Fei Bao Jets Dolphin build thread by RCISFUN
06-23-2014, 06:42 PM
#1
Fei Bao Jets Dolphin build thread by RCISFUN
This will be my build thread for the new Fei Bao Sport jet, the Dolphin
In this thread I will attempt to cover the building sequence and the design of internal mounting components that I made during the assembly of this great model.
Additionally I have been asked by the factory to write the manual.
I starting working on this model in the beginning of May for a couple of evenings a week and have been photo documenting my work as I proceeded. I designed all of the internal mounting parts in AutoCAD and have forwarded to the factory for inclusion into the production model.
Drawings will include fuel tank mountings, two nose mounted battery boxes, UAT mounting, mounting plates for servo connections and a balancing fixture.
I will start off with photos of the completed model, specification of the various parts and then start posting my build sequence.
The model has just been test flow by three competitive pattern pilots, Jim Hiller, Lewis Patton and Joe Stek. The feedback from these three gentlemen was unanimous, FB Jets has a winner on their hands.
The basic specifications are as follows:
Length: 104 1/3" (2650MM)
Wingspan: 91 3/4" (2330MM)
Dry Weight w/all components: 35 Lbs (15.9 Kg)
Power: 32 Lbs to 40 Lbs (140 N to 180 N) Jet Central Rhino used in prototype
Fuel Capacity: 155 oz (4.6L) (Prototype)
Main Wheel Diameter: 4.3” (109 mm)
Main Strut Length: 7.5” (190.5 mm)
Pipe Length: 37” (940 mm)
Pipe Diameter: 3 ½” (89 mm)
Bell Mouth Length: 2.75” (70 mm)
Equipment Used:
Elevators (2) Hi-Tec HS-7955TG
Ailerons (2) Hi-Tec HS-5625
Rudder Hi-Tec HS-7955TG
Flaps (2) Hi-Tec HS-7955TG
Steering Hi-Tec HS-645MG
Door Valve: Jet Central Dual Action
Landing Gear Valve : Jet Central Dual Action
Brake Valve: Jet Central Single Action
Door Sequencer: Jet Central
ECU Battery: 5000 mAh LiPo 2 cell Hard Pack
Receiver Battery: 5000 mAh LiPo 2 cell Hard Pack regulated to 6V w/Liner voltage regulator
In this thread I will attempt to cover the building sequence and the design of internal mounting components that I made during the assembly of this great model.
Additionally I have been asked by the factory to write the manual.
I starting working on this model in the beginning of May for a couple of evenings a week and have been photo documenting my work as I proceeded. I designed all of the internal mounting parts in AutoCAD and have forwarded to the factory for inclusion into the production model.
Drawings will include fuel tank mountings, two nose mounted battery boxes, UAT mounting, mounting plates for servo connections and a balancing fixture.
I will start off with photos of the completed model, specification of the various parts and then start posting my build sequence.
The model has just been test flow by three competitive pattern pilots, Jim Hiller, Lewis Patton and Joe Stek. The feedback from these three gentlemen was unanimous, FB Jets has a winner on their hands.
The basic specifications are as follows:
Length: 104 1/3" (2650MM)
Wingspan: 91 3/4" (2330MM)
Dry Weight w/all components: 35 Lbs (15.9 Kg)
Power: 32 Lbs to 40 Lbs (140 N to 180 N) Jet Central Rhino used in prototype
Fuel Capacity: 155 oz (4.6L) (Prototype)
Main Wheel Diameter: 4.3” (109 mm)
Main Strut Length: 7.5” (190.5 mm)
Pipe Length: 37” (940 mm)
Pipe Diameter: 3 ½” (89 mm)
Bell Mouth Length: 2.75” (70 mm)
Equipment Used:
Elevators (2) Hi-Tec HS-7955TG
Ailerons (2) Hi-Tec HS-5625
Rudder Hi-Tec HS-7955TG
Flaps (2) Hi-Tec HS-7955TG
Steering Hi-Tec HS-645MG
Door Valve: Jet Central Dual Action
Landing Gear Valve : Jet Central Dual Action
Brake Valve: Jet Central Single Action
Door Sequencer: Jet Central
ECU Battery: 5000 mAh LiPo 2 cell Hard Pack
Receiver Battery: 5000 mAh LiPo 2 cell Hard Pack regulated to 6V w/Liner voltage regulator
Last edited by RCISFUN; 06-23-2014 at 06:44 PM.
