Hello,
As you will quickly find out, I am new to this hobby. I have a Concept 60, and it seems to be of balance (tail heavy). By this I mean that the center of gravity is on the last 3 inches of the skids (landing gear) I have no Idea it this is normal, but it doesn't seem right to me.

I have only flown it with the safety gear on, so I'm not sure how it affects it normally. My best guess is that the tail would hit ground every time I land. Any input on this? The only thing I can think of is that this helicopter was designed for an older and much larger Gyro. Were the older ones heavy?

On the average helicopter, where is the center of gravity on the skids? I.E. if you balanced the skids on a pencil, where would the pencil be in relation to the skids? Dead center? Toward the back?

Again, any help would be appreciated.

Thanks - Gimmick

Pick up the heli by the fly bar with the blades stright out fore and aft, hold your fingers close to the head, not by the paddles (if that has to be said)

It should be very slightly nose heavy. If not either get a bigger battery or move the battery as far forward as you can. I built a Concept 46 and it came out tail heavy, you may even need a stick on lead.

Take some time to get it balanced right because if you dont, once you trim it for a hover its going to want to pitch forward or backwards in forward flight.

Andy
AMA 77227
http://www.jaxrc.com

Thanks for the speedy response. I'll check it out.

- Gimmick

CONCEPTS TAIL HEAVY

Oh yeah, all Nitro powered Concepts tended to be tail heavy. I would avoid the use of forward ballast though and simply use the RX battery to effect the perfect CG . Since your fuel tank is not perfectly beneath the mainshaft and you are a novice I respectfully suggest the following:

1. Remove the mainblades because they will throw your perception of CG off if not perfectfectly extended along their chord CG.

2. Fill the fuel tank half way.

3. Besure that the canopy and all electronics are installed as they will fly and leave flexability in the for and aft positioning of the RX battery for CG adjustment.

4. Pick up your C60 by the innermost position on the flybar with 2 hands whilst the flybar is perpindicular to the boom and you will get a glimpse of how close or far off that you are.

You will find that the C60's usually need the RX battery strung pretty far out on the end of the plastic tray depending on the size. The goal is to get the skids reasonably level if not a couple of degrees forward but never aft. Things like tail mounted rudder servos, metal stabilizer sets, glow remotes and header tanks all add to the problem because they are mounted usually BEHIND the mainshaft where the the CG should be. So I'm not saying not to treat yourself to a header tank when you are ready or upgrade to a R60 boom mounted rudder servo and carbon pushrod. But remember that you must pay for all of these in CG differential. They must be compensated for by some sort of clever extension of the tray to allow you to push the RX battery out farther yet. Here is a link, to my old website with pics of my old SRX dragster with a large RX battery and tray extension in pics 1 & 4 I believe:

http://users3.ev1.net/~ollar1/

If you have any questions on Concepts, I flew them for many years and will be glad to help. I've tried just about every modification to save weight and slop and parts that I could think of. Might even have a few parts! Which version of the C60 do you fly the:

C60 (big canopy, polymer head/frame)

C60 Champion (big canopy, polymer head/frame, FAI driven tail & SS torque tube upgrade + misc bearings)

C60 SR ( tapered canopy, tall metal head, polymer frame, tapered maingrips)

C60 SRII (tapered canopy, shorter metal head, slotted mainshaft, polymer frame, straight heavy 5MM maingrips) or the last

C60 SRII Graphite (as C60SRII with full carbon framing and gold zeal lugs +++ extras!?

As a matter of fact, I still have one of the SRII Graphites mostly new in the box! Good luck to ya.

"I keep my feathers numbered for just such an occasion"- cred, Leghorn Foghorn, est.1946,

I have no Idea which version I have. I know it's not the SR. Here is a photo of it. My brother has my camera right now, so I'll have to get a better one later.

Thanks for the help guys! It's appricated! - Gimmick

Looks like and SR to me !

