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???? NO.1 RC???? ??? :: X-DRIVE TB (TwoBelts)
X-drive TB (Two Belts) Specification:
# Drive Unit (TB / Super Silent Unit)
Two Belts Type (Single Belt: 1ea / Twin Belt: 1ea)
RPM Lock Contra Drive system (Coaxial)
L: 220mm W: 80mm H: 115mm Weight: 660g (CD Unit + Motor + soft mount + Rear supporter)
Spinner : 82mm cabon (25g)
Pinion 17T / Pully 64T
Gear ratio 1 : 3.764
# BJ FORCE MOTOR (CD Special)
L: 50mm D: 50mm W: 335g
Max RPM : 19.822 @ 40.4v (10S Lipo)
MAX: 4500w (10s 130A / 3 second) Continues : 2800W (10S 80A/ 1 minute)
Shaft: L:40mm / D:6mm
Mount: 4mm*30mm + 3mm*25mm
10 pole / 8khz / Timming 0~5 Degre
Inspection before use.
Recommend to use soft type "threadlocker" of Locktite 222.
This unit has been assembled in BJ Craft, but there may be able to exist mistake.
Before your use, please check and follow the order specified below.
1. Tension check for single belt
1 out of 2 motor mount bolts is supposed to be able to adjust tension for the single belt.
The best efficiency of belts is the most loose tension as long as slip does not happen.
When belt tension is unnacessarily strong, motor baring life is shortened.
2. Check of the 2 motor mount bolts.
Check and confirm again motor mount bolt is secured tightly after checking the belt tension .
3. Recheck and confirm all the bolts are fixed tightly.
If the above three check points are OK, the X-Drive can be operated.
Mount
Please make mount to be matched to the plane reffering to the pictures.
If you do not use soft mount, you may not need to use rear supporter.
Installation of propeller and spinner
The carbon spinner for contra drive is included in the unit.
BJ Craft contra spinner is 82mm diameter x 90mm long only.
1. Takeout 4mm hex bolt of rear drive washer,push back drive washer completely with propeller.
Recommend to use threadlocker when reinstall the 4mm hex bolt.
2. Installation of back plate and rear propeller :
Check the positions of spinner 6 bolt holes, propeller slot in spinner, rear propeller position then fix rear propeller bolt.
3. Takeout 4mm hex bolt of front drive washer, push back drive washer completely with front propeller,
then fasten 4mm bolt tightly (do not need to use threadlocker)
4. Installation of rear spinner : Fasten 6 pcs of 2mm bolts with + drivers.
5. Installation of rear centering disc, Install front propeller.then put washer and tighten the bolt.
6. Installation of 3mm bolt of front spinner and silicon tube : As front spinner is fixed by the tension of slicon tube, which must be over 10mm.
7. Fasten the bolt to become 1mm gap between the front spinner and rear one and check the 3mm bolt slightly to be toutched centering disc to front spinner
# 3 pcs of different size of centering disc are included in the kit. Sellect centering disc to fit your case.
ESC
Recommend to continuous on/over 100A (22*22 F/R maximum 130 A）
“BJ Force Motor" 10 poles, Maximum 20,000 RPM.Timming 5 dgr, frequency 8KHZ, Hard brake.
BJ Force Motor can be used for Low level cheap ESC. most cheap ESC can support to 10 poles / 35,000RPM.
If you want to use 80A-90A small ESC, on the ground check ampere (current) and limit the full throttle to fit your small ESC spec.
As BJ Force motor has relatively strong power compare to its size, tempreture of motor and ESC is high ( shall be explained in detail in the part of motor)
The higher KHZ easily finds out pole position so timming is more accurate, motor runs more smoothly.
Though that lowers tempreture of motor more than lower KHZ. but reduces maximum power and hikes tempreture of ESC.
