700e F3C Second Flight

[aramb]

Today I flew my F3C for the second time and had the wife video a few minutes of it. I apologize in advance for the poor video quality. In my haste, I grabbed the camera and did not set it up properly for the lighting conditions.

I noticed that the tail bobs up and down occasionally (actually more than occasionally). It will do it for 10-15 seconds and then stop for a little bit and then start again. I currently have the headspeed governed at 1450. It occured to me after quitting for the day that maybe the bobble is a result of too slow a headspeed. Any suggestions on this?

Second, what is good starting point for the gyro gain setting on this heli? I am using the GP780. My radio is the DX8 which means that -1 to -100 is rate mode, 0 is off, and +1 to +100 is heading hold mode. I currently have it set to +60.

Here is the video:

[ame]http://www.youtube.com/watch?v=JfDr3bqSYsk[/ame]

[smaze17]

Originally Posted by aramb

Today I flew my F3C for the second time and had the wife video a few minutes of it. I apologize in advance for the poor video quality. In my haste, I grabbed the camera and did not set it up properly for the lighting conditions.

I noticed that the tail bobs up and down occasionally (actually more than occasionally). It will do it for 10-15 seconds and then stop for a little bit and then start again. I currently have the headspeed governed at 1410. It occured to me after quitting for the day that maybe the bobble is a result of too slow a headspeed. Any suggestions on this?

Second, what is good starting point for the gyro gain setting on this heli? I am using the GP780. My radio is the DX8 which means that -1 to -100 is rate mode, 0 is off, and +1 to +100 is heading hold mode. I currently have it set to +60.

Here is the video:

http://www.youtube.com/watch?v=JfDr3bqSYsk

I think 60 is a good starting point. I had my 550 with a DS620 and GP780 at 62 which worked out well. I also set the delay on the gyro to red (small helis) instead of green and the slight wag completely went away. Something to consider

Sm

[tmodelli]

Originally Posted by aramb

I noticed that the tail bobs up and down occasionally (actually more than occasionally). It will do it for 10-15 seconds and then stop for a little bit and then start again. I currently have the headspeed governed at 1410. It occured to me after quitting for the day that maybe the bobble is a result of too slow a headspeed. Any suggestions on this?


http://www.youtube.com/watch?v=JfDr3bqSYsk

Waayy too slow headspead! You need another 200 RPM to start getting in the right range. 1800 to 2000 is where you should be, 2000 to 2200 is where you get crazy power with good electric power train (completely unnecessary)....

[wonderd]

Hey there,
At 90% we are talking about 2000rpm.
I work with 1800 on Idle1 set rpm gov mode and it's perfect for me.

[aramb]

Originally Posted by tmodelli

Waayy too slow headspead! You need another 200 RPM to start getting in the right range.

I set 1450 as per the manual for hovering. The manual has 1900 and 2000 listed for Idle Up 1 and 2 respectively.

I will try increasing today and see how it helps.

[SidewaysLS4]

I like parking space sized helis

Is there a softer durometer head damper option for the T700's? That would fix the bobbing. Some Logo SE guys go down to 1000-1200 for slo-mo flying.

Note the DX8 has a different gyro gain scheme than the DX6 or 7. 60 seems a bit high for Align gyros. My DX8 is running in the 25-40 ranges depending on the gyro. Might cause a wag 'o death if you start getting frisky on the tail.

[aramb]

Okay, I increased the headspeed to 1700 RPM and the bobble is gone. I still have a tail wag, though. Also, what is the proper way to switch from Normal (1410 RPM) to Idle Up (1700 RPM)? Do I switch while on the ground before lifting off? Why even use normal? Why not just spool up in Idle Up?

Here is the latest video:

[ame]http://www.youtube.com/watch?v=wTQLTY-3jUs[/ame]

[scoti333]

You can spool up in idle up if you want. Just make sure your throttle hold is on and then flip to idle up, and start the heli by flipping TH off. It's generally a good habit to NOT do it that way for safety reasons and especially if you are new. Why use normal mode? Well, why waste power you don't need? It just depends on your style of flying really. Also it's just about what your comfortable doing as far as switching flight modes on the ground or in the air. I think it's best to do it in the air, but make sure your pitch curves are more or less equal at hovering pitch or you'll get a quick jump or descent. If all else fails, just send the bird to me and I'll take very good care of it.. Good luck bud, hope this helps.

[aramb]

I am using governor mode on the ESC so all my throttle curves are flat (30% on Normal, 70% on Idle Up), so if the heli is not in Throttle Hold, it will start to spool up even if the throttle is at minimum on Normal mode. So, I guess I don't see the point in Normal mode if the headspeed is too low. One question though... If my pitch curves match and I switch from Normal to Idle Up while hovering, the headspeed will jump from 1410 to 1700. Won't the heli jump up just from the sudden increase in headspeed even if the pitch is still the same?

[tmodelli]

Originally Posted by aramb

I am using governor mode on the ESC so all my throttle curves are flat (30% on Normal, 70% on Idle Up), so if the heli is not in Throttle Hold, it will start to spool up even if the throttle is at minimum on Normal mode. So, I guess I don't see the point in Normal mode if the headspeed is too low. One question though... If my pitch curves match and I switch from Normal to Idle Up while hovering, the headspeed will jump from 1410 to 1700. Won't the heli jump up just from the sudden increase in headspeed even if the pitch is still the same?

If you match via numbers, yes it will, but what i do, if I want such big headspeed difference, is to change the pitch curve to allow for a smoother transition...

