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Joined: 5/24/2003 From: Rochester,
NY, USA Status: offline
The linkage was very easy to install. All the parts for the rudder and elevator linkages came in their own bags. The wooden dowels and metal rods were pre-cut and pre-bent for easy assembly. The pre-drilled holes in the control rudder and elevator halves were marked with pinholes through the covering. This provided perfect alignment for the control horns.
My only change from stock parts was to replace the supplied quick links with Dubro E-Z links. The E-Z links cannot slip as the metal rod is bent 90 degrees through the servo arm and securely held in place. There is no need to have both ends of the linkages adjustable.
I ran the antenna wire from my Futaba R127DF 7-channel receiver into a plastic tube (not supplied) and taped it into the rear of the fuselage inside.
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Joined: 5/24/2003 From: Rochester,
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To power the AXI 5320 motor, I am using two BalancePro HD packs in series. The 6s and 4s packs are combined to create a 10s pack with a 3200mAh capacity. The diagram/photo shows the hook-up for a single 6s BalancePro HD pack using the Discharge Protection Module (DPM) and the optional LED/Spkr module. The DPM also connects in-line with the receiver throttle channel to ESC signal. This allows the DPM to monitor the throttle setting and pulse it if any one of the cells in the pack goes below the danger threadhold that can damage the pack.
For my 10s setup, the DPMs simply daisy-chain together by connecting the power output lines in series and routing the receiver throttle channel through one DPM and then the other DPM. The last DPM in the daisy-chain gets connected to the ESC.
For my servo and receiver power, I'm using a Power Force Regulator from FMA Direct set to 6v. This device eliminates the need to keep a seperate receiver pack charged, has a fail-safe On/Off switch, and can handle the higher current needed for my heavy duty servos. The On/Off switch has a flush slide switch that I mounted on the side of the fuselage with the supplied plate and hardware. I powered the regulator from the DPM connected to the 4s BalancePro HD pack. Note that this pack must be connected to the ground side of the wiring and the other 6s pack is wired in series to power the Jeti 90-amp ESC. Optionally, you can also supply the Power Force regulator with a separate 2s, 3s, or 4s Lithium pack or 5-12 cell NiCd/MiMH pack.
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Joined: 5/24/2003 From: Rochester,
NY, USA Status: offline
After first testing my motor direction without a prop attached, I installed the APC 20x11 e-prop using the spacer made by my friend, Paul Weigand. Although I couldn't find any 12mm hubs, I thought it would look nice if I drilled out a Higley Safety Hub to fit on the end of the prop shaft.
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Joined: 5/24/2003 From: Rochester,
NY, USA Status: offline
The instructions for the pilot tray were quite sparse so I decided to make some simple modifications to better suit my electric conversion. I wanted the pilot tray to be easily removeable to better access the batteries for recharging. I cut one of the two trays so that it could slide in and out. I then used the cut away sections to strengthen the assembly underneith. The trays were glued with 5-minute Z-poxy and also screwed into the channel of the main hatch door.
Since I plan to test fly the Cub tomorrow, I will use the stock screws to hold the pilot tray in position. The tray rests on a channel on the inside of the left window area. The rubber pilot is pre-painted and comes with a double-sided sticky foam pad to hold him on the tray. I used some medium CA to help hold the pad to the wooden tray.
Note that the front windshield is held in place with supplied screws and rubber inserts to protect the plastic.
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Joined: 5/24/2003 From: Rochester,
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The windows came in the kit as a single piece for each side and only needed to be cut on one line to separate them. I glued them in place with Pacer POLY ZAP(tm). Designed to work on plastics, delron, polycarbonate, nylon, and rubber...is is ideal for clear canopies and windows. It dries clear and is non-fogging when kicker is not used.
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Joined: 5/24/2003 From: Rochester,
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The wing assembly is straightforward. Two aluminum rods are inserted in the right wing first and held with machine screws in pre-tapped holes. Once the wing is in position, the left side is held by drilling holes into the aluminum rods via the pre-drilled holes in the wing. The left wing half is then held by sheet metal screws. To dissassemble, you remove the machine screws in the right wing half.
Look forward to hear a flight report on this beauty.
Two weeks ago a friend of mine maidened his electric converted 1/4 scale PA18 Cub. It have been flown with an OS120FS for several years, but suddenly he bought a Cyclon 160 and connected it to 10S5000 FlightPower EVO through an Jeti 90 ESC. AUW appr 7,5 kilo. It flew nice already on an 16x8 APC-prop at just 50A on WOT. More power than the OS gave, and still it is not tested with a better prop! It is planned to work as a TUG for our 1/4 scale wintage gliders and there are no doubt it has enough power!
Do you use the 5320/28 or 5320/34? I suppose the /34...
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Joined: 5/24/2003 From: Rochester,
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Hi,
I used an AXI 5320/28 motor. The maiden flight demonstrated so much power that the 20" prop is not needed. I used it because it was all I had at the time. An 18" or 19" prop should work fine.
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Joined: 5/24/2003 From: Rochester,
NY, USA Status: offline
I had an opportunity to test fly my Cub over the weekend so I rushed to finish the assembly to make it air worthy.
It was rather funny as I hesitated and squinted at the first part of the large callsign decal. I was about to apply the large decal to the wing, leaving the others for after the maiden flight, when I noticed that the "N" in the plane I.D. was a mirror image. I cut out the center portion of the "N" and then applied the decal. Once applied, I cut the correction from a piece of black sticky-back Monocote trim sheet that I had from a previous project.
I notified Fai Chan of Airborn Models (the U.S. distributor for World Models) and he found that his new stock had the corrected decal. Apparently my model was one of the last from the previous production run.
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Joined: 5/24/2003 From: Rochester,
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The final step of my assembly was to attach the struts and their supports. The design of these struts were very good and proper for a plane this size. All the wing inserts were pre-installed so you only needed to find the pin holes in the covering. My only change after the maiden flight will be to make the attachment to the fuselage a quick release post and pin instead of the supplied screws and locknuts.
The maiden flights were perfect yesterday! I'll post photos and video soon...
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Joined: 5/24/2003 From: Rochester,
NY, USA Status: offline
Here are some Ready-To-Fly photos of the J3 Cub. For now, we'll assume an all up weight of about 16lbs. The power system delivers 2500 watts at 68amps for about 156w/lb. Obviously, I have much more power than needed which will be seen on the second video (I made 2 of them) showing slipping and stall turns. For the most part, we used 1/4 to 1/2 throttle and then throttled up to 3/4 or full for various power maneuvers.
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All Forums >> Electric Aircraft Universe >> Glow to Electric Conversions >> RE: World Models J-3 Cub 1/4 Scale 
RE: World Models J-3 Cub 1/4 Scale - 