# Attention
Use acceleration speed slow or make throttle delay big not to happen belt slip
# Idle to full throttle 4 seconds is recommended
If you are in difficulty landing your EP plane, that bcause you did not set delay.( when you use ESC brake strongly)
After maiden flight, slowly reduce delay by inividual throttle work. (as individual throttle work style has big difference)
In case of programable acceleration delay (low to full throttle speed) of ESC, set slow
acceleration at recommended 4 second not 1 sec (factory setting). then make a maiden flight.
For Futaba 18MZ, which enables throttle delay programming, program a delay of at least 4 seconds for acceleration (AFR / Speed / IN 10 , OUT 23)
Do not set the transmitter if ESC can be set.
If the transmitter can set the delay, ESC in its normal state. If you set all of both, it shall be too slow.
If you have ESC and radio which are not able to program throttle delay, you must practice the skill to use very slow throttle.
The belt drive is connected with 2 propellers which have large diameter and motor with strong tension,
motor can be reacted by quick acceleration but propeller does not react due to belt. slip may be happened.
Quick throttle work to be used in 3D flight can cause the belt slip and ESC broken (fire) by wrong timming.
In the case of ESC gets fire, BJ Force motor can also be got fired in its coil.
The slower throttle work is the safer, then step by step reduce the delay to be fit to your own throttle work style.
The X-drive stability margin (perfect non slip of belt) of the drive increases weight,
so problem does not happen in the limit of possible F3A flight.
Most case setting of drive fits to users’ style, but in case of X-drive, user needs practice.
Propeller
#ATTENTION
If you are a fixd throttle contol style ( regardless of speed of plane, control the throttle only low, middle, high), or rough control of throttle and not exquisite throttle management.
Recommend to use 22*18 F/R propeller for maiden flight.
In order to avoid Belt slip, Battery and ESC fire
#The followings are for the F3A flyers who control constant flying speed
22*22 F/R
FALCON 22*22 F/R
The recommended propeller (Ideal for all types of airplanes, Maximum current consumption is 107A)
Brenner 22*22 F/R
TOP PERFORMANCE (Highest performance, but with a higher load than the recommended propeller. Maximum current consumption is 115A)
Mejzlik 22*22 F/R.
(Performance is the same as FALCON. But the load is larger than the Brenner. Maximum current consumption is 130A)
If full open throttle, it is not good, but around 85A is good efficiency.
22*20 F/R
Mejzlik 22*20 F/R.
(Best match, speed/sound/pattern tracking)
Brenner 22*20 F/R.
(It has less load and speed than Mejzlik and is a little noisy.)
Sound improves when you modify a propeller tip, better than Mejzlick
Different propeller matches of F/R
Pattern tracking is worse than using the F/R same propeller.(Better than free type contra system)
See the below Description of Lock/Free Type contra system
Sound is better than in case of using the F/R same propeller.(Air easily passes through the front and rear propeller.)
So far, the Contra drive has not shown any good results in vertical up in use of the 22*22 F/R propeller.
So the prop wasn't used.
The biggest issue with the Contra drive is the lack of speed in strong winds.
So BJ wanted a system that could turn the largest propellers(22*22) to its basic specifications, and that was realized.
Specifically, the motor was developed in order to make 22*22 available for the use of all throttle.
Install the propellers so that they overlap at 45 degrees as shown in the picture.
The X-Drive is a lock type contra drive system that always rotates the propeller overlapping in the same position.
If propeller overlap at vertical and horizontal, not at 45 degrees, it's not good because it's noisy when you control the rudder and the elevator.
This creates a special noise by howling when the rudder and the elevator control and start to move the plane overlapping the propeller tip at the same demension
If not use soft mount the noise is greater when the direct hard-mount is used
In case of this must fit propeller at 45 degrees.
Battery
The following data are the case for a good battery for the F3A and differ greatly depending on air density/ individual flying style.
The current battery is not accurate in the C-rate and capacity shown. This is because each manufacturer tend to describe differently for sale.
BJ has been involved in the research and development of LIPO batteries and has used it since 1999,
but current batteries are all lower capacity than that of the 25C batteries (5000mah 10S weight of 1230g) used by BJ in 2005.
