FBL servo question

[dharwood]

OK guys, I need some assistance here. I posted this in the main FBL area but as with my last post there, I got no response. You guys were very quick to help with my need for rx cables for my sk360, I will now hang out here.
See my below post for my question:

snip^--------------------------------------

I think I already know the answer to this but I will ask anyway.

As a step towards FBL, I decided to experiment on my "beater" R30 to see what it was like with the thought of making one of my Panteras FBL this year.

I purchased an RJX head and fitted it to the R30, set phasing so with blades parallel to the boom, elevator input does not move the blades, and with the blades perpendicular to the boom, aileron inputs have no effect.
Hardware is as follows:
550mm woodies
Pit, Ail, Ele servos JR NES-517 (40.3oz @ 4.8v .25ms)
+ - 13 degrees collective
8 degrees cyclic

I do not have any FBL electronics fitted yet. (trying to add one problem at a time) At this time, I am only interested in the feel and proof of concept in hovering. If all pans out, I will move forward.

I test hovered today and can see I need less collective at this point as it was VERY responsive.

I did have one problem however, cyclic seemed perfect on the ground but once hovering, it was almost as if I had no cyclic response. Further investigation (as best I could tell while viewing it while hovering) the swash was not moving, while under load.

My question is this: for a .30 - .50 sized bird, how much servo do I need. I am guessing that 40oz is not enough to directly drive the grips which posed the situation that I saw today with "stalled servos" under load. (I guessed this prior to putting the bird in the air but had to start somewhere. Again, this was just to test hovering characteristics and power differences. Thus far, I am sold (-: )

Can someone point me towards a sticky or FAQ where I can educate myself.

From my 6 minutes of playing today, I can see that this is a direction I will be going (-:

/snip^--------------------------------------------

As I said, I am adding one problem at a time as to not chase my tail. I will probably make the move from the R30 to my 550 sized Pantera which does have 70oz servos instead of the 40oz like the R30. This is a FFF only bird with no flippy floppy planned and is the platform I intended to put the 360 in.

As before, thanks in advance!

Dale

[rceccleston]

Originally Posted by dharwood

OK guys, I need some assistance here. I posted this in the main FBL area but as with my last post there, I got no response. You guys were very quick to help with my need for rx cables for my sk360, I will now hang out here.
See my below post for my question:

snip^--------------------------------------

I think I already know the answer to this but I will ask anyway.

As a step towards FBL, I decided to experiment on my "beater" R30 to see what it was like with the thought of making one of my Panteras FBL this year.

I purchased an RJX head and fitted it to the R30, set phasing so with blades parallel to the boom, elevator input does not move the blades, and with the blades perpendicular to the boom, aileron inputs have no effect.
Hardware is as follows:
550mm woodies
Pit, Ail, Ele servos JR NES-517 (40.3oz @ 4.8v .25ms)
+ - 13 degrees collective
8 degrees cyclic

I do not have any FBL electronics fitted yet. (trying to add one problem at a time) At this time, I am only interested in the feel and proof of concept in hovering. If all pans out, I will move forward.

I test hovered today and can see I need less collective at this point as it was VERY responsive.

I did have one problem however, cyclic seemed perfect on the ground but once hovering, it was almost as if I had no cyclic response. Further investigation (as best I could tell while viewing it while hovering) the swash was not moving, while under load.

My question is this: for a .30 - .50 sized bird, how much servo do I need. I am guessing that 40oz is not enough to directly drive the grips which posed the situation that I saw today with "stalled servos" under load. (I guessed this prior to putting the bird in the air but had to start somewhere. Again, this was just to test hovering characteristics and power differences. Thus far, I am sold (-: )

Can someone point me towards a sticky or FAQ where I can educate myself.

From my 6 minutes of playing today, I can see that this is a direction I will be going (-:

/snip^--------------------------------------------

As I said, I am adding one problem at a time as to not chase my tail. I will probably make the move from the R30 to my 550 sized Pantera which does have 70oz servos instead of the 40oz like the R30. This is a FFF only bird with no flippy floppy planned and is the platform I intended to put the 360 in.

As before, thanks in advance!

Dale

I would agree that your servo are both too weak and extremely slow for a flybarless system.

For best value and performance, I would recommend the Align DS610 digital cyclic servos with metal gears.

[dharwood]

Wow, thanks for the quick response!

I know I have picked the right FBL system. Even if the SK-360 or my (most likely next purchase SK-720) does not work, at least I have GREAT support.

I have been lurking here for weeks trying to educate myself and you guys are simply awesome.

I have DS-610's on my Pantera 50 with 600's which will likely get converted later this year of the 550 goes well with the 360.

Prior to the last 2 flights of 2010, I was flying the 600 bird with Futaba 3010's and it was performing great for my flying style (mostly big air scale type flying with the occasional flip, roll, and loop). I changed to the 610's and did not notice any difference, again with my flying style. I have since then built built up the same bird as the 600, using 550's, OS.32, and shortened boom, which is where I want to start with my FBL project, and is the reason I purchased the 360.

