patryn

My Feedback: (1)

I just finally received my receiver and battery. Man, the 2200 battery barely fits under the hood. I tookthe heliout to the nice windless warehouse at work to get it dialed in. I kept adjusting linkages until I had it almost balanced mechanically. Then I realized I hadn't done any subtrimming to make sure my servos were sitting at the midpoint. So I started all over again but ran out of battery to complete it, so I came home. Well, in the process I started wondering if I fubared the pitch in the process of adjusting. However I noticed that the linkages aren't solid like the CP Pro2. I could just unplug the motor and push the stick to halfway in Mode1 to make sure I was hitting zero. With the 400, the blades can still flop around. So I'm sort of at a loss. I'm guessing I need to buy a pitch gauge to make the magic happen? What's the process I should follow?

Subtrim servos to center (not sure what "centered" is for the double linkage front servo)

Level swashplate

adjust blade pitch

Btw, I have nothing to level the swashplate or do the blade pitch. On theCPP2,I'd just keep making linkage adjustments, see which way it'd go, make more adjustments, see which way it'd go, rinse, repeat.


I also noticed it wants to bob the nose left when giving it a throttle kick. A really good bob. The EFlite manual didn't say anything about mixing channels. The gyro setting suggestions are a lot lower than CPP2 as well. I upped it but anything over 80 seemed to make the tail servo constantly make noise. This helped a bit but I still had more kick than I'd hope for.

9sec240

You can test for zero pitch using the hang method. Fold both blades forward and then hang the heli nose down holding the tail boom. At zero pitch, the flybar and blades should hang parallel with the boom and be parallel to each other.

You can level the swash by using a ziptie. Put a small ziptie around the main shaft and trim it so that the end is just over the end of the swash balls. Rotate the head and make sure all three balls are an equal distance from the ziptie.

What throttle curve are you running? If you are running the linear TC that the manual states, that is a huge reason your tail is kicking. Try 0-35-70-75-80.

Proper order for adjusting your B400 head is:

Subtrim servos to provide 90° at mid stick.
Level the swash at mid stick.
Adjust swash height till your washout arms are level at mid stick.
Adjust blade pitch for zero at mid stick.

Use the factory suggested swash mix for pitch range.

patryn

My Feedback: (1)

Sweet tricks. I'm going to have to go through and try that. After I posted, I started going back through the heli and just pulled the flybar parallel and eyeballed the pitch. I have it steady after doing a little subtrim adjustment but it seems to require a little extra stick to get it off the ground. There's a point throttling up that the body just starts trying to dance a jig. It does it every time no matter if I'm spooling it up or spooling it down. Is that natural for the 400? It's brand new, never wrecked. I do have the curves set via the manual. I'll try upping the speeds and see how it behaves.

9sec240

Yes, they hit a resonance at a certain point and start shaking. Search "ground resonance" on YouTube for examples of it.

9sec240

One of the best videos showing ground resonance.

[youtube]http://www.youtube.com/watch?v=fln6I2bhk6I[/youtube]

patryn

My Feedback: (1)

Wow. Yeah, mine's not fall apart bad, but it did worry my a bit as the CPP2 has never done. It torques the body pretty hard. I think I may video it next time out and mix in some riverdance music in the background.

Solman

I would have to disagree with that throttle curve for a 400. 0-29-55-76-100 is what I use for the 400. Before you get in trouble, there is more to checking your pitch than using a pitch gauge. It is a combination of adjusting your rods and your transmitter as well. Also if you use the hold switch to move your pitch, make sure your hold pitch settings match your flying pitch settings. It takes a bit to set up on the 400 because the factory really tames it down for the beginner. I had tons of positive pitch and very little negative. Also make sure you check your tracking first before doing your pitch adjustments because you can screw up your pitch adjustments. I would suggest either finding someone who is competent to help or be able to follow instructions very well.

In that video, it looked like his pitch curves were all jacked up. I had a weird situation once on my CPP2 when the pitch curve was screwed up and had some interesting results. I think he had more problems than resonance.

9sec240

Why do you disagree with the throttle curve I posted? How do you screw up your pitch adjustments by adjusting tracking? What in that video showed that his pitch curve was all jacked up?

Inquiring minds want to know.

Solman

If his pitch curve dipped down at all, it cause it to go up and down quick. Like I said, I think he had other issues going on. My tracking was pretty far off when I did mine and required a lot of adjustment. Depending on whether you go up on one or down on the other, it can change your pitch adjustment. It did on mine and threw it off a few degrees. To adjust your tracking, you are either increasing or decreasing the pitch on one blade.

