Full Throttle no Lift

[martinfbrown]

Hi,
Just joined the forum. I have a Honeybee CP2 which I have had for a couple of months now. I was getting on great flying indoors, but decided I needed to try flying out side. I have a fairly large grassed area just outside my back gate, so decided to try it there. Flew great, got to about 15 ft and it was very steady, but then I came down quite hard(nose first). I replaced the shaft pin, set the blades up again, and tried to fly, I had full throttle but no lift at all. I checked the head, found the feathering shaft to have a slight bend in it, so I replaced it and the head(I have since straightened out the feathering shaft in my Lathe). I went through all the normal checks and altered the links, and now I have approx 1ins of lift. I am presuming now that my blade pitch is not yet correct. I am not sure also if I have the blade tracking correct. Does anyone actually know what sort of lengths that the servo to swash plate links and the swash plate to head links should be. I was hoping that this would give me some idea as what to set them at. I think that I have achieved something in my adjustments, but I am still not getting full lift at full throttle. Has anyone any sugestions please. Thanks.
Regards
Martin

[G-MRM]

HI, welcome to Heli-Town Martin.

First thoughts, servos should not need resetting after a small crash, is everything back on OK??

Next un-plug the main and tail motors from the 4 in 1 box. Turn on and move the throttle up. Do you see the blades change pitch from maybe -6 to + 8 or so of pitch? If yes is the blades turning at the correct speed ? If no, what pitch change are you seeing? Hover pitch should be at about +5 deg.

Are you still using the Tx that came with it ?

Martin

[martinfbrown]

Hi,
Thanks. When I move throttle to up position, there is very little movement on the main blades. I have the main and tail motor disconnected when I am trying all this. With the throtle at zero, I have a little positive pitch. I am still using the same TX.
Martin

[eddiemoth]

Hi Martin, like G-MRM said - the pitch might be off. I would strongly recommend you get a pitch gauge. It is about $12 and it is very handly. You know longer guess about your pitch range any more. Another thing you may want to look at is the main motor - it you flew it approx 40 or 50 flights you might have to replace it.

[martinfbrown]

Hi,
Thanks. Actually, I have a pitch gauge, but I find it quite difficult to use without being accurate. I understand that it has to be in line with the flybar to give an accurate reading. Re the main motor, I have a spare motor and that was the first thing that I tried after the crash, but it made no differance. I now have the original motor on. I havn`t actually flown it for that many times. So I guess that the problem is with the pitch, so I will work on the use of the pitch gauge. Does anyone actually know what sort of lengths the links should be, or does this vary between helicopters.
Martin

[G-MRM]

But why would the links have moved ? All three servos move up together to change pitch, so is the swash level at low stick and is it still level at hi pitch, I recon it is as you say it hovers an inch off the ground... Try moving all three links the same to make more pitch at center stick, 5 deg is good... flybar must be level and the top part of pitch gauge level with the flybar, then read the pitch ! There is post on use of the pitch gauge, have a look for it.

Martin

[swatson144]

my links measure 30mm from the bottom of the socket to the bottom of the Z bend, while the links running fron the swash to the mix arms show 20 mm of rod between the links. This gives me full deflection with the esky servos (if memory serves someting along the lines of -8 to +8).

Don't know if it's right for you or not as I set mine up from a basket case with seps/brushless. I tried a bunch of different ways but finally setup with the servos neutral and the flybar carrier in the middle of the slot. Adjusted the linkages for 0 pitch and let the mixer arms be at any angle they wanted. Set limits in swash AFR on my 9CHP. With the stock TX you'll likely need to select the correct holes in the arms vice electronic limits.

