Tail setup hmmmm!

Hi guys
Hope you all managed to get out and have a fly around this weekend.
I did an hour with my b450 sat

Anyways enough waffle. I I'm trying to set up the tail on my raptor 30. I have mechanically set it up, programmed my quark gyro so far so good. The tail blade v stick & gyro direction is correct.
Down to buisness. I mounted it to a lazy susi in rate mode, when I start to spool up slowly increasing speed. When it's at say a quarter throttle I can hold the tail for a second then the heli wants to spin but if I correct it quick enough, it will hold until it wants to spin the other way. If she does spin it is at a right rate of knots which to be hounest is a bit worrying!
I'm using a Dx6i and the gyro settings are HH 60 and rate 40
The tail blades sit at about 8deg at centre stick and there is plenty of pitch in both directions.
Any suggestions please.

Dave

[squeaky pete]

try reversing the gyro

[RcRotaryMadness]

Yeah sound like somethings working the wrong way - check TX movement AND check which way the gyro is moving the tail (power on, lift tail and move side to side, see what correction the gyro is doing)

[dbull46]

Ok guys. I will check the direction of both the gyro and stick when it is on the bench.
Thanks

[RcRotaryMadness]

Hi guys
Hope you all managed to get out and have a fly around this weekend.
I did an hour with my b450 sat

Anyways enough waffle. I I'm trying to set up the tail on my raptor 30. I have mechanically set it up, programmed my quark gyro so far so good. The tail blade v stick & gyro direction is correct.
Down to buisness. I mounted it to a lazy susi in rate mode, when I start to spool up slowly increasing speed. When it's at say a quarter throttle I can hold the tail for a second then the heli wants to spin but if I correct it quick enough, it will hold until it wants to spin the other way. If she does spin it is at a right rate of knots which to be hounest is a bit worrying!
I'm using a Dx6i and the gyro settings are HH 60 and rate 40
The tail blades sit at about 8deg at centre stick and there is plenty of pitch in both directions.
Any suggestions please.

Dave

I don't know how experienced you are but heres a couple of notes:

For mechanical setup you need the minimum amount of "Mechanical gain" - In other words, try to match the servo arms full travel with the full travel of the tail pitch slider (IF your servo only needs to move a little bit to obtain full movement of the tail pitch slider, then you have high mechanical gain which you need to reduce by moving the ball link on the servo arm in towards the centre of the servo)

The idea is to minimise Mechanical gain while maximising the amount of electronic gain in the gyro - also referred to as "Resolution" - A certain amount of both is needed.

You mention you have it on a lazy susi (I'm assuming its somehow fixed to it), in rate mode at only a 1/4 throttle, all this in itself might induce some odd behaviour

Gain Settings: to me 40% Gain seems very low (I use futaba so can't be sure if the spektrum works in the same way) - which In part made me wonder if the mechanical setup is right - I'd of thought 75% would be closer the mark or should be anyway.. What Gyro are you Using?

Also 8deg of pitch on the tail blades sounds a lot also - about 3degs for torque offset should be all thats needed

Also Make sure that your pitch offset is the correct way for offsetting the torque, else it will just add to the problem!

Good luck!

[dbull46]

I don't know how experienced you are but heres a couple of notes:

For mechanical setup you need the minimum amount of "Mechanical gain" - In other words, try to match the servo arms full travel with the full travel of the tail pitch slider (IF your servo only needs to move a little bit to obtain full movement of the tail pitch slider, then you have high mechanical gain which you need to reduce by moving the ball link on the servo arm in towards the centre of the servo)

The idea is to minimise Mechanical gain while maximising the amount of electronic gain in the gyro - also referred to as "Resolution" - A certain amount of both is needed.

You mention you have it on a lazy susi (I'm assuming its somehow fixed to it), in rate mode at only a 1/4 throttle, all this in itself might induce some odd behaviour

Gain Settings: to me 40% Gain seems very low (I use futaba so can't be sure if the spektrum works in the same way) - which In part made me wonder if the mechanical setup is right - I'd of thought 75% would be closer the mark or should be anyway.. What Gyro are you Using?

Also 8deg of pitch on the tail blades sounds a lot also - about 3degs for torque offset should be all thats needed

Also Make sure that your pitch offset is the correct way for offsetting the torque, else it will just add to the problem!

Good luck!

Hello Young gun.

I had a look at the Mechanical Gain firstly fitting the ball link 1 hole closer to the centre of the servo horn. Then I checked the amount of servo travel against the tail pitch slider. It indicated that the travel on the tail slider was less than the servo so I put the ball link out 1 hole. This gave me a pretty good match between the two.

I did put the ball link on the other side of the horn as it was closer to 90 deg at centre stick with the trim and sub trim at zero. The travel adjust on the rudder is set at +100%/-100% and the Gyro is the same.
I am using a Spartan Quark gyro which I reprogrammed again after re-doing the above.
The gain ratio is different with the Dx6i. The gyro on the Tx is set to 2 position switch mode on the gyro toggle switch. I set the gain value in the Tx at 71% in (0) position which will give me around 30% true gain for somewhere to start from. In pos. (1) I set the value to 60% giving me around 14% for rate mode.

