Kyosho Breitling CAP Setup, Flight Report and Elevator Pull Pull Pics
06-28-2004 | 11:34 AM
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Thread Starter
Kyosho Breitling CAP Setup, Flight Report and Elevator Pull Pull Pics
After reading a lot of comments on the Kyosho Breitling CAP on the forums, I decided to build the plane (had one in the attic for rainy days
) and incorporate some modifications based on the observations of people that have flown it. Here’s my setup with comments, so that everybody interested can be benefited just like I was:
Engine & Prop: Saito 72 with APC 13x6. Gives unlimited vertical on 10% nitro (Coolpower) and great authority for any manoeuvre, including 3D (YES, the plane will do it, read on..[8D]). Hovers the plane at about 60-70% throttle. Perfect prop, no need for more speed.
Servos: Hitec 605BB on rudder, 925MG on elevator and 225MGs on ailerons. The 605 is slow, heavy and has really bad centering[:@]. Good only for flap actuation on warbirds imho. I will replace it in the near future. On the other hand, the 925 and 225s are probably some of the best non digital servos around for high performance 40-60 size planes. Great speed, precision and dependability
. A protech micro servo powers the throttle. It is a bit slow and I will replace it with a Multiplex digi micro soon (wonder why none other of the other manufacturers produce digi micros??). For 3D, throttle control speed is as important as that for elevator/rudder.
Radio: A Futaba 9ZAP coupled to a Dual Conversion FM Rx powered by a 1100mAh NiCd battery controls the lot above. Always use an FM Rx on new planes in case of inherent radio glitches (see below..). With PCM you will go into lock and lose the plane without having a clue what went wrong. The battery is rather heavy but needed to balance the plane.
Control Throws & Balance:
Elevator +/-28mm at widest point with –30% expo (normal) and +/-50 deg. with –80% expo (3D).
Rudder +/-50mm at widest point with –20% expo (normal) and max throw (+/-50-55 deg.) with –60% expo (3D).
Ailerons +/-12mm at aileron root with –38% expo (normal) and max throw (+/-30mm) with –60% expo (3D).
Balance: 95mm from LE measured at wing centreline (3 3/4in).
All-up Dry Weight: 2.520 grams (5.55lbs).
Flight Report: With the above setup the plane will fly very nicely on normal flight mode. Take-off requires little or no rudder correction. The .72 allows near vertical climb-out with a couple of snap-rolls thrown in for good measure or snap to knife edge from horizon to horizon. Contrary to what I have read elsewhere in the forum, I found the plane un-snappable with really pleasing flight characteristics! Full speed horizontal flight and sudden full up elevator produces a nice square corner without wing drop. Same with slow speed loops. Landing can be 3-pointed all the time and is really slow. No tendency of wing drop there either. Knife edge needs some sorting with mixes, especially when flying left wing down (pulls to the canopy). At high rudder deflections the plane will climb but forget the KE loop since the coupling gets worse and worse.
In 3D, this little plane can do the lot! Blenders are very violent, although I still find the roll rate a bit low on max deflection on the down line. The resulting inverted flat spin is beautiful and can be stopped dead with throttle. Harriers are really stable for a relatively highly loaded small plane like this Cap. Go into a shallow dive (1-1.5 sec), throw the switch to 3D rates and pull full up elevator. The plane will enter a parachute with little wing rock (which can be damped out with small aileron corrections). Start increasing the throttle a click at a time (slowly... the torque reaction will instantly destabilise the wing otherwise) and at about 3-4 clicks above idle the tail will be pushed down further while the plane will stop loosing height and will only move forward at walking pace. Correct the heading with subtle rudder corrections. Beautiful! The hover is a little difficult to hold. I think that the CG is still a bit forward for an effortless hover. This is also true for waterfalls: the plane rotates about a point ~6 inches in front of the spinner rather than the CG. I will gradually move the CG to 100-105mm (~4in.) while reducing the elevator throw in normal mode in order to improve the 3D performance.