Steve

[basic]

there's actually a link on the main page of the website on how to use a pitch gauge - http://www.helitown.com/PitchGuage.html

[martinfbrown]

Hi,
Thanks for the help. I will try and set the pitch, and see what happens after that.
Martin

[martinfbrown]

Hi,
Swatson 144, you say your link measurements are 30mm and 20mm. For the 20mm,is that from the servo to swash plate link, showing 20mm of rod, and the 30mm, is that the length of the swash plate to head links at centre to centre. I have not checked mine as yet, but in the previous message, why should the links move in a crash situation. Obviously when I did crash, it landed nose down and actually broke one of the wooden blades and bent the feathering shaft, which I replaced anyway. After doing this, it would still not lift off, but I will check the link lengths and work from this. I was also just thinking of upgrading the helo too, to the Trex 45SE, but I think I will wait for the moment. Thanks
Martin

[swatson144]

On the servo links 30mm from the hole to the far side of the Z bend. Or another way of looking at it is from bottom of the ball to the bottom of the hole in the servo arm.

20mm of wire showing on the "long links" from upper swash to mixing arms.

Upgrade the heli? You have it now and can get along very well with it just fixing it up and keep trucking. Don't spend any real money on the airframe. Do get a real transmitter (if you are still running stock) as an upgrade on the CP2, and a step towards the next heli.


Steve

[martinfbrown]

Hi,
Thanks for that Steve. I am going to check the lengths of my links and go from there.
Martin

[G-MRM]

Been thinkindg(I know very hard for me !!) maybe you put the washes on wrong when you put the feathering shaft back? The washes at the ends that go onto via the two screws have a very small step in them, this MUST go to the bearing or it will stop the pitch changing then the head speeds up and the grips thus the bearing get pushed onto the washers????? Before changing too much have a look, sure way to tell is if you get over +6 deg of pitch without the blades spinning...........

Martin

Remember thread lock on those screws !

[swatson144]

I know this is true as mine came in with the washers backwards. G-MRM is correct on looking at the stuff that could have changed and leave the stuff that couldn't have changed to mess with on a rainy day. I just figured someone should directly answer the Q though. :wink:

Steve

[Fireant]

The washers should only affect the pitch when the head is spinning. If it's static and they were wrong, you should still be able to check the pitch range.

Martin. When you use the pitch gauge, it's important that the flybar remains level. Where are the servo horns at hover stick? (mid throttle). If you are using ccpm, the horns on the aileron, elevator and pitch servos should be 90 deg to the servo.

Did you check if the horns did not slip in the crash? Have you also checked that the servo gears are ok? When moving the throttle, do the servos move through a small arc or large arc?

[martinfbrown]

Hi,
Thanks for all the help coming in. When I stripped out the head and replaced the feathering shaft, there were two small washes, one large one and one small one. They were assembled with the larger washer first and then the smaller washer on the outside. So you are saying that the smaller washer should be on the inside. That would account for the step, and enable better movement of the blade grips, but as it was originally assembled like this and it was working okay, it sort of puts that theory out of the window. I will check them again though and change them around. Rergarding the servos, they are all okay, and operating with full movement. When I have checked the blade tracking though, it is quite a way out, so I would presume that would cause no lift. I am sure with the help I have received up to now, I will manage to fly again shortly.
Martin

[G-MRM]

Hi Martin,
Yes they have always made these helis with the washers the wrong way around !!! They were told 2 or more years ago but.......
I had the same, the heli was brand new and was fine, once use to it, I would fly it in the house. One day I spooled up and no lift, more power, then I added a little more and up like a rocket just missing the light fitting !!

It was then I found the washes were on wrong, July 2005 ! The big washer grips both the inner and the outer of the ball race thus it can't turn under load ie when it is spinning at 2000rpm and is being pulled up to that washer. Swap the washers over and I bet it will lift and fly like it did before !!

Bad tracking will still give lift but should be tracked once it is hovering Ok.

Martin

[martinfbrown]

Hi Martin,
I am going to check the washers today. I have been nightshift and I am away this weekend, but I will certainly check the washers. Regarding the tracking, I have weighted the helo down, and spun the blades to about half-throttle, and I can actually see one blade that does look a lot higher than the other. I will try to correct that. Thanks.
Martin

[G-MRM]

Ok, lets us know what you find and good luck !

