KDS Ebar Flybarless System

A BIG THUMBS DOWN FOR THIS PRODUCT!!! I CANNOT RECOMMEND IT!!!

Just arrived 30 minutes ago from RC711:
http://www.rc711.com/shop/kds-ebar-3...ox-p-5304.html

Amazing work from HK post and NZ post. I was told it shipped on the 15th, it's the morning of the 17th here.

I think KDS has done a very good job of the packaging. Nice looking box and the inside packaging is all soft foam. This should ensure the system arrives in good condition, no matter how rough the delivery service is.

The Ebar flybarless unit is bigger than the Align 3GX, which is a pity. You will not be able to fit this unit on a 250 anywhere, and it will not go inside the frames on a 450 Pro, so gyro mount only. Unlike the BeastX and like the 3GX, you cannot put this gyro on the side of the frames.

The Ebar flybarless unit weighs 12.2 grams, on it's own, and with the 5 leads, 23 grams.

The double sided foam looks to be firm enough and I doubt, with the weight of the flybarless unit, that it would move much on the foam, even though I've read that some thought it was too soft.

The PPC looks nice and the buttons have a nice positive click to them. The unit feels like it could take a good pounding in the tool box. More about the unit later, when I flash it up.

5 servo connector leads are provided for connection the Ebar to the Rx. I'm surprised they have provided leads with all 3 wires in each lead. Personally I think 3 of them could have been a single wire and just two carrying the power (mini Vbar has 2, 3GX has 1 in and out but you can use both for in). This would save weight and clutter. Going in a 450, I will probably remove the ground and power from 3 or the leads, myself.

The programmer lead is half a meter long, which should be long enough for most.

A mini disc is provided with the manual in Chinese and English. Don't attempt to put this disc in a slot drive. You can also download the English manual from the link above.

I'll post back with more as I progress with the install and flight tests.


* Currently there is an unresolved aileron issue and both KDS and RC711 have not replied to any emails. *
* Update: A replacement unit has resolved the problem, but it took months to get a replacement after *
* having to return the unit to China. *

Internal pictures: http://www.rcgroups.com/forums/showp...03&postcount=2
Installation 1: http://www.rcgroups.com/forums/showp...48&postcount=5
Installation 2: http://www.rcgroups.com/forums/showp...74&postcount=6
Setup 1: http://www.rcgroups.com/forums/showp...29&postcount=7
Flight test 1: http://www.rcgroups.com/forums/showp...93&postcount=9

For those wondering about the quality of the Ebar, I just pulled it apart.

The board is machine soldered. I would rate the quality of the PCB, components and soldering, as excellent. I can't fault it in any way and electronic design is my job.

The board is glued into the case with a white rubbery glue, which is very strong and the board would be near impossible to remove. The board is sitting level in the case.

Thanks for the link and info so far, keep up the good review.

I really hope it works out.That would save a bunch of money outfitting my helis.

KDS Ebar - Installation 1

The first interesting thing about the Ebar flybarless system is that it has no LED. The only way you know it's running and has finished initializing, is by a single kick up of the collective, and back to neutral.

Also, this unit must use a normal receiver. There is no option for satellite receivers. This does not concern me, because I like to use the telemetry features of the Optima receivers, but it may be a good reason to spend extra on another unit, for others.

The programmer (PPC) is a very nice unit. The display is clear and the buttons work well. You can plug it in before or after the helicopter is powered, but it would be a good practice to have it connected the first time you power up, like I did, to make sure it's up and running (the PPC display comes on).

As the PPC unit can store 8 models, I hope KDS will sell the flybarless unit on it's own, in the future, at an even lower price. This would be another big selling point for me.

I decided to fit the Ebar on the stock Align 450 Sport, using the Tarot 450 Pro FBL head, I had spare. What swayed me to fit it on the 450 Sport, in the end, was the size of the unit. It looked a little bulky on the gyro tray of the 450 Pro, and it would not fit in the frames of the 450 Pro. There appeared to be enough room for the Ebar in the bottom of the 450 Sport, if I moved the receiver up onto the gyro tray.

