CG change vs. line spacing?

[Larry Renger]

My Ringmaster is pretty much where I need it to be, but it needs a bit more control sensitivity. It just feels "heavy" on the controls and doesn't turn tight as easily as I would like.. (The control linkage is so free of drag that the elevator flops down from its own weight, so that isn't a problem source)

How do I figure out the right combination of moving the CG aft versus adding a bit of line spacing at the handle, or even moving the pushrod in on the elevator control horn? 

Is there a logical way to approach this, or do I just start flailing away in the dark and hope to hit the magic set of adjustments.  There are at leasr 4 variables to deal with here, and a logical approach would be wonderful!!!!

I suspect that the control horn is OK, since it can throw farther than I should ever need. 

Just to complicate matters, the system uses the RSM exponential handle, and if more line spacing is needed, the links could just be made longer. This would keep the level flight smooth, while giving even more "kick" to maneuvers.
 

I am not going to mess with it until after VSC, of course, as it is close enough for the level of flying I can do! 

Afterwards, the plan is to go back to a 10x6 prop, move out to 65' lines, lower the compression to use higher nitro fuel, and really tune this puppy in! At 28 ounces, it has great potential to be an outstanding OT performer. 

[Tim Wescott]

How does it behave with engine off?  If it speeds up when the engine goes off it's nose heavy.  If it balloons and slows way down it's tail heavy.  If it's easy to whip with the engine off it's nose heavy -- on a 28 ounce Ringmaster this probably means that if you can whip it at all it's nose heavy.  Paul Walker's trimming guide probably goes into better ways to tell, although you'll have to figure out how much applies to a Ringmaster.

Being a Ringmaster -- if it doesn't stall when you really nail the control, it's probably nose heavy.

I wouldn't worry about bellcrank-elevator if you can change line spacing.

[Motorman]

If you make it adjustable with little lead weights bolted to a mount point under the tail you can quickly experiment with balance. 65' lines on a ringmaster seems long.


MM

[Brett Buck]

My Ringmaster is pretty much where I need it to be, but it needs a bit more control sensitivity. It just feels "heavy" on the controls and doesn't turn tight as easily as I would like.. (The control linkage is so free of drag that the elevator flops down from its own weight, so that isn't a problem source)

How do I figure out the right combination of moving the CG aft versus adding a bit of line spacing at the handle, or even moving the pushrod in on the elevator control horn? 

Is there a logical way to approach this, or do I just start flailing away in the dark and hope to hit the magic set of adjustments.  There are at leasr 4 variables to deal with here, and a logical approach would be wonderful!!!!

I suspect that the control horn is OK, since it can throw farther than I should ever need. 

Just to complicate matters, the system uses the RSM exponential handle, and if more line spacing is needed, the links could just be made longer. This would keep the level flight smooth, while giving even more "kick" to maneuvers.
 

I am not going to mess with it until after VSC, of course, as it is close enough for the level of flying I can do! 

Afterwards, the plan is to go back to a 10x6 prop, move out to 65' lines, lower the compression to use higher nitro fuel, and really tune this puppy in! At 28 ounces, it has great potential to be an outstanding OT performer. 

      If it feels heavy, the usual solution is to remove nose weight. However, this is also a function of the exponential control system, which I think is probably a mistake - although probably less of a mistake on a Ringmaster than a conventional airplane. The way it is made exponential also reduces the control mechanical advantage as you deflect it more.

     Still, just nudge the CG aft a bit at a time, and reduce the spacing to get the desired sensitivity. The further aft the CG goes, the less effect of the exponential control will have.

     Brett

[Tim Wescott]

65' lines on a ringmaster seems long.

 

[frank williams]

Hi Larry,
Certainly it’s a trial and error solution …. No set formula I don’t think. 

Last years plane showed some of the same characteristics you mention.  It had a good turn, but as I moved the cg forward to get a groove in the rounds, the controls got heavy.

Very seldom through the years have I played much with handle spacing … sometimes a bit of overhang adjustment, but I never went too large on line spacing.  I finally pulled out a handle that had some larger than usual line spacing adjustment and found that it really worked wonders. It wasn't more than about a half inch greater spacing in this case.  I maintained the solid groove in the rounds and got back the sharpness of corner that had been lost.