Martin

[martinfbrown]

Thanks again,
Hopefully I may get somewhere this time!!
Martin

[martinfbrown]

Hi,
I have checked the washers, and one of them was the wrong way round, I have changed this. I have set the link lengths to what swatson 144(Steve) said, I think that the swash to servo links are now okay, but the swash plate to head links are a little too long I think. At zero throttle, I work out that I have about 8degrees of + pitch, it tries to lift, but this pitch is wrong, it should be zero at zero throttle(Am I correct). So now I presume that I need to adjust the swash plate to head links until I get the correct pitch using the gauge.
Martin

[swatson144]

Using the stock tx dis the motors and shift the tx to idle up. You should have 0 pitch at mid stick in IU. That will give you the correct setup in NORM.

Steve

[martinfbrown]

Steve,
No in IU there was still a little positive pitch with stick at mid position. Thanks.
Martin

[martinfbrown]

Hi,
As yet I have not finished setting up my CP2. One question, has anyone any idea if the cnc aliminium rotor head upgrade for the CP2 is any good? I was thinking of upgrading to the cnc head. Thanks.
Martin

[swatson144]

I can recall of no single person who has been pleased with the metal head on a CP2/BCP. Many that were disappointed though. Weight and slop are the issues. You'd probably be pleased with a H2 head from Duzi but you'd still have the motorized tail to deal with.

Steve

[martinfbrown]

Hi,
Thanks for that. I will just stick to the original rotor head, less expensive to repair!
Martin

[G-MRM]

Less thoughts of upgrades, will this one fly again, that's what we are all waiting to hear !

Martin

[martinfbrown]

Martin,
Hopefully, yes it will fly again. I have not worked on it since last week, so hopefully this weekend it may be flying again--watch this space! Thanks
Martin

[martinfbrown]

Hi,
Been setting the cp2 up today. Set corect pitch and everything else and tried to fly--no luck again. So, I have been using plastic blades, so I changed them for wooden ones and now I have good lift at full throttle. Problem now is that it is very unstable, it is drifting to the left, when I adjust the trims, it does not seem to make any diference. Does the fact that it is drifting one way have anything to do with the adjustments on the 4 in 1? Thanks.
Martin

[swatson144]

Do me a little test and before take off turn the throttle trim up all the way and see how it acts. Be carefull though you need to not crash without turning it down as the blades won't stop at low stick.

I'm thinking you have too low HS.

Steve

[martinfbrown]

Hi Steve,
Just turn throttle trim up, and leave throttle stick in down position, is that correct. What is HS?
Martin

[swatson144]

HS = head speed

I'd like for you to turn the throttle trim up. The blades will begin turning. Then try to hover if you feel comfortable.

There is some danger here for equipment as chopping throttle won't stop the blades and there is no TH (throttle hold) on the stock TX. So if you crash you have to lower the stick and the trim.

If you have too much pitch and are trying to fly around with too low a HS this will bring the HS up before the pitch comes on and make it less wallowey. If you like it better you can adjust linkages for less pitch.

Steve

[martinfbrown]

Thanks Steve,
I will try that tomorrow now, been too busy working in Daughters house today. I also have the flybar and paddles top check, as I had not checked these.
Martin

[swatson144]

Cooll I think you'll like it with the HS up a little. They typically punt off at too low a HS and tends to make them seem to not respond and then zoom off.

Steve

[martinfbrown]

Steve,
I have tried what you said.(moving throttle trim up). it does now actually take off, but is very unstable in the hover. It is very difficult to keep it in one place. As yet though, I have not checked the blade tracking.
Martin

[swatson144]

Fidgity is the trademark of a heli. It ain't easy and takes lots of practise! It is no secret that I'm not overly fond of the CP2. It's great for what it is an RTF entry level heli it'll fly and it's wonderful to learn to hover and dabble in FF. After that it's pretty much out grown. It's also reasonably safe. One thing they really have a problem with is after a couple of tip to ground incidents the covering may open up and form little parachutes that make for suboptimal performance. You can use equal lengths of office tape on both blades to fix them.

OK so now we are back to getting it setup correctly.

Observe the motor connections and then disconnect both motors.

switch on the TX in and put it in IU (acrobatic switch) center the throttle stick exactly, and center all trims.

power up the heli sans motors. All servo arms should be straight across and the swash level. If not make it so (or as close as possible).