I think KDS needs to look closely at the size of the Ebar. It does not need to be as big as it is. The box does not need to be as tall as it is, at the moment, and if they used the method of three of the Rx servo signals coming from one plug, then the unit does not need to be as wide (too sockets removed). Hopefully they will have a smaller MkII version in the not too distant future.

In the mean time, anything from a 500 up should not be a problem and I did manage to squeeze it into the frames of the 450 Sport, but I had to use different double sided tape to do it and slightly modify the frames to get the PPC plug in. It will also work fine on the gyro tray of the 450 pro, it just overhangs the sides of the frames and the back of the tray, but servo lead length could become an issue

The width was not a problem in the bottom of the 450 Sport frame, but if I'd used the foam supplied the top of the Ebar would have touched the gyro tray. I decided to use 3M 4010 clear double sided tape, as I've had good success using this on several tail gyro installations (including the 250). Using this tape I had about half a millimeter of clearance between the top of the Ebar and the gyro tray, which I needed for the receiver.

I was very nervous about using this tape, especially after Justin's Dad reported having a crash due to head speed vibration issues with his KDS 700, but I had no choice. What gave me confidence, is that Align supplies what looks like standard thin 3M foam with the 3GX, and I had no issues with the 3GX relating to vibration.

The good news is the tape works fine, more about that later (and some pictures as well)...

KDS Ebar - Installation 2

The next trap with the installation of the Ebar is the servo output channels. No where in the manual does it say which servo connects to which output channel marked CH1, CH2, CH3 & CH4. I started by using the layout the BeastX uses but then found out the aileron and pitch servo had to be reversed, so the layout I ended up using is this (click to enlarge):



Unfortunately I found this out after I'd installed everything, so it was a real pain to get the leads out and back in again, but never mind, my hardships is your gain.

You'll know you have it wrong when you find the aileron cyclic works backwards and the swashplate gyro reacts in the wrong direction, so you can't just reverse the Tx. In fact I don't recommend, and it shouldn't be necessary, to reversing anything in the Tx, except the rudder channel, if required.

I ended up using the 5 leads provided with all of their wires, but I still feel that 3 of the leads do not require the power and ground, especially for a 450 helicopter. A 10 amp BEC only provided power through two servo leads and plugs. But I didn't want any doubt in my mind if something odd was going on further down the track.

I marked the servo leads with small dots at each end so I knew which lead was which:



I had to modify the frame to get the PPC plug into the Ebar. One of the joys of fitting the unit inside the frame:



I mounted the Ebar on the bottom plate with a square piece of 3M 4010 clear double sided tape:



I figured it's not going anywhere at 12 grams, so just the tape is holding it down. This orientation in the Ebar setup is called "Rear" (Ebar label up and servo plugs facing forward).

The receiver was mounted on the gyro tray above the Ebar, and all of the leads were bundled up between the motor and the Ebar.



I thought about putting the Ebar under the main shaft, with the leads facing the back, but this would have required the front servo leads and BEC to go past the Ebar, and the bottom plate has a large hole at this point also.

All ready to be powered up and setup...

KDS Ebar - Setup 1

Setting up the Ebar is very easy. Here are the steps I used:

1/ Create a new model on your Tx that is a 1 servo swash type helicopter

2/ Power up your heli with the PPC connected. You'll get the connecting screen if the Ebar has power:

Needed 3 hands for this shot



3/ Center the throttle stick on your Tx.

4/ On the PPC, select the menu option 1. Bar Monitor (with enter):

Sorry, I didn't have the throttle stick centered when I took the picture.

5/ Adjust your sub trim until Aileron, Elevator, Rudder and Collective read zero (ignore the 02 in my aileron (read my problem below)) and adjust your gyro gain until this reads 32 :

6/ Press ESC to return to the main menu.

7/ Select the menu option 2. Mounting (with down arrow) and then press enter:


8/ Press enter and then adjust the orientation to match your installation, as shown on page 6 of the manual, by using the up/down keys. Press enter again when finished.

9/ Do the same for the Rotor direction, if you need to change it. (CW is the most common)

10/ Do the same for the swash type, as per page 6 of the manual, if you need to change it. (HR-3 is the most common)

11/ Press ESC to return to the main menu.