I can’t say that it’ll work all the time for every plane, but it sure helped last year.  Al Rabe allowed me to fly his Big Bearcat a few years back.  I was a little worried and anxious in flying it since he had one of his super extended handles attached to it.  Bottom line .. it flew great …. Great groove and good turn.   You gotta do what you gotta do.
Frank

[Ted Fancher]

Hi Larry,

Too many unknowns, ergo, a WAG approach is called for.  Before doing anything else find out where your ship balances the way you've been flying it.  An excellent ballpark figure for almost any flapless stunter would be 15% aft of the leading edge of the chord HALFWAY out each wing panel.  If you're not with a fraction of an inch or so of that location or slightly forward (you'll almost certainly find it is forward of that) You can anticipate ultimately ending up with it between 12 and 15% aft of the leading edge.  There is rocket science involved in that number but I'm not at liberty to discuss it.  Whatever else you do when trimming the ship always keep 12 to 15% in your thought process.

Now, to address the issue you've described on a stand alone basis

No idea what size bellcrank or handle line spacing you're using, so do this:  First, measure the amount of up and down elevator available on the airborne system.  Pull the lead out "at the wingtip" full up to whatever stops movement and measure deflection, then full down and measure.  Now, attach your handle "as you've been flying it" and have a buddy hold full up and down while you check to insure that the handle is capable of providing full deflection.  Second: if full deflection is available and its over about 20 degrees or so (much more than that and otherwise decently trimmed Ringmasters will stall religiously any time full control is given (these numbers are WAGs in and of themselves, by the way, so don't take them as a scientific certainty.  They will however, give you a basis on which to evaluate the response rate.  You DO NOT want a lot of deflection on the elevator if your intent is to fly brisk "cornered" maneuvers with a Ringmaster.

Third: if your existing ground based pilot to elevator system is capable of producing all the deflection available (and if the pushrod has an effective fairlead to prevent the pushrod from bowing under load in inside maneuvers) and you can't obtain the turn rate you desire the airplane almost certainly needs tail weight.  Add it in small increments (maybe a half oz to begin with given your description) and, assuming that proves to be helpful but not enough, smaller increments on subsequent flights.  Ideally with a Ringmaster which is prone to stalling at the least excessive input a good safety valve is when you first start to get stalls back off to the tail weight that eliminates the stalls.  As the final safety valve narrow handle spacing a 1/16 on an inch or so on both lines.

After you've gone through these exercises what you've got is what you're going to get with a Ringmaster.  One trimmed in this fashion is capable of pretty competitive modern patterns in the right hands and enough finesse...the once very youthful Mr Fitzgerald has flown numerous 500 plus patterns in Classic with just such a ship.

At the risk of running out of ink...

The other prime culprit in mediocre Ringmaster performance is the use of classic era power trains.  4-2-4 .35s with six pitch props.  The secret to patterns like David flies is lots of power with speed controlled by prop pitch and RPM rather than the needle valve.  Yup, a powerful .19, .20 or .25 spinning low pitches at high revs will keep the airspeed consistently within the narrow comparatively high speed necessary to allow the ship to complete repeated brisk corners without slowing...and thus stalling.

Hope you didn't fall asleep before you finished all this!

Sorry,  gotta add this for your consideration.  David flew a number of 500 flights with my Ringmaster powered by a Veco 19BB running a cut down Rev up 10 X 4.  Just to show off he like to fly consecutive vertical square eights after the pattern with typical Fitz corners.  Pretty impressive stuff....until...

David crashed my little Ringmaster three times as I recall when the engine quit inverted at the 45 degree intersection coming down into the inside loop.  Each time the engine quit abruptly and...although the airplane had just flown several very respectable vertical square eights in a row...his attempt to bring the ship back to level flight for a safe landing failed each time as, when he attempted to simply pull out upright, the draggy little critter slowed. stalled and pancaked into Mother Earth flattening the landing gear and snapping the fuse just aft of the trailing edge each time.  That's how important proper power is to a Ringmaster.

The good news is he was man enough to put it back together each time.

Ted

[Tim Wescott]

Ted's comment about engines made me think I could add value by posting my Ringmaster setup.  I'm not David Fitzgerald, but I've scored 475 points with it in Classic.

