E-flite J-3 Cub 25 ARF
07-13-2006, 07:10 AM
#1
Senior Member
Thread Starter
E-flite J-3 Cub 25 ARF
Hi,
I'm reviewing the J-3 Cub 25 ARF from E-flite at [link=http://www.horizonhobby.com/Products/Default.aspx?ProdID=EFL4000]Horizon Hobby[/link]. The J3 Cub has great scale appearance and performance which include scale ailerons. The ARF model is built from quality balsa and light ply construction making for a sturdy, lightweight airframe that handles incredibly well in most any flying situation. The firewall is set up for use with an outrunner motor, such as E-flite’s Power 25, making a perfect power match for the airframe. Optional floats add a new dimension to the scale flying experience, and the one-piece wing allows for easy transportation to and from virtually any flying field, pond or lake. The model can be flown with either a 10-cell NiCd/NiMH pack or 3-cell Lithium pack.
Key Features:[ul][*] Outstanding scale detail, including the factory-painted fiberglass cowl with molded engine detail[*] Scale aileron design sets the E-flite J-3 Cub apart from other 25-size electric Cubs on the market[*] E-flite's optional 25-size floats are easy to assemble and attach to the J-3 Cub, and offer thrilling performance during water taxi and take-off[*] Built-in float mounts[*] Removable one-piece wing for fast transition to the flying field[*] Factory-painted landing gear with authentic Cub wheel caps[*] Quality balsa and light-ply construction, and genuine Ultracoat covering[*] Outrunner-ready firewall—perfect match for E-flite’s Power 25 Outrunner, 870 Kv[*] Flies great with LiPo (THP42003S2PPL) or Ni-MH (EFLB4010) packs
[/ul]
Specifications:[ul][*] Wing Span: 62 inches (1575 mm)[*] Overall Length: 35.5 inches (900 mm)[*] Flying Weight: 4.0 - 4.25 lbs (1.8 - 1.9 kg)[*] Motor Size: Recommended: E-flite Power 25 Outrunner (EFLM4025A) - not included[*] Radio: Minimum Requried: 4 channels - not included[*] Servos: Required: 4 Mini Servos - not included Recommended: 4 JR Sport MN-48 (JSP20040)[*] Trim Scheme Colors: UltraCote Cub Yellow (HANU884) & Black (HANU874)[*] Prop Size: 12x6E[*] Speed Control : Required: 40 amp brushless Recommended: E-flite 40A brushless (EFLA312B)[*] Recommended Battery: E-flite 10-cell 12V 1800mAh Ni-MH (EFLB4010) or Thunder Power 3-cell 4200mAh Li-Po (THP42003S2PPL) - not included
[/ul]
I'm reviewing the J-3 Cub 25 ARF from E-flite at [link=http://www.horizonhobby.com/Products/Default.aspx?ProdID=EFL4000]Horizon Hobby[/link]. The J3 Cub has great scale appearance and performance which include scale ailerons. The ARF model is built from quality balsa and light ply construction making for a sturdy, lightweight airframe that handles incredibly well in most any flying situation. The firewall is set up for use with an outrunner motor, such as E-flite’s Power 25, making a perfect power match for the airframe. Optional floats add a new dimension to the scale flying experience, and the one-piece wing allows for easy transportation to and from virtually any flying field, pond or lake. The model can be flown with either a 10-cell NiCd/NiMH pack or 3-cell Lithium pack.
