tomcatguy74

My Feedback: (4)

Ok, to all you heli masters out there, I'm stumped. I have been posting thread after thread about this and that on my Blade 400. I programed my radio per the manual, setup my swash and linkages and checked my blade tracking. After hours of tweeking her I THINK I finally got her ready for Radds training on my garage floor with the square. So, I took her out to the garage and and set her up, placed her in the square and slowly spun her up. Apon first spool up The tail would swing alot due to the initial onset of power. I tightened the blades a little and that problem kinda went away. Next once she started rotating the heli would start to jiggle alot untill I got the power up a little and then it faded. Radd said to keep the tail at 6 o clock. Tried to do that and it was doing kinda ok. Per Radd I was to increase head speed till she started leaning to the left and then counteract with right aileron. I went up to FULL RIGHT AILERON to try and keep it in the square and she still slid left plus she was violently shaking at full right aileron.
Now I have flown my T-28, mCX and I am very mechanically inclined and know how to use very small inputs to work diferent thinks. Lets just say I have ALOT of common sense. I know how to use hair sized commands to control something.

I think there is something wrong with my heli I just don't know what!!

Here is a video of what is going on. Sorry I used my blackberry. Hope it helps.

http://www.youtube.com/watch?v=ZB3OR1TskPo



Robert

DVI

I had a problem with the stock servo's. Put weights on the landing gear skids, Such as sand bags. With the helicopter secured down spool the helicopter up and watch the servo's to make sure they react as they should.
Before I switched out my servo's, I had three of them go bad and act erract when the motor running. Two crashes due to stock servo's going bad!

jon6565

Hi Tomcatguy

Hmmm, I have had these problems before too. Mine turned out to be a faulty DX6i and it had to go away for warrantly repair. The pots (potentiometers) were not working to their full amount. You can go to the Monitor menu setting and see if you are getting full throws, I say this because you say you are giving 'full' right aileron. ordinarily that would tip the heli over.

The tail will kick out a little but not so much with a gentle spin up like it seems in your video. Is your Gyro switch in heading hold (up at '0')? Even so it should keep the tail steady. Also with the Radd method - you have the groundwash effect - plus the natural Translating Tendency (drift to left) but that should mean a handfull of right aileron still.

Sorry - not much help, but something ain't right by the sounds of things.

I swapped out my servos too...

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

My other post with some photos:

http://www.rcuniverse.com/forum/fb.asp?m=8885143

Jon

JPEE

Hello Robert, the video is not bad but I dont really the see the action your speaking too. Often to find a bug we start taking things off to isolate the problem. I would ofter these suggestions.

Has the heli EVER BEEN crashed? Anything or parts been rebuilt? Was the heli new?

1. Check your belt for proper tightness, if you adjust it then re spool the heli and see what you have.
2. Take off the main blades.........spool up, not better then re install AFTER you have re-verified they are perfectly BALANCE! ! !
3. Check the blade pitch, when it is out the heli will vibrate: set the heli on a flat and kinda rough surface. Stick a crowbar through the skids to hold it down and in place. Then spool up to a SAFE 3/4 throttle as up to 1/2 throttle your blades have ZERO pitch, so at 3/4 they are pulling up and if out of tracking it will be noticeable. Make sure you have the colored tape red/black on each blade BEFORE you try to check your tracking. After all of this go to step 4.
4. Take off tail blades, spool up,
5. Make sure your gyro in the transmitter is set at approx 67

Generally there are only a couple of things that make a heli shake and they are stated above. Let me know how this works or if you need more information feel free to PM a message to me.

Good Luck JPEE

tomcatguy74

My Feedback: (4)

Hey DVI
Before I reattached my mains I spooled her up on the dining room table and tested with just the flybar and paddles and all servos were working great I got full range in all directions. I will however recheck the tail servo since I was mostly focused on the main rotor head and its servo.

