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MINI TITAN PROBLEM

Started by premvijay, June 14, 2009, 02:18:58 AM

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RotorZone

The problem I have faced is the weight of the pitch gauges. As Anwar said, the weight coupled with the play makes it very difficult to get accurate readings.

nabam

#76
guys.pls help me set up my newly acquired MT E325.Ive set it up using a JR RS77 seven Ch rx.Tx-JR PCM 9XII.Therefore have used the gyro as dedicated one with eccpm mixing done on the Tx.As for sim practice,I fly decently on RF G4.Took note of all the points from this thread also.was a gr8 help.Thx anwar,Rotorzone and ofcourse Prem.
set up the pitch and throttle curves as per manual for beginners.actually,couldnt set the throttle curve right,as the illustrated one in the manual had a 5 pt throttle curve and my Tx has 7 pts.I've left it as linear curve now.is it ok?If not how to do it.Im thinking of plotting it on a graph paper to get a similar curve. ;D.Tried this morning to maiden and actually did manage to get the first hover of my life before rain interrupted.also before leaving ground the heli  vibrated a lot,at around 1/3rd throttle.it was smooth at higher throttles.is this normal.
And is there any significance of cg in rotory flight?i mean to the extent of it being a factor as to how the model will fly.like in aeroplanes,nose heavy=good for beginners thing.As a beginner what else are the areas i should look into?thx in advance.and yes the pitch gauge we r discussing over(TT precicion Pitch guage) doesn't suit 450 size helis.hv ordered an align version.

regards
nabam


nabam

#77
ny advice-how to upload pictures greater than 128 kb in size.and how do u use this insert image function? ???

RotorZone

Quote from: nabam on August 04, 2009, 12:45:49 PM
set up the pitch and throttle curves as per manual for beginners.actually,couldnt set the throttle curve right,as the illustrated one in the manual had a 5 pt throttle curve and my Tx has 7 pts.I've left it as linear curve now.is it ok?
That is exactly the way to do it. Setup a linear curve with the end points as per the manual.

Quote from: nabam on August 04, 2009, 12:45:49 PM
also before leaving ground the heli  vibrated a lot,at around 1/3rd throttle.it was smooth at higher throttles.is this normal.

Are your blades tracking properly ?

The blades will automatically align due to centrifugal force once the heli spins up. It should be smooth once this happens. Spin up once to align the blades and start again without distrubing the blades. Do you still see a lot of vibration ? Some amount of vibration at low throttle is normal.

Quote from: nabam on August 04, 2009, 12:45:49 PM
And is there any significance of cg in rotory flight?i mean to the extent of it being a factor as to how the model will fly.like in aeroplanes,nose heavy=good for beginners thing.

For the 450 size heli's it is easiest to check CG by lifting the heli by the flybar. Get the flybar 90deg to the tail and lift it, the heli should hang level. For beginners, a little nose down is also fine.

anwar

Quote from: nabam on August 04, 2009, 01:07:55 PM
ny advice-how to upload pictures greater than 128 kb in size.and how do u use this insert image function? ???

Just use http://www.webresizer.com to get the image to a manageable size and format.
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nabam

#80
Here are some pictures of my TT E325 (:|~
and thx Anwar for that info on resizing stuff.

anwar

Would I be the only one to admit that seeing a heli naked is so tempting  :P

Tempting..... to.... go fly one.... right away !
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nabam

#82
Aww man!!!!.Flying this machine(hovering for now) is just so awesome.it feels completely magical. :oeverything holds perfect.im using the gyro in heading hold mode(red led).it does a good job.if this comparatively cheap TG-6100M gyro is this good,then im really eager to see how a more standard gyro like a Futaba GY401 would perform!!im definitely upgrading someday soon.but no qualms for now whatsoever.im very satisfied with this buy.Fultoo paisa vasool.today i flew three sorties of about 6-7 min each,all on 3s 2200 mah lipos.thank god i had these extra lipos already. {:)}

pics attached-
not so good picture quality regretted ;D

anwar

#83
Quote from: nabam on August 04, 2009, 12:45:49 PM
set up the pitch and throttle curves as per manual for beginners.actually,couldnt set the throttle curve right,as the illustrated one in the manual had a 5 pt throttle curve and my Tx has 7 pts.I've left it as linear curve now.is it ok?

also before leaving ground the heli  vibrated a lot,at around 1/3rd throttle.it was smooth at higher throttles.is this normal.
nabam

If you are using a linear pitch curve in normal flight (which means the heli will lift off some where around 65% throttle position), then it is usual to bump up the throttle curve in the quarter to mid point range of the throttle stick.  It will also help you with better throttle authority on landings.  There is a long range from 0 to 65% where you are having no lift (or not enough lift).

