Hornet X-3D

Update:

I have some time on the X-3D now can comment more on how it is flying. The improvements in the X-3D include quite a few things that I was already doing in my own Hornet 2. The rear servo mount is definitely better and results in better control for the tail. The upgraded head is really nice and I am very happy with the quality and flight characteristics of the head. The new main gear and 1 way are much improved over the previous versions.

A couple of updates. I am now running an HS50 for the tail rotor servo. The Futaba 3108’s work very good on cyclic, but it is just a bit slower than the HS50 and on the tail the speed is critical. The 3108 will work on the tail, just not as well as the HS50.

The MCP motor is working well. It is producing very good amounts of power and it is nice and light weight. I am seeing 10 min of flight time under VERY hard flying and the motor is just warm and my ThunderPower 1320 battery is around 120F which is about perfect.

Overall I am very happy with the X-3D and the improvements. The Hornet has been the top of the line in Micro helicopters and with the X-3D they are still on top with Micro 3D technology. I hope you enjoy the information, and I look forward to seeing some of you at the funflies!

The Hornet X 3D is being marketed as the top of the line in the Hornet series. It is the most capable Micro 3D helicopter currently available.

My schedule finally let me get time to assemble the new Hornet X-3D from MS Composit. The kit I received came in the same packaging used by MS for their Hornet series. I also installed the MCP (Mr. Carbon Performance Products) 320 motor and 25 tooth pinion. Last I will also be trying out the TE1000 aluminum swashplate and anti-rotation, TE1001 aluminum main rotor head, and TE1002 aluminum tail rotor. The upgrade TE parts are by no means necessary, but they appear to be nice high quality parts that should improve the way the heli flies. The main rotor head in particular looks very nice and quite a bit stiffer than the stock plastic head. I am also using the MS upgrade carbon fiber tail blades. They are lighter and stiffer than the stock plastic ones.

I get tremendous amounts of questions on the Hornets. I will do my best to give you some techniques that I use to get a nice flying heli. Micros are much more detail orientated than their larger brothers. A larger heli will fly fine when things are not 100% correct. Micros need to be very close to 100% correct to allow them to fly well. Small things like drag in linkages, small vibrations, and or alignment problems will doom your project. Vibrations are probably the #1 problem I answer questions about. I will explain my process to eliminate vibes in the Hornet later in this write-up. If you have vibes, the machine will never fly right!

My equipment:

MS X-3D kit
TE 1000 swashplate and anti-rotation
TE1001 rotor head
TE1002 tail
MCP320 motor and 25T pinion
MS-116 motor controller
ThunderPower 1320 – 3 cell 10-12c discharge batteries
Deans 2 pin micro plugs
Futaba GY240 gyro set to 50% gain in AVCS mode
Futaba 3108 servos
Berg 6 channel receiver
3M heavy duty “gray with red backing” double sided tape for servo install

Important notes:

• I am using the carbon tube drive, as I was not successful in getting the metal one to work. You may have different results. My steel shaft was not completely straight and was a bit undersize. The shaft not being straight caused a vibration I could not eliminate, and the shaft being undersize caused my rear conical gear to slip under load. Again, yours may work fine.
• The tail grip screws in my kit where different length causing a balance and vibration problem. I shortened the length on the longer screw and got them both the same. This is a MAJOR source of vibrations and is something to pay attention to. Look at the gap between your tail hub and tail blade grips, they both need to be the same! I just used my Dremel to shorten the length of the longer screw. It was not a big deal and an easy fix. It is just something to be aware of.
• Use caution tightening all of the 1.5mm screws. It is easy to over tighten them and strip or break something. Tight is tight…. And for a 1.5mm that is not much.
• My TE1000 swash ball was very tight. I worked with it for a long time before I got it loose enough to use. If yours is tight, you may try to work with it to get it seated in more, or contact MS USA for help. The swash needs to be smooth. Mine works well now, and the new antirotation with the swash is very nice and seems pretty darn strong.
• As seen in the pictures and with the equipment installed and stock wiring my machine weighs 370 grams. This includes a small amount of weight on the tail to get the X-3D to balance correctly.

Getting started I assembled things in Step 1 as per the directions. The only change is that I used the TE1000 antirotation unit instead of the stock parts.