Hey Jon,
Nice to talk to ya again, I am pretty sure my DX6i is ok but I will recheck that as well. Now you said "at full aileron the heli should tip over" ,
I don't think I had enough head speed to do that yet. I was pretty nervous. Maybe I will try again tomorrow after checking everything else. Also I don't think I am getting any down thrust untill like 1/2 stick. Is that normal? I will also check that gyro setting since I have not even looked at it yet. (I'm such a noob haha). Servo swap will be quite a ways down the road. Money is tight.[:'(]

Hey Jpee,

The heli was crashed but I am not sure how bad. I will ask my friend tomorrow and ask him what all he replaced.
I will check that belt tomorrow. How tight should it be?
How do I balance the blades without a balance system? Can I use anything primitive? Pen?
I will check the pitch as well but again no gauge.


Guys, amonst other things stated above I really need to focus on the tail system tomorrow. I really over looked that part( What a noob)haha!!

Thanks for all the responses fellas. This means alot to me that I have some support.

Rob

jon6565

hey Tomcat

Yeah head speed will have a bearing on whether the heli tips over - if it is high - then yes most likely. (mind you if you trainer gear is 4ft wide maybe not ).

You should have about 3 or 4 degrees positive pitch at about half stick and the skids getting light - the lift ratio then becomes smaller - i.e. another 1/2 degree but more rpm will lift the heli.

I don't advocate you trying this yet - but I modified my pitch and throttle curves to give me higher revs at lower pitch. I have found this to give me "way" more control - it could however get you into trouble if you aren't past that hopping stage which is when tip overs happen generally.

It's all a bit confusing isn't it! Do you know about expo settings and what they do? I find now that less expo helps.

I found this last week on Gyro's. I was looking specifically for info on Gyro "Gain" and this info was like a shining light... I am now way more aware:

http://www.raptortechnique.com/gyrogain.htm

This one is ona different site but written by the same guy - very good:

http://www.electric-rc-helicopter.co...oconfusion.php

Have fun

Jon

Coyote64

It sounds to me like it could be loose or too tight tail rotor belt, if its to loose it will slip just a little then the gyro tries to compensate but as the belt slips again will start wagging the tail, as apposed to a very loose belt where it spools up fine but as soon as it gets airbourne it will spin uncontrolably.

A nice trick with the blade 400 is to remove the pully tensioner wheel next to the tail assembly and take up the slack by pulling the boom out, works wonders and has no ill effects on the blade. To check tightness of the belt simply lock the main rotors with your hand and turn the tail rotor with your other hand, the belt should slip but only with quite a bit of pressure. if the belt wont slip then the belt is too tight.

Other than that vibrations come from the following :

1 : Main shaft

2 : feathering shaft

3 : Missing bearing after previous crash ( happens a lot espcially with main shaft )

4 Bad tracking of main blades

5 : Tail rotor blades too tight so cant spread symetrically

6 : Bent tail rotor shaft

7 : Twisted tail belt in boom

tomcatguy74

My Feedback: (4)

Hey Jon and Coyote and all

I have been pretty ill for the past few days with strep and broncitis(whatever) and not had a chance to pull the little lady out for those checks you were telling me to perform. I hope to return to work tomorrow and start getting back into my routine of things.
Jon that gyro page confuses the crap out of me. I don't know if it's because I'm sick or not that I can't comprehend all those numbers.
Please remember that I am stupidly new to the DX6i and CCPM helicopters. Just the two (DX6i CCPM) would make a noob freak out!!
Anyway, I don't know anymore about my radio than what I was told to program into it for my T-28 Trojan and what I am learning or trying to learn about programming such a beautiful and technilogical masterpiece such as the Blade 400. I don't know what "expo" and all that stands for and means.
I think today I will take some of my bed ridden time to look up all the terms and words associated with my DX6i.
Want to laugh?
Ok, check this out, I am an FAA Certified Aircraft Mechanic and this stuff still blows my mind!!!![X(]
I know what blade pitch, gyro, blade tracking and all that other stuff mean. Translating tendency, expo, and all that stuff has been forgotten or never learned.
Okok stop laughing.

I am going to need alot of help to get this baby airborne and I WILL NOT STOP TRYING untill I do.
I really appreciate all of your help and hope you will continue to help me now that you know that I am a "certified" Nooby[8D]

Robert

jon6565

Hey Tomcatguy – I’ve been at home too – inner ear infection and balance problem… no flying due to high, cold winds coming up from the Antarctic! Having said that I got 2 packs in yesterday afternoon up the local school oval (after school) in a lull in the winds, which was neat because it was the first flights since the new servo’s – and all seems fine.