Key Features:[ul][*] Outstanding scale detail, including the factory-painted fiberglass cowl with molded engine detail[*] Scale aileron design sets the E-flite J-3 Cub apart from other 25-size electric Cubs on the market[*] E-flite's optional 25-size floats are easy to assemble and attach to the J-3 Cub, and offer thrilling performance during water taxi and take-off[*] Built-in float mounts[*] Removable one-piece wing for fast transition to the flying field[*] Factory-painted landing gear with authentic Cub wheel caps[*] Quality balsa and light-ply construction, and genuine Ultracoat covering[*] Outrunner-ready firewall—perfect match for E-flite’s Power 25 Outrunner, 870 Kv[*] Flies great with LiPo (THP42003S2PPL) or Ni-MH (EFLB4010) packs
[/ul]
Specifications:[ul][*] Wing Span: 62 inches (1575 mm)[*] Overall Length: 35.5 inches (900 mm)[*] Flying Weight: 4.0 - 4.25 lbs (1.8 - 1.9 kg)[*] Motor Size: Recommended: E-flite Power 25 Outrunner (EFLM4025A) - not included[*] Radio: Minimum Requried: 4 channels - not included[*] Servos: Required: 4 Mini Servos - not included Recommended: 4 JR Sport MN-48 (JSP20040)[*] Trim Scheme Colors: UltraCote Cub Yellow (HANU884) & Black (HANU874)[*] Prop Size: 12x6E[*] Speed Control : Required: 40 amp brushless Recommended: E-flite 40A brushless (EFLA312B)[*] Recommended Battery: E-flite 10-cell 12V 1800mAh Ni-MH (EFLB4010) or Thunder Power 3-cell 4200mAh Li-Po (THP42003S2PPL) - not included
[/ul]
07-13-2006, 01:11 PM
#8
Senior Member
Thread Starter
RE: E-flite J-3 Cub 25 ARF
My rule is to typically build it and fly it stock first unless there is a blatant problem. We'll see if it has sufficient ground steering on grass and/or pavement...then it gets some floats. 
07-13-2006, 01:16 PM
#9
Senior Member
Thread Starter
RE: E-flite J-3 Cub 25 ARF
The J3 Cub 25 came very well packaged and each part was individually wrapped in plastic. The covering looked great and the 51 page manual was very well written with plenty of photos.
Although the Cub came already trimmed with decals, the kit provides an extra sheet for the various brand names.
Although the Cub came already trimmed with decals, the kit provides an extra sheet for the various brand names.
07-13-2006, 01:20 PM
#10
Senior Member
Thread Starter
RE: E-flite J-3 Cub 25 ARF
I removed the individual plastic bags and found the control surfaces were taped to their respective part of the plane. Everything was already painted and looked great!
07-13-2006, 01:25 PM
#11
Senior Member
Thread Starter
RE: E-flite J-3 Cub 25 ARF
The 30" fuselage was well built; being both strong and light. The motor mounting holes, control rod tubing, and, air-cooling system were already done. The front bottom hatch is held in place with pre-mounted magnets for easy battery access.
07-13-2006, 01:32 PM
#12
Senior Member
Thread Starter
RE: E-flite J-3 Cub 25 ARF
I'm using the E-flite 40A brushless (EFLA312B) ESC and there a warning note about the BEC having an overload at very high temperatures when using higher-current servos. Note that the ESC comes with mating connectors and wire extensions for the motor.
Important Note:
We have found during continued flight testing, the possibility of a rx/servo current overload to the BEC in the speed control, causing the motor and radio to shut down in flight. This has typically happened on extreme high temperature days with continuous extreme flight control inputs. Most speed controls on the market today are designed for use with 4 sub-micro servos with relatively low current draw like the E-flite S75. The newer sub-micro digital servos, as well as most micro and mini servos, have a higher current draw and can cause a BEC to shut down due to high temperatures.
In order to provide the most reliable product, E-flite recommends the use of a separate BEC (like the Ultimate BEC), or receiver pack and switch using the following items to ensure trouble-free operation:
- (EXRB100) Expert 720mAh NiMH 4.8v Receiver Battery
- (EXRA050) Expert Standard Switch
Use these items to power the receiver and servos after disabling the BEC on the ESC. E-flite does NOT recommend using the speed controller's BEC in the applications described above.
We have found during continued flight testing, the possibility of a rx/servo current overload to the BEC in the speed control, causing the motor and radio to shut down in flight. This has typically happened on extreme high temperature days with continuous extreme flight control inputs. Most speed controls on the market today are designed for use with 4 sub-micro servos with relatively low current draw like the E-flite S75. The newer sub-micro digital servos, as well as most micro and mini servos, have a higher current draw and can cause a BEC to shut down due to high temperatures.
