My Heli wont take off....Twister 3D

[Peter Budd]

Having flown fixed wing for 8 years I have decided to have a go at helis.  I bought a simulator and can hover and fly with reasonable precision.  I now have a twister 3D and have made some nice wide trainer undercarriage.  I have set it up by the book and programmed in all the settings recommended in the manual for my transmitter (DX7) BUT when I throttle up above half throttle it spins like a demented balerena and responds very little to rudder inputs.  Below half throttle you can see the heli responding perfectly to inputs but obviously it's not off the deck yet.  When I throttle up further the motor sounds laboured and the rotors lean forward and to the left and looks as though its being sucked to the deck.

 

I have no idea what all the jarghon means so if anyone can expalin these two problems and how to cure them in mono syllabul words I'd be very appreciative.

Cheers Pete

[Paul Course]

 

Hi Pete sounds like you could do with an experience heli pilot having a look and trimming it in for you.

Perhaps the twister 3d isn't the best choice for a first heli I started with a Hummingbird 3d pro, big mistake, one attempt at flight get the wallet out buy spares to repair also bought a contra rotating heli, progressed from there to nitro heli's

 

Hope you sort it regards Paul

[Peter Budd]

Hi Paul, problem I have is that I have moved to Cyprus now, one of the reasons I went to the Twister.  I appreciate that its not the ideal starter but having fixed wing experience, my B etc I didn't want to fork out on a contra then again on something else.  With a simulator and training undercarriage I am confident with patience and access to a large sports hall I can teach myself slowly.  I have used the sim for many weeks now and have got the basics sussed, but not the setting up. Also I fly mode 1 and most if not all the beginners ones come with mode 2 transmitters.  I went for the Twister because it had all the set up figures in the manual.  There is a local club that fly helis on the salt flats here so I will go and speak to them at the weekend. 

Cheers Pete

[Lindsay Todd]

Peter

 

I fly mode 2 but a couple of things need checking on basic set up

1. check that your gyro sensing is in the right direction as this would explain the rotation and little impact of rudder control.

2. your cyclic control mix sounds like it has some issues. I dont know this heli but if the control is ccpm then you have a mix either mechanical or via tx causing the problem. check this out without power to the motor.

 

hope that helps a bit 

[Peter Budd]

Thanks Lindsay but everything is set exactly as stated in the manual.  Anyway how do you do number 1 and 2.  I may need to find someone who knows what they are doing. 

Cheers Pete

[simon burch]

Peter, have you checked the pitch range ??. I've set a few of these up for people, and those symptoms sound to me like you have too much pitch on the blades in the hover.

You don't mention what Twister you have, there's a few of them. Is the tail driven by a belt of is it a seperate little motor ??. If it's belt driven, I'd put money on it that you don't have enough head speed, which equates to a low tail rotor speed, which means it will not counter act the torque of the main blades...........and basically spin around on the spot.

If it's got a small electric motor on the tail, then the tail rotor speed is controlled/mixed electronically. This is usually adjusted by a small pot on the mixer board.

If you are going to fly collective pitch models, a pitch gauge is a must. Just make sure you disconnect the motor when checking the pitch ranges. Rough guess on pitch range -2 bottom, 4-5 degrees mid stick, 8 degrees at the top.

Let me know how you get on. Can try and explain things in more detail if you are struggling to get local help.

Cheers,

Simon

[Peter Budd]

Hi Paul, thanks for that.  It's a Twister Storm, sorry I forgot to add that.  I bought it because I knew I wouldn't be able to get help setting it up and they are advertised as being set up at the factory and in the manual all the percenatges, throws, mixes are quoted for different transmitters.  Sounds like it's well out and I don't understand all the jargon, although I do have an idea how the different movements of the flying surface make it fly.  Nevertheless it makes no sense to me in the programming.  The tail rotor is belt driven and everything seems to move ok when I twiddle the sticks! 

 

Cheers Pete

[simon burch]

There are a few topics on here for stting up basic throttle curves, this would be worth a check first, but with a Twister Storm 3D, spinning is either a sign you have your gyro reversed, ot you have way to much pitch on the blades for the amount of throttle.

 

Checking the gyro is simple. Firstly make sure the tail is working in the correct sense, then the way I check is have a look which way the servo moves when you put a left input in. Then grab the heli and give it a short sharp twist to the right (rotating around the mainshaft axis), whilst doing this keep an eye on the servo, it should be moving in the same direction as previously i.e it will be putting in a left tail input to counter act the right yawing movement.