Dog walkers kept stopping and asking stupid questions and there is NO WAY you can fly when someone is twittering in your ear… and the infected one at that! 2 batteries took almost 45 minutes!

I was about to go get a new Gyro earlier and checked my wallet but my wife has pinched my cash I was reserving!

Your post above will prompt me to put down my thoughts on all this confusing stuff about gyros and numbers, flying etc and my theory on assisting my learning process…

Your admission as to your qualification did make me laugh I have to say – but if you are a fixed wing rated mechanic then there is no shame attached!

Watch this space!

Jon

jon6565

This is a general diatribe which is my take on the learning process for CCPM Heli's - namely in our case the Blade 400.

Before I bought my Blade I was fence sitting over fixed wing or Heli. I have flown fixed wing before but it was short lived and over 20 years ago (I'm 44). it was fun and I went through a similar but less technical learning curve with that high wing .40 size nitro. Shortly before my emigration to Oz it came home with me in a carrier bag. The heli route has proven to be a wise choice. Why so?

The challenge. Both to fly and to set up or vice versa!

Fixed wing planks are still fun - and can get as technical but the process of discovery about how all these little things about CCPM heli's comes together has been truly gratifying. My father builds model steam locomotives - and is very good at it - and revered by his peers - but he let's another guy drive it... why? Because he enjoys the build, test and fixing process - another challenge.

I find heli's very similar, sure they can be frustrating but the challenge of understanding, setting up and ultimately flying well are all very rewarding. Where am I going with this? well I guess I am trying to say that you can't just pick up one if these babies and fly it WITHOUT understanding how it it all works - it an holistic process.

Each success, be it from competent and valuable advice from these very forums (thanks to all) to your own research or discovery is a piece of the puzzle slotted into place.

Tomcatguy74 ~ Your comment about the Gyro texts and it being confusing is entirely understandable - but you will reach the point where you 'have' to know and it will sink in. I read this stuff like 3 or 4 times. With that Gyro topic, I actually drew it out how I understood it to be, a little graph showing 1ms to 2ms cut in half at 1.5ms and HH and Non HH on either side. I now understand % Gain but I will need to refer to my notes for a while yet!

Yesterdays win was figuring out that setting the Blade pitch was also Blade tracking - or at least the same process. Until then I ignored "tracking". Running through that process made the blades sing like day one out of the box, until on that day they hit the deck about 30 mins later and bent the shaft!

My theory tends to ring true when you consider how many "blinged" heli's there are out there but few "excellent" pilots. They get the thrill of tinkering - me, I'm middle of the road. I like to tinker, but on a budget and I also want to fly well.

I'm sure my sentiments will be echoed (or looked upon as ramblings), but summed up what i am saying is:

THIS ***** IS ADDICTIVE!

I think I will be at this for a while to come yet, whether my wife likes it or not. I have found a hobby that is not nerdy and requires some genuine "nouse" as we say here in Oz.

Anyhoo, no need to comment on this except to say "I agree" or "W.T.F?" - that scribbling was in itself therapeutic.

Roll on flight time and shed time - it all works for me!

Jon

Coyote64

What expo is tomcatguy :

If you have a servo set with zero expo in it the servo will move in a liniar fasion, ie : At mid stick the servo is at 50 % travel, at 60 % stick the servo is at 60 % of its travel at 40 % stick its at 40 % of its travel etc etc, now what we find is at centre cyclic stick the b400 is really really twitchy , just the slightest touch of the stick has a lot of movement of the chopper.

What you want is to dull the servos movement down so with the same stick movements the servo moves less compensating for over corrections, this is what expo does.

What you want to do is set yor aileron elevator and rudder to about 30 % expo, when you do this you will notice that around centre stick that your stick inputs that use to be very sensative now seem to react a bit slower, you still get full throw of the servos but greatly reduced movement around centre stick. As you get more confident and use to how much easier it is you can reduce your expo little by little until you find your perfect and managable rate. I personally fly at 25% expo now and dont see any reason to go any lower it flies nice and my dumb thumbs dont overcompensate anymore.