Apology accepted here, too.

Chad

Team HeliProz 12-13
US Navy Chiefs...Unity, Service, & Navigation to the Fleet since 1893

Thanks for the support and kind words, folks. And by no means do I mean to insinuate that Wayne Mann doesn't know his stuff. He's a top-notch pilot. For some reason, he rarely posts ANYWHERE on RR. I don't think it's because I contradicted his advice. I don't have that kind of power.

Keep in mind that his post is nearly four years old by now, and was made about the time that the Caliber was new to the market. If you had actually seen the wobble that he is trying to correct, it is a very pronounced wobble that occurs DURING FLIGHT, in the air, not on the ground. It has nothing to do with wobble while spooling up or down. It's very distinct, and has no connection to the ground resonance problem. My first Caliber scared the living daylights out of me when it did this the first time -- I was about 75 feet in the air, making a simple 180 degree turn to bring the heli back to me. The thing started gyrating like it was about to toss a blade or two. It took all I had just to get it back down again. I did notice that the wobble would come and go, and seemed to happen when I put a demand on the heli other than simple forward flight.

I saw that post of Wayne's and seriously gave some thought to doing it. Then, I ran across some other posts that indicated the root cause was running a low head speed. I figured tweaking the pitch and throttle curves (and getting the old OS 32 broken in) was a bit more practical than all the disassembly and modification of parts. I'm glad I saw that second post, as when I got my head speed up to at least 1800, the Caliber not only stopped any hint of the wobbles, it began to fly very well. Maneuvers that before hand were difficult, or seemingly bogged the machine down, became doable.

The other thing that kept me from doing the flip was the fact that at the same time this flip post appeared, many other helis that had bad woof/poof troubles seemed to all have trailing edge control of the MR blades, and the grip flip on those helis (going from trailing to leading edge control) was a common cure that actually worked to cure them.

Wayne had an article that I believe appeared in an issue of Model Aviation (maybe RC Modeler) about the same time frame as his post, where he went into deep detail about negative delta, positive delta, and their effect on heli control systems. From that article, and the experience of other helis having woof problems with trailing edge control, I decided that leaving the Caliber set up stock with leading edge control gave a much more stable control geometry for the head. The last thing I wanted to do was to introduce the potential for having an unstable head into my new helicopter.

The past four years of experience I've gained with my Calibers seemingly has paid off. One of the main reasons I went ahead and purchased a new Caliber 5 , in spite of some of the troubles it's reportedly seen (and against candid advice NOT to buy one from someone whose opinions I truly respect here on RR), was so that I could post my opinions and suggestions based upon actual experience with the machine. I didn't feel good offering advice on the Caliber 5 at times, as I wasn't familiar with the entire heli and its mechanics. But even when I did offer help on the Caliber 5, it was based on past experience with the Caliber 30s (that share quite a bit in common with the 5), and on general experience in trying to get everything from a DuBro Whirlybird 505 to my current fleet of choppers in the air. There are a lot of threads here on RR where I never tread, as I don't own the machines and feel it's not right to offer build advice on a heli I've never touched. I try to stick to the topics I have direct first-hand experience with.

As for this particular nugget from the earlier post:

You say in your posts over and over that your Caliber doesn't or has never done this, yet you continue to post and tell people what you think is wrong.

Go back and read this thread carefully. You will discover that "what I thought (think) was wrong" -- turned out to be THE problem. The skids were correctly reinstalled, and the wobble disappeared. Not a bad "guess" on my part, having never seen the helicopter do its thing in person. It's not all that easy diagnosing problems only by reading descriptions on a machine you've not seen in person. The video that was posted helped a great deal in the diagnosis.

Yes, I've not seen many of the reported problems with my Calibers. I don't think that's just an odd coincidence that I haven't. No, I'm not a heli god, not even close. I'll probably never be a Jason Krause, Alan or Danny Szabo, or Curtis Youngblood. But I do have quite a few years of heli building and flying experience to work from. I've also met quite a few fellows a lot more knowledgeable than I, I've learned from them, and hope others learn from me.

I simply try my best to help others with their heli problems. Sometimes I'm wrong. When I am, I usually apologize, and learn from the mistake.

Once again, go ahead and flip your grips, after all, it's YOUR heli, not mine. I can't force you to set your heli up "my way". I wouldn't try to. That's not my place here on RR. But I can warn others who might stumble upon this thread that the flip is a lot of work to go to and most likely isn't necessary in the first place. My EVO when I first started hovering it, also exhibited this same wobble phenomenon. Based on my Caliber experience, I simply tuned the motor and the curves, and it's not wobbled since. I didn't resort to rearranging the head set up. I knew better than that.

