blw

My Feedback: (3)

The weights in the blade tips do matter in full scale helicopters. There are two kinds- low inertia and high inertia. Low inertia blades are light at the blade tips and are known to not keep rotor RPMs efficiently during aurotation. Most if not all teetering (2 bladed) systems like the Blade CP are high inertia systems. I see where we could experiment with the Blade rotors. My first set of blades are ready to change anyway, so I'll dissect them and see what kind of weights we have. Maybe they could use more???

autoeject

My Feedback: (1)

I've replaced the factory woodies with cf and no longer experience pitchup to the extent before. I'm inclined to believe it is due to flexing of the advancing blade in fff. Stiffer cf blades would seem more resistant to this. I did not experiment with weighting the woodies to see if that would tend to keep them from flexing as much. jmo
Mark

boostcrzy

bd--- be careful....i think your Blade is catching a very serious and common Blade CP disease...its called T.M.Y..............(Too Much Yellow)

J/P heres my Blade

battlemg

bdavison, I got this from wattflyer from someone who programmed a 7C. May be close enough for you or get ya in the park.
EFlite Blade CP and Radio Programming
Anybody tried programming their Futaba 7CHP to run the Blade? I've had some success. Here's my initial settings for anyone that's interested:

Lipo, 9T pinion, symmetrical wood blades

PARAMETER: HR3
The toughest part was sorting out the SWASH

SWASH:
AIL +70%
ELE -70%
PIT -35%
The -35% PIT was because I heard the pitch servo running constantly when I tried anything more. Seems to work fine this way though.

REVERSE: Channels 2,3 and 6

TH-CV(N): Looks strange, but works for hover at 50% stick. These come from SFCOFFEE:

P5 75%
P4 65%
P3 51%
P2 45%
P1 0%

PI-CV(N)
P5 70%
P4 60%
P3 53%
P2 52%
P1 47%

REVO MIX
HI +30%
LO +30%

I actually don't know if the REVO is doing anything yet. I have it set up on switch G so I can experiment.

That's a place to start anyway...let me know if you have a better way!
__________________
David
Tioli Creative Center
Kona, Hawaii

battlemg

bdavison, I got this from wattflyer from someone who programmed a 7C. May be close enough for you or get ya in the park.
EFlite Blade CP and Radio Programming
Anybody tried programming their Futaba 7CHP to run the Blade? I've had some success. Here's my initial settings for anyone that's interested:

Lipo, 9T pinion, symmetrical wood blades

PARAMETER: HR3
The toughest part was sorting out the SWASH

SWASH:
AIL +70%
ELE -70%
PIT -35%
The -35% PIT was because I heard the pitch servo running constantly when I tried anything more. Seems to work fine this way though.

REVERSE: Channels 2,3 and 6

TH-CV(N): Looks strange, but works for hover at 50% stick. These come from SFCOFFEE:

P5 75%
P4 65%
P3 51%
P2 45%
P1 0%

PI-CV(N)
P5 70%
P4 60%
P3 53%
P2 52%
P1 47%

REVO MIX
HI +30%
LO +30%

I actually don't know if the REVO is doing anything yet. I have it set up on switch G so I can experiment.

That's a place to start anyway...let me know if you have a better way!
__________________
David
Tioli Creative Center
Kona, Hawaii

battlemg

Darn, double posted. Sorry folks.

Skiddz

Late response, but this sounds like retreating blade stall.. Relative wind over the retreating blade is too slow to produce much lift so that blade drops.. The flapping down increases the vertical vector of the relative wind, increasing AoA until critical angle is reached. The blade stalls. Gyroscopic precession causes the rotor disc to tilt back, resulting in a pitch up movement. Kind of a self-correcting issue in that the pitch up slows the helicopter causing the relative wind on the retreating blade to increase.. I haven't seen this on my Blade, but I haven't really got it going fast yet...

frenchstan

I'm a fairly new heli flyer, and still working on a consistent hover. I tried the Carbon Fiber blades for my CP, but for me, they were a DISASTER! The CF is so strong, it chopped through two tail booms. The crashes that caused the damage weren't major, just the kind of minor tip-overs and hard landings I've done dozens of times before with the wood blades. For me, I'd rather patch up a nicked-up pair of wooden blades or replace them than go through the work and time of fixing the boom. Once I get experienced, I'll go back to CF.

I've been doing all my learning/training/crashing WITHOUT the body on the CP. I figured it would help cooling, and it saved me time between battery changes and minor repairs. Is this OK as long as I'm still working on hovering and "scooting"?

