Prop Testing for Most Pace and Efficiency

Prop Testing for Most Pace and Efficiency

I actually get pleasure from flying RC plane of every kind, however a few of my favorites are System One pylon racers. I needed a race airplane that I might prop for velocity, however I additionally needed to have the ability to attempt propellers that may produce good torque. I additionally needed a airplane that may enable me to do some sport aerobatics. One among my favorites is the Kyosho Phantom 70 EP. It’s no 3D monster aerobat, however it’s going to do a good quantity of maneuvers, so for my testing this was an ideal plane.

kyosho phantom ep fast flyby, kyosho phantom ep, slimline pilot figure

THE RACER

Let’s take a better take a look at this high-quality Kyosho race plane. Each the GP (glow) and EP (electrical) variations of this mannequin have high-quality fiberglass components that embody the fuselage, wheel pants and cowl. The EP fuselage is one piece with out a cowl however with a big battery entry door on the underside. It has the firewall epoxied to the entrance of the fuselage and a battery tray glued in proper below the hatch opening. You may connect your battery to the plywood plate with Velcro after which bolt this plate to the tray in numerous places so you’ll be able to transfer the battery to attain the right stability. The wings and stabilizers on each kits are the identical utilizing balsa and plywood development with heat-shrink masking. The {hardware} bundle is full and consists of all the things it’s essential to end up your plane. The development guide is kind particular and mine included all the things on putting in all the electrical parts.

axi motor, fuselage

The Axi motor mounts on to the entrance of the fuselage, straightforward and fast. The small air holes on both sides of the firewall are all that’s wanted to maintain the motor cool.

factory-made vent holes, fuselage

Vent holes on the underside of the fuselage preserve the facility system cool.

THE BUILD

The construct on the airplane could be very straight ahead and development begins with the decrease wing. That is the one wing that has ailerons and the servo area is relatively restricted, for this I used 2 HS-85 Hitec (hitecrcd.com) servos. Then I hinged the ailerons, then epoxied the four-part gull wing collectively and hooked up the aileron servos. Quick pushrods make the connection between the servo and the aileron. To finish wing development, I glued the fiberglass wheel pants and stomach panel in place. Though the gull wing appears relatively sophisticated, the meeting went quick and was relatively straightforward.

After the stabilizer is epoxied in place and the elevators and rudder are hinged, it’s time to put in the motor. Earlier than doing that I made a decision to bolster the firewall as a result of I will likely be utilizing a strong Axi 4130/16 moto rand swapping out props for testing. I stood the fuselage on its nostril and used a combination of BSI 15-minute epoxy and micro balloons to type a bead of epoxy across the firewall. Watch out to not get any this on the firewall face as a result of it’s going to have an effect on the way in which the motor sits once more the wooden. I actually like BSI 15-minute epoxy as a result of it units up up quicker than the 20-minute stuff however nonetheless has loads of working time. After I bolted the motor to the firewall, I hooked up the ESC contained in the fuselage with Velcro.

Earlier than I epoxied within the stabilizer/rudder servo tray to the within of the fuselage, I hooked up the receiver and servos to the plywood tray. The rudder has a pull-pull system for management and I used to be capable of thread within the cables to the servo from the again and connect them to the servo management horn. The tray is glued in utilizing epoxy and micro-balloons. The elevator pushrod has one wire on the servo facet with two wires popping out of the again, every one going to an elevator. The simplest approach I discovered to do that is by threading skinny wires by way of the holes behind the fuselage and attaching every one to the separate pushrod wire. Then it’s only a easy matter of pulling them by way of to the elevator management horns. All that was left now to complete up the Phantom was to put in the highest wing, pilot, cover and decals. I balanced the airplane barely nose-heavy and used the producer’s beneficial throws for the management surfaces.

TESTING

The tools I used on the bottom for testing included the AstroFlight Watt meter and a Cermark One Contact Tachometer.As soon as the airplane acquired airborne the knowledge was gathered by way of the Eagle Tree Micro-Energy E-Logger (eagletreesystems.com). We clocked the primary three passes with a radar gun to get the common velocity. Happily there was no wind on the check day that may have an effect on the velocity. I used a 5000mAh 6s battery pack for every check. I absolutely charged every battery the day earlier than the check. I flew the airplane for 7 minutes and the packs solely required 2300 to 3000mAh to recharge them, so I might simply get about 10 minutes of flight time. All of my numbers are taken from the start of the flight when the battery has essentially the most energy. So let’s see how the testing went.