Modifications: If you already have a snappy Kyosho CAP and are wondering why on earth this guy has such a rearward CG and does not have problems… read on. Basically, the flight reports here in RCU indicated a plane with really sensitive elevator. So what can one do about it? Basically, throw away the stock pushrod and install an elevator pull-pull to avoid flutter and elevator differential on the travel extremes, seal the gaps, adjust the up-down travel volumes really carefully, and the snap is gone. I am aware of some people asking about split elevator pull-pull setups, so here are some pics of my set-up. First, you must install the elevator servo on its side relative to the fuz floor and the horn must be bang-on the fuz centreline. The high stab of the CAP design favours the placement of the servo in the cockpit floor of the model. You only need to make a new servo mount. Make sure it is strong and screw it down as well as glue it, though, so that is does not get pulled out. Use a dual BB servo to take the strain of 4 taut lines to the elevator halves. The only difficult thing about this installation is the careful marking of the wire exit holes so that they have a minimum diameter and also to ensure that the wire runs completely straight from servo to control surface. In order to do that, you need to rip the covering of the bottom aft fuz away to pass the wires through the formers. However, that is a great opportunity to lighten the back end of this typically tail-heavy model! If you look at the pics carefully you will see some lightening holes on the ply formers. In fact, I lightened the aft section enough by the deletion of the pushrods to be able to move the rudder servo right in the back and use a short straight pushrod. This allowed the ply servo mount inside the plane to be removed completely saving even more weight. The end result of low overall weight (5.55lbs) with a 4-stroke engine also helps minimise the snapping tendency of the plane by reducing the stall speed.
Problems: Yes we can all do without those but in this case I was hit by some radio interference on the first flights. The faults were basically the use of a single conversion Rx coupled to some metal-to metal noise stemming from the pull-pull system. Since two wires go back to the elevator halves, per actuation side, I initially drilled out some stock threaded rod to take both of them from the servo side (via a clevis) to the surfaces. The drilling-out produced a shard-edged hole that cut into the wires and created some RF noise. Now, there is a good reason for the price difference between single and dual conversion Rxs. Basically the quality of the materials inside, apart from the second RF conversion, is very low. So they get easily affected by metal-to-metal contact noise such as that from metal-geared servos or rubbing pull-pull wires. I discarded the clevises of the elevator pull-pull on the servo side and simply run the wires through the servo horn holes. By changing to a dual conversion Rx all glitches were gone for good. I also used counter-locknuts to ensure that the wire ends near the surfaces would not vibrate/rotate inside the clevises.
Sorry for the long report, I sincerely hope some of you thinking to buy the plane or are currently building it get some helpful info on set-up and general qualities.
) and incorporate some modifications based on the observations of people that have flown it. Here’s my setup with comments, so that everybody interested can be benefited just like I was:Engine & Prop: Saito 72 with APC 13x6. Gives unlimited vertical on 10% nitro (Coolpower) and great authority for any manoeuvre, including 3D (YES, the plane will do it, read on..[8D]). Hovers the plane at about 60-70% throttle. Perfect prop, no need for more speed.
Servos: Hitec 605BB on rudder, 925MG on elevator and 225MGs on ailerons. The 605 is slow, heavy and has really bad centering[:@]. Good only for flap actuation on warbirds imho. I will replace it in the near future. On the other hand, the 925 and 225s are probably some of the best non digital servos around for high performance 40-60 size planes. Great speed, precision and dependability
. A protech micro servo powers the throttle. It is a bit slow and I will replace it with a Multiplex digi micro soon (wonder why none other of the other manufacturers produce digi micros??). For 3D, throttle control speed is as important as that for elevator/rudder.Radio: A Futaba 9ZAP coupled to a Dual Conversion FM Rx powered by a 1100mAh NiCd battery controls the lot above. Always use an FM Rx on new planes in case of inherent radio glitches (see below..). With PCM you will go into lock and lose the plane without having a clue what went wrong. The battery is rather heavy but needed to balance the plane.
Control Throws & Balance:
Elevator +/-28mm at widest point with –30% expo (normal) and +/-50 deg. with –80% expo (3D).
Rudder +/-50mm at widest point with –20% expo (normal) and max throw (+/-50-55 deg.) with –60% expo (3D).
Ailerons +/-12mm at aileron root with –38% expo (normal) and max throw (+/-30mm) with –60% expo (3D).
Balance: 95mm from LE measured at wing centreline (3 3/4in).
All-up Dry Weight: 2.520 grams (5.55lbs).