Step 2: I ran into a problem here. I tried to use the supplied metal torque tube drive and found that I could not get it to work to my satisfaction. The plastic gears always seem to slip on the steel shaft. I am using the carbon tube drive as was used in the original Hornet 2 kits.

As stated above, you may have much better luck with the steel drive shaft. Mine had a bow in it causing a vibration and the shaft seems a bit undersize causing the rear gear to slip under load. The carbon shaft has always worked well for me, so until I get some new steel shafts and can sort it out, I am using the carbon one.

When you assemble the tail box, use some caution. I use an arbor press to insert the tail shaft into the bevel gear. You do not need an arbor press, but they are a good investment and nice to have. Also use some caution to not crush the orange spacer. My stock spacer was the right length, though you may need to trim or add shims to get the correct spacing here. When you set the tail gear mesh, it should be VERY smooth. Get the gears as tight as you can but it is OK to have some backlash or “play” in the gears as long as they are smooth. I installed the TE1002 tail rotor hub as per the step 2 directions. My only note here is that you need to make sure the pins in the tail hub run smooth in the plastic pitch slider. If the pins go in hard, you need to use a small drill bit “#52” to open up the holes to get a smooth fit. Also when you install the tail pitch bell-crank, you may need to use a “#46” drill to get that to run smooth.

Notes on the tail:

• When the steel output shaft is inserted correctly, you should have bout .500 inch of shaft extending outside of the tail box and the tail hub. This will give your tail pitch slider the correct amount of throw and the right center position.
• Look closely at my pictures of the tail servo linkage installation. You need to get your tail servo horn exactly 90 degrees to the linkage. You may have to try several servo horns to get that to line up right.
• Again the tail gears need to be SMOOTH. A little play is ok.
• Add a drop of light oil to the tail output shaft after install.
• DO NOT CA or otherwise glue any of the gears to the shafts. If a gear is slipping, you need to replace the gear. I only get maybe 2 installs on a gear before it needs to be replaced. This is just the price we pay for press fit gears. If you don’t replace them after a couple installs, they will slip and cause you to loose control of the tail.
• Follow my balance section to get the tail to run smooth at ALL rpm without the main rotor head installed.

Step 3: I used the TE1001 main rotor head. If you are using the stock head, I recommend running some thin CA into the E082 o rings after they are inserted into the head block. I do this when the block is on the main shaft, but before attaching the main blade grips. Locking down the head block will give you a nice solid flying head. I installed the head on the main shaft by holding the seesaw dome on the main shaft and adjusting the head up to the point it just touched the dome when the dome was all of the way down on the main shaft.

Step 4-5, were per the directions.

I initially adjusted my linkages per the directions. I then fine tune them on the machine.

My final linkage lengths: “all lengths are center to center”

• Cyclic servo links: 1.050 inch
• Swashplate to bell-hiller mixer: 1.360 inch
• Bell-hiller to main blade grip: .650 inch
• Rudder servo to bell crank: 1.170 inch

I installed 3 – 3108 futaba servo’s on cyclic. I used the middle hole on the longer side of the servo arm. I attached them to the heli with 3M heavy duty double sided tape and find that it works better than anything else. It sticks like hell, but is easy to remove and leaves no residue. I also clean the servos and mounting surfaces with Acetone. If you don’t clean the oil and residue off, the tape will not stick as well.

NOTE: make sure you plug in your servos into the receiver and center all of the sticks on the transmitter. Plug power into the receiver and then install the servo arms so that the side you will use is 90 degrees to the linkages. Get them as close as possible then use sub trim to get them all aligned correctly. If you don’t get them all even at center stick, you may fight control problems.

Eliminating vibrations:

The first thing is to assemble the machine. Next you will take some of it apart….. sorry but it is a good idea to make sure everything goes together right before this next step.

1. Take the main blades off, take the tail blades off, and remove the flybar assembly from the rotor head.

2. Now turn on your radio and plug in the battery. Hold the machine in your hand and run it up. It should be very smooth and quiet. If it is not, find and correct the problem.

3. Install the tail blades. Now the next part is up to you. You can run the machine up on the ground or USING EXTREME CAUTION and ALWAYS WEAR SAFETY GLASSES hold it in your hand by the landing gear and run it up to RPM again. What you are looking for is that the output tail shaft is dead true and smooth running from stop to full rpm. If the shaft vibrates are appears to move up and down you have a problem. Look very carefully at the gap in-between the tail blade grips and the tail hub. They need to be equal when you pull out on the tail blades. If they are not, you need to trim the longer screw some. If the tail is not smooth after that, then swap tail blades and see if the problem improves or gets worse.