12/ Select the menu option 3. Servos:


13/ Adjust the servo directions until aileron and elevator works correctly. Don't worry if the collective is reversed at the moment.

14/ Adjust the servo neutral position until all of the cyclic servo arm's are centered.

15/ Press ESC to return to the main menu.

16/ Select the menu option 4. Controls:


I personally feel this menu is out of order. It should go in this order (Coll. dir, Cycle pitch, Coll. pitch, Cycle travel)

17/ Adjust the Coll. dir to get the collective working in the correct direction.

18/ Select the Cycle pitch and adjust your blade arm pushrods for zero blade pitch.

19/ Adjust the Coll. pitch for 12 degrees of collective pitch.

20/ Adjust the Cycle travel for 7 degrees of aileron cyclic (the swashplate tilts to full aileron when this option is selected):

21/ Press ESC to return to the main menu.

22/ I left the 5. Fly mode menu as the default for the maiden:


You'll get use to pressing enter to accept each option change. If you don't and press ESC the change will be lost.

I had a problem at this point. My cyclic, rather than stay level would drift to the left. If I entered the Bar Monitor screen the cyclic leveled and worked as expected. The aileron value showed 00. I even tried restoring the factory defaults and setting up the Ebar again, only to end up with the same result. It would appear that my aileron MEMS sensor is not zeroed correctly and I can't find a way to recalibrate the sensor zero, like you can in some tail gyros. At the moment two clicks of right trim, solves the problem and the Bar Monitor screen shows 02 for the aileron (I've since adjusted the sub trim to get the main trim back to 0). I've emailed KDS to see if they can shine any light on this issue, as I probably have no deadband on the Aileron stick with this setup.

I also tried flying with the Bar Monitor aileron value showing 00, and the helicopter does drift to the left until I put in the 2 clicks of right trim. The helicopter tried to roll severely left on take off until corrected with the stick (because it had drifted to the left while spooling up). Then it was just a slight drift after that. This could definitely have been a bad moment for a beginner.

With the above settings you will need a reasonable amount of expo and possibly even some dual rates, depending upon your flying ability.

The tail setup is also very easy.


1/ Select the menu option 6. Tail adjust:


2/ Select the servo frequency to suit the servo you are using.

3/ Select the servo pulse width to suit the servo you are using.

4/ Check whether the tail servo needs to be reversed, by moving the tail, and change if required.

5/ Set the two end points by selecting the option and using the up/down buttons to adjust and then enter to save.

Don't forget to check that your tail moves in the correct direction with the rudder stick. If it's wrong then reverse it in the Tx. This is the only reverse that should be used in the Tx.

That's it. Ready to fly...

Very good , can't wait to see your flight review and video.

Flight Test 1

Sorry no video yet but I have flown a few flights with it at home. I'm not happy with the aileron issue and KDS haven't replied to my email, but once it's airborne, it actually flies very nicely. First impressions are much better than I had with the Align 3GX on a 450.

The tail is amazing. To be honest I would pay $128 for this unit if it was just a tail gyro, it's that good. I notice they are using tail torque pre-compensation (tail servo moves when you move the throttle stick), which is obviously setup very well. Hopefully it wont cause any strange effects in ticktocks, like the Vbar can.

Note: I will have to take back this statement about the tail. The torque pre-comp was hiding a very loose tail in flight. Pitch pumps are fantastic, but to get it to hold in reverse flight you have to use a much higher level of gain that causes a slow wag and stop bounce. This was using a DS420 and a MKS DS92. Perhaps this gyro needs a much bigger tail servo to work well.

I'm flying it with stock fly mode settings (medium & 80). I'm noticing a small shake at 80 percent throttle but it goes away at 100 percent. It could be the gain is a bit high but I also need to try a different set of blades, just in case, even though they appear to be balanced well. Remember I'm using the thin foam as well. More about this later.

Using medium the helicopter is still very stable in the hover, but even with 40 percent expo the heli is pretty touchy using the recommended setup. I dialed in some dual rates to smooth it out a bit for now. We'll see if i need to remove this and add in more expo, when I fly it at the field.