In order to provide the most reliable product, E-flite recommends the use of a separate BEC (like the Ultimate BEC), or receiver pack and switch using the following items to ensure trouble-free operation:
- (EXRB100) Expert 720mAh NiMH 4.8v Receiver Battery
- (EXRA050) Expert Standard Switch
Use these items to power the receiver and servos after disabling the BEC on the ESC. E-flite does NOT recommend using the speed controller's BEC in the applications described above.
07-13-2006, 01:40 PM
#13
Senior Member
Thread Starter
RE: E-flite J-3 Cub 25 ARF
I'm using the recommended JR Sport MN-48 servos (JSP20040) and E-flite Power 25 Outrunner (EFLM4025A) ...when it arrives.
The two recommended battery packs are the E-flite 10-cell, 1800mAh NiMH (EFLB4010) or ThunderPower 3-cell, 4200mAh LiPo (THP42003S2PPL) pack. Although both packs weigh a similar amount, the power density of the Lithium pack is doubled over the NiMH pack which doubles for your flight time for about 4 times the cost.
The two recommended battery packs are the E-flite 10-cell, 1800mAh NiMH (EFLB4010) or ThunderPower 3-cell, 4200mAh LiPo (THP42003S2PPL) pack. Although both packs weigh a similar amount, the power density of the Lithium pack is doubled over the NiMH pack which doubles for your flight time for about 4 times the cost.
07-13-2006, 01:58 PM
#14
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RE: E-flite J-3 Cub 25 ARF
Greg
Have you chosen the RX ? Do you reckon that a 'normal' size RX - eg. a GWS R8MSL (Size - 65x25x15.5mm Weight - 22g) would be ok ?
I like the look of this bird but that LiPo !! Gonna cost a fortune !
Thanks
Have you chosen the RX ? Do you reckon that a 'normal' size RX - eg. a GWS R8MSL (Size - 65x25x15.5mm Weight - 22g) would be ok ?
I like the look of this bird but that LiPo !! Gonna cost a fortune !
Thanks
07-13-2006, 06:09 PM
#15
Senior Member
Thread Starter
RE: E-flite J-3 Cub 25 ARF
Yes, you can use a full size receiver on this model. The E-flite Power 25 Outrunner with a 12x6 prop will provide plenty of power so an additional few ounces of weight are not a problem. The JR Sport MN-48 Mini Servos weigh 22.4g each as well.
I'll see how long it flies on the NiMH pack and also take a video with that pack.
I'll see how long it flies on the NiMH pack and also take a video with that pack.
07-13-2006, 06:54 PM
#16
Senior Member
Thread Starter
RE: E-flite J-3 Cub 25 ARF
Just after testing the J3 Cub 25 on wheels, I'll try out the optional E-flite 25-Size Fiberglass ARF Floats (EFLA500). The E-flite quick-mount floats are designed specifically for 25-size planes that are float-ready out of the box, so you can go from pavement to pond in just minutes.
07-14-2006, 07:10 AM
#17
Senior Member
Thread Starter
RE: E-flite J-3 Cub 25 ARF
Assembly starts by mounting the gear mains with 4 straps and 8 screws into pre-drilled holes. The gear mains fit snuggly into channels in the bottom of the fuselage.
An innovative wheel design hides the collar and 4 screws inside for a very clean look. The plastic Cub cap covers the assembly.
An innovative wheel design hides the collar and 4 screws inside for a very clean look. The plastic Cub cap covers the assembly.
07-16-2006, 10:48 AM
#18
Senior Member
Thread Starter
RE: E-flite J-3 Cub 25 ARF
The landing gear fairings are secured with 3 tywraps.