06-23-2014, 07:18 PM
#4
Landing Gear details
Note: Make sure to remove wheel axial's and use a fine grit sand paper with the axial chucked in a power drill to spin and remove a slight amount of material and then apply grease, I noticed that the wheel bushing was galling with the axial. Also make sure to file a grove in the axial where the set screw make contact, the same hold true for the nose wheel pin, file two groves for the two set screws.
Note: Make sure to remove wheel axial's and use a fine grit sand paper with the axial chucked in a power drill to spin and remove a slight amount of material and then apply grease, I noticed that the wheel bushing was galling with the axial. Also make sure to file a grove in the axial where the set screw make contact, the same hold true for the nose wheel pin, file two groves for the two set screws.
Last edited by RCISFUN; 06-24-2014 at 01:58 AM.
06-24-2014, 02:47 AM
#7
Fuel System:
The majority of effort in this prototype build was coming up with a method to secure the fuel tanks and to get extra fuel capacity.
There were three fuel tanks supplied with the prototype, they consisted of two saddle tanks and one main tank, the shape of the main tank in my opinion is not conducive to an aerobatic sport jet as the depth is shorter than the height, this makes for bad clunk geometry.
Each saddle tank volume is 37 oz (1.1L) and the main tank is 47 oz (1.4 L) for a combined volume of 121 oz (3.6L).
For an airframe of this thrust class I felt that it not enough fuel so I added an extra 34 oz (1L) tank and positioned it below the main tank. It was able to slide underneath the inlet ducting, I made a shelf above the extra tank for the main tank to sit on. This brought the total volume up to 155.5 oz (4.6L).
For the test flights the timer on the transmitter was set for six minutes, most of the test flights were conducted at around half throttle, after landing and taxiing back there was one full saddle tank and the main tank was full, i.e. 84 oz (2.5 L) of remaining fuel.
Note: A external taxi tank was used for start up and taxing out to position.
The brass fuel line and the "rubber" clunk hose supplied with the prototype were not used as they were too small for this thrust class, they are shown below for reference only.
The stopper plates were drilled out to accept 3/16" (5mm) brass tube. All external fuel and vent hose used was large diameter Tygon tubing.
The tanks were supplied with aluminum ring fittings for the rubber tank stoppers, they were prepared to be cemented to the tanks by drilling 1/16" (1.5 mm) holes around the shoulder perimeter to allow the Hysol to penetrate and add extra cementing area.
The tank mounting I designed for these particular tanks is shown below, the saddle tanks bolt into the fuselage and the main tank is held into position by a bracket.
The clunk set-up for the saddle tanks and the main tank is shown below, as you can see the travel for the main tank is limited by the short length of hose connected to the clunk and the saddle tank geometry is not an issue.
The inner connection of the tanks are in series, i.e. the extra 1L tank is connected to the outside vent and feeds the left saddle tank. The left saddle tank in turn feeds the right saddle tank, and the right saddle tank feeds the main tank. Because of the large diameter tubing used I had no issues during filling, i.e the tanks did not balloon up due to restrictive venting.
I believe that the factory has since come up with a different set of tanks, I am waiting for confirmation from Catherine.
The majority of effort in this prototype build was coming up with a method to secure the fuel tanks and to get extra fuel capacity.
There were three fuel tanks supplied with the prototype, they consisted of two saddle tanks and one main tank, the shape of the main tank in my opinion is not conducive to an aerobatic sport jet as the depth is shorter than the height, this makes for bad clunk geometry.