Small circuits were smooth, with no sign of any bobble or pitch up on stop. Pretty impressive for default settings.

Other than my aileron issue, no regrets fitting this to the 450 Sport. It flies very nicely so far, for sports flying. I'm not a 3D pro but I'll throw it around a bit at the field and see how it performs.

What is the aileron issue , can you explan?
You say it is pretty touchy with 40% expo , I would want to use it for a scale bird is that possible or is it 3D and sport only?

Using DR you can make it as docile as you want. 50% aileron/elevator DR would equate to 3.5 degrees of cyclic. I would say it's ideal for a scale bird, and I haven't tried the more stable agility setting (Precise).

Re the aileron issue, read after step 22 in post #7 above.

Hhhmm , That's very odd I would like to hear what KDS has to say about that issue. So you that one could tame it down to fly a 700 scaler ?

Yeah, me too. I'm hoping there is some sequence to zero the mems sensors, and I won't have to pull it out of the 450 and send it back. I also emailed RC711 yesterday, but no reply from them yet, either.

I'd hate to think that all the current stock of KDS Ebars have this issue, due to a factory setup problem.

The bigger the heli, the smoother it is anyway. Even my 550 3G is way smoother than my 450 3GX. I personally don't think a 700 would be any problem at all to tame, but I have no experience with helis bigger than the 550.

Originally Posted by beenflying

Yeah, me too. I'm hoping there is some sequence to zero the mems sensors, and I won't have to pull it out of the 450 and send it back. I also emailed RC711 yesterday, but no reply from them yet, either.

I'd hate to think that all the current stock of KDS Ebars have this issue, due to a factory setup problem.

The bigger the heli, the smoother it is anyway. Even my 550 3G is way smoother than my 450 3GX. I personally don't think a 700 would be any problem at all to tame, but I have no experience with helis bigger than the 550.

Beenflying, I'm glade I was not the first to buy the kds e bar. It took me some time to get it right on the set up. But finally done. I have installed it on to my 450 hausler (clone trex). I had the same experience with it wanting to tip or drift to the left on take off. I have converted the Flybar head down to a flybarless head using the stock head and stripping it down to give me direct linkage control from the Swash to the blade grips. I never did get it to a hover. I'm pretty new at flying. So I ended up with two pairs of broken blades :-). I noticed that the Swash plate doesn't move up the main shaft evenly or level it wants to tilt to the right or the right side of the Swash is a bit higher. Thus it leads to the heli wanting to tip over before it gets off the ground. I have my dr +100% and my expo +60%. Do I have them set correctly or should they be both neg numbers? With the heli being so sensitive I'm actually back at square one again on flying the heli. It's scaring the crap out of me. It's like learning to hover again but not knowing that you can hover because your afraid to tip it over. At lease with the Flybar it was more stable on take off.

Sorry to hear you have the same problem, and it's caused you to crash. Yes, what you describe is exactly how mine is. The aileron servo either moves more or less when you move the collective up and down and the swash plate ultimately ends up tipped to the left. In Monitor mode it works fine.

Unfortunately, I've had no reply from KDS or RC711. It's very disappointing and after hearing you have the same problem, I currently have to advise anyone thinking of getting the KDS Ebar to think twice about doing it.

What I do at the moment is, before throttling up, I feed in full right cyclic and then release it, throttle up and lift off. I know it's not ideal, especially when you are learning.

Well done making your own FBL head! How have you compensated for the FBL blade arms, where the ball is further out from the pivot point. Perhaps you have moved the ball in on the servo arms. Is your cyclic 7 degrees and pitch 12 degrees?

As far as toning the helicopter down, drop your DR to something like 70% and then reduce you expo. Expo when learning is very dangerous, as the first time you get in trouble you over control and usually loose control. You want to fly initially with as little expo as possible and use DR instead. Just increase the DR to suit how much control you want to have at this stage.

One more thing. Make sure you have set your Rx fail safe after setting all the Monitor values to 00. When setting the monitor values, make sure you set your sub trims so they are center of the monitor value going to 01 either side. See if that helps any.