I wouldn't be so sure Gimmick. That is definetely an SR or SRII canopy. If she has a metal head; she is in the SR family. Get a better still with the canopy off and closeup of the head both from the side and the top and I'll positively ID her for you. I can even ID a hybrid if necessary. We've gotta get you on a better designed training gear though. Don't wreck her! She is hard to find parts for now since Kyosho has abandoned its customers. Your bird, like the venerable 30sized SRX, is one of the fastest out of the box birds to come along. Thats another reason I said not to wreck her because she can get up to speed in a flicker and get well out of hand for a novice. Not to mention that such a large bird can be intimidating to a novice. So be careful and get competent help. Good luck to you.

"I keep my feathers numbered for just such an occasion"- cred, Leghorn Foghorn, est.1946,

I wouldn't be so sure Gimmick. That is definetely an SR or SRII canopy. If she has a metal head, She is in the SR family. Get me a better still with the canopy off and closeup of the head both from the side and the top and I'll positively ID her for you. I can even ID a hybrid if necessary.

Nope, no metal head. But yes, I thought it might be a different body since the decals said SR II. I'll work on the stills, but like I said, my brother has my camer, and he is in Colorado. As for the training gear, what would be a better design?

So be careful and get competent help. Good luck to you.

I would love to get better help. However the best help I have been able to find is the previose owner. He had it for 5 years, ran it about 10 times, and never lifted it off the ground. My nearest hobby shop that sells heli fuel, is 80 miles away. There is one 50 miles away, but the owner deals only in cars and trucks. So, the best "competent help" i can find, is online.

P.S. Without the training gear, it is tail heavy. With, it's almost right on. I'm not going to mess around with it's balance much, because I'm working on building a camera mound on the front. So, tail heavy will help with that. And I'm still using the training gear.

Thanks for the help! - Gimmick

training gear and competent help

Gimmick, if you give me an email, I'll drop you a couple of pics of my simple but extremely effective design. As fas a help goes, it is imperitive that you get minimal hands on help with your first flights so that you don't hurt yourself. You are doing a good thing by researching all that you can, yet something is missing. A modern simulator will give you at least an idea of what to expect before liftoff. A 60 sized bird can be very intimidating for a newbie and a crash will hurt you more than others in a crash. Consider visiting a local funfly or 2 and immerse yourself in the heli crowd and culture will invariably rub off on you and you will likely become a safer pilot and more knowledgable heli mechanic much faster. Good luck to you.

"I keep my feathers numbered for just such an occasion"- cred, Leghorn Foghorn, est.1946,

why not use figure eights to learn nose in?

Hi Gimmick:

That is 1 way, but a way that I dont agree with because of the danger involved. You have only been flying a short time and likely havent learned 1st hand yet the propensity for these complex machines to have problems during flight starting with the tail. Forward flight, however slow has the potiential to get completely out of hand and very very quickly for a novice. If that happens to you; you will need every ounce of concentration and skill to rein your model back under control from whatever vantage point that is available at the time. During an episode of this magnitute everything usually happens within 5 seconds or less and rarely and I mean rarely are you luckly enough to be in the home position where you are comfortable. BTW, the home position is basically with you looking @ the rear of the helicopter simulating you being in the driver's seat. Beware of the happy go lucky guys who put caution and prudence behind having fun. That machine that you have is truely a REAL helicopter in every sense of the word. Indeed it is somewhat MORE complicated than the real thing because of the 5 fine stepper motors onboard called servos used to replace the presence of a live pilot.

The practice of learning the nose in by slow forward flight in figure eights is, IMHO, old fashioned and more dangerous than the technique that I use. My L1 course stress ORIENTATION and CONTROL. You should stand a minimum of 15' from the bird and hover gradually and slowly moving the tail left to right from 45 degree to 45 degree positions until you are comfortable. Next you increase this slowly until you are comfortable throughout the first 180 degrees inclusive of takeoffs and landings on BOTH and I mean BOTH sides. You will find 1 side considerably easier than the other as we all do. The purpose of this is to arm you with a bailout skill that is less than 90 degrees away should you encounter difficulty in the nose in training. Early during my training, I usually hold the left stick and control altitude and bearing so that my student can concentrate on the right stick alone. He or she is further instructed to rythmically move the aileron right and left to maintain a mental contact with the bird as she moves about the varying angles. The mind tends to relax a bit too much until its too late, I have found. When the student has progressed to the point that he can take off and land completely under control and routinely uses the rythmic aileron movement to maintain his orientation and get out or trouble, he is ready for the first nose in experience. Again I hold the left stick and cold turkey on the training gear we get her light on the skids with him moving the aileron back and forth and walla, nose in IS possible. The rest is stick switching, talking about wind and lift and set up and more practice and climbouts and 5' autos.

