velcroed the receiver to the under side of the deck forward of the servo tray and ran the whip antenna along the starboard side under the deck and have had no problems.
The boat can be powered by four AA alkaline batteries but a 850 mAh Lithium Iron Phosphate ( LiFe ) battery is available from the DSNA web site for $16 and a quick charger is $35. The servos are compatible with the LiFe battery 6.6 voltage.
If you use the FS-I6 receiver, it is mounted in the aft space of the servo tray open above. If any water leaked around the hatch, it could get into the receiver or battery. To prevent that, go to the party aisle at Walmart. Get a bag of your favorite color balloons. Put the battery and the receiver each in its own balloon with the electrical leads outside. Seal the balloon with a twist tie and attach the balloon package with Velcro to the servo tray.
There is an upgrade rudder servo available for $35 that has 3X the torque of the standard servo. Its a tight fit to get it in the servo tray but once in, it works great.
There are four suits of sails and rigs designed for this boat: A, B, C and D. According to the DSNA website for the Mylar sails, the A range is 0 - 17 mph, the B range is 15 - 20 mph, the C is 20 - 25 mph and the D is 25+. The Mylar sails do not come with telltales. You can use old VHS tape split down the middle to make telltales. The DSNA website has templates for sail numbers and country designations and their locations for various suits of sails. You can use vinyl cutouts or use Magic Markers to apply sail numbers, letters and decorations to your Mylar sails. Register your boat online and pick a number by reviewing the list of registered boats.
After market sails are available also. Don Burwell of Sirius sails makes great sails with materials appropriate for the wind range.
The kit comes with a build stand you can assemble but without further additions to the base, it is too narrow to keep the rigged boat from flopping over in the wind.
Most parts are reasonably priced. A replacement rudder is $9. The most expensive part is the carbon fiber keel fin at $94 so it is wise to protect the leading and trailing edges of the fin and the keel bulb with split foam pool noodles or pipe insulation. The trailing edge of the keel fin is SHARP! A replacement hull is $64 and it comes with the rubber bow bumper, keel fin box, rudder post insert fitting and servo tray. Oddly enough you can get it in eight different pre painted colors although the kit only comes only in pre painted white.
On The Water
For the on the water evaluation, I used the A rig Mylar sails that come with the kit.
The DF 95 can be launched off the dock with a Soling launcher but it usually results in picking up debris on the keel bulb. Because of its light weight and narrow beam, the best way to launch it is to grab it across the beam behind the mast support and give it a gentle toss into the water about two to three feet out. That puts it into deeper water and clears the close-in debris. Just make sure the rubber drain plug is seated in the drain hole.
For the initial setup, the assembly manual gives the position for the mast step. Several websites gave recommendations for sail camber, twist, boom positions and mast tip dimensions.
Right from the start, the boat was fast on a run or a reach. I was tagging along behind the Soling and EC-12 races and the DF 95 was closing on both classes on a run. On the first day, I measured winds between 7 and 10 mph but I knew there were occasional sudden gusts well above that. I was on a broad reach midway through a jibe when I got hit with one of those gusts and the boat pitch-poled on me but quickly popped up with no harm done.
On upwind sailing, you would normally want to keep a boat at a heel angle of 25 to 30 degrees with a brief max to 45 degrees to minimize hull drag and yawing moment. Because of its narrow beam, this boat likes to heel more. It seemed to sail its fastest upwind heeled at 45 degrees.
I took a guess at setting backstay tension but quickly saw the main sail wrinkles starting halfway up the mast at the luff and extending to the clew indicated that I was over bending the mast. Normally a lower shroud would limit mast bend to match the curve built into the main sail luff but because there is no lower shroud, you have to balance forestay tension with backstay tension to limit mast bend and smooth out the main sail.
Because of it’s light weight, you have to be more deliberate when tacking but when you get the rest of the setup correct and learn what the boat likes, tacking is not a problem. As with any boat class, you have to build up speed at close-hauled, get the boat more upright and throw it over with the rudder only.
I was warned before hand to not get too close to the buoys otherwise the bulb keel could snag the buoy anchor line. I did not have a problem but I could see where that would be a problem with very small buoys and rounding a leeward buoy coming onto a windward heading. One boat did get caught on a small buoy but I used the rubber bow bumper on my boat to gently nudge the other boat back off the anchor line.
