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Old Jun 29, 2012, 02:23 PM
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Update on TRex 450 Sport V2 and some mCPx notes.

Well I did some mild 3D (lost the tail while hovering). Throttle hold brought it down with only a mild clunk and no damage. It was my bad in assembly--the Allen screw that holds the rotor hub to the rotor shaft had come loose, because I had not thread locked it. I thought I had got them all, but this was a preassembled part with a black Allen screw into a black hub and I simply missed it. I disassembled the necessary tail pieces and redid everything with locktite and I was back in the air next morning.

Around here, early morning seems to have the least wind, though there was some gusting this morning. A gust causes the heli to bob up which requires a collective adjustment and then when the gust passes you have to readjust, so this requires much more attention to collective. Since I am hovering not all that high off the ground, I have ungracefully bumped the ground a few times, but again with no apparent damage, just bumping the skids. Having the additional positive collective stick range that a "scale setup" gives you is really very helpful for flying in the wind. Also, those bumps might have been disaster to a torque tube tail, but my belt drive the heli seems tough enough to survive my learning curve.

mCPx Notes: My mechanical pitch is quite close to zero at 50% collective on the mCPx, but if I run the throttle and pitch curves suggested here, I run out of collective and end up hovering too close to full stick. I found that using a pitch curve of 40%,50%,75%,85%,95% (more like 5 degrees than 3 degrees at mid stick) in stunt mode worked better for me. It still keeps a fairly constant head speed, but now I am hovering with more altitude control.
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Old Jun 29, 2012, 09:44 PM
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CONGRATULATIONS ALAN!! GREAT work - GREAT report - GREAT results!!

You are an exemplary student and makes me proud to be part of your achievement and success!
CaptJac, have you written anything about setting up a gyro for rate mode flying? I would be interested in something like that to make the tail swing smoothly in turns during scale flight. No one seems to know how to do that where I fly. I have just been using rate mode to adjust servo center to tell the truth.
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Old Jun 30, 2012, 03:03 AM
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Setting up rate-mode is 2 parts trial and 1 part error. Add 2 parts of trial to 1 part error and stir! After that concoction you'll be ready to fly!

Start with the rate-mode gain at 30% - adjust the position of the tail servo - or length of the tail-rod link so when hovering the tail does not turn (or hardly turns) with no rudder input. This usually takes a few hovers to dial in. Once it is reasonably stable - get ground clearance by climbing to 6 feet - maintain your altitude and hover - apply a little aileron to initiate a roll - the nose will turn in the direction of the roll at about 5 knots. Verify smooth and consistent turns - with no tail wagging. Adjust the gain (CH-5) to fine tune. A Futaba 401 gyro is typically between 20-30% - your mileage may vary.
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Last edited by CaptJac; Jun 30, 2012 at 03:37 AM.
Old Jul 01, 2012, 06:55 PM
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Hi CaptJac

Well, you have another happy student, albeit with a bit of lateral thinking.
The story so far.
I have an HK 450 ver2, which has always been a sweet flier, but suffered from the common problem of vague pitch control, especially in a breeze. That's when I came across your thread and decided to give it a try.
Initially, I used your pitch settings of -2,+3,+7.
As I mentioned in an earlier post, I could not get on with these, the model barely being able to lift off.
Anyway, then I had a bit of an accident, not because of the settings, more my complacency, which put it out of commission for a while.
After repairing that lot, I gave it a test flight using my standard settings of:
Pitch -2,+2+5,+7+10
Throttle 0,40,70,85,100.
Found it had not lost it's handling qualities, if fact, gained a few, of which more later.
After that, time to re-visit the CaptJac Academy of Heli Setting.
Decided to go along with the ideas you suggest, but using my known pitch settings. So set up a -2,+5,+10 on Idle Up, with a flat 70% on the throttle curve.
For Normal I went with
-2,+2,+2,+2,+2 on pitch
0,50,70,70,70 on throttle.
I set the low intermediate at 50% because I felt that 0 to 70% in one jump might be a bit harsh.
I also reset the throttle hold curve to match the idle up.
The wind and rain finally subsided enough to give me a short window for a test.
Initial impressions are, major improvement.
As expected, much easier to maintain a steady height in the hover, but also improved pitch response all round.
Although the wind had died down, it was still a little blustery. In the past, when hit by a gust, it would be almost on the deck before I could catch it, now the pitch response is almost instantaneous.
Much more fun to fly.
Another unexpected benefit was this. I only have a cheap gyro fitted. Despite playing with gain settings, I was never able to cure a tail kick when adding pitch. Nothing serious, just annoying.
Anyway, that is now gone. Tail held steady, whatever I did. In fact, tried some quite serious pitch pumps, and felt more comfortable with them than ever before.
So, what next?
Now that I know it's not going to do anything strange, next step is to bump up the Idle Up throttle to 75%, or possibly 80% flat across.
I would expect the pitch response to be even sharper at these levels, so moving in the right direction.
I also have an HK 450 Pro, which, in its standard, flies even better than my V2. Might be another candidate for the CJ treatment.
That's it so far. Still work in progress, but big thanks to CaptJac for starting this thread.

Have fun

Borderlord
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Old Jul 08, 2012, 09:03 AM
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Good stuff!!! Let's keep this thread going so you don't have to 3D to find it.
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Old Jul 08, 2012, 05:21 PM
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Setting up rate-mode is 2 parts trial and 1 part error. Add 2 parts of trial to 1 part error and stir! After that concoction you'll be ready to fly!