 

You didn't mention of you have a pitch gauge or not ??.

 

Cheers,

 

Simon

[Edgar Playfoot]

Hi Peter, I am learning to fly helicopter with a Twister Storm and can now fly circuits. I now also have a Trex 250 and am finishing the build of a Trex 500.

I am using the DXi 6 channel radio with my Twister which I think is very similar to your DX7.I used the recommended settings as for the DX7 but found that I had to reverse the elevator servo and I wonder if this may be your problem. The swash plate must remain level as you advance and reduce pitch. When increasing pitch the swash plate lowers on the spindle.

 

I did reduce the Travel Adjust for Rudder on the transmitter setup to 50% each way to avoid the servo over running.

 

I think there is an error in the setup instructions for the swash mix. I found mine had to be a plus for pitch and not a minus. I also reduced the percentage for pitch from +90% to + 75 which gives me a pitch range of about -2 to +10 which has been recommended for beginners many times on this forum.

 

I don't think the gyros are very good on the Storm. Mine wags a bit. My gyro responds to the Flap/Gyro switch. Up for Rate mode, down for Heading hold mode. The gain is adjusted by Travel Adjust  60% as the instructions but I find I have to reduce this a bit in a wind.

 

Hope this is of help. Edgar

 

[Peter Budd]

Thanks Edgar, I have made your adjustments and now at least it seems to want to take off, but it stll whirls around like a top.  Simon I will try the giro test you describe.  Once it lifted fine...once mind.  But as soon as I put the slightest rudder movement in it just gets worse, so maybe it is the giro.  I will let you know. 

Pete

[Former Member]

[This posting has been removed]

[Edgar Playfoot]

The HL400 Gyro that came with my Twister Storm does not appear to respond correctly to the Gyro setting on my DX6i tranny. I have to leave this setting in INH. It does however respond to the FLAP/GYRO switch. Rate is in the up position and Heading Hold in the down position. Gain is adjusted on the Travel Adjust and the Storm instructions say 60% but I usually have to reduce this to 50% to lessen tail wag. Sometimes on spool up I get terrible tail wag which sometimes goes away if I switch off and back on. The instructions do say that the gyro is affected by temperature and humidity and this problem occurred mainly back in the winter. But in fact I have been flying today and the gyro behaved much better after the first flight so perhaps it needs to warm up!

 

The GP750 gyros on my T-REX 250 and 500 work much better and are adjusted via the gyro setting facility on the tranny. But the GP750 gyro costs well over half the cost of the complete Twister Storm!

 

I am not sure if my Twister would have flown OK straight out of the box, because I promptly crashed it on first spool up and before I could fly again I have to learn how to set it up.

 

One thing is for sure, a beginner needs to reduce the amount of control movement which one can do either on the Swash Mix or Dual Rate and Expo. I have my Twister Storm  Dual Rate and Expo set at 80% & 40% for ail & Ele and 90% & 20% for Rudder.

Perhaps these comments will be of help.

 

 

[Edgar Playfoot]

I have just been reading Eric's comments again and he is correct in saying that on switch on the heli must not be moved until the gyro light comes on which is red on my Twister Storm.

[simon burch]

Peter,

Had an idea, these little models need head speed for stability, and to get authority in the tail. Assuming your swash plate is now moving correctly, and the gyro is working in the correct sense (might be worth checking the gain i.e I'm sure the gyro sensitivity can be adjusted on your transmitter). It's very difficult to explain how fast the head should be, so I found this

http://www.youtube.com/watch?v=8_7cA29spYk&feature=related

 

The head speed on this sounds about right to me, was your model like this when it was getting close to being light on the skids ???. If not, you need to reduce the pitch in the hover. I never heard back on whether you had a pitch gauge or not, so I thought this might be a good comparison.

 

Cheers,

Simon

[Peter Budd]

Hi all, thanks for all the advice, no I don't have a pitch guage, I wasn't intending to get into helis in a big way yet and besides I bought this twister because it was supposed to to fly almost out the box (I wasn't expecting perfection) but this is ridiculous at the moment.  I have reversed the gain on the giro and there is no change...strange

 

Yes I do leave the giro to set itself first before touching the heli, but what I did notice is that after changing the giro reverse the servo movement didn't change when I moved the tail one way or the other.