So if your throttle curve is 0-25-50 (linear) in the lower part, increase it to something like 0-35-55  (for 5 point; or 0-25-40-55 for 7 point curves).  That extra throttle in the low ranges will take some of the vibration and instability away.  Again, these values are just suggestions, find the ones that work for you using a bit of trial and error.

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nabam

yes Anwar.even i felt the same.so do u mean to say that i bump up the lower half of the throttle curve and leave the upper half untouched?

anwar

#85
Well, not exactly leave the upper half untouched, but small increment to complement the change done to the mid point.  If the midpoint went from 50 to 55, then you might want to raise the 3/4th point by 2 or 3 (something like that, just to give you an idea).  In other words, don't make the curve looks like it has "jumps". 

If you increased the mid point from 50 to 60, then the 3/4th point should be increased by like 4 to 6.

If you put it in math terms, make it a "fitted" curve ;)   

Again, there are no hard rules regarding this.  Just play with the values, and see if you can make the heli stay in one spot without gaining and losing altitude, and without you have to constantly apply the throttle stick (I mean for the hover point, around 65%)
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anwar

#86
One thing I do recommend to everyone is to keep a single pitch curve in all flight modes (normal, idle-up1/sport, idle-up2/3d, and hold).  Most people have separate pitch curves for normal, hold and idleup.

It is much easier if you get used to a single curve.  Setting up of the heli is easier, the heli does not jump or dip when you change modes, and you do not have to get used to a separate pitch response in case you have to do auto-rotations etc.

People give me a weird look when I suggest this to them initially, but after they try it and get used to it, they always come back and say "thank you for suggesting that!".
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nabam

#87
Quote from: anwar on August 04, 2009, 07:54:01 PM
One thing I do recommend to everyone is to keep a single pitch curve in all flight modes

Very valuable advice there.a million thx.

anwar

BTW, wonder what is going on with the other MT from Prem ?
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nabam

Hi Anwar/rotorzone.
After today's(2nd day) hovering practice,i noticed that the tail gradually wags to the left,i.e the heli turns right.so wt to i do,i mean to correct the wag and get a still hover?
Should i use the rudder trim or should i increase the gyro gain?
-Nabam

anwar

#90
You should NEVER have to apply any trim to the rudder for these type of helis.  If you feel the need for rudder trim, that just indicates something else is wrong.

The first thing to check is is you have enough gain in the gyro.  Try increasing the gain until the tail starts to wag, and then back it down a little bit so that it stops wagging. 

But more likely, the issue is of mechanical setup.  Try lengthening (or shortening) the tail control rod (that one that connects the tail pitch slider to the tail servo) by one turn at a time, and see if the drift is improving or worsening by hovering the heli.  Adjust accordingly.

PS: Hopefully you have a "ball link plier" to make it easy, since you may be removing and reattaching the link multiple times.
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nabam

Aw... well,the ball link plier is in transit.should be receiving it shortly.nyways, thx for the answer.
nabam

RotorZone

Why do you need to wait ? In case it wasn't clear, you need to adjust dirft in normal mode by adjusting the length. It is not dependent on the rod length in heading hold mode. In heading hold mode, drift occurs when gyro gain is low.

In short, increase the gain and try. Anwar has already given you the process.

nabam

thx rotor.will giv it a try tomorow.the wag i was refering to is very minimal and slow,though.can live with it for now.
As for setting up mechanically,i'll wait for my tool kit to arrive.

RotorZone

Some clarification of heli terms is in order here. When the tail rotates slowly in one direction, it is called "drift". Usually caused by low gain in HH mode.

"Wag" is a rapid left and right movement of the tail. This is caused by too high a gyro gain.

nabam


nabam

#96
here are some pics of my bird with the new Rotortech CF main blades. ;D.looks awesome n flies too.being a newbie still,cant tell the difference in flight characteristics,but the flight times sure have increased.!!
Increased the gyro gain to about 55%,and guess what-the tail drifts gone.
Once again anwar and rotor thx for the helpful answers.

anwar

RotorTechs are premium quality, and a bit cheaper than other blades in the same class.

A friend (who is currently the best heli 3D pilot in Qatar) tried many other brands, and finally settled on these. Because he does stuff close to the ground, he kisses the ground more often than others; so the price point helps ;)

This is the only video I could find of him; gotta take more when we fly together again.


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premvijay

#98
Dear Mr. Anwar, Got all the things checked and re checked but still the mini does not lift off the ground even on full throttle but just waivers a bit left and right, tried to get a video of the smae in the night but it has not come out well, sounds are not clear will try again tomorrow but for the time being plase make do with this. the video is with full throtle.
the video is here


premvijay

Dear Mr. Anwar would be grateful if u could provide me the ideal pitch setup in the low throttle, mid and high throttle positions as i am now confident of using the pitch guage.regards