Each saddle tank volume is 37 oz (1.1L) and the main tank is 47 oz (1.4 L) for a combined volume of 121 oz (3.6L).
For an airframe of this thrust class I felt that it not enough fuel so I added an extra 34 oz (1L) tank and positioned it below the main tank. It was able to slide underneath the inlet ducting, I made a shelf above the extra tank for the main tank to sit on. This brought the total volume up to 155.5 oz (4.6L).
For the test flights the timer on the transmitter was set for six minutes, most of the test flights were conducted at around half throttle, after landing and taxiing back there was one full saddle tank and the main tank was full, i.e. 84 oz (2.5 L) of remaining fuel.
Note: A external taxi tank was used for start up and taxing out to position.
The brass fuel line and the "rubber" clunk hose supplied with the prototype were not used as they were too small for this thrust class, they are shown below for reference only.
The stopper plates were drilled out to accept 3/16" (5mm) brass tube. All external fuel and vent hose used was large diameter Tygon tubing.
The tanks were supplied with aluminum ring fittings for the rubber tank stoppers, they were prepared to be cemented to the tanks by drilling 1/16" (1.5 mm) holes around the shoulder perimeter to allow the Hysol to penetrate and add extra cementing area.
The tank mounting I designed for these particular tanks is shown below, the saddle tanks bolt into the fuselage and the main tank is held into position by a bracket.
The clunk set-up for the saddle tanks and the main tank is shown below, as you can see the travel for the main tank is limited by the short length of hose connected to the clunk and the saddle tank geometry is not an issue.
The inner connection of the tanks are in series, i.e. the extra 1L tank is connected to the outside vent and feeds the left saddle tank. The left saddle tank in turn feeds the right saddle tank, and the right saddle tank feeds the main tank. Because of the large diameter tubing used I had no issues during filling, i.e the tanks did not balloon up due to restrictive venting.
I believe that the factory has since come up with a different set of tanks, I am waiting for confirmation from Catherine.
Last edited by RCISFUN; 06-24-2014 at 03:10 AM.
06-24-2014, 03:16 AM
#8
UAT
The UAT used was the BVM style, I designed a UAT holder that I have used in my other models.
I test my UAT in a bowl of water and pump it up to around 30 psi (2 bar) with my air compressor.
That's all for now, until later!
The UAT used was the BVM style, I designed a UAT holder that I have used in my other models.
I test my UAT in a bowl of water and pump it up to around 30 psi (2 bar) with my air compressor.
That's all for now, until later!
Last edited by RCISFUN; 06-24-2014 at 03:46 AM.
06-24-2014, 03:50 AM
#9
Join Date: Apr 2006
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Hi Rich,
As I like the Futura, I also might like this Dolphin, but I do not like a so complex fuelsystem: Would it not be possible to omit the air conducts and just use one tank like oll these Futuras and Vipers do?
As I like the Futura, I also might like this Dolphin, but I do not like a so complex fuelsystem: Would it not be possible to omit the air conducts and just use one tank like oll these Futuras and Vipers do?
06-25-2014, 03:41 AM
#11
Battery Box:
In order to get the CG on the Dolphin it was obvious that weight was going to be needed up front in the nose.
As I was presented with a clean slate with the prototype it was decided to create two battery boxes and to make them as long as possible to allow the batteries to be shifted to make CG corrections. It was decided that the best live weight would be hard cased 5000 mAh 2 Cell LiPo's used for RC cars. I used one for the ECU battery and the other with a linear regulator to run the receiver. You don't have to worry about charging that during a flying session! As it worked out this was the perfect nose weight as the CG came out spot on with the batteries slid fully forward, I used pieces of high density white foam as the "keeper" to hold the batteries into the box, these can be easily removed (not too easy as to let the battery slide during flight) to allow the batteries to be removed for charging.
In order to get the CG on the Dolphin it was obvious that weight was going to be needed up front in the nose.
