Short answer... it will give you more setup options. Rajesh has more hands-on experience on the Mini-Titan, so it would be interesting to hear his opinion on this.

My experience is also limited as I don't fly a mini titan. My preference is to set up on the radio and use the 6100 just as a gyro. It doesn't matter to you at this stage. In later stages, when you feel the need to tweak the curves according to your needs, radio setup will be the way to go. I don't recall now, but I believe you cannot setup a throttle hold with 6100.

"Throttle hold" is another key component / setup in heli flying. Enabling it and using it at the right times can save the flyer his heli, and is an important aspect of safety when it comes to heli flying.

And what exactly is throttle hold ?

Throttle hold, in simple terms, is like disconnecting the main blades from the motor. Think of it as putting a car in "neutral" gear, or pushing down the "clutch pedal" of a car all the way in. 

In electric helis, this is done by shutting down the motor (regardless of the throttle stick position). In nitro helis, this translates to taking the engine to idle rpm, where the clutch disengages and the slow rotation of the engine is NOT transferred to the main blades.

Once you put a heli on "throttle hold" (after you have correctly enabled that in the radio), you can move the throttle stick up without having the main blades spinning up, thus allowing you to check the pitch of the main blades (without having to disconnect the motor, in the case of electrics).  Needless to say, if you put the heli on hold after you connect the battery (or start the nitro engine) until the time you actually start flying, the risk of the heli doing something bad if you inadvertantly hit one of the other controls (including throttle) are greatly minimized.  We tend to follow this as a best practice on our field.

More importantly, throttle hold allows you to do auto-rotations. For example, if the tail belt of your heli broke and you lost tail authority, then hitting hold will allow you to control the pitch and land the heli safety, without worrying about the motor driving the main blades at any throttle/pitch position (assuming your heli has a one-way bearing on the main gears that allows such a feature).

Finally, if you lost your orientation and are about to crash, hitting "hold" before impact greatly reduces the amount of damage your heli will sustain.  The crash is much more severe if the heli hit the ground while the motor/engine is still driving the main blades.

Wonderful explanation. Thanks !
I guess i will use my TX's programming over the ECCPM mixer, as this will give me access to these features.

Got a question.
As you know i have been flying around the mini Titan. Now i havent yet really put the canopy on. But i figure it would be best if i do this ( will protect the motor from dust etc ) .
Now i am concerned as to how would i charge the battery without removing the canopy everytime. Is that possible > Taking the canopy e very time is an added task i would like to avoid, but not sure if there is any way out.

Another question. Should i use a switch between the battery and ESC ? Currently i just plug in the wires, not sure if this is the standard practice.

Thanks

Removing canopy is the standard practive for electric helis. Most people will have more than one battery so they don't need to wait an hour for charging between every flight. So no other way around.

Do not use a switch. The current is too high to use a reasonably sized switch. Addition of even mOhm resistance of the switch in the path is going to reduce the power available.

Thanks Rajesh,

Now that i connected my servos directly to the RX, thereby using my 10C's mixing functions, i have a question.
So far i have the reversing properly setup so the swashplate descends when I increase the collective, and tilts in whichever direction i give the cyclic.

Now I am trying to get a pitch reading of 0deg at mid-collective. The servo arms are perpendicular at mid-collective, but i am having a hard time getting the pitcha gauge to read 0 degrees in all 4 directions..If i change thethrottle linkage height at the rear to get a pitch reading of 0 degrees, the settings in the front change, and if i touch the front two , the setting at the back changes.

Any idea on what i may be doing wrong ?
BTW to check the pitch i have placed a bubble-level on the flybar, and one on the pitch gauge. i chechk the pitch with both these at level...

Don't think you are doing anything wrong. By adjusting the lengths you can get close, you'll need to use subtrim to get the final adjustments.

BTW, do not kill yourself on swash leveling. Regardless of your efforts there, you may still need slight trim (which means that you move the swash out of its level position) to handle CG issues or when beginners prefer to have the heli always have a little forward elevator (so that the default action is for it to move away from you).

Just do the best you can (without spending an inordinate amount of time on this part), and do the rest of the trimming while on an actual hover.

Thanks Anwar and Rajesh.

One more thing, the manual suggest the following pitch curve for beginner :
1    2   3    4    5
40  -   75   -    100
-2        +5        +10
And for throttle :
1    2    3    4    5
0    45  65   85  100

Is this a good / recommended setup ? I see this as a 5 point curve, what values would i need to feed in for a 7 point curve on 10C ?

Thanks again. I want to fly this tomorrow but want to double check everything.
-Gaurav

Those are pretty good values to start with.  It sort of ensures that you can hover around middle position on throttle.

About the pitch, go by the degrees only (-2, +5, +10) that you measure from the blades and NOT the by the actual values you set in the radio (40-75-100).  This is because of the fact that those numbers assume that you have a perfect setup (0-50-100 on the radio translates to -10,0,+10 on the blades), but in practice you are a little bit off most of the time.

one quick one on the curve. Why do we need the slight negative on 0 throttle position ? I mean since I do not plan on inverted flying ... What that does is when I lower the throttle the helicopter comes down very fast almost slams down... If I had 0 pitch at idle perhaps this wouldn't happen ?