Apology accepted, by the way.

Dave

Dave, you are a class act and you continue to impress with your knowledge of the Caliber. You could have gone off on RC Thumbs, but you did the right thing. Very good post by the way!!!!

It's nice to have someone here to back me and Fromme2u up!!! Don't know how it is at your field, but we are the only Cal flyers at ours, and we get sh!t all the time!! It's nice to have someone out there that knows that yes, it is a pretty dang good heli to fly!!!

Rick

Good things come to those who wait, and PRACTICE!

I third that Dave. You are a class act. It's amazing how much knowledge you have on helicopters, their set ups and their mechanics. I can't imagine what Runryder would be like without your posts and your vast knowledge.

Also, thanks for not going off on me. This was my first time posting on Runryder in a very long time. I learned a great deal.

I usually try to remain civil, there's no point in getting into a shouting match on a forum. No one "wins". Besides, I've been hammered a few times here and know how it feels.

I know what it's like to be the only Kyosho guy in the crowd. But lately my Caliber 5 is turning some heads around the local flying field. I've gotten quite a few compliments on the way the heli looks and flies. I think I'm making progress!

I attended the Rotary Ring Out again this year. 130 pilots registered, probably at least 400 helis at the field, and besides two of my Caliber 30's and the Caliber 5, I spotted an OLD Concept 30, a new Caliber 5, and a very old Caliber 30. The rest of the field was littered with Raptors, with a smattering of Furies and Hirobo EVOs and Freyas.

I usually take my EVO to the field so I can rightfully rag on the few Raptors that show up.

Dave

Okay.......now that we have all of that out of the way, I will start over.

My Caliber 30 used to have a nasty wobble. It no longer does thanks to the grip flip mod by Waynne Mann.

I can now spool up my Caliber 30 very slowly, with no wobble.

Can you?

I can now spool my Caliber 30 down without any wobble.

Can you?

I can now spool up and spool down my Caliber 30, on pavement, WITH rubber skid stops on my gear with no wobble.

Can you?

I can fly my Caliber 30 at ANY headspeed I feel like ABOVE or BELOW 1800rpm.

Can you?

If you can, then great! You have a great flying Caliber and don't need to be reading or posting to this thread. If not, and you have tried everything else and still have a wobble below 1800rpm, then you just might want to look into this mod.

http://heliprodigy.homestead.com/caliber30.html

I don't know the author of this article, but it has the article from Wayne Mann posted in it.

And just to clear the record on some previous information (although it was slightly off topic)...having your blade pitch controlled by the leading or trailing edge, in itself, has NOTHING to do with control stability and NOTHING to do with "prevention or insurance against woof and poof". If you don't understand Delta 3 angles, don't try and explain them to others.

Scott

And just to clear the record on some previous information (although it was slightly off topic)...having your blade pitch controlled by the leading or trailing edge, in itself, has NOTHING to do with control stability and NOTHING to do with "prevention or insurance against woof and poof". If you don't understand Delta 3 angles, don't try and explain them to others

From a very good explanation of Delta angle and its effects on the rotor system found at http://www.scotiabladerunners.ca

it would seem that your quote above isn't quite correct with regard to the "woof" (flutter) issue:

Tracking or blade flutter issues may also be corrected with the proper use of negative delta. Some single spindle models which have trailing pitch horns have exhibited this property. The corrections or errors induced, depending on proper application are small, but they are part of the rotors geometry and should not be dismissed so quickly. One machine covered on this web site had blade flutter problems (the earliest Raptor Version I) although the manufacturer has presently fully corrected the issue on the latest Version II. By flipping the blade grips on the V-I, blade flutter has been removed.

And the portion of your statement that leading vs. trailing edge control has NO effect on stability would be true only in the case where the Delta angle is zero. Note that this contention of yours is directly contradicted in the article to which you linked as one of the side effects mentioned of doing the flip is that the controls became much more sensitive -- and indication that stability of the control system was directly affected.

Changing the head from its stock configuration (Leading Edge control) to the "flipped" configuration (trailing edge control) changes the Delta angle correction from a Negative value, to a Positive value in the Caliber. In engineering lingo, a negative delta system is a negative feedback control loop, while a positive delta system is a positive feedback control loop.