 

Thanks for the youtube clip.  No, mine soundsa nothing like it.  Spins like a top, hovers ok but obviously have no control.

Edited By Peter Budd on 24/06/2009 14:07:00

[Paul Course]

 Hi Pete did you disconnect the power and then recheck some of these things need the power supply romoving after each adjustment to allow the gyro to initialize' make sure the gain little screw on the front of the gyro box is at about 90 % to start, if the chopper doesn't spin but wags it's tail turn down the gyro gain bit by bit until it stops wagging disconnecting power after every adjustment. if its a headlock gyro try switching this out to std mode.

Regards Paul

[MGTF]

Hi Peter

 

Try this site for help with your Twister

 

www.heliguy.com/Forum/twister-rc-helicopters-f49.html

 

Intel

[Peter Budd]

Hi Paul, yes poweroff each time.  Not sure what you are taliking about re gain adjustment etc, but will have a fiddle tomorrow.  The heli takes off ok but just spins so it must be a giro issue. Thanks MG, lot to read there but will do when I get time. Thanks

Pete

[Paul Course]

Hi Pete The gyro unit (between the reciever and tail servo) should have a small hole in the casing marked gain, below that there should be a small screw type head that is the gain adjust on the gyro carefully find the limits of this screw and set it at about 90% to the + then back off the screw by small amounts if the tail wags like a dog. The more gain the more control the gyro has. P.S don't forget to disconnect and power up after every adjustment. If you have switchable heading lock from the transmitter set it at normal.

Good luck Paul

[Peter Budd]

Cheers Paul, will have a fiddle tomorrow

[Graham King]

Had 2 of these. The standard HL400 gyro didn't work on either - centered in a different place all the time.  Upgraded to the HL800 and they both flew like a dream.  All linkages were set perfectly straight out of the box. The only adjustments made were on the transmitter ( FF9)  Fully 3D capable, they are brilliant , and for a little electric helicopter they even flew in quite strong winds.  LIke aircraft though, the bigger machines are far easier to fly and far more stable.  After flying a Raptor 50 for 12 months, my son really struggled to just hover the Storm the other evening!  "too twitchy" 

[Paul Course]

 

Hi pete just a thought when the heli is in the air do you watch the nose or the tail to correct the turning (spin) of the heli, you should watch the nose if you watch the tail it makes the spin worse,as i say just a thought

Regards Paul

[Peter Budd]

Thanks for all the help everyone.  I am working for the forces here and coincidently a model shop has just opened up on the base.  There is a cypriot guy working there who knows his helis.  He's had a look and the spinning was caused by the giro switch set to reverse.  I thought I had to reverse it on the transmitter.  He is also going to set it up for me....hopefully, just waiting for him to get back to me.  He said it would be easy and more responsive to fly if the throttle controlled the pitch and the blades spun at full rpm all the time like a real heli.  Makes sense I guess.  At the moment nothing is set right...so much for the settings provided by the manufacturer for the spectrum.  Fingers crossed. He cant really help me fly it though as no-one here flys mode 1, so its steady as I go.

Pete

[Peter Budd]

Well success at last.  I have now used 4 battery packs...about hours flying on and off and can hover, albeit drifting around a bit.  I can more or less land it where I want, although everyhthing goes pants when its facing towards me.  Don't know why when with fixed wing I'm fine.  I can move around the sports hall at will also, but only moving forwards and bacvkwards and side to side.  So keep practicing eh?  Simulator was invaluable...only the cheap 19.99 one but it got me used to what the heli would do.  So you can fly a heli on mode 1.....I would have done this sooner if peolple hadn't tried to put me off saying it was difficult or impossible.

[John Privett]

Posted by Peter Budd on 08/07/2009 16:08:30:
I can more or less land it where I want, although everyhthing goes pants when its facing towards me.  Don't know why when with fixed wing I'm fine. 

 

I was surprised too that so much of my fixed-wing experience seemed to count for nothing when taking up helis.  And other club members who've flown f/w for years then bought a heli have found the same thing.  Even after learning to hover nose-in (mainly by lots of practice on the sim!) I still found flying circuits quite challenging/worrying for some time.  

 

I'm now fine with circuits but summoning up the courage to try a loop...   Trivial with a fixed-wing,  but my mind just sees £££ signs whenever I contemplate looping the heli!

It's all good fun though - and I now use the rudder far more on my fixed-wing models than I ever used to!