You are not using the full range of your throttle. You are only going up to 80% of your throttle for starters for the high end. The middle seems a bit high, but if it works for you.

patryn

My Feedback: (1)

I'm not a beginner....per se. I've been fairly successful with my CPP2. I was hoping the 400 would be a little more stable since it isn't a motor on a stick. That was one of the main reasons I bought the 400. Plus I keep hearing how direct drive sucks and a servo controlled tail is the way to go. Blade tracking is fine on it. That was one of the first things I checked once I had it in the air halfway straight. From what I could tell when adjusting the pitch is that it was set pretty heavily to the positive side at the factory. I had to raise the swashplate quite a bit to get it to zero out at mid stick in stunt mode. Now it takes a little more to get it off the ground in regular mode and it sounds like it's spinning a bit quicker to do so, but it seems a bit more stable. Might just be me though.

Solman

I have a CPP2 as well and did the same route.  Yeah, my 400 was set like 15+ and 5 -.  I would suggest buying a pitch gauge and going through the whole setup instead of just setting it to zero.  You will be much happier with the results.  I know I was after I got my 400 tuned.

patryn

My Feedback: (1)

I'll probably get around to it eventually. I need to stop spending money though. It's always "one more thing". Now I have three electrics and inherited a nitro that needs work. And I finally broke down and bought a sim. Oh, I shipped the 2in1 today on lunch.

9sec240

Please do a search on ground resonance before offering up your opinion on what might have caused the issues with the MD500. The heli was clearly shaken apart when ground resonance happened. Had he lifted off again, everything would have been fine. I think it is pretty bold of you to suggest his pitch curve had a dip in it. The heli looked great up till he lifted off and set down quickly and started the ground resonance.

When you adjust blade tracking, you always adjust ONE blade. This way your pitch range is never being moved. If you set your heli up properly, you should have never needed more than a turn or two to get it tracked. A few degrees off suggests you need to be a bit more careful when setting up your head. Mark one blade and one grip and make that your "reference blade" Make sure it is at zero pitch at mid stick and then adjust the other for tracking.

What says you need to use the full range of throttle? Why do you have to go to 100%? 100% would be for maximum head speed and lots of cyclic and collective pop. Why would you need that when flying in normal mode? The object is to use PITCH to move the helicopter up and down and not head speed. The reason you ramp up the throttle curve is to add power for the increased drag of the added pitch. You should be shooting for a constant head speed. I suggested the flatter throttle curve to help with the tail kicking out when the throttle was punched. This way the motor does not torque the body around when the throttle is punched. Your suggested throttle curve is kind of all over the place and is still quite ramped.

How long have you been flying and building RC helicopters? How many do you own and have you set up? Just curious.

Solman

j

Are we trying to start a pissing match? Throwing remarks like that is pretty sad. If you think I am wrong, please feel free to explain it to me. There is no need for you to come up with annoying remarks. I spent many years on jet aircraft maintenance, not helicopters. So please feel free to correct me, but don't talk to me like an idiot. It is because of attitudes like yours why people don't want to join flying clubs. I know of 3 local clubs here and I here about all the attitudes like yourself all the time from people who go there.

9sec240

You disagreed with the throttle curve I suggested. I explained why this throttle curve works. You gave no input on your curve other than you use it and it uses the full range of throttle. Can you explain why you feel your curve is better?

You made a pretty bold assessment of a helicopter destroying itself stating there might have had jacked up pitch curves. How could you possibly say that? Were you watching the stick movements when he was lifting off? You stated that you felt there were other problems besides resonance... can you enlighten us as to what those other issues were and what made you determine that?

You stated that the B400 is set up tame from the factory for beginners. You state that they give more positive pitch than negative intentionally. How is that more tame? Why would they want the heli to lift off prior to getting the head up to speed? This causes instability and sluggish cyclic response. This would also be disastrous if the heli was switched to stunt mode. Your B400 may have been that way but it was not SUPPOSED to be that way. If you read the manual, you will see how it is supposed to be set up from the factory...

If you have three clubs with people like me that try to help people by offering sound advice, I would suggest joining one of them.

Solman

PM sent, I am done dealing with your arrogance in the open forum.

9sec240

I am the one that is arrogant? LOL.

Solman

Yes, I sent you a pm to settle this outside and you continue here. Have a nice day!

patryn

My Feedback: (1)

There's only one way to settle this. A 1980's dance competition. I'll get the cardboard.