Start with the rate-mode gain at 30% - adjust the position of the tail servo - or length of the tail-rod link so when hovering the tail does not turn (or hardly turns) with no rudder input. This usually takes a few hovers to dial in. Once it is reasonably stable - get ground clearance by climbing to 6 feet - maintain your altitude and hover - apply a little aileron to initiate a roll - the nose will turn in the direction of the roll at about 5 knots. Verify smooth and consistent turns - with no tail wagging. Adjust the gain (CH-5) to fine tune. A Futaba 401 gyro is typically between 20-30% - your mileage may vary.
Thanks for the advice! I have a good FB 450 heli I will try this on. If it goes well, I'll try out the guidelines for the pitch etc. and start looking around for a scale Bell fuselage.
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Old Jul 10, 2012, 10:07 AM
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Here is a video of my Hausler 450 flying with the CaptJac throttle and pitch curves. I did have a little bit of a tail bob so I upped my throttle curve from 80% to 85% for the fix. This aircraft is much easier to handle since I started flying with a fixed head speed.

RWW

Hausler 450 (6 min 18 sec)
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Old Jul 10, 2012, 10:50 AM
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Roger Roger!! Nice controlled lifts and landings. Keep up the good work! Looks like you got forward and reverse wired - start working left and right. Roll 15 feet to the left - hover - roll back to center - hover - roll 15 feet to the right - hover. Keep practicing until you can maintain the same consistency - in both position and altitude. This gets you ready for following the nose side to side - aka lazy 8's - and those are more fun than a tornado in a trailer park!
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Last edited by CaptJac; Jul 10, 2012 at 11:01 AM.
Old Jul 10, 2012, 02:12 PM
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Thanks CaptJac, I have been doing a little bit of the left right. I need some practice for sure. I am doing some of that on the sim and it is pretty hard for me to maintain the line. My out and back on the sim is weird for me. I can get out to the pad, stop and land darn close, on the return the speed builds up and I usually end up overshooting the pad. If I try and keep it slower I usually end up stopping. All a matter of finesse on the sticks, I know. But struggling a little bit, I am.

RWW
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Old Jul 10, 2012, 02:22 PM
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I have habit of always landing in stunt mode and sometimes is quite a hard landing. Also I been landing it like airplane coming down horizontal oppose to hovering and then down.

I'm not a 3D flyer, but my heli is 3D settings, due to fying FBL system only (Beastx and Walkera 3-axis gryo) I'm force to go zero at mid-stick to get my heli properly working with 3-axis gryo. However I want to try your scale flying recommendation.

My setup is -3.0,+11 and -11,0,+11 and I would take off in Normal and fly/land in stunt mode. Throttle is 0,50,80,90,100 and 100 Flat curve for stunt-mode.

What do you recommend for setup for landing in windy conditions? My area is always windy. I don't think my landing are bad, just like to improve on it.
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Old Jul 10, 2012, 04:50 PM
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What do you recommend for setup for landing in windy conditions? My area is always windy. I don't think my landing are bad, just like to improve on it.
When you have a little wind you need a little negative pitch. -2 degrees will bring it down and to hold it on the ground. The more negative pitch below center stick - the less resolution for maintaining constant altitude. The more negative pitch the faster it comes down - - which for soft landings is not what you want unless your landing pad is a pillow.
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Old Jul 10, 2012, 10:46 PM
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When you have a little wind you need a little negative pitch. -2 degrees will bring it down and to hold it on the ground. The more negative pitch below center stick - the less resolution for maintaining constant altitude. The more negative pitch the faster it comes down - - which for soft landings is not what you want unless your landing pad is a pillow.
Thanks, not a little wind but very windy to gusty , sounds like you recommend flipping back to normal, hover and land with -2?
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Old Jul 11, 2012, 02:17 AM
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When it very windy and gusty I'd recommend a completely new setting - where there is no wind!!
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Old Jul 12, 2012, 06:33 PM
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Nice thread! What I like about it is that it also emphasizes that CP helis are not so scary. I bought a fleet of little FP helis thinking I needed to take small steps to fly the big, bad CPs, only to realize that I can tune the CP to do what I want and they have the control authority to fight some wind. I wish I had a few hundred bucks back that I spent on FPs and parts that are now collecting dust on my shelf! Exept for the quad mQX, I only fly CP now and believe that most beginners could and should make the leap to CP sooner. Not interested in 3D? No worries! But you can still fly a "real" heli and have fun. Phil
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Old Jul 13, 2012, 06:16 AM
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Originally Posted by fastphil_v View Post
Nice thread! What I like about it is that it also emphasizes that CP helis are not so scary. I bought a fleet of little FP helis thinking I needed to take small steps to fly the big, bad CPs, only to realize that I can tune the CP to do what I want and they have the control authority to fight some wind. I wish I had a few hundred bucks back that I spent on FPs and parts that are now collecting dust on my shelf! Exept for the quad mQX, I only fly CP now and believe that most beginners could and should make the leap to CP sooner. Not interested in 3D? No worries! But you can still fly a "real" heli and have fun. Phil
+1. However, I think the biggest advances have been in the gyros. After having one coaxial and doing a TON of reading, I found the Genius CP with it's 6-axis gyro. With appropriate configuration, it could be made to fly like a FP, so I bought one and set about configuring it up as such. I found it to be a perfect entry point into CP helis. I too was scared of the big, bad CPs, but after the first take-off, I thought this isn't so bad.

I've since disabled the 6-axis and reconfigured my settings to what can be found in this thread, and my CP flies even better!

Now I've stepped up to a V120S and found that it's even easier to fly than the CP!

If you're thinking about taking the plunge into CPs, there are plenty of helis out there to make that jump a lot easier than you think.
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