APC 15x8E

The bottom numbers on this APC (apcprops.com) prop have been fairly good with the motor pulling 36.63 amps at 21 volts. This mix was producing about 773 watts at 7,350 rpm. As soon as within the air the motor was pulling 30 amps at 22.2 volts and producing 730 watts. This prop acquired the airplane into the air relatively shortly and, as soon as within the air, the Phantom carried out aerobatics very nicely with a powerful up-line earlier than stopping. Our common velocity on the three passes with this prop was 73mph.

XOAR 15×8

The Xoar was the one picket one we examined that’s made particularly for electrics. This prop is a pleasant trying blade and will maintain its pitch with little or no flexing within the air. The bottom numbers have been 15.4 amps at 21.9 volts. This mix was producing about 335 watts at 7,650rpm. As soon as within the air, on common, the motor was pulling 15.3 amps at 21.75volts and producing 335 watts. The airplane took up about the identical size of the runway to get into the air however as soon as within the air the Phantom carried out aerobatics virtually the identical because the APC prop 15x8E with up-lines virtually similar as the opposite props. This picket prop appears to drag the airplane by way of maneuvers with out slowing down. I used to be actually shocked at how low all of our readings have been particularly when our common velocity on the three passes with this prop was 70mph.

battery hatch, fuselage, large battery pacl, xoar15x8

The battery hatch on the underside of the fuselage is held in place with two screws. As you’ll be able to see, there’s room for even the biggest battery pack!

kyosho phantom

We examined the rpm of every prop on the bottom at the start of the flight, after a 10-second motor run.

APC 15x10E

The bottom numbers on this prop have been a bit increased with the motor pulling 39 amps at 21.9 volts. This mix was producing about 870 watts at 7,230 rpm. As soon as within the air, on common, the motor was pulling 36 amps at 21.75 volts and producing 808 watts. This prop acquired the airplane into the air shortly (about the identical because the 15×8) and, as soon as within the air, the Phantom carried out aerobatics rather well with an excellent up-line earlier than stopping. This prop appears to drag the airplane by way of maneuvers with out slowing down and maintained good velocity across the pylons. Our common velocity on the three passes with this prop was 79mph.

MASTER AIRSCREW 15×10

Grasp Airscrew (masterairscrew.com) has props made particularly for electrics; sadly, they cease at 13 inches in diameter. This prop is far thicker and heavier than the APC E props, nonetheless it produced numbers like these: 42 amps at 21.64 volts. This mix was producing about 935 watts at 7,110 rpm. As soon as within the air, on common, the motor was pulling 30 amps at 21.12 volts and producing 676 watts. The airplane took a bit longer to get into the air, however as soon as within the sky, the Phantom carried out aerobatics very nicely with up-lines virtually pretty much as good as the opposite props. This thicker prop appears to drag the airplane by way of maneuvers with out slowing down and the white suggestions regarded nice. Our common velocity on the three passes with this prop was 73mph.

APC 14×12

The bottom numbers on this prop regarded good particularly with such a big pitch, the motor pulling 36 amps at 22 volts. This mix was producing about 815 watts at 7,380 rpm. As soon as within the air the motor, on common, was pulling 35 amps at 22 volts and producing 817 watts. This prop acquired the airplane into the air relatively shortly and, as soon as within the air, the Phantom carried out aerobatics very nicely with a powerful up-line earlier than stopping. Our common velocity on the three passes with this prop was 83mph.

I discovered that if I needed some velocity out of the Phantom I wanted to make use of the APC 14×12, and this wasn’t surprising. If I simply needed to do aerobatics and a few enjoyable flying with the Phantom then I might use any of the opposite props with a decrease pitch and extra blade size for that additional airflow over the surfaces. The shocking factor for me was that if I needed an extended flight to observe my aerobatics, all I needed to do was use the Xoar prop.

Textual content & Images by John Reid

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