• Weight: 34oz.  That's way heavy for a Ringmaster.  I don't recommend it -- but if I can do it with my porker, you can do it with your feather.
• engine: OS 20FP with the "BBTU" (i.e., leave it alone and use an APC 9-4 on it).  If I had it to do over again, I'd use the same engine.  I think the 25LA is a bit too big.
• lines: 60' eyelet to eyelet.
• bellcrank: Copy of a Sig 3" with the elevator rod in the inner hole -- which was a mistake.  For a Ringmaster you want to drill a new inner hole on the bellcrank about 5/8" out from the pivot.  I ended up with a Really Long elevator horn

In flight, the airplane only stalls if you really hit it hard.  As long as I'm careful, and make the corners no tighter than the little critter can handle, it flies beautifully.

[Paul Smith]

I have an overweight Ringmaster that was given to me a club meeting.

The model was built with a strong emphasis on surface finish and strength.  It weights 31 ounces and balances 2.7 inches behind the leading edge.  If flys OK as a sport model.  I don't use it to compete.

Balance and control throw are two different things.  A tail-heavy model will always be unstable no matter how much you reduce the control throw.

[Brett Buck]

Ted's comment about engines made me think I could add value by posting my Ringmaster setup.  I'm not David Fitzgerald, but I've scored 475 points with it in Classic.

• Weight: 34oz.  That's way heavy for a Ringmaster.  I don't recommend it -- but if I can do it with my porker, you can do it with your feather.
• engine: OS 20FP with the "BBTU" (i.e., leave it alone and use an APC 9-4 on it).  If I had it to do over again, I'd use the same engine.  I think the 25LA is a bit too big.
• lines: 60' eyelet to eyelet.
• bellcrank: Copy of a Sig 3" with the elevator rod in the inner hole -- which was a mistake.  For a Ringmaster you want to drill a new inner hole on the bellcrank about 5/8" out from the pivot.  I ended up with a Really Long elevator horn

In flight, the airplane only stalls if you really hit it hard.  As long as I'm careful, and make the corners no tighter than the little critter can handle, it flies beautifully.

    34 ounces is not prohibitive with a decent engine. I would wager the Ringmaster that inspired for our small engine experiments was in that ballpark and it flew fine with a 15FP.   -once we got the controls slowed down sufficiently. As noted in some recent threads, some of the super-light airplanes (and you can build one, with a 15FP, in the mid-upper teens) appear to be too light to fly well.

    Brett

[Jim Kraft]

Mine fly's way better than I do at 28 ounces and a McCoy 35 Red Head. I run either a 10-5 or 10-6 APC on 58' lines eye to eye. It is pretty consistant and is easy to fly. The old McCoy runs the same from start to finish just beeping into a 2 stroke in the right places.

[Larry Renger]

I think, from all this great input, that increasing the line spacing is the first thing to try. But AFTER VSC! The model is smooth and controllable as is, and it would be nice to bring it home intact!

I do have a further question. It was said somewhere above that the exponential handle was not a good idea on a Ringmaster. Why? I use that kind of handle because I have VERY shaky hands and need it to smooth out level flight and round maneuvers. (A judge once mentioned that he never saw a 16 point loop before, if it is any clue!)

[Steve Helmick]

"I do have a further question. It was said somewhere above that the exponential handle was not a good idea on a Ringmaster. Why?"

Your Expo handle gives more control as the angle of your hand increases. The Ringmaster stalls so easily that giving more control in general isn't thought to be a good plan.

I'd move the CG back, but maybe you just need a different cam shape in the Expo handle? Can you do that? I'd also be using a hard point handle. That might be something you could try before VSC starts?  Steve

[Brett Buck]

I do have a further question. It was said somewhere above that the exponential handle was not a good idea on a Ringmaster. Why?

  In part, *because it tends to cause the problem you were complaining about*. Additionally, you need to be able to move the elevator quickly but accurately to the maximum tolerable angle. Increasing the rate as the travel increased makes the finding the limits of the elevator motion far more difficult.

      Brett

[Brett Buck]

"I do have a further question. It was said somewhere above that the exponential handle was not a good idea on a Ringmaster. Why?"

Your Expo handle gives more control as the angle of your hand increases. The Ringmaster stalls so easily that giving more control in general isn't thought to be a good plan.