At this point you will have the tail blades on in the smoothest location but you may still have a vibe. Now you need to go get some scotch tape or clear packing tape. Start with a small about, maybe ¼ inch and attach it to one of the 2 blades about ½ of the way out. Run up the machine and see if it is better or worse. If it is better then adjust the tape amount to get it 100% smooth. If it got worse then try the other blade and do the same.

Using that technique you should be able to get the machine very smooth up to this point.

4. Next install the flybar assembly and the linkages. You will now need to run the machine up and check for vibes. Use the same process as the tail blades to get a smooth running machine.

5. Now for the last setup, installing the main rotor blades. NOTE: it is VERY important to run the model up on the ground in normal mode with very little or NO negative pitch. If you have negative pitch you are risking a boom strike.

If you run the model up in your hands with the main blades on it you are on your own. It is the best way to feel if the machine is smooth, but it is also a great way to really hurt yourself. If you run it up while holding it, by all means wear safety glasses and a heavy glove. Also you may want to keep a cell phone close or have your wife standing my to run you to the hospital if things go badly ? Use the same technique as on the tail blades on the main blades until the heli is as smooth as you can get it.

By using that vibration elimination technique you can isolate problems and you really know where the problem is as you are working step by step. If you try to eliminate vibes when the machine is fully assembled, you are just chasing your tail. Use a methodical method and you will fix your problems much faster and more reliably.
Radio setup and flying:
I am currently flying my Hornet on my 14MZ. Here is my setup that you can download. If you don’t have a 14MZ then below is some info on my setup for a Futaba 9C. Other radios will require a similar setup.
This is my setup in my 9C. Other radios will be similar:
Dual rates 100%, Expo at -20% on cyclic and +5% on rudder
End Points all 100% except rudder CH4 is 120% both ways.
Reversers: Throttle and Pitch are reversed.
Swash AFR AIL/ELE = 100%, PIT = 35%
Throttle curve NORMAL = 0,25,40,55,100 – IDLE 1&2 = 100,90,85,90,100
Pitch NORMAL = 27.5,40,50,75,100 – IDLE 1&2&HOLD = 0,25,50,75,100
Revo mix = OFF
Prog Mix 1 Elevator>Throttle = 25% “cyclic to throttle mix”
Prog Mix2 Aileron>Throttle= 25% “cyclic to throttle mix”

I always run normal mode on the speed control. Governor mode does not work well. Simple enough, normal mode with a standard throttle curve is the best method! If you must use governor mode, just be aware you are sacrificing quite a lot of power.

TROUBLESHOOTING and FAQ:

– Vibrations:
Please review the vibration section! You must proceed step by step or you will never find the problem.
– My tail hunts around:
All of your tail parts need to be smooth. Start with the tail pitch slider and unhook the tail bell crank. The tail pitch slider must be smooth and if it is not, adjust the holes in the tail pitch plate so the pins in the tail blade grips run smooth.
Next make sure the tail pitch bell crank is smooth. Drill it out if it is not.
Your tail linkage needs to be setup so that the tail servo horn is 90 degrees to the linkage when the servo is at center. Do this by temporarily putting the gyro in normal mode and centering any trim or stick position. If the horn you are using will not allow for a 90 degree install, you need to get some new horns and find one that works. The spline spacing on a Futaba 3108 is the same as hitec so the hitec horns will work.