With my new-found expertise at repairing tail booms, I'm thinking of running the tail motor's wire leads OUTSIDE the hollow CF tail boom, and just tacking them into place on the underside of the boom. Comments?

Can the Blade CP Tx be used on a fixed wing craft if I use a plain Rx? Elevator, rudder and aileron should work, no? What about throttle?

autoeject

My Feedback: (1)

Well Skiddz
Get it going fast and let me know the results.lol According to bdavison's prior post, his retreating blade stall resulted in rapid right roll. Not sure what to think myself.
Thanks
Mark

Skiddz

He's right. The heli will roll in the direction of the stalled blade. Again, gyroscopic precession will tilt the rotor disc backwards, pitching the nose up as well. Pushing forward on the cyclic only deepens the stall as the retreating blade's AoA is further increased. Aft cyclic produces a flare which also increases AoA. Recovery should be lowering of the collective to reduce AoA then apply aft cyclic to slow and cyclic opposite the roll direction.

As for getting my Blade moving fast, not really possible flying in my back yard. I live in an East/West canyon and there's always a good breeze blowing in from the coast. Too much for my skills to handle with this light model.. In the backyard, I'm sheilded by the neighbor's house and the slopes around half the yard.

autoeject

My Feedback: (1)

Skiddz
So far, I've only run into the pitchup. No rolling right at all. And as you pointed out before, It is self-correcting. No amount of forward cyclic had reduced pitchup. Collective reduction has only resulted in a return to hover from fff.

I know what you mean about the on shore breeze. Used to live in the coastal area myself. One could probably witness this problem while the blade was right in front of them in a good Santa Anna wind, huh? Nothing like fff with 0 ground speed.
Thanks again
Mark

Skiddz

Yeah, I hear you. Was out in the East county yesterday in an R22 goofing around and came to a hover with the nose pointed into the breeze, about 100' AGL. ASI was showing 25 knots and I was actually slowly moving backwards..

Brought the Blade into work today and took it out to the cul-de-sac/field we work near. Got into FFF and couldn't get it to do anything but go fast... It sure wants to climb once it gets cooking tho...

One thing I'd like to see on these things.. Some sort of one-way bearing so you can do autos or real aggressive quick stops..

autoeject

My Feedback: (1)

Skiddz
yeah it can climb cant it! Had mine out when some good gusts blew in. Had to use good bit of negative collective to get it back down. Nearly lost it as it went up so fast. And for all the nay-sayers, that was on cf's and stock battery.
Auto feature would be nice. I'll be going nitro this spring and would rather practice on the blade with its less expensive parts.

I wish someone I knew had a full size bird. I haven't gotten to fly rotory since '87. Sure do miss it. R/C is fun but not like that.
Mark

Skiddz

I practice autos on RFG2 with the Raptor 60 model and do ok. Maybe 3 in 10 I wad up at this point. Still can't hover nose in tho.. ehehhe Tried again to get the thing fast enough to get retreating blade stall - no joy... I don't recall if the OP said he was running the hot motor and LiPos or not. I'm flying in "Stunt" mode with NiCads. I wonder if it just dones't have enough power to get moving fast enough. What's the head speed like with the hot motor and 11.1v LiPo?? It's gotta be faster than the stock stuff but still too low to encounter retreating blde stall??

autoeject

My Feedback: (1)

I haven't tached the head to know what the speed difference is since the change. No doubt there is an improvement. Especially with the CF blades. When I first posted this, I was still flying with the stock setup. Shortly afterwards, a 30' spruce attacked my defenseless blade. The second one was promptly equipped with CF's. Initially, I did experience a much milder pitchup. It has now become more pronounces. The only change I can detect is softening of the o-rings in the head. The grip assembly pivots much more freely than it did when new. So, I don't know what's going on with this thing. I hear there are different oring in the bell-hiller upgrade kit. I feel I've just about gotten to the point that I will be able to use the improved responsiveness that should come with the upgrade. I just hope that takes care of the pitchup problem. Or else I'll just have to work it into a hammerhead, tailslide or something so it looks intentional?j/k
Mark

catfight

autoeject,

My bet would be that the loose grip assembly would be helped greatly by replacing the center hub assembly and spindle. That is what solved my problem that sounds the same - replacing those components tightened everything up and solved several other problems at the same time (Slow response to cyclic, wobbly rotor head assembly ,etc).

autoeject

My Feedback: (1)

catfight.
I have noted a slight slowing in cyclic responsiveness. Thought it might just be my imagination. And there is definately a pronounced wobble as I spool up. It goes away as head speed increases. I'll have to stop at LHS for a new head. Thanks
Mark