I'd move the CG back, but maybe you just need a different cam shape in the Expo handle? Can you do that? I'd also be using a hard point handle. That might be something you could try before VSC starts?  Steve

  Moving the CG aft also reduces the required control throw, putting you closer to the center, straight-line section of the exponential movement. In fact, that's part of why it is to difficult to use - because it's almost impossible to control where on the curve you are running as you change anything else.

    Brett

[Larry Renger]

The handle is hard point, by the way.

It is set up so that the spacing at neutral is narrower than usual, but normal at the extreme hand movement. Thus, there is no tendency to overcontrol. I have been using these handles to good effect for years.

[Steve Helmick]

I just went to the RSM site and looked at pictures of the 1/2a and .15 sized Expo handles, which are both "cable impaired". There is no larger size listed. It seems to me like you could use levers in place of the cables and get a similar effect, except that you might then have increased "overhang" to some extent.  Excess overhang will certainly cause that sluggish feel. I'd love to see a picture...or drawing...of your handle. It sounds interesting. If Eric is making a bigger, hardpoint Expo handle, prod him about getting it on his site! Steve

[Tim Wescott]

The handle is hard point, by the way.

It is set up so that the spacing at neutral is narrower than usual, but normal at the extreme hand movement. Thus, there is no tendency to overcontrol. I have been using these handles to good effect for years.

I'm going to second what Brett's saying about exponential controls and the Ringmaster.  I think you should at least try a regular old hard-point handle (maybe wrap some tape around your exponential handle, just for the sake of experiment?).  It shouldn't be a hard test to undertake, and I suspect that -- at least when there's a Ringmaster out there -- you'll like the results.  Because while I've flown other planes that benefit from being flown through the corners rather than just banging them, the Ringmaster is the only plane I've flown that needs to be flown through the corners.

There.  Now at least two people who fly at least fairly well and who have flown Ringmasters in competition are suggesting it.

[Sean McEntee]

     I'm still out flying at GDSCC and feel like starting trouble  

I built an RSM Ringmaster that weighed about the same.  I put an L&J Fox 35 on it (WAY more power than it needed) with a tongue muffler and an RSM 10x6 prop.  I do not remember where mine balances at but the 15% MAC sounds about accurate.  I fly it on 68' lines....no typo..68 foot lines nose to handle.   With power to spare, longer lines puts the model on a bigger hemisphere and it is my belief that the model appears to be turning tighter than if it were on shorter lines.  I cant remember why I stopped at 68".  I could probably take it all the way out to 70".

Again, this is a theory, but my workhorse ringmaster has also garnered 500 point scores in classic and even a couple wins against bigger and supposedly badder beasts.  Its around 32 oz now after 10 years (yes dad, I built it in the barracks in 2006....I feel a bit old from that too) and around 2500 flights worth of oil absorption.  It could probably use a retrim to correct for the added weight but it still flies well.  Makes me want to build another one...

[Dennis Moritz]

Add tail weight. 1/4 to 1/2 ounce at a time. If turn feels quick enough you're good. If plane grooves and controls are too quick go to smaller handle. Shorten lines. 58 to 60 ft eyelet to eyelet. Your handle has too much junk hanging off the front. Assemble a light hard point or try different combat handles.


Sent from my iPhone using Tapatalk

[Larry Renger]

Have any of you naysayers actually TRIED my hard point exponential handle? Do you have a clue on how it works, and how I use it?

I just scored  402 on my first flight at VSC having screwed up the exit to the inside loops, and losing pattrn points. I would have been in the very high 400s on the second flight except for flaming out in the cloverleaf. Even so I scored 391 with a 10 on the clover, no landing and no pattern points! Those are excellent scores for my skill level. I have only broken 500 once in my life (so far).

The secret is that the handle spacing is very narrow at center and only becomes "normal" at the extreme deflection of my hand. Thus, it does not cause the overcontrol you guys are moaning about, but smooths out my level flight and round maneuvers while allowing full deflection when needed. There was NO sign of stalling in either flight, and this at Tucson's 3000 ft altitude.

[Brett Buck]

The secret is that the handle spacing is very narrow at center and only becomes "normal" at the extreme deflection of my hand. Thus, it does not cause the overcontrol you guys are moaning about, but smooths out my level flight and round maneuvers while allowing full deflection when needed. There was NO sign of stalling in either flight, and this at Tucson's 3000 ft altitude.