I sailed for about three hours and the LiFe battery still seemed strong even in medium to heavy air. I did notice that the main sail Dyneema sheeting line had frayed. The line has to pass through a ring on its way to hooking up to the winch line. The DSNA website did warn that this could be a problem. You are allowed to polish the ring or replace it with with another. I changed the line to Spectra to provide more wear resistance. The shock cord also showed distress but it had been sitting in my garage in the heat for several months. That can be replaced by elastic cord from a sewing or craft store but needs to be checked regularly.
Summary
There is still much to learn but overall I can see why the DF95 has rapidly grown in popularity. It places a premium on tuning and sailing skills instead of boat building skills. It is easy to assemble, reasonably priced, easy to transport and set up and it sails well. Also, since every one has the same exact boat, the other sailors will have a spare part that you need at the lake.
As far as naming goes, DragonFlite 95 is a mouthful. Dragons sounds like you are dragging something around the lake. DF 95 sounds too much like DNF which is never good. It may be best to refer to this boat class as a 95.
Terry McMullen Sail # 2916
Design
The DF95 kit comes with a one piece plastic hull painted white with a full height rubber bow bumper, a carbon fiber keel fin, a bulb keel painted black, a plastic rudder with a steel shaft, A rig Mylar sails, a spool of Dyneema line, installed servos, a build stand and a partially assembled rig. It took me about 5 hours to complete assembly. Since it is an international class, all dimensions in the manual are metric. There are two upgrades to the kit. One addresses the need for more sealant around the keel fin box and mast support and has its own how to YouTube video . The other allows you to re-sleeve the rudder post insert fitting with a closer tolerance aluminum tube to address a wobbly rudder shaft problem. The kit is available with or without the FlySky FS-i6 transmitter and receiver from the Dragon Sailing North America ( DSNA ) website.
Unlike the Soling One Meter or EC-12 which are fractional rigs, the DF95 is a masthead rig. The jib sail is almost the same height as the main sail and the forestay attaches to the top of the mast. There is a topping lift to adjust jib leech twist and leech tension. The main has an adjustable compression strut vang to set main twist and leech tension. Both sails camber and downhaul tension are adjustable. It does not have upper or lower shrouds. It has a sliding deck plate and mast socket which supports the mast and keeps it centered. The sliding deck plate is attached to the deck with an Allen head cap screw. In order to adjust helm, loosen the screw, slide the mast forward or back and retighten. The keel assembly is attached to the hull by another Allen head cap screw. The kit comes with three Allen head wrenches for various screw sizes to assemble and adjust features on the boat. The sails are moved by a sail winch servo that keeps the line tensioned with an elastic shock cord which lies on the deck. The rudder has an arm servo. The boat has an external on/off switch and a drain plug. The hatch cover is a simple clear plastic piece which has no retention feature on its own. The hatch cover has to be taped to the boat to keep it on. The servo tray is attached up high beneath the hatch opening. The servo tray contains the sail winch and rudder servo on the port side and spaces for the battery and receiver on the starboard side. The boat is designed around the FlySky FS-i6 transmitter and receiver.
Once the rig is assembled, putting it on the boat at the lake is easy. Slide the mast into the mast socket. The mast socket will hold the rig in place without any other attachment. Hook up the jib line, attach the back stay, attach the jib sheet and the main sheet to the winch line, put in a battery, tape the hatch shut, make sure the drain plug is seated and you are ready to go.
Additional Info
I use a Spektrum DX6 transmitter with a AR610 receiver. The AR610 receiver has a small body but a long whip antenna and amplifier which would not fit in the servo tray. I Velcroed the receiver to the under side of the deck forward of the servo tray and ran the whip antenna along the starboard side under the deck and have had no problems.
The boat can be powered by four AA alkaline batteries but a 850 mAh Lithium Iron Phosphate ( LiFe ) battery is available from the DSNA web site for $16 and a quick charger is $35. The servos are compatible with the LiFe battery 6.6 voltage.
If you use the FS-I6 receiver, it is mounted in the aft space of the servo tray open above. If any water leaked around the hatch, it could get into the receiver or battery. To prevent that, go to the party aisle at Walmart. Get a bag of your favorite color balloons. Put the battery and the receiver each in its own balloon with the electrical leads outside. Seal the balloon with a twist tie and attach the balloon package with Velcro to the servo tray.
There is an upgrade rudder servo available for $35 that has 3X the torque of the standard servo. Its a tight fit to get it in the servo tray but once in, it works great.
