nitro for weekends

[xircom]

yes aux 2, well if 100% on TX corresponds to 100% on HH then at least I know what I have to search for ... seems to be much out of line

[xircom]

put a description here after playing around 2 hrs !!!
http://www.helifreak.com/viewtopic.php?p=246416#246416
I have a master in electr/science, but I don't get the point ...
THANKS AGAIN !

[xircom]

today 10 flights without any issues ... super !

[Jafa]

:smokin: Cool!

[xircom]

still I am tuning that engine still, as I took a new glowplug, and the situation seems again different. I am now around 1 1/4 turns - it seems to me, that even I turn leaner the smoke does not get less, and the motor starts to sound a bit metallic in a way "clicking", now - is this already too much ?

For the stock tails, they seem to be a bit damaged, due to a stone after landing - now thinking about carbons, 90 or 95mm ... is carbon worth, and what length ? Still I am not 3D-junkie, just some aerobatics ...

[Jafa]

I cannot remember your fuel mix
I run 20% Klotz KL198 LV and 20% nitro
That would run safe down to 1 turn
I canot remember your exhaust either - sorry

If you hear high pitch and many quick crackling then you are very lean

I use blue Freya plastic tail blades, they do 3D fine
Keep the heli cheap while you are learning
But I cannot remember if these tails fit in Sceadu tail holder
I use the Freya tail spindle and holders also

If you do decide to use carbons, try to get 26mm wide
as the 30mm wide are a bit noisy and drain power from the engine

[xircom]

have 23% nitro, and muffler is that one http://64.233.179.104/translate_c?hl=en&u=http://www.fun-tech.info/Line_UP/a131_hn50tf_left_syosai.htm I am currently down to 1 1/8, but further down I can hear this crackling noise I think. The thing I was wondering, was most say when lean it does not produce lots of smoke, but in my case it seems still quite some smoke, so that's probably not an indicator.

Yes, you are right - plastic ones will do in my case, I want it cheap at the moment.

[Jafa]

Yes - smoke can be hard to tune to ,
it's a relative thing but if you have no base line it's hard
Absolutely don't run lean - as long as you can hover at 1600 to 1700
and about 45 to 50 % throttle
and about 5 to 5.5 degrees of pitch
then you are ok
As long as it spools up reliable, and cuts to idle reliable
As long as it's not too hot - 40 degrees on backplate is safe
45 degress is fun and 55 is on the hammer!

[xircom]

Indeed, as for the smoke it's probably better to check the color than the amount, if it's very white, then it's not good. For the temp, just also bought a temp gun, so hopefully I can check this.

The throttle I am re-tuning now, because of the revmax I have to get close to 100/100. It's a pity that Hirobo specified the system so (position, rod-length), that 100/135 fits good, because evryone will add a gov sooner or later, and then it needs to change anyway. Means I have to re-work the throttle % again, because end-points are different now.

Anyway attaching this sensor holder to the side of the engine I think the current screws (M3X12) need to be about 2mm longer I guess ? This because of the thickness of the plate that holds the sensor in place ... otherwise I am afarid the motor could shake out.

[xircom]

.. ah yes, one more thing I realized, although the heli is holding very well in HH mode, it starts to turn when switching into normal mode. HH is the one I initialize, and I learnt nothing to be tuned in trim for the normal mode, once it's working good in HH ... THANKS !

[Jafa]

Yes - I never fly normal mode and love Futaba HH

Should always have equal ATV on the throttle
so you get same throttle response from 50% (going up and down)

Yes - you need longer engine mounting bolts

[xircom]

yeah I love it too, and it holds well in HH. Now from the gyro pages I can read, once the HH works well, go to normal, and try to stop the drift by shortening/lengthen the rod again, once this is done, switch back to HH, then then it would be perfect. Point is, that doing this does make the servo center position to be the right angle (force) so that the heli isnt drifting, I understand this. On the other hand, it also changes the travel in both directions again not to be the same. Now I don't know if normal adjustment is needed - or not.

Will also check the throttle ATV, right now it seems I cannot get just close to 100, and also I have to use the subtrim, because the teeth of the servo to servo arm and the holes in it are just not very nicely aligned but I am working on it :D

thanks thanks

[Jafa]

Futaba gyro tends to work well with equal ATV's
but still works with unequal ATV's

With Hirobo the mid point with equal ATV's
tends to give almost enough tail pitch to hold hover
None of my friends adjust/trim the normal mode
You wont get better HH performance by triming normal mode

[xircom]

Thanks a lot, I think I start to understand the difference between normal and HH. When I set the gyro up in middle stick for equal throw and 90 deg on all links, then in means in hovering the position will not be center anymore because of the anti-rotation torque the tail got to produce. Shortening the tailrod means centering servo in hover, but not tail link and blades anymore, which means unequal travel - and still revo-mix must be added in case of torque changes (e.g. climb). This is why it's maybe better set up all equal and 90 deg for HH, and not change to normal at all. If the sensitivity in normal is very high, then still it works in this set-up too, but otherwise the normal mode would "let go" the tail always.

If I understood that right, in theory, for using HH and normal on the heli - the tail would need to be set-up in a way, so that all links and levers would be equal throw and 90 deg and only the tail pitch in center position would be adjustable.