   It works on principles not amenable to the rules of mechanical advantage?  That's interesting.

     Brett

[Ted Fancher]

Larry,

After reading your most recent I had to go back and re-read your original post as the most recent suggests you are now very happy about your Ringmaster's performance.  Apparently you did something to it to rid it of the problems you were concerned about prior to VSC.  What changes resulted in the improvement?

Ted

p.s.  I'd be interested to see a picture of the exponential handle.

[Larry Renger]

Yes, the Ringmaster is getting better and better tuned in.

As far as the handle is concerned, I only had one with me and have loaned it to Jim Hoffman to try out. I'll see about posting a photo when I get home from VSC.

As far as violating the laws of mechanics, I just ain't that clever.

[Steve Helmick]

"Have any of you naysayers actually TRIED my hard point exponential handle? Do you have a clue on how it works, and how I use it?"

No, haven't read anything about it previously, haven't seen any pictures, and it's not on the RSM website. Don't blame us for not trying this marvel.  Steve

[Mark Scarborough]

I remember reading about it
so I looked and I was right, it was on here in a thread some time ago,,
http://stunthanger.com/smf/open-forum/hardpoint-exponential-handle/

so there all you **Naysayers**,,

[Ted Fancher]

I remember reading about it
so I looked and I was right, it was on here in a thread some time ago,,
http://stunthanger.com/smf/open-forum/hardpoint-exponential-handle/

so there all you **Naysayers**,,

Thanks, Mark.  I checked out the pictures and still have question marks in my mind about how the expo function is activated.  Might just be my old timer's mind but it isn't obvious to me what makes the arms expand to increase line spacing due  solely to handle angle with respect to the flight track.  Do the up and down lines move independently of each other??? i.e. if you give aggressive "up" does the up arm expand and the down stay in the neutral position or do they move together increasing spacing on both the up and down lines???  Is the expansion "load" activated by increased pull on the respective up or down input??

Ted

[Tim Wescott]

Hey Ted:

The arms are pivoted, and normally ride against stops on the handle.  When pull hard, one arm or another comes off the stop and "idles", while the other arm keeps pulling.  The effect is to increase the distance between the line attachment points.

I know there's a picture somewhere, because I'm going from the memory of what I've seen.

I'm still skeptical that it's what you want for a Ringmaster, but it's what Larry likes and he did well with it, so I guess I can't shout too loudly about it.

[Steve Helmick]

I guess my "Old Timers" kicks in at about 4 years or so. The problems I see are that the spacing isn't adjustable, plus the "overhang" is considerable. I think the fairly extreme overhang might be causing Larry's Ringmaster to be a little sluggish feeling, maybe contributed to by what I still think would be variable bias. All those variations would probably freak me out.  Steve

[Brett Buck]

Yes, the Ringmaster is getting better and better tuned in.

As far as the handle is concerned, I only had one with me and have loaned it to Jim Hoffman to try out. I'll see about posting a photo when I get home from VSC.

As far as violating the laws of mechanics, I just ain't that clever.

   Right, so what happens is that as the spacing increases, so does the lever arm upon which the control loads act, causing the required torque for a given control deflection to go up - which is exactly what you were originally concerned with:

My Ringmaster is pretty much where I need it to be, but it needs a bit more control sensitivity. It just feels "heavy" on the controls ...

     So it needed to be more sensitive, and it needed to be less "heavy". Moving the CG aft is the solution, which both relieves the control loads (by requiring less deflection of the controls overall) and also reduces the amount of "added spacing" required.

    Moreover, the way you have implemented it causes a very large overhang, so you are fighting the line tension, too. Attaching the lines at very edge of the "bar" in front of your fingers results in much more overhang than a more conventional handle, and extending it even further by putting the pivoted arms with stop increases it even more. Maybe this was a non-issue with 1/2As with their extremely light line tension, but on a conventional-sized airplane this can become a substantial effect. I would guess, from the pictures in the previous threads, that you might have as much as 8-10" from your wrist to the end of the arms. Combine what with intentionally-slow-around-neutral nonlinear response, and you might have to move it 20-30 degrees, line tension (say, 6-7 lbs) times 8" times sin (30) degrees is a fair bit of torque. Much more than a conventional setup where the overhang might be only 4" and you don't have to move it as far.