Slowly move the throttle stick up and down and see that the swash doesn't touch anything at either extreme. (slowly so you can stop moving before it stalls the servos or strips gears) adjust the servo links as needed. *note that at this point we are getting a good starting place and not too worried about what the head is doing*

Return thr stick to center. and have a look at the head (just an observation period and don't mess with anything until the next step) with it in ready to fly position level the flybar. 1, Are the paddles flat and level? are they still level if you rotate the other paddle towards you? if you rotate the paddles does the outer ring follow them or does the flybar turn in a broken ring? 2 are the blades inline with the flybar (both) in various positions? I'm betting they are but you have some + pitch on the blades.

Now comes the fiddley part as most any adjustment upsets other adjustments and it's kinda rinse repeat,

make the paddles flat with the flybar carrier outer ring.

Adjust the long links from the inner/upper swash to the mixing arms until the blades are flat compared to the flybar. If you have a pitch gauge adjust for 0 pitch. If not back up a bit and align a straight edge across the chord of a blade and adjust the long link until the end of the blade is parallel with the flybar, repeat on the other blade. them at diferent positions and sides. Grab the gripes and gently flex them up/down for/aft check for 0 pitch again, do this by trying to flex the end of each grip down and the inside up on both grips at the same time etc kinda like you are trying to bend the feathering shaft. (if it's out now probably a bent flybar).

Ok now we have 0 pitch center throttle in IU. raise the stick slowly and check for binding. Observe the positive pitch now go negative (down on the thr. if the pitch looks equal and nothing binds you are pretty much done.

If one direction has much more pitch than the other raise or lower the swash with the 3 servo links and rest 0 at center throttle with the long links and check again.

Rinse, repeat.

Steve

[martinfbrown]

Thanks Steve,
Been working on it all morning here. I have set it according to your instructions, I then set the blade tracking. How I set the blade tracking is as follows:I anchored the helo down,marked one blade tip red and the other black. I then ran it up to half-throttle and used a piece of folded card, and moved it towards the rotating blades. At first the red tipped blade was higher than the black tipped one, but I finally got it so both marks were together. I have given it a test flight, and I would say that the full lift is there now, only thing is, that it is tending to wander a lot, I have played around with the trims. I do feel now that I have achieved something with the helo, and have learnt quite a lot of how to set a helicopter up. Actually, before I had the crash, I was thinking of getting the Belt CP, you can get some pretty good deals here in the UK. Have you had anything to do with the Belt CP/what do you think of it? I am going to have a bit practise now, as it is a month since I flew. Thanks for your help(I will still come back if I get stuck). Another thing, should I need to adjust the 4 in 1?
Martin

[swatson144]

I'd slow down on the next heli until you've outgrown this one :) .

You'll need a real TX for the next heli and I'd set my goals on that 1st. The CP2 is much better to fly when you can setup the TC PC the way you want.

You might need to turn the mixer up as the tail motor wears out.

Steve

[martinfbrown]

Hi,
When you say turn up the mixer, is that turning the gain on the 4 in 1/ Thanks
Martin

[swatson144]

if memory serves it's the "center" (other POT) which as the motor gets aged it'll send more throttle to the tail per % on the main. You'll know your tail motor is going TU when you need to adjust it often.

Steve

[martinfbrown]

Thanks. On this 4 in 1 there are two adjustments: gain and proportion, so I should need to adjust the gain.
Martin

[swatson144]

Nope the proportion would be the one. It'd send a higher proportion of mix to the tail motor. Ie with a new tail motor you may only need 12% tail at 50% throttle to hold, with an older weaker tail motor you'd need to bump it up a bit to hold. That's actually the Mixer part of the 4n1 (gyro mixer ESC and RX) its the same as revo in a computer TX which is a fancy way of saying throttle - rudder mixing.

Steve

[martinfbrown]

Thanks again Steve,
I have quite good lift now, but it is still wandering a bit, so I will try adjusting the prop.
martin

[SinxarKnights]

I am glad you got it working.

I see you mentioned a crash, nose first. The first thing that pops into my head is you fried the main motor. A fried motor will still get you airborne, but you will have to turn up the trim almost all the way to get any real lift out of it. I am already in the habit of buying 2 motors at a time just for that specific issue, since I am flying around in Idle Up now.