As I was presented with a clean slate with the prototype it was decided to create two battery boxes and to make them as long as possible to allow the batteries to be shifted to make CG corrections. It was decided that the best live weight would be hard cased 5000 mAh 2 Cell LiPo's used for RC cars. I used one for the ECU battery and the other with a linear regulator to run the receiver. You don't have to worry about charging that during a flying session! As it worked out this was the perfect nose weight as the CG came out spot on with the batteries slid fully forward, I used pieces of high density white foam as the "keeper" to hold the batteries into the box, these can be easily removed (not too easy as to let the battery slide during flight) to allow the batteries to be removed for charging.
06-25-2014, 10:02 AM
#13
Hey Keith, absolutely
Check out this thread, post # 28:
http://www.rcuniverse.com/forum/rc-j...t-event-2.html
I knew that Louis liked the Dolphin when we had to pry the "Futaba" transmitter out of his hands!
Check out this thread, post # 28:
http://www.rcuniverse.com/forum/rc-j...t-event-2.html
I knew that Louis liked the Dolphin when we had to pry the "Futaba" transmitter out of his hands!
06-26-2014, 09:01 AM
#15
Thanks Keith,
I just was informed about another surprise... it looks like there might be a New Jet Central Turbine offering that will be installed in the Dolphin for KY Jets, more details to follow.
Sorry that I wasn't able to post more of the building sequence, I was tied up a bit.
I just was informed about another surprise... it looks like there might be a New Jet Central Turbine offering that will be installed in the Dolphin for KY Jets, more details to follow.
Sorry that I wasn't able to post more of the building sequence, I was tied up a bit.
07-01-2014, 06:44 PM
#18
Been busy getting ready for JOK so I haven't had time to post much. I did manage to work on the main gear door retract cylinder geometry which didn't seem to be able to close the doors once the air speed was up.
The factory location had the cylinder inside of the wheel well
I cut out the original mount and moved the cylinders inboard, I cut new mounts and hysoled them in.
The cross brace needed to be repositioned
Extra cross braces were hysoled in to stiffen the new cylinder mounts.
New cylinder mounts
I guess we will find out if this takes care of the main door issue at JOK
The factory location had the cylinder inside of the wheel well
I cut out the original mount and moved the cylinders inboard, I cut new mounts and hysoled them in.
The cross brace needed to be repositioned
Extra cross braces were hysoled in to stiffen the new cylinder mounts.
New cylinder mounts
I guess we will find out if this takes care of the main door issue at JOK
07-02-2014, 03:05 AM
#20
On the maiden flight the right retract did not come down resulting in a scrapped wing tip, of course the gear worked every time on the ground during testing
During the post flight inspection it was discovered that there was an interference on the strut at the wing / fuselage junction where the rib was cut out, it was only about a 1/16" (1.5mm) interference, but is was enough to not let the retract disengage. It was a simple fix to gring away a bit of the rib.
For the repair a carbon fiber plate was attached to the affected area on the wing tip.
During the post flight inspection it was discovered that there was an interference on the strut at the wing / fuselage junction where the rib was cut out, it was only about a 1/16" (1.5mm) interference, but is was enough to not let the retract disengage. It was a simple fix to gring away a bit of the rib.
For the repair a carbon fiber plate was attached to the affected area on the wing tip.
07-16-2014, 07:38 PM
#25
I finally got the Dolphin unpacked and sorted out and plan on hitting it hard the next few days.
Rich, send me your final CG and throws when you get a chance. I hope to have it flying for Michigan.
I'm going to try to make the gear doors work too. The easy fix may be two cylinders per door but I'm going to try something else first.
The hardest part of of finishing this plane will be finding a pilot for it
Rich, send me your final CG and throws when you get a chance. I hope to have it flying for Michigan.
I'm going to try to make the gear doors work too. The easy fix may be two cylinders per door but I'm going to try something else first.
The hardest part of of finishing this plane will be finding a pilot for it