The JR Sport MN-48 mini servos fit perfectly into the bay openings. I am using an [link=http://www.fmadirect.com/detail.htm?item=2098§ion=1]M5 v2[/link] receiver in my J3 cub 25 for glitch-free performance. Alternatively, the [link=http://www.horizonhobby.com/Search/Default.aspx?SearchTerm=encore&CatId=]Encore[/link] receiver provides the same glitch-free performance but allows for the 5th channel to be re-programmed for channel 5 or 6 in case flaps are used.
The JR Sport MN-48 mini servos fit perfectly into the bay openings. I am using an [link=http://www.fmadirect.com/detail.htm?item=2098§ion=1]M5 v2[/link] receiver in my J3 cub 25 for glitch-free performance. Alternatively, the [link=http://www.horizonhobby.com/Search/Default.aspx?SearchTerm=encore&CatId=]Encore[/link] receiver provides the same glitch-free performance but allows for the 5th channel to be re-programmed for channel 5 or 6 in case flaps are used.
07-18-2006, 06:41 PM
#19
Senior Member
Thread Starter
RE: E-flite J-3 Cub 25 ARF
My E-flite Power 25 Outrunner has not arrived yet so I will skip the motor and cowl installation for now.
Here is a photo of my 30" J3 Cub 25 fuselage next to a much larger 1/4 scale Cub I am currently converting to electric power.
Here is a photo of my 30" J3 Cub 25 fuselage next to a much larger 1/4 scale Cub I am currently converting to electric power.
07-18-2006, 06:44 PM
#20
Senior Member
Thread Starter
RE: E-flite J-3 Cub 25 ARF
I used ZAP Thin CA to glue the hinges in place. Remember not to use CA accelerator (or kicker) here as we want the CA to soak into the hinge material and balsa.
The JR mini servo mounted to the hatch plate using two supplied blocks. All the hardware needed for this procedure is supplied in the kit.
The E-flite manual is extremely detailed so I will be glossing over many areas clearly covered in the manual. One area not covered is that you will need 12" extensions for the aileron servos.
The JR mini servo mounted to the hatch plate using two supplied blocks. All the hardware needed for this procedure is supplied in the kit.
The E-flite manual is extremely detailed so I will be glossing over many areas clearly covered in the manual. One area not covered is that you will need 12" extensions for the aileron servos.
07-19-2006, 01:54 PM
#21
Senior Member
Thread Starter
RE: E-flite J-3 Cub 25 ARF
The wing joiner is made from two thinner pieces of plywood glued together with epoxy and then glued into one wing half. After first test fitting the wing halfs, they are glued together with epoxy.
The two aileron servos must be connected together with a "Y" adapter or an FMA [link=http://www.fmadirect.com/detail.htm?item=1762§ion=52]605SB[/link] Servo Buffer.
The two aileron servos must be connected together with a "Y" adapter or an FMA [link=http://www.fmadirect.com/detail.htm?item=1762§ion=52]605SB[/link] Servo Buffer.
07-20-2006, 08:18 AM
#22
Senior Member
Thread Starter
RE: E-flite J-3 Cub 25 ARF
The stabilizers were attached with epoxy after first cutting away the section of covering to be glued. I checked the incidences and needed no offset for creating a perfect alignment.
The tail wheel assembly is glued in place before attaching the rudder.
The tail wheel assembly is glued in place before attaching the rudder.
07-21-2006, 07:51 AM
#23
Senior Member
Thread Starter
RE: E-flite J-3 Cub 25 ARF
The linkages installed without issue. The two elevator half pushrods are combined using two wheel collars which are then secured with epoxy after alignment.
Note that I added a white spacer to center the tail wheel and used a toothpick with a dab of CA for a strain relief on the antenna wire.
Note that I added a white spacer to center the tail wheel and used a toothpick with a dab of CA for a strain relief on the antenna wire.
07-23-2006, 02:58 PM
#24
Senior Member
Thread Starter
RE: E-flite J-3 Cub 25 ARF
The canopy comes pre-trimed and painted so you just need to prepare the surfaces to be glued with a little sanding. The windows must be cut with a 1/16" border before gluing. I used Pacer PolyZAP glue which is designed to work on plastics, nylon, and, rubber. It is ideal for clear canopies and windows.