I suggest your replace your main motor. If that isn't the problem, then you have a spare motor.

For the "wandering", it could still be the same thing. Your head spead just isn't high enough for stable (I use "stable" loosely) flight. Also check to make sure your swash plate is level. Also make sure your blades are tracking as good as you can possibly get them, this is very important for accurate flight.

[G-MRM]

I must say i never bothered with upgrades to this heli. I used it as a tool to learn on and saved the money for a 'better Tx and a better heli'

They are good but once you try a little larger heli like the T Rex 450 or TT Mini Titan, it is so much better, like you can fly in some wind and have good control. I stil fly my one for fun of a low wind day in the garden.

Inside, say a hall or gym they are very good and flying costs are low!

Just my $2 worth !

Martin

[martinfbrown]

Hi,
Thanks. Actually, I had thought about changing the main motor as I have a spare. Tomorrow, I will try adjusting the 4 in 1, and try a new main motor. You say blade tracking has to be accurate. The way I have been checking it is as follows:Mark tip of one blade with a black marker pen and the tip of the other blade with a red marker pen, anchor the helo down and run it up to about half-throttle, and then with a folded piece of thin card, move this carefully towards the rotating blades and on contact, I get a red and black mark on the card. When I first did this, the black mark was quite a way above the red mark. Now I have it with the black mark a fraction above the red mark. Is it worth trying to get this more accurate or not? I was a bit worried about setting blade tracking, but I find this method to be quite easy.
Rgds
Martin

[swatson144]

Be careful securing a CP2 as there ain't much secure about them. Landing struts can pretty much pull out.

Steve

[SinxarKnights]

To be honest, its hard to get perfect tracking on the HB CP2, it just needs to be pretty close. Please listen to swatson144 and be careful. I have not had that happen but it is definitely possible.

I seen that method of checking tracking but it just seems easier and safer to look at the blades from edge on. Just mark the blades, about 1 inch on the leading edge of the tip, one red and one black. hold it down and spin it up and look at the blades edge on and see witch is higher/lower and adjust as needed. If you can hover fairly well, you can put it in a hover and look at the blades edge on like that. Careful doing it like that because while you are looking at the blades the heli could be doing something bad.

I will admit, I am guilty of flying my HB with horrid tracking and sometimes broken/bent parts. It will fly but will be hard to control if it is not setup properly. After a while you will see what you "can get away with" and still fly it, but on something this small, blade tracking is one of the very important points you have to check. Especially after a crash, even if you replaced head parts. I don't mean to bore you but its just that important. :P

After you do the motor replacement, try it out and tell us how it went.

EDIT: Ok sorry for talking to you like your a newbie. I just went back and read all your post. Just get the heli into a hover and look at the blades (after you color the leading edge of one. I have one red and one black, strangely its easier for me to see the black mark against a dark background...

[martinfbrown]

Hi,
Thanks, I will try the 4 in 1 adjustment first, then try the motor replacement, as I do now have considerable lift. I will post my outcome of this tomorrow.
Martin

[swatson144]

I usually just color a bit of the end of one blade with black. While hovering the black tip will look shorter and easy to see against most any background. Doing the other in red just muddles things for me.

On CF blades I don't want to mark I paint one pivot screw then just adjust the link leading it and if it gets worse go the other way. Thats without being able to tell which blade but being able to tell the blades apart when it stops.

Steve

[G-MRM]

Fixing it down is a way to do it until you have hover on the spot and just look at the two marked blades.

As Steve says, that UC just pushes together ! I would try to get use to looking at the blades than marks on the paper, that way your be fine when you can hover on the sopt and see the blades.

Martin

[martinfbrown]

Hi,
Update so far. Had it flying today okay. Got to about 3 feet and helo was spinning slowly anti-clockwise, but managed to correct with the trims. I had a couple of hard landings(square on under carrage) so I now have a problem with the under carrage, but I have done a small mod to overcome this. Other than that no more damage to helo.
Martin

[G-MRM]

Well, I am glad you up in the air again Martin, try to keep it away from the ground till your ready to land !! haha

You just need to put the time in flying and it will get easier !