Because the heli would refuse to come down if it is windy    I typically ask other beginners who have a separate curve for normal to use -3 or -4. 

Yet another reason is for it to aid with auto-rotation (especially for fuel powered ones), although many have a separate curve for throttle hold.  Having negative in normal mode helps if you forget to hit throttle hold before doing an unplanned auto.

Thanks Anwar,
I didnt understand the Autorotation part but i guess I am still far away from that.
Now i couldnt resist going out in my driveway to test the heli . here is a video :



Now the major things i did in the last week was :
1 - Replaced bent shaft, tail boom and a blade grip from a crash last week.
2 - Now using my 10C programming . Used the recommended throttle/pitch curve, as posted earlier.

Now there were a few things i found different from my earlier experience :
1. The heli seems to be bobbing around in the hover. There was some wind today, due you think thats the cause of it  ?
2. The tail boom got slightly warm after the flying, i had installed the belt with care, so do you think i need to open it up to check ?
3. The sound of the motor/gear was a little different, maybe since i replaced the shaft, the gear position changed and it needs to re-mate ?
4. The motor was quite warm after a 7 minute hovering practise. is that normal ?

Thanks again, I owe my heli flying to this forum, without which i wouldnt have got into Helis.
Gaurav

Oh man, I am jealous of you now. Iam still struck with my build.

Quote from: gauravag on January 30, 2010, 04:37:12 PM
Now there were a few things i found different from my earlier experience :
1. The heli seems to be bobbing around in the hover. There was some wind today, due you think thats the cause of it  ?
2. The tail boom got slightly warm after the flying, i had installed the belt with care, so do you think i need to open it up to check ?
3. The sound of the motor/gear was a little different, maybe since i replaced the shaft, the gear position changed and it needs to re-mate ?
4. The motor was quite warm after a 7 minute hovering practise. is that normal ?

One major possibility that can cause this type of wobbling is not enough head speed, so try increasing your throttle curve.  The wobbling is not consistent with wind effects. Also, double check your belt and its tension.

The gears should overlap each other as much as possible. To get the right tension between your motor pinion to the main gear, take a small piece of paper, and fold it in half, so that you have double the thickness of a standard notebook sheet of paper. Now place that piece of folded paper between the main gear and the motor pinion, and close the gap between them as much as you can and tighten the motor firmly in its place.  The paper will get crushed into a zig-zag pattern between the two sets of gears.  Now rotate the main gear manually so that the paper bit falls out. This leave the right gap (or lack of gap) between the main gear and the motor pinion.  This also makes sure there is no undue forces on the motor shaft, which can cause early bearing failures (and possibly heat issues). 

Motors to tend to get hot during flight. But they should not be too hot that you cannot even touch it.

And congrats on your heli flights !  Looks like the training skids are really helping you, you would have sustained some damage without them already with this type of test flying. Please fly in a larger area, and keep the heli at a bit more distance from you.

Thanks Anwar,
Increased headspeed helped. The 10C has two dials VR(A) and VR(C) to independently tweak the pitch/throttle curves at hover . I used them to correct the bobbing, and will go program them in the curves.
Now the next issue i seem to have is that when the heli is light on the skids, ie just below the hover point it wants to go to the left side, but when its in a hover, it is balanced. Looks like i need to tweak the end points of the 2 forward servos. What do you suggest, should i decrease the end point of the left servo ?

Yes the training skids do help me, and i plan to go a park near my house to fly . Sometimes i cannot resist flying at home, but i try to be very very careful.
I will post some picture here soon,
-Gaurav

The Vr(A) and Vr(c) things are a boon and a bane at the same time   I ask people to disable them, and do any tweaks on the pitch and throttle curves directly so that they are permanent, and safe from unintended changes (it is easy for people to rotate those knobs my mistake while handling the radio).  It can also cause funny issues like the curves being not straight lines even though you have set the intermediate points linearly.

My experience is to NOT try any trimming unless you are at least a couple of feet above the ground.  The "ground effects" are significant, and they tend to mislead you.  And even if the heli shows a tendency to drift, the right thing is to adjust the trim/sub-trim (not end-points). If there is wind, point the nose of the heli into the wind while you are trying to trim it.

Hope to see more of your progress, from a bigger field

Hmm. Looks like i am addicted to Helis now.
I tweaked the subtrim/trim and did not touch the EPA and i think i resolved the problems i was encountering earlier today. I flew 3 battery packs today ( i have a 2200mah one on this heli ) so each flight lasted for around 8-10 minutes.
Now i have a few more questions :
- At what point should the servo arms be straight - ie 90 degrees to the servo. Should it be at 0 pitch ? or hover ?
- Ever since i switched to 10C programming, i noticed that the heli wants turn to its left, ie i need to give very slight right rudder. Do i need to increase the gyro gain ? I checked to ensure that the "revo" mix is INH on the radio.
- Should Lipo batteries be allowed to fully cool down before recharging ? ( i have just one pack and cannot wait to take the heli into a hover again.