   The internal exponential systems like ExpoCranks and elliptical pulley systems have a variation on the first problem (where the required line tension differential goes up exponentially instead of the lever arm at the handle), but not the second.

     Brett

   

[Larry Renger]

You are correct about there being more overhang than a standard handle, but it is only half as bad as it seems, since only the pinned line is causing extra tension, the other line is floating free at the pivot point.

[Steve Helmick]

You are correct about there being more overhang than a standard handle, but it is only half as bad as it seems, since only the pinned line is causing extra tension, the other line is floating free at the pivot point.

Yeah, but it's the "pinned line" causing that listless, unresponsive feeling of your Ringmaster. Have you tried this handle on another plane? Have you tried this plane with another handle? Should!  Steve

[Larry Renger]

I have been using this style handle for years with every model I fly. No, I have not flown the Ringmaster with any other type of handle. I don't think I own one. 

[Steve Helmick]

The question was, "Have you used this handle on other planes?"

The Expo handle with cables doesn't have nearly as much "overhang" as this one with the levers. Would you consider offsetting the grip so that you could pivot the levers somewhere around your fingertips? I think that would be awesome. Could be wrong, of course!  Steve

[Brett Buck]

You are correct about there being more overhang than a standard handle, but it is only half as bad as it seems, since only the pinned line is causing extra tension,

   The one with the majority of the tension on it.

   I'm not trying to talk you out of it, of course, just pointing out the downside.

     Brett

[Dennis Moritz]

Aside from the unconventional handle, issues of control liveliness typically respond to cg location. If the plane is flying true, wings level, insides and outsides near symmetrical, I'd add tail weight judiciously until plane responds quickly (granted subjective, to each our own) and continues to groove. Trade offs in groove/quick response, suited to taste. I'd then adjust with line spacing to reduce over-control. Aerodynamics, how the model flies, my first consideration. Handle adjustment, increasing or reducing leverage, used to tune my own reactions in relationship to the model flying as well as possible.

[Larry Renger]

The question was, "Have you used this handle on other planes?"

The Expo handle with cables doesn't have nearly as much "overhang" as this one with the levers. Would you consider offsetting the grip so that you could pivot the levers somewhere around your fingertips? I think that would be awesome. Could be wrong, of course!  Steve

I haven't figured out how to do that, but have been thinking about it since Brett pointed out the overhang situation.

[Ted Fancher]

Aside from the unconventional handle, issues of control liveliness typically respond to cg location. If the plane is flying true, wings level, insides and outsides near symmetrical, I'd add tail weight judiciously until plane responds quickly (granted subjective, to each our own) and continues to groove. Trade offs in groove/quick response, suited to taste. I'd then adjust with line spacing to reduce over-control. Aerodynamics, how the model flies, my first consideration. Handle adjustment, increasing or reducing leverage, used to tune my own reactions in relationship to the model flying as well as possible.

Dennis!

Best statement I've seen from you re the order of preparing a new plane for competitive flight.  Let me restate what you said in terms I've used over the years trying to make exactly your point.

Trimming the "handle" is totally ancillary to trimming the airplane.  The belief that an airplane can be trimmed by handle tweaks is probably the single biggest downside to the (properly celebrated) birth of the adjustable handle.  Too many fliers look first at the handle rather than trimming the airplane to be happy as a first priority and using the "handle" to "adapt" the "pilot" to fine tune his/her needs to what is required by that "well trimmed" airplane.  Your first job is to make the airplane "happy" and your second to leave the happy airplane alone and make the pilot "smile" by adapting himself to that airplane via the adjustments available at the handle.

I think this is largely the point that commenters on this thread have been trying to make from the very beginning.  A well trimmed airplane that is remotely aerodynamically suited to fly "stunts"  requires only that the handle be able to adapt the pilot to the airplane...never the reverse.

Ted

By the by...one of the clearest signs of a stunt ship most likely not yet properly trimmed is to see a handle in the pits with gross disparities from a stock Hot Rock.  Up line attachment point significantly greater or lesser than the down line attachment or notable bias of overhang.  60+% of the time this promises a poorly trimmed airplane at the other end of the lines.

What about the other 40 or so per cent you ask?  Attempts by the pilot to overcome the "debilitating to good pattern effects" of a handle not held vertically at neutral.  Oh boy!  I'm in for it now.