Although a bit difference, all the LIPO batteries in the world use the same powder, the most accurate method of measuring battery output is battery weight.
X-Drive to Battery Match.
C-rate and capacity are not significantly different from the results of the description of following,
because C-rate and capacity are ultimately proportional to their weight。
The following data and results are under the condition of 。。。。。。。。
10 Cell battery，wind speed 5m/sec, biplane, 22*22 F/R , P-19 , 170m of distance
1000g, even if you have a top quality battery, you use a full throttle without limitation,
you will find that it is difficult to perform the second half of the maneuver.
(Limit maximum power to 80A to perform the second half of the maneuver.As the indibidual difference is so big, you shall find out it to fit to you)
1100g, Careful use of throttle work most cases enables second-half of the maneuver. However, it is necessary to be careful about the use of the battery.
(you may need to limit the throttle to the capability of the battery)
1200g, A strong windy day needs attention.
Because of its strong power of battery, a throttle delay can be used to prevent possible belt slip.
1300g, Requires little throttle restriction to finish the maneuver. If you use 85A of throttle limit, you can fly longer time
Throttle delay is essential and should inhibit sudden throttle work to prevent belt slip.
1400g, No throttle limitation is required. The throttle delay must be set sufficiently large.
# Caution
If we don't finish the second half of the maneuer and motor is very hot, we suspect overheating of the motor,
but the BJ FORCE MOTOR will operate normally at high temperatures unless the motor stops.
We recommend changing your battery to a larger one or setting the throttle limit.
The concept of design.
This system is a drive unit which was designed on the position of aircraft designer and flier
This drive is the system which focused only for the improvement of perormance and easier flight.
For instance, higher shaft torque in the middle low throttle position increases stability of the plane in the slower speed.
When i asked that increase motor shaft torque, the engineers who design motor said that this case motor does not perform the smooth turning, we take to increase middle low motor shaft torque instead of giving up the smooth turning
At first, I was satified that the drive unit carried out the improved aircraft design perormance but passing the time,I recognized that exclusive motor will improve performance.
finally exclusiv motor has been produced, right now I need to develop propeller for better performance.
Development is going on and on, as the performance is going better and better,I couldn't decide that which is optimist time to launch.
Even though I launched the drive unit now,the system and the performance of that shall be improved continualy, it shall be also developed for present buyers to upgrade the system easily.
Aircraft design / development of drive system to match to each model / start the development of propeller
Balance of all of the above shall show better performance of BJ CRAFT planes.
Every F3A flier wishes his own customized plane that is not the models I have produced for general fliers.
Being the accomplishment of the above, in future custom shop shall be runned for the specialized individual flier.
X-Drive TB component and its limitation.
X-drive has 2 belts and very calm sound. The composition of the system is very simple and trouble free.
This system is
"RPM Lock Type Contra Drive System" that
always keeps the same RPM of front and rear propellers.
This system include "BJ FORCE MOTOR", recommend Falcon 22*22 F/R propeller, consumes over 130A at full throttle 100% even if it is different from the batteries used.
You must check the current and recommend to limit 85A at full throttle.
ESC can use 80A though recommendation is on/over 100A, at this moment, also recommend to check your ampere to resist your ESC and to limit ampere full throttle.
Common F3A flight is possible with about 85A at full throttle (it can be different depending on the ESC,if you limit at 70% AFR of full throttle, it shall be 80A)
Power of
drive was not limited on the general safety level when the drive system was developed (explosion of ESC and battery).This helps to have very good throttle curve.
For your safe use,you must check the current and recommend to limit 85A at full throttle.
There are many contra drives in the market, they were limited power for their safe use, we sell this system without special limitation of power.
If user does not fully understand the limitation in the above,you may face the states which get fire, belt slip or can be difficult to finish last maneuver because of not enough battery.
If you fully understand these limitation and set the drive fit to you and caefully impeove performance step by step, that will show maximum capacity.
Finally these shall be the source of defeating your competitors in the competition.
here is a link the original page, which had far less information
???? NO.1 RC???? ??? :: BJ Drive system