I still think 1410 is waaayy too slow. The problem with too low headspeed is that you need to compensate somewhere else, and the only other place is pitch.

Also, it depends on which blades you are swinging, maybe if you use 710's 1410HS wont be as bad, but i don't know for sure.

I use normal mode with a lower headspeed than idleup 1, idle up 1 with 90%ish trow and good headspeed, and idle up 2 with a big higher headspeed and less expo, to bring the heli to its max potential...

I always aim idle up 1 for max flight time with enough performance, and normal just to do he basics, like takeoff, land, and basic orientation, but still performing enough so the heli feel similar to when flying dile-up.

[smaze17]

Originally Posted by aramb

Okay, I increased the headspeed to 1700 RPM and the bobble is gone. I still have a tail wag, though. Also, what is the proper way to switch from Normal (1410 RPM) to Idle Up (1700 RPM)? Do I switch while on the ground before lifting off? Why even use normal? Why not just spool up in Idle Up?

Here is the latest video:

http://www.youtube.com/watch?v=wTQLTY-3jUs

Regarding your wag, are you still at 60% gain? Go into the 5th setting on the gyro which is the delay setting. Change it to red which is the small heli setting. Give it a try. It totally got rid of my wag when I tried it

-Spence

[aramb]

Originally Posted by smaze17

Regarding your wag, are you still at 60% gain? Go into the 5th setting on the gyro which is the delay setting. Change it to red which is the small heli setting. Give it a try. It totally got rid of my wag when I tried it

-Spence

Thanks, Spence. I forgot to change it before the flight in the second video, but I did change it right after and lifted the heli off for about 30 seconds. It seemed to reduce the wag quite a bit. Now I just need to fool with the gain a bit. Yes... I am still at 60%.

BTW... are you running governor mode? If so, what are you headspeed settings for normal and idle up?

[aramb]

Originally Posted by tmodelli

I still think 1410 is waaayy too slow. The problem with too low headspeed is that you need to compensate somewhere else, and the only other place is pitch.

Also, it depends on which blades you are swinging, maybe if you use 710's 1410HS wont be as bad, but i don't know for sure.

I am running the standard 700mm blades that come witht eh F3C. I understand that they are heavier than standard 700mm blades.

[smaze17]

Originally Posted by aramb

Thanks, Spence. I forgot to change it before the flight in the second video, but I did change it right after and lifted the heli off for about 30 seconds. It seemed to reduce the wag quite a bit. Now I just need to fool with the gain a bit. Yes... I am still at 60%.

BTW... are you running governor mode? If so, what are you headspeed settings for normal and idle up?

Hi there. I am running governor mode and use the settings directly from Castle's website:

http://www.castlecreations.com/suppo...0mx-510kv.html

S

[JustinS]

I have the 550E fbl with DX8 tx, my optimal gyro gain seems to be around 38.5%. 3G on small heli mode & she flies nice.

[tmodelli]

Is the DX8 a -100 to +100, different than the DX7 that is fro 0 to 100?

I'm a futaba guy, so this spektrum thing is kind of alien to me.

[aramb]

Yes, the DX8 is -100 to +100.

[aramb]

Originally Posted by smaze17

Hi there. I am running governor mode and use the settings directly from Castle's website:

http://www.castlecreations.com/suppo...0mx-510kv.html

S

Since I am running the 470kV motor with 700mm blades, I wasn't sure if I could use the same headspeed numbers as the 510kV.

[K2Freak]

I am using governor mode on the ESC so all my throttle curves are flat (30% on Normal, 70% on Idle Up), so if the heli is not in Throttle Hold, it will start to spool up even if the throttle is at minimum on Normal mode. So, I guess I don't see the point in Normal mode if the headspeed is too low.

One thing a lot of guys do is roll the bottom (0 input) throttle curve setting to 0. That way in Normal mode, you have 0 headspeed at 0 stick. I use Normal for this purpose exclusively (it can be argued that I waste one of my conditions) and set the HS at 1000 so that I will never take off in Normal and mistakenly flip it over. I spool it up, flip into a flight mode, and go. Note that with CC you re-engage soft-start every time you hit this 0 point on the throttle curve.

As far as the jumping around in the air with headspeed changes goes, I have never seen this cause trouble as long as the pitch curves are IDENTICAL. For fun, I set mine up with 1750 and 2200 HS yesterday in idles 1 and 2, and there was no tendency to rise or fall when changing. It also happens at a speed corresponding to the "head change speed" setting in CC software. Again, as long as the PITCH curves are the same in both idle modes, you should not have any trouble in this area...

I also agree with everyone that said 1450 HS is way too low. Unless this is some kind of special application, that really IS way too low. You will probably like how it feels at 1800 much more.

Good luck!

[tomra]

Interesting video!

I like how it just sits steady in it´s own ground effect in the first video. 1450 might be a tad too low if you get bobbing behavior. Try to increase it by 50 or 100, this beeing a F3C model after all. Many pilots prefer very low headspeed for hovering. 1450 might work too if you change blades or dampeners.

I would set up idle 1 for hovering and idle 2 for upstairs flying and simply keep normal mode as a testmode or transition mode.

A lot of the F3C/contest guys says the T-Rex 700 F3C provides a very good starting point as a FAI model. Read up on some of the articles available on the web regarding setting up a model for FAI flying. I´m pretty sure this one is darn close straight out of the box.

Really, really cool sounding machine in 1450