Well i have not yet gone to a bigger field yet, and still practicing hovering at home. I know its like calling for trouble, but i am extra careful, and my next video today will hope fully show that i can keep the heli at same place now for the entire hover.

During my initial hovering attempts, to bring the heli down, i used to bring the throttle lever completely down , perhaps out of practise from airplane flying, where reducing the throttle did not create an "instant" effect like on helis, so what that caused was that the heli used to literally drop to the ground, so i have now improved upon it.

I will stick to hovering the heli in the same place with the tail towards me for the next 10 flights or so ( you think this should be good enough ? )  Then perhaps try to practice side hovers , before moving to nose-ins ? My goal is to first master hoverings from all angles before moving to forward flight..

Will post videos / pictures today.
-Gaurav

Many many questions   That is a good sign 

For the swash servos, you want the servo arms to be at 90 degrees when you are at mid-stick. At this point, if you have done everything right, the swash should be almost at exactly the middle point of its maximum range of travel (both up and down from the middle point), the swash should be level and the pitch on the blades should be zero.  Note that it not at hover, it is at mid-stick on the throttle.

For the tail servo, it should be 90 degrees in rate mode, with no rudder input and no rudder trim (I also avoid any sub-trim on rudder)..

Like I said before, you are better off putting the gyro in rate mode, and adjust the mechanical setup first (ensure there is no trim at all on rudder). You should do that at a rate mode gain of around 50.  Now switch to heading hold, and if you are still seeing a drift, that could be due to low gain, or your connections being wrong in that the gain set in the radio is not being communicated to the gyro properly.

Let the lipos cool down, it helps with their life is what I have found from other sources.

Stick to hover for a few more flights, and then try side hovers.  I would suggest forward flying (circuits) before trying nose in.

Thanks Anwar ( I guess thats going to be my first line of every post )
I got the heli on the bench and tried to get the arms to be 90 degrees at 0 pitch with the TX throttle stick at middle ( and the pitch curve rest so that the mid throttle says 0 . Now i am a little confused with the Pitch curve numbers . In the mini Titan manual it seems to assume that 50 is 0 deg pitch. thus 40 is referred to as -2 pitch.
However on 10C, there is a range of +100 and -100 , so in that case 0 , or the midline in the graph should be the 0 pitch ?
Do you think that i am doing this correctly ?

Now, regarding the gyro. , you said "if you are still seeing a drift, that could be due to low gain, or your connections being wrong in that the gain set in the radio is not being communicated to the gyro properly."

Where is the gain set in the radio ? or does it need to be ? Should i try a hover with the Gyro in the rate mode ?
I did setup the servo linkage so that in rate mode, with the tail blades's pitch to 0 the servo arm is 90 degrees.

So far i have been flying in the Heading hold mode only ...

Get out of the habit of looking at the numbers in the radio when you set the curves.  Go by stick position alone. So whatever your radio shows when you are at mid-stick, that is when you adjust the links and servo-arms for zero pitch. In your swash menu (you should have one on the Futaba 10C), make sure your numbers are 50,50,50 (can be positive or negative depending on how you have wired up your servos.

If you have wired the remote gain settings wire to the gyro channel (typically channel 5 on Futaba), then you can use the "Gyro" menu to remotely adjust the gain.

Like I said before, you can continue to fly in heading hold, and your "less than perfect" settings will be handled by the gyro.  Keeping the slider right in the middle and using heading hold is the easy way out.

Note that in a perfect setting in rate mode, you will have slight pitch on the blades (to compensate for the main blade induced rotational torque), so this "put it in the middle" quick-fix is NOT the perfect setup *for rate mode*. It only gives you a good starting point for heading hold.

The right thing is to try to hover in "rate" mode, and length/shorten the tail servo linkage rod (or move the tail servo on the tail boom) to ensure that you have no drift in rate mode (with a gain of around 50).  This ensured your mechanical setup is almost perfect. After that you can switch back to heading-hold and keep it there; as you now have a solid tail.

One thing that ha e confused through this entire thread is, you say that when the throttle is at id stick position, the pitch should be 0 AND the servo arms perpendicular.
Also, I understand that i should be hovering at mid-stick position. SO how is this possible, i mean how will I hover with a 0 pitch at mid throttle ?
The pitch curve given in the manual says :
1    2   3    4    5
40  -   75   -    100
-2        +5        +10
That means that there should be a +5 pitch at mid stick, is that kind of pitch needed for hovering, and should the arms then be perpendicular at mid-stick with a +5 pitch ?

Please help !

Regarding the gyro, the TG-6100 Gyro I have has a CH5 connection that just switches the gyro between Heading lock and normal modes, using the CH5 switch on TX.
Now, from what i understand , you say that for a perfect setup ( which is what i am aiming for ) , i should switch the Gyro to normal mode, and have it hover in such a way that the servo arm is perpendicular during a hover ?