There are four suits of sails and rigs designed for this boat: A, B, C and D. According to the DSNA website for the Mylar sails, the A range is 0 - 17 mph, the B range is 15 - 20 mph, the C is 20 - 25 mph and the D is 25+. The Mylar sails do not come with telltales. You can use old VHS tape split down the middle to make telltales. The DSNA website has templates for sail numbers and country designations and their locations for various suits of sails. You can use vinyl cutouts or use Magic Markers to apply sail numbers, letters and decorations to your Mylar sails. Register your boat online and pick a number by reviewing the list of registered boats.
After market sails are available also. Don Burwell of Sirius sails makes great sails with materials appropriate for the wind range.
The kit comes with a build stand you can assemble but without further additions to the base, it is too narrow to keep the rigged boat from flopping over in the wind.
Most parts are reasonably priced. A replacement rudder is $9. The most expensive part is the carbon fiber keel fin at $94 so it is wise to protect the leading and trailing edges of the fin and the keel bulb with split foam pool noodles or pipe insulation. The trailing edge of the keel fin is SHARP! A replacement hull is $64 and it comes with the rubber bow bumper, keel fin box, rudder post insert fitting and servo tray. Oddly enough you can get it in eight different pre painted colors although the kit only comes only in pre painted white.
On The Water
For the on the water evaluation, I used the A rig Mylar sails that come with the kit.
The DF 95 can be launched off the dock with a Soling launcher but it usually results in picking up debris on the keel bulb. Because of its light weight and narrow beam, the best way to launch it is to grab it across the beam behind the mast support and give it a gentle toss into the water about two to three feet out. That puts it into deeper water and clears the close-in debris. Just make sure the rubber drain plug is seated in the drain hole.
For the initial setup, the assembly manual gives the position for the mast step. Several websites gave recommendations for sail camber, twist, boom positions and mast tip dimensions.
Right from the start, the boat was fast on a run or a reach. I was tagging along behind the Soling and EC-12 races and the DF 95 was closing on both classes on a run. On the first day, I measured winds between 7 and 10 mph but I knew there were occasional sudden gusts well above that. I was on a broad reach midway through a jibe when I got hit with one of those gusts and the boat pitch-poled on me but quickly popped up with no harm done.
On upwind sailing, you would normally want to keep a boat at a heel angle of 25 to 30 degrees with a brief max to 45 degrees to minimize hull drag and yawing moment. Because of its narrow beam, this boat likes to heel more. It seemed to sail its fastest upwind heeled at 45 degrees.
I took a guess at setting backstay tension but quickly saw the main sail wrinkles starting halfway up the mast at the luff and extending to the clew indicated that I was over bending the mast. Normally a lower shroud would limit mast bend to match the curve built into the main sail luff but because there is no lower shroud, you have to balance forestay tension with backstay tension to limit mast bend and smooth out the main sail.
Because of it’s light weight, you have to be more deliberate when tacking but when you get the rest of the setup correct and learn what the boat likes, tacking is not a problem. As with any boat class, you have to build up speed at close-hauled, get the boat more upright and throw it over with the rudder only.
I was warned before hand to not get too close to the buoys otherwise the bulb keel could snag the buoy anchor line. I did not have a problem but I could see where that would be a problem with very small buoys and rounding a leeward buoy coming onto a windward heading. One boat did get caught on a small buoy but I used the rubber bow bumper on my boat to gently nudge the other boat back off the anchor line.
I sailed for about three hours and the LiFe battery still seemed strong even in medium to heavy air. I did notice that the main sail Dyneema sheeting line had frayed. The line has to pass through a ring on its way to hooking up to the winch line. The DSNA website did warn that this could be a problem. You are allowed to polish the ring or replace it with with another. I changed the line to Spectra to provide more wear resistance. The shock cord also showed distress but it had been sitting in my garage in the heat for several months. That can be replaced by elastic cord from a sewing or craft store but needs to be checked regularly.
Summary
There is still much to learn but overall I can see why the DF95 has rapidly grown in popularity. It places a premium on tuning and sailing skills instead of boat building skills. It is easy to assemble, reasonably priced, easy to transport and set up and it sails well. Also, since every one has the same exact boat, the other sailors will have a spare part that you need at the lake.
As far as naming goes, DragonFlite 95 is a mouthful. Dragons sounds like you are dragging something around the lake. DF 95 sounds too much like DNF which is never good. It may be best to refer to this boat class as a 95.
Terry McMullen Sail # 2916