Intro to multi-blade

[dannyhough]

Difficukt to see exactly what sort of head setup you have from the pics but if it uses a swash follower as appossed to built in phasing the same principles apply for the 5 blade head as the 4 blade.

The phase angle still needs to be 90 deg in advance so the ball link on the inner swash needs to be 90 deg of the blade it's attached to.

Couple of vids i made recentlyto try and explain what to do, the 5 blade phasing video was made when i was getting to grips with a 5 blade head for the first time.

What if any stabilisation system are you using?

Some systems offer electronic phasing so you can have the control rods straight. Be aware though you may need to use shorter control rods to work this way as the swash gets lower the straighter the rods become.

[ame=http://www.youtube.com/watch?v=bmBvnBPC8PY]YouTube - CX 5 BLADE PHASING[/ame]

[ame=http://www.youtube.com/watch?v=mPINNY8_Kdc]YouTube - RC Helicopter Multi blade phasing, HOW TO![/ame]

Hope that's of some use.

[Cuppa]

Mega Dan, nearly lost the plot there materealy
nice vids now i can finish the set up, what pitch would you
say? i was thinking colective @10 cyclic @6 i have it set up on a
3G at the mo 1220kv motor @22.2v on a 14t pinion, looking at about 1700rpm thanx again mate
I would like to get my head round the physics envolved, like why its
set up in this way?

[dannyhough]

No worries glad i could help

6S and 1220 KV motor with 14T would give you a max HS well in excess of 1700, i'm running 1210 Scorpy with 13t on 6s on an experimental setup with a fenestron tail to get a HS of less than 1800rpm (to keep fen speed below 15,000rpm) i am running the motor at a flat 80% throttle curve.

All the calculations i did were well out compared to 2 independent tacho readings.

With regard to collective and cyclic pitch, the collective is going to depend alot on what blades you are spinning. With scale blades from TF model i set max pitch to 9.5 deg on both the 500 with 4 blade head and 450 MD500E with 5 blade head.

A slightly concave PC above 50 % works well for me on both helis.

Cyclic on the 450 MD500 is down to 4 deg for a nice scale like response using 20% expo running 3g stab.

On the 500 i couldn't get the BeastX to give me less than 5 deg but the limited testing with that setup showed it to be ok with 20% expo.

All depends on what suits you best but i would suggest some expo to begin and then work it from there.

I have read reports of the 3G hunting for heading with sudden unexpected yaw but it's been fine for me so far.

MD500E flight video, judge for yourself...

[ame=http://www.youtube.com/watch?v=htOof8CWj_U]YouTube - MD500E FFF.AVI[/ame]

Hmmmm, looks decidedly like a thread hijack. Sorry!

[Cuppa]

Ok thanx again Dan, i have TF blades from sports moto so i will
give it a go as you say mate, still a little confused with the phazing
thang!, so if i'm uesing a 3G fbl unit i can lock off the top plate
with the locking ball inline with the ele ball (almost straight rods)
Think i may need to hold someones hand with this one

[dannyhough]

Hi

Just follow the steps in the video mate, looking at that last pic you posted your head uses a swash follower so the phasing needs to be set mechanically.

The 3g unit does not offer phasing adjustment. If the phasing is off the heli will not react to cyclic inputs as expected, too far behind and the heli will pitch forward for right aieleron input etc. The 3g will only correct uncommanded pitch roll and yaw movements it cannot compensate for phasing as iy allows the heli to do what the sticks tell it to do.

Just put a blade to 90 deg right of the heli then line up the corresponding inner swash ball with the AR pin (opposite for CCW rotation) and bingo 90 deg advanced phasing, slight adjustments may be neede depending on head speed but you will be looing at 1 or 2 deg max either way.

Without electronic phasing the rods will need to be angled into the direction of rotation.

[Cuppa]

Difficukt to see exactly what sort of head setup you have from the pics but if it uses a swash follower as appossed to built in phasing the same principles apply for the 5 blade head as the 4 blade.

The phase angle still needs to be 90 deg in advance so the ball link on the inner swash needs to be 90 deg of the blade it's attached to.

Couple of vids i made recentlyto try and explain what to do, the 5 blade phasing video was made when i was getting to grips with a 5 blade head for the first time.

What if any stabilisation system are you using?

Some systems offer electronic phasing so you can have the control rods straight. Be aware though you may need to use shorter control rods to work this way as the swash gets lower the straighter the rods become.

YouTube - CX 5 BLADE PHASING

YouTube - RC Helicopter Multi blade phasing, HOW TO!

Hope that's of some use.

MEGA thanx yet again dan the penny
has finaly droped only took me untill 640am this morning for it to sink in mateIMO your lil vid's are the best explenation i have seen ever!
now i undestand whats going on i'l feel much happyer when i test fly this
HIND of my'n tho i'm still going to need good pants on!

thanx Cuppa