[martinfbrown]

Hi,
Yes, back in the air again. I have been managing to hover great, but on Sunday I found one of the ball links on the rotor head set broken. I have spares for that, so I will change it. Another thing,but which has not stopped me flying, is the little piece of plastic that goes in the swash plate guide has broken off. I must have missed that, but it is still flying okay. I have a spare also for that. I tend to keep quite a lot of spares just in case. When I got everything working again,I initially flew in doors, but I do have quite a lot of grassed area near to me. One question, we do have a grassed area nearby, but the grass is rather long(it is actually a short cut to my local!!) What is your opinion on flying where there is long grass. I had thought that if I was going to crash, it would be better landing in the long grass and less damage maybe. Thanks.
Martin

[G-MRM]

Yes, a box of parts is how I run my helis !!

Long grass is better if your bring it down without control, kill the power as soon as you can ! For take offs I take a old mat or a sheet of hardboard to take off from and to land when in control !! You don't want anything stopping the tail motor as they will have an even shorter service life !

Martin

[martinfbrown]

Hi,
Thanks. The long grassed area does have some short parts where I could take off from, but thats a good idea using a mat or piece of board. I will try that.
Regards
Martin

[martinfbrown]

Hi,
Was flying great yesterday, but landed a little heavy and udercarrage was damaged. The problem I found was that the fixings for the skids were badly worn(I have never had them unscrewed). I just presume this is due to the many hard landings that I have had. I could not see any easy method of repairing the frame, so I have ordered a CP2 barebones kit from heliguy.com. I have also ordered the extreme skid mod, as they do look a little stronger than the original skids. A little bit of advice:Is it better to use some Loctite on the fixing screws for the skids? Thanks.
Rgds
Martin (flying getting better as long as I don`t crash!!)

[dutchie]

Hi,

I followed the advice given in a different thread to use slightly longer screws. The tiny plastic extensions that go into the undercarriage fixings tend to snap, this does not change with the nes skid mod. Using the longer screws fixes this problem, without the need for glue.

I got my CP2 flying again thanks to postings on your thread. Sticky collective due to incorrectly placed washers. By the way, do you need to re-tune the gyro after each hard landing? I find that once everything is perfectly trimmed & tuned, any hard landing puts you back 15 minutes in checking feathering shaft still being straight, blades still at 0 pitch, swash plate still level, gyro & ruddertrim reset. Or is it just me?

Brgds
Martin from Norway

[martinfbrown]

Hi,
Thats a good idea using longer screws. I have ordered a barebones CP2 and also the extream skid kit. I will use longer screws for the skid kit. After each hard landing that I have had, I check everything on the helicopter. I have never had to alter the 4 in 1 though. After my last big crash, I did check the 4 in 1 and had to adjust it.
Martin

[G-MRM]

Hi Martin, last time I ordered a kit to use as parts I ended up building it up and flying it. What are you going to do with your kit ?

Martin

[martinfbrown]

Hi,
I am going to build it up again. The damage caused to my original CP2 was to the undercarrage, so I just thought that getting the barebones kit and building it up would be a better option. It comes with everything except the radio gear. I have also ordered the extream skid mod, which looks more substatial than the original skids. Hopefully back in the air once I built it up. I should have it tomorrow.
Martin

[swatson144]

Yah me too. Every airframe I order winds up being built. Looks good on paper though. I've learned that I can't have one around for spares.

Steve

[martinfbrown]

Hi,
Yes, I am just going to fit the servo`s and the 4 in 1 to the new frame and the extream skid kit, and then back in the air(hopefully).
Martin

[G-MRM]

At that point I would then fix anything that was broken on the old air frame, order servos and a 4 in 1...........

[swatson144]

You surprise me G-MRM , I'd have taken you for the servos, 2 ESC, gyro, and go all seperates with the left over. Pretty much what I did. :rolleyes:

Steve

[G-MRM]

Well..... I would have but, on e bay some one was selling a working 4 in 1 motors servos very cheap ......... At that point I had 2 CP2's and one std CP. I then sold 2 of the 3 to help fund the Swift !