[Jafa]

The main difference between Normal mode and HH
is that the gyro will hold the current tail position.
When you fly in normal mode you need to constantly work tail
for every significant change in main blade pitch and engine throttle input
When you fly in HH mode the gyro is constantly working the tail servo
hold the current heading regardless of why the heading is trying to change

The other advantage of HH is that the rudder input becomes a 'piro rate' request
and the gyro tries to give a constant rotational rate (the 401 is not good at that)

With the Sceadu, when you set up the tail/gyro/servo
do it in normal mode
get the servo ball bang on 12 o'clock
get the left/right ATV's exactly the same and max travel
(and I mean max travell, right into the tail box and right out to the spindle)
When you bind on one side only, move the servo on the boom and then repeat
When you have finished, you will have pitch on the baldes at neutral position
Hirobo designed this in mechanically
then just flick into HH and you are up up and away
with 90 degress and

[xircom]

today I made what you described for the gyro, and also I took the RevMax into use for 1650 (hover) and 1850 (Idle up) oh man, what a difference ... this bird flew like in the sim, so smooth !!! Also took your advice for the 92mm Freya blades, those really hold a lot better than original EVO ! The needle now goes easily towards 1 turn without any issue, before this I think I just had too much RPM always !

After 12 flights, just I realized, that the washout block - washout-arm-screw is somewhat overturned, does not hold anymore well, maybe will switch to the metal one, as people say that one wear out fast anyway ?

And also the SD servo frame broke under stress where the box for the receiver is attached, this does not kill in flight, because it's hold by the canopy as well, but anyway needs to be replaced ... huh !

Anyway thanks so much, that was greatest success so far !!!

[Jafa]

Yes, now you see the true character of OS50 and Sceadu
They both love RPM
I find hard to get a nice hover below 17000
You should have 1850 idle1 and 1950 idle2

The plastic radius block can split - get metal for sure

Wow - bever heard of battery tray breaking

So glad to see you making lots of progress and having fun :lolol

[xircom]

Well at 1900 or higher I felt there is quite much vibration, I can see from the fuel in the tank, I'd not see a straight line anymore, but bubbles/foam...?

I think I will get metal, although this is not because of split, but just maybe I did tighten the screw a bit too much of the lever ... plastic does not like this. Anyway metal is better, before it split.

Never seen broken tray ? I think I put too much foam around the receiver in the box, this is why the box broke up. I never opened the canopy all the flights, just saw that back home !

Anyway yes lots of progress, thanks !

[Jafa]

Wow - that's interesting - good to know things to avoid

Sounds like you need to dial indicate your clutch to fix the vibrations
I can run 2000 on the head and the fuel is crystal clear and still

[xircom]

interesting from your side also, yes I assume that 2000 shall be ok - what means "dial indicate" ? :shock:

Currently I assume, that the main mast might be the problem also, because I did not 100% check it after last crash, and according to my experience this almost always gets bent a little, even not visible, guess need to roll it on the table to be sure. :WOW

In addition I think the radio bed is a bit weak breaking that place actually - I want to receiver in the box and firmly fixed ... :lolol

[Jafa]

Receiver in boz and battery on top of tongue balances the heli better

Yes, roll the main mast on glass
The alloy hub on the top is pretty soft and common to bend also
But both of these would create serious vibrations in horizontal fin
(blades out out of track can also cause same effect)

Fuel shaking and frothing is usually from high frequency vibration,
only engine and tail run that fast

Dial indicate clutch means put dial indicator onto very end of clutch shaft
and turn engine - check the run out - must be 0.03mm or better
For best result, remove piston/conrod to ensure good reading
(all this done with engine out of heli)

[xircom]

I don't hope I have to do this clutch thing too, because I have no measure for 0.03mm ! :WOW

Anyway I took the main mast out, and it's clearly not straight - not visible, but whobbles over the glass table, and also stops always same position, so this at least I have to change for sure ! :twisted:

BTW, as for the gov sensor stator screws, do they need locktite drilled into the motor mount ? Metal normally needs, but motor mount is something different material ..

and also once I have everything out already, do you recommend the delrin gear ? I have it in Lepton, and it runs supersmooth ... I guess not the whole DTDS set is needed, but only the counter gear (414 169) and SD-G Second Gear housing (0412 259). Or instead of second gear maybe whole SD DTDS set (0412 168) from the EX, but I don't know if this brings additional benefits ? See picture :idea:

Sorry so many questions, and finally the washout (see picture) at least I need the lower block because of the screw is loose now, but is the upper part usually splitting ? So is it better to get the whole set including even arms and levers ?

[Jafa]

Yes, get the entire washout and upper radius block for sure

Main shaft bent - that's easy to replace

The lower DTDS gear is different, you can't use it without the blue metal hub
Best to wear out your black gears while learning
and pick a safer time later to buy full DTDS

DTDS is good for high headspeed - black can break when old and flown hard

[xircom]

thanks ! BTW, how to you test the head or gear is running smoothly ? With the Lepton I can run on low power next to desk without blades - but with engine and no professional tools I don't know what is possible ... :roll:

[Jafa]

You normally just weight the blades and paddles,
measure the flybar cage to paddle distance on both sides (equal)
stuff like that - spool her up and see how it goes

The alloy yoke on the top of the main mast is the biggest pain,
I have not worked out how to check that for true
other than trying a spare one