NOTE: I am now using the HS50 servo on the tail. The 3108 works ok, but the HS50 is faster. The HS50 is not the quality of the 3108 but speed is more important on the tail. I am using the 3108’s on cyclic with very good results.
You need to run a Futaba 3108 or Hitec HS50 servo. You also need a Futaba GY240 and set it at 50% gain. You also need to mount the gyro and tail servo in the stock position for the X-3D.
If all of the above is correct, your problem is vibrations. Review the vibration section and proceed step by step. The equipment I describe will work, as I have used it on a lot of Hornets. If you use different equipment, beware that I have tried many combinations, and this is one of the very few that work well.
The heli suddenly drops or the speed control cuts off
This is caused by glitches. I use a Berg receiver and a full length antenna. Even though this is a good combo, I still get glitches now and then. They don’t really bother me much and I just fly threw them as it only happens maybe 1 time per flight. I you are getting more, try different antenna locations and or a different receiver.
I have had some problem with some phoenix 10 speed controls cutting off in flight as a result of a glitch. This seems to be a problem of the past, but if you are having the problem you may want to contact Castle Creations and see if they can help you out. The Phoenix is a very good speed control, it just did not like glitches very well. The Jeti seems to tolerate glitches fine. Jeti also makes Hacker and MS Composit speed controls.
My head speed is low or I don’t have good power:
You need the MCP320, Twister, or equivalent motor and 25t pinion. If you do, and still have a problem, make sure your speed control is NOT in Gov mode. Do some testing by setting your throttle curve to 100% all of the way across in idle up 2 and see if the head speed rises. If it does you may need to re-adjust your throttle curves. If it still does not seem right, you may have a bad battery, motor, or speed control. Try a different battery. You need a 3 cell 1200+ MAH battery capable of 10C. I run the ThunderPower 1320 packs with good success. Make sure it is a 10C discharge pack.

Again you need to run the speed control in NORMAL mode. Constant speed or Gov mode will result in power lag and lost power. I have tried it every which way I can and I have never been happy with Gov mode. Running in normal mode with a standard throttle curve works much better and is simple to do.


My tail does not hold well in backward flight or anytime for that matter:

You may not have enough head speed or you may have too much collective pitch. Bump up the head speed and or reduce the collective. Again, vibrations are your enemy and your machine must be smooth to get the gyro to work right. Make sure the tail linkage is correct and you have the right tail setup described above in tail hunting.
Also grab your main gear and tail at the same time. Try to twist them against each other. You will feel some flex in the tail drive shaft, but you should not get ANY slipping. If something slips, find it and fix it. If the gears are slipping on the carbon tail drive shaft you can remove the gear and apply a thin layer of CA to the carbon shaft where the gear will be installed. LET THE GLUE DRY, then install the gear over the dried glue. The fit should be much snugger. I never glue my gears to any of the shafts.

One other note is that you need to use the HS50 servo mounted and the linkage setup per my pictures. It is critical to have all of that right. The GY240 is the best gyro for this application, the GY401 will work, but not as well. We are limited on how good the tail will hold by the servo’s that we have available, so don’t expect the tail to hold like a larger heli. It will hold good, just not as rock solid as the larger nitro machines.
The heli is unstable:
Well it is a micro and it weighs around 300 gram’s 🙂 Run the solid flybar paddles. Also you can use small RC wheel weights for flybar weights to get a more solid feel. Don’t be afraid to add expo and turn down the controls until you get the hang of it. Also be careful flying too far away…… it gets small VERY fast.
You do not need the extreme throw on the controls that I have in my setup. Adjust the machine to your feel. I like mine very aggressive for 3D flight. Because of the weight and size of the machine, it will take a good stick to fly fast and very aggressive.
My heli pitches up in forward flight:
That is very common in micro helicopters. The reason has very little to do with C.G. as some may think. The cause is the flybar flexing. The small flybars we use flex in flight and that will cause the pitch up. I have used some small carbon tubes as flybar stiffeners with decent success. You may want to experiment.
I recommend flying the heli at moderate speeds and you will not have the problem. If you fly at high speed, just be ready and keep on the sticks.

Duralite Batteries

I have been using Duralites lithium ion receiver packs for a few years now and have been very impressed with the quality, durability, ease of use, and great performance. Some of the advantages that I see are, increased flight time without charging, constant servo speed, and extremely easy charging.

What I use

Receiver: 2800mah redundant lithium ion pack
5.1v regulator with fail safe switch
Charger Duralite 4 port charger
Volt meter Duralite digital load test meter

Use

It is very important to check your pack voltage before you go fly. Stop fly voltage is 6.9 and you should recharge at that time. Lithium Ion has no memory effect, so you can charge at any time.

Tips

Use a 5.1 volt regulator with digital servo’s. You will see better servo life and reliability.

Use the fail safe switch regulator. If the switch fails, you will simply not be able to turn off the heli. It is a cheap safety item. I have personally lots heli’s due to a bad switch for another mfg.

Always check your batteries before every flight. You can spot battery problems quickly if you get into the habit of testing regularly.