Is there a FAQ or sticky with guidelines on servos / heli size somewhere?

My thoughts are to install the FBL head on the 550 bird, move the balls inboard on the horns from 19mm to which ever location that gives me enough collective/cyclic for my needs. (this bird will only see FFF, no flippy/floppy stuff)

Thoughts?

Thanks guys,

Dale

[dharwood]

Woops, clicked twice

[rceccleston]

Originally Posted by dharwood

Wow, thanks for the quick response!

I know I have picked the right FBL system. Even if the SK-360 or my (most likely next purchase SK-720) does not work, at least I have GREAT support.

I have been lurking here for weeks trying to educate myself and you guys are simply awesome.

I have DS-610's on my Pantera 50 with 600's which will likely get converted later this year of the 550 goes well with the 360.

Prior to the last 2 flights of 2010, I was flying the 600 bird with Futaba 3010's and it was performing great for my flying style (mostly big air scale type flying with the occasional flip, roll, and loop). I changed to the 610's and did not notice any difference, again with my flying style. I have since then built built up the same bird as the 600, using 550's, OS.32, and shortened boom, which is where I want to start with my FBL project, and is the reason I purchased the 360.

Is there a FAQ or sticky with guidelines on servos / heli size somewhere?

My thoughts are to install the FBL head on the 550 bird, move the balls inboard on the horns from 19mm to which ever location that gives me enough collective/cyclic for my needs. (this bird will only see FFF, no flippy/floppy stuff)

Thoughts?

Thanks guys,

Dale

To allow any flybarless system to add corrections quickly and effectively, the cyclic servos require speed and more torque due to less mechanical leverage on the fly-bar cage.

Personally, I would use the spec of the DS10's as the required standard, because there are faster about but the DS610's work very well.

[georgi UK]

Originally Posted by dharwood

Is there a FAQ or sticky with guidelines on servos / heli size somewhere? Dale

=] yes, you are in the right hole here!!

610 is alotta servo for the money, £120 for three in the UK..

my 600 swash can lift 36kg!!

fast transit times assist the control loop, torque assists holding and accuracy,

325mm blade heli: CCPM- 15oz minimum, Single Servo (non CCPM)- 20oz
425mm blade heli: CCPM- 25oz minimum, Single Servo (non CCPM)- 40oz
500mm blade heli: CCPM- 40oz minimum, Single servo (non CCPM)- 60oz
600mm blade heli: CCPM- 50oz minimum, Single servo (non CCPM)- 80oz
700mm blade heli: CCPM- 70oz minimum, Single servo (non CCPM)- 100oz
800mm blade heli: CCPM- 80oz minimum, Single servo (non CCPM)- 120oz

this is absolute minimum...

georgi UK

[dharwood]

Ahhh, once again, quick answers! I am no doubt in the right place

Looks like for my 550 project, using ccpm 72oz will be good enough to get me started for testing. I was thinking after my original post last night which followed my R30 FBL maiden test, it was indeed at a disadvantage with the 40oz servos due to being single servo driven. That did not dawn on me until this AM.

I will proceed with the 360 project using the somewhat slower than ideal servos and see where that gets me. The 600mm Pantera already has ds610's so when I get to converting it, it is ready.

Thanks again!

More to follow

Dale

[dharwood]

OK guys, first off, thanks to everyone that answered my questions. Very valuable information was gained, and paid off this weekend.

"The Project"
A fun flying cruiser set up mainly for FFF on a lazy afternoon.
I love flying my Pantera 50 but sometimes it is just overkill for laid back buzzing the field. Enter the Pantera "Cub". Pantera 50 kit, different motor mount, Raptor 30 boom and supports, shorter belt, combined with an OS.32 for power (haha), swinging 550's.
I flew this conversion a couple of times last year but it was lacking in the power and maneuverability department, mainly because of of the mass the Pantera 50 head has (set up to run 700's if you wish), along with a 480x4mm flybar. (a lot to swing)

I changed the head to an RJX 50 head, added the SK.360 and wow am I impressed. I did start with far too much collective (+- 12 degrees) and too much cyclic, at least for its intended purpose. Aside from that, it flys GREAT.

Below is the video of the second hop with the only change from the first hop being adding 35% expo in the radio on A & E channels. Still more sensitive on cyclic than I liked but that will be adjusted prior to the next outing. As you would have guessed, a noticeable increase in usable power, and more responsive on cyclic. Not a 3d machine but for what I wanted out of it, it is perfect. I did throw in a flip and even with my poor collective management, bogging the head, it behaved very well (I paused to let it recover not knowing what to expect (-: )

My first FBL experience and it was pretty much plug and play. I am hooked.
Even with the Futaba 3010 analog servos, this thing is absolutely great!
My P50 will get the FBL treatment later this year.


Thanks again for all of the answered questions!

Dale

[ame]http://www.youtube.com/watch?v=jJDMzPaQiWI[/ame]

[Gadflyii]

I swing 550mm blades and the Align DS610's work perfectly.