Both positive and negative feedback systems are useful, and can be made to respond to changes in inputs very quickly.

A control loop designed with positive feedback has the inherent risk of going wildly out of control to the point of system failure, when responding to disturbances in the system. This is because the feedback actually increases the amount of the disturbance in the system, instead of damping it out. Oscillations can increase rapidly to the point of system failure in a positive feedback system.

A negative feedback system is inherently stable. Disturbances introduced into a negative feedback system are damped out instead of being amplified as in a positive feedback system. Systems designed with negative feedback rarely self-destruct when responding to disturbances in the system.

As for your questions...yes, yes, yes, and I've flown at low head speeds with other helis and was not impressed with the handling qualities. Controls to me felt a bit mushy, not crisp or positive. (We all see the guys who fly any form of 3-D running consistently low head speeds, now don't we? ) This point about running at low head speeds is a personal preference based on how you want your heli to feel in the air.

Odd how that last post starts out friendly and conciliatory, then launches into an argumentative tone restating that those who don't see a need for the grip flip are just plain ignorant, and finally ends with a not very well disguised put down intended to show an intellectual superiority.

Please don't assume that we don't understand delta angles. You may be wrong.

As stated earlier a couple of times now, go ahead and flip if that's what floats your boat. For the majority of Caliber owners, it's not an issue and not worth the time, trouble, or effort.

Dave

Maybe I am just displaying my ignorance but I bought a Caliber 30 with the Grip Flip mod and I really do not see how it is any different from setting up the head with the RRS as per the Caliber 30 instruction manual.

The positions of links and levers were changed and the transmitter had some reversed settings BUT the actual movement of the grips and flybar was identical to the RRS setup. Partly on the advice of dkshema and also on my own observations of the mechanism from the swashplate up, I changed mine back to the standard Kyosho setup with FRS. This grip flip thing seems more hokum than improvement.

I have no doubt that careful assembly of the linkages will ensure good flight characteristics. I just don't think this grip flip thing does anything except make you assemble the parts with care.

It does not say in the article that the grip flip made it less stable. You are now confusing the blade grip flip with the increase in cyclic rate by moving the ball in one hole on the bell mixer. Also by the use of different paddles. Please read the article again slowly or have someone else read it to you.

My statement is correct. Which side of the blade is controling the pitch, IN ITSELF, does NOT have any effect on stability or woof and poof prevention. Delta does, not which side of the blade is controlling the pitch.

And you wonder why top pilots don't post here? Do you really????

Time to give this thread up...the solution to the wobble was found a LONG time ago, was related to GROUND RESONANCE due to the improper installation of a set of third party landing skids.

Now, it's degenerated into a pi$$ing match, insinuations, and name calling. The crop of nits must be extra tasty this year.

And you wonder why top pilots don't post here?

Guilt by association?

Dave

A few notes:

About the flip in and of itself not affecting stability or woof-ability.

From my post:

And the portion of your statement that leading vs. trailing edge control has NO effect on stability would be true only in the case where the Delta angle is zero.

Seems that I took that into account...I'm not aware of ANY model heli kit that runs a zero delta angle. So, flipping the grips, without going to a great deal of trouble to modify your grips to get the pitch link arm long enough to get you zero delta -- WILL, BY DESIGN, affect stability and woof-ability. I live in the real world like the rest of us.

Also, further down the article linked above, there is some discussion that the delta angle only comes into play as long as the swashplate is NOT parallel to the rotor disc.

What many people fail to understand about delta employed into a main rotor head is that once the rotor disk becomes parallel to the swashplate tilt the effects cease. This is because the rotor is now cyclically aligned to the control input.

If that's true, then this grip flip will NOT affect the wobble you might have seen at spool-up or down, unless you tend to do this with a lot of cyclic input. That would be a strange way to run your cyclics while spooling up/down. While spooling up, the rotor disc and swashplate would most likely be parallel to each other, as you haven't changed any cyclic inputs at this point. I don't believe many of us do weird things on cyclic while spooling up and down.

Finally, since the top pilots don't post here because the forum is full of idiots, what are you doing posting here?

Dave

Again Dave, your right. It seems this post was a good wealth of information at one time, and it was my intention to help other pilots, but it has turned into something that has no bearing on the subject.

So, this will be the last post. Thanks to all that helped me with my problem and I hope someone learned something from this post.

Happy flying!!!
Rick

Good things come to those who wait, and PRACTICE!