Ted

[Larry Renger]

I guess my "Old Timers" kicks in at about 4 years or so. The problems I see are that the spacing isn't adjustable, plus the "overhang" is considerable. I think the fairly extreme overhang might be causing Larry's Ringmaster to be a little sluggish feeling, maybe contributed to by what I still think would be variable bias. All those variations would probably freak me out.   Steve

The spacing is adjustable in 3/16" intervals. Also, different levels of expo are possible by varying the length of the control arms.  You could even make it reverse expo by putting the limit pins outside the arms instead of inside!

Here are photos of the current design.

[Steve Helmick]

Thank you for posting the pictures, Larry. I don't think it would be that difficult to offset the lever side of the handle from the grip side of the handle, while moving the lever side aft. I'd expect that a 1/2" to 3/4" offset would give enough room for those pesky fingertips. What I'm not sure of, is how the wrist would like the resulting torque, and how that would affect the guy wiggling the handle. I'd expect it would be bad for a big/heavy plane that pulls a lot, but should be ok for a Ringmaster or Flite Streak sized plane.  Steve

[Tim Wescott]

By the by...one of the clearest signs of a stunt ship most likely not yet properly trimmed is to see a handle in the pits with gross disparities from a stock Hot Rock.  Up line attachment point significantly greater or lesser than the down line attachment or notable bias of overhang.  60+% of the time this promises a poorly trimmed airplane at the other end of the lines.

What about the other 40 or so per cent you ask?  Attempts by the pilot to overcome the "debilitating to good pattern effects" of a handle not held vertically at neutral.  Oh boy!  I'm in for it now.

Two exceptions to this that I know of:

First, John Leidle, who uses a handle with something like an 8-inch spacing.  He's got something going on with his wrist that significantly reduces his mobility, so he makes up for it in the handle.  It looks bizarre -- but flies well.

Second, me.  I use about 70% of the spacing of "normal".  It's not a trim issue because when I fly someone else's plane it's too fast unless I move the lines in on the handle, and on one memorable occasion Steve Helmick demonstrated the opposite effect by putting the bottom of a loop right at 0 relative altitude while using my handle set up for me on one of my planes -- he later flew the plane with "normal" handle spacing and was happy with it -- until the muffler fell off due to the earlier discussion with the ground about altitude.

[Dennis Moritz]

Thanks Ted. Kind of you to notice my statement.


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[Steve Helmick]

Two exceptions to this that I know of:

First, John Leidle, who uses a handle with something like an 8-inch spacing.  He's got something going on with his wrist that significantly reduces his mobility, so he makes up for it in the handle.  It looks bizarre -- but flies well.

Second, me.  I use about 70% of the spacing of "normal".  It's not a trim issue because when I fly someone else's plane it's too fast unless I move the lines in on the handle, and on one memorable occasion Steve Helmick demonstrated the opposite effect by putting the bottom of a loop right at 0 relative altitude while using my handle set up for me on one of my planes -- he later flew the plane with "normal" handle spacing and was happy with it -- until the muffler fell off due to the earlier discussion with the ground about altitude.

Tim, I don't think "quickness" is the (latest) topic. It's asymmetrical overhang and asymmetrical attachment points in general, to the centerline of the hand (or wrist?)...things done to mask trim flaws in the airplane. Always fix the airplane at the airplane, then adjust the handle to tune it to the pilot's preferences for responsiveness...but keeping the handle symetrical.

No, I can't fly with your handle spacing or John's, but maybe, after a lot of flights, I could get used to it. Given a choice, I'd make the adjustment in 1/4" or less changes, before each day's flying. With John's 5"-6" spacing, it'd take a lot of days, 1/4" at a time.  When I flew my SV-11 in the high desert of E. California, I found that my "bottoms" were lower....actually pretty good! Thought about this on the drive home and remembered what Brett wrote about his  trip to SW Regionals...he had to widen the handle spacing for the thin air. So, when I got home, I narrowed the handle spacing on the SV-11, and it helped. This last year, I tried narrowing the spacing of the Eagle's handle 1/4" (at Auburn), and scared us both silly. I always do these sorts of experiments on the first flight of the day, so I'm not confused (as much) by muscle memory.    Steve