When my student can hover under complete control in all 360 degrees with the bird piroetteing very very slowly in BOTH directions with me simply offsetting the rudder trim a bit AND he can land and take off in any ODD position that I set the bird down in; my L1 course is over and he has graduated. At that point his money is better spent on fuel and practice. Very few have retained me beyond that point because it is just not necessary. It is also not necessary to rush into forward flight before the 360 orientation is achieved because the RISK to you and your bird are simply too high. Figure eights and forward flight look cool but are deceptive and not truly indicative of you level of competency like true 360 orientation. That bird you have is hard to find parts for so heed my warning. This msg was too long for PM Gimmick.

"I keep my feathers numbered for just such an occasion"- cred, Leghorn Foghorn, est.1946,

Simulator

In one of our PMs you said:

Avoid using your TX as a sim box and use the included sim box.

I don't understand why. I would think you should practice with the actual transmitter (TX) that you will be using for real flight. So that you become more confertable with what you will really be using.

I learned to hover with an old Conquest 6ch Remote (completly analog) After I got a nice digital one, had to become confertable in hover again. Basicly relearn how to hover.

P.S. after relearning, the digital makes it easier to hover.

risk to your TX

The statement that I made concerning the use of your TX for a simulator box was general in that risks are increased when you TX is out of her case and unsecured about the house. Children or clumsy adults in the home drastically increase that risk. In fact having a long cord attached to any expensive auxiliary device in and around your PC workstation puts that device at increased risk of the old trip drag and drop scenario. It is not an absolute rule just a guideline that you will learn anyway over time and experience. I am simply trying to save you the heartache. It is one of those things that most veterans abide by because they simply do not want to ever ever have to question the past or present security of their TX. Your flight born heli absolutely depends on it.

Imagine having a bird go in because someone knocked over your TX while stumbling around your computer where you were practicing last night and didn't tell you because she appeared undamaged. So they simply put her back onto the table and plugged the cord back into the usb and walked away! Even though you don't have an expensive TX, you DO have an expensive 60 sized bird that depends on it and as such I believe that you would benefit in the long run by choosing a SIM that includes a BOX. My JR 10SX is a freaking jewel to me and not to be used to screw around in the house. Hell, with all the goings on and the telephone ringing and my 9 year old about, dinner being made, TV on and such, I yes I might even mis-step and knock her over or trip over the attached cord whilst trying to get the phone or catch that news moment! I just prefer her in her closed metal box, double latched and sitting at the bottom of a deep closet until fly day Sunday is all. Now, if you are donated a great SIM like XTR Reflex or some such, I would probably find a broken planker box or some such to use. But, thats just my opinion. I've seen far too many enthusiastic budding pilots quit because they simply spent too much money on crashes and careless damage. Lets face it. We all have the potiential to be careless now and then or mistep or falter around some of this relatively expensive equipment that we use.

To put it in perspective, let try me out for size. Lets say I break down and start using my TX for a SIM BOX and my son knocks in over and believes all is ok and simply replaces it and plugs her back up. The next Sunday I wreck my Excell during a low inverted pass and total the kit and take out part of the onboard electronics.

KIT $900, BLADES $110, 10CH PCM RX $200, PAINTED CANOPY/FINS $200, GY-502 GYRO $300, 2 X NES 8231'S + GEARSET $200, HATORI MUFFLER $100 + MISC UPGRADES (CF BOOM SUPPORTS, METAL BOM CLAMP ETC.)

The replacement cost for the bird and electronics + blades etc is approximately $2400 and the TX can be repaired for $70 through JR plus shipping both ways. So here I am out $2500! I can replace my hot water heater, my PC, my microwave and my vacuum cleaner for that! The moral here is that: A LITTLE PRUDENCE GOES A LONG WAY MY FRIEND.