I reduced the tail pitch from 8 deg to about 4 deg. With the top edge of the tail blade turned in towards the boom
I double checked the stick direction against the tail blades. Checked the gyro correction direction against the tail blades. When the nose turns to the right, the tail blade pointing to the main shaft turns away from the boom. (The leading edge on tail blade is the thick edge rotating c/clockwise.
I have the heli fixed down to the lazy susi with 2 steel braces so it won't fall off. My concern is because the piro rate was a bit rapid, I didn't want the whole thing to tip over. I have set the 5 point pitch curve to a flat line at 50% which gives me zero degs of pitch. I did that cos it would be one less thing to worry about.?

I know this is long winded, but I hope it makes sense???

Dave

[dbull46]

I haven't had another go at running it yet cos it's too windy today.
When you said running with the throttle at a quarter may induce some odd behaviour, do you think it would be better once I'm sure the blades have straightened out to give it more than a quarter throttle so that the tail blades would have a higher speed to counter act the torque from main blades.

Dave

[KevDavies]

incorrect with regards to gain settings for rate. Above 50% is heading hold and BELOW 50% is rate mode so you have (1) as heading hold aswell as (0)

To set a spartan up you need to go through the electronic setup as normal and then you test hover in RATE mode you cannot do this on a lazy susan, it gives false readings.

When you hover in rate mode you need to adjust the mechanical trim of the tail rod so it hovers without needing any input to stop it pirouetting. Then you flick to Heading hold. And you turn up the gyro as much as you can without the tail wagging. The gyro is then fully setup.

If the pirouette rate speed needs adjusting you adjust it via the endpoint adjustment of the rudder channel, decreasing makes it slower, increasing speeds it up. Also do not use any expo in the controller as there is already expo applied to the gyro from the factory

[KevDavies]

to add to this aswell you say your using 25% throttle, you will need 50% atleast as you need to be hovering the heli with collective pitch loads on the air frame aswell as gyroscopic forces on the airframe

If you dont mind a drive up to me I will gladly go through your heli and set it up fully for you including the gyro, I also have the flash link so I can access the computer setup for the quark gyro aswell

[RcRotaryMadness]

I think the raptor 30 tail unit/setup is pretty much identical to my align 550 with a clockwise rotating main head (Anti clockwise tail), which means to offset the torque the leading edge of the tail blades should point towards the tail boom (or point to the left if your standing behind the tail)

more pitch to the left = nose goes right,
More pitch to the right = nose goes left.

Which seems to be what your gyro is doing - so can only think your gain is just too low?

The rest of your setup sounds ok, think its a gain issue and low throttle..

edit: Good offer from Kev there ;-)

[dbull46]

Hello Kev. Firstly, thankyou for your very generous offer to help me set up my raptor. But I hate driving and its a bit far for me. Thankyou anyway.

I understand what you said about the difference between rate and HH mode regarding percentages. What can I set the rate value too?
One think I'm pondering on is, if in rate mode even with a really low value of say, 20 in the Tx gyros menu. Why does the gyro still adjust the servo when the tail is moved?

I will make amends to the other settings on the throttle, piro rates etc.

As for the lazy susi. I will have to make up a training gear from some wooden dowels and a wooden hub in the middle. Just to give me a bit of assistance till I get the tail set correctly. Then I'll give it ago in rate mode.

Young gun.
Thanks for your reply. Does give reassurance knowing that mechanically the tail isn't far off.

Thanks guys.

[RcRotaryMadness]

If you would like to make yourself some low cost landing gear, get down homebase/b&q, you can get aluminium tube, 8mm outside dia I think it is.

Buy 2 x 1 meter lengths, bend the ends up so they don't stick into the ground... cross them over in the middle, cable tie round it, then twist them apart, but another cable tie round and pull tight... then a little tape to neaten it up job done.

As for tail settings, just make the said adjustments and keep playing with it until you get it right - Its all part of the learning curve =)

[dbull46]

If you would like to make yourself some low cost landing gear, get down homebase/b&q, you can get aluminium tube, 8mm outside dia I think it is.

Buy 2 x 1 meter lengths, bend the ends up so they don't stick into the ground... cross them over in the middle, cable tie round it, then twist them apart, but another cable tie round and pull tight... then a little tape to neaten it up job done.

As for tail settings, just make the said adjustments and keep playing with it until you get it right - Its all part of the learning curve =)

That sounds like a plan. I like your idea will do that.
Cheers.

[dbull46]

Well guys, just a quick reply to say thanks for the help and advise.
Today she flew. I started with the training gear on just in case something unexpected happened. I couldn't go on a hard standing as preferred when the gear was on cos it slides around easier so the grass had to do. Popped up into a hover, did a little bit of tweaking on the trims, not to much though which is better than expected. Quark solid as a rock, there was a little breeze from the left but not a problem
Practised a few landings, all ok then took the gear off. Off to go again, so far so good nice and stable. Did some lazy 8s, landed to adjust D/R and Exp settings. On the second tank full now feeling more confident so I got to do some bigger 8s with a couple of circles. At this time I'm on such a high I felt like I was floating. LOL

I think I quite like the smell of Nitro too. Is this a good think or not?

It's been a long time since I started to over hall all the electrics and it's soooo nice to finally see her up again.

Mission complete.

I did have a bit of trouble with the engine cutting out, but that's for another post.

Many thanks to you all.

Dave