Flight Report: With the above setup the plane will fly very nicely on normal flight mode. Take-off requires little or no rudder correction. The .72 allows near vertical climb-out with a couple of snap-rolls thrown in for good measure or snap to knife edge from horizon to horizon. Contrary to what I have read elsewhere in the forum, I found the plane un-snappable with really pleasing flight characteristics! Full speed horizontal flight and sudden full up elevator produces a nice square corner without wing drop. Same with slow speed loops. Landing can be 3-pointed all the time and is really slow. No tendency of wing drop there either. Knife edge needs some sorting with mixes, especially when flying left wing down (pulls to the canopy). At high rudder deflections the plane will climb but forget the KE loop since the coupling gets worse and worse.
In 3D, this little plane can do the lot! Blenders are very violent, although I still find the roll rate a bit low on max deflection on the down line. The resulting inverted flat spin is beautiful and can be stopped dead with throttle. Harriers are really stable for a relatively highly loaded small plane like this Cap. Go into a shallow dive (1-1.5 sec), throw the switch to 3D rates and pull full up elevator. The plane will enter a parachute with little wing rock (which can be damped out with small aileron corrections). Start increasing the throttle a click at a time (slowly... the torque reaction will instantly destabilise the wing otherwise) and at about 3-4 clicks above idle the tail will be pushed down further while the plane will stop loosing height and will only move forward at walking pace. Correct the heading with subtle rudder corrections. Beautiful! The hover is a little difficult to hold. I think that the CG is still a bit forward for an effortless hover. This is also true for waterfalls: the plane rotates about a point ~6 inches in front of the spinner rather than the CG. I will gradually move the CG to 100-105mm (~4in.) while reducing the elevator throw in normal mode in order to improve the 3D performance.
Modifications: If you already have a snappy Kyosho CAP and are wondering why on earth this guy has such a rearward CG and does not have problems… read on. Basically, the flight reports here in RCU indicated a plane with really sensitive elevator. So what can one do about it? Basically, throw away the stock pushrod and install an elevator pull-pull to avoid flutter and elevator differential on the travel extremes, seal the gaps, adjust the up-down travel volumes really carefully, and the snap is gone. I am aware of some people asking about split elevator pull-pull setups, so here are some pics of my set-up. First, you must install the elevator servo on its side relative to the fuz floor and the horn must be bang-on the fuz centreline. The high stab of the CAP design favours the placement of the servo in the cockpit floor of the model. You only need to make a new servo mount. Make sure it is strong and screw it down as well as glue it, though, so that is does not get pulled out. Use a dual BB servo to take the strain of 4 taut lines to the elevator halves. The only difficult thing about this installation is the careful marking of the wire exit holes so that they have a minimum diameter and also to ensure that the wire runs completely straight from servo to control surface. In order to do that, you need to rip the covering of the bottom aft fuz away to pass the wires through the formers. However, that is a great opportunity to lighten the back end of this typically tail-heavy model! If you look at the pics carefully you will see some lightening holes on the ply formers. In fact, I lightened the aft section enough by the deletion of the pushrods to be able to move the rudder servo right in the back and use a short straight pushrod. This allowed the ply servo mount inside the plane to be removed completely saving even more weight. The end result of low overall weight (5.55lbs) with a 4-stroke engine also helps minimise the snapping tendency of the plane by reducing the stall speed.
Problems: Yes we can all do without those but in this case I was hit by some radio interference on the first flights. The faults were basically the use of a single conversion Rx coupled to some metal-to metal noise stemming from the pull-pull system. Since two wires go back to the elevator halves, per actuation side, I initially drilled out some stock threaded rod to take both of them from the servo side (via a clevis) to the surfaces. The drilling-out produced a shard-edged hole that cut into the wires and created some RF noise. Now, there is a good reason for the price difference between single and dual conversion Rxs. Basically the quality of the materials inside, apart from the second RF conversion, is very low. So they get easily affected by metal-to-metal contact noise such as that from metal-geared servos or rubbing pull-pull wires. I discarded the clevises of the elevator pull-pull on the servo side and simply run the wires through the servo horn holes. By changing to a dual conversion Rx all glitches were gone for good. I also used counter-locknuts to ensure that the wire ends near the surfaces would not vibrate/rotate inside the clevises.
Sorry for the long report, I sincerely hope some of you thinking to buy the plane or are currently building it get some helpful info on set-up and general qualities.