"I keep my feathers numbered for just such an occasion"- cred, Leghorn Foghorn, est.1946,

This may explain why it seems so tail heavy.

This may explain why it seems so tail heavy.

I was searching for parts on eBay, and came across this.

Look at the size of the Hump pack. My best guess is that the Concept 60 was originaly designed for a larger Hump pack like that, than for what is availible today.

Bye the way, kyoshokamper, as far as I can tell, that is exactly the same as mine.

square pack limits your options. but...

The pack in the picture is not a hump pack but what is called a square pack. I believe that a hump pack is basically a flat pack with an extra cell sticking out ontop conspiciously, as in the hump. The square pack limits your options but I'll explain wherein certain situations it can be a viable option. Normally a flat pack would be used to allow more flexability in the fore and aft sliding of the pack along the front tray for adjustment of the CG. If one cannot achieve an acceptable CG correction from this, and all viable methods of keeping weiglht forward of the main shaft have been exhausted, then a fabrication of an extension of the front tray is in order. Gimmick, remember when one of the guys earlier spoke of using ballast weight in the nose of your canopy? This is an absolute LAST resort. It is preffered to use the RX battery and a tray extension to effect the same CG adjustment. The ballast is simply performance draining dead weight. A larger RX battery can, at minimum, be utilized for extended no charge flying sessions and safety buffering. The square pack concentrates more weight into a smaller area and thus may be more effective in adjustment of CG provided that ample clearance exists in your narrow tapering canopy and provided that your tray extension is of considerable stiffness and strength to support battery weight affixed out on its end without bouncing and flexing dangerously in flight. From my experience, even with a rear servo mounted with a CF push rod and a header tank behind the main mast, you will not come to that extreme on any C60. The C30 can be slightly more challenging.

There are no absolutes here gimmick but, in general items with considerable mass/weight are better secured if their mass/weight is spread out a bit. (flat pack) Consequently, you will have more surface area and opportunity to get several good points to tie them down as opposed to concentrating them into half their nominal size (square pack) and having to rely on half the surface area and thus half the opportunity to secure them. Having established the foregoing, I believe that in MOST scenarios, the flat pack is the superior choice. If I already owned the square pack, I probably would experiment with varied methods of securing the pack onto the end of the OEM tray fo CG correction. If I found a viable method of securing her onto the end, I would go with it. If not, I would rig up a tray extension and see if my canopy would tolerate the large square battery either above or below the tray and secure as necessary to prevent the waste of my square pack. Failing all that, I would likely break open the square pack and convert her into a flat pack, providing my soldering skills support the excercise.

"I keep my feathers numbered for just such an occasion"- cred, Leghorn Foghorn, est.1946,

Thanks for clearing that up for me. I though that the Hump pack meant the reciever's battery. As for moving the flat pack to adjust the CG, I'm going to have to add some something to makeup for it. Even with the pack in the farthest forward possition, it is still tail heavy.

I'm going to try 2 flat packs, so I can move them about to get the perfect CG. And this will aslo give me the extended flying sessions before charging that you mentioned.

If in the future I mount a camera on the front, I may remove the extra pack. Or move it farther back. In anycase, the tail heavy problem should come in handy when mounting a camera on the front.

Thank you all for your advice and help.

- Gimmick

Concept 60 Gears make rattle sound when main Rotor head rotated by hand

Hello I recently bought a secound hand concept 60 from this fella who said his dad handnt touched it since it last flew.

But i find this Concept 60 main inside Gears make a rattle sound when main Rotor head is rotated by hand ?

I Disconnected the tail boom to narrow down my problem

Anyway when i rotate the main rotor (by hand i can hear the gears inside making this rattle sound
(like they are not meshing each other properly)

But cant see due to the Plastic gear housing !

They do bite because if you stick you finger inside where the tail boom goes you can feel the X thing rotating

I was wondering if this was usual for a concept 60 when the engine not running

or when you run the engine a clutch thing will engage a some point
and tighten all the inside gears up?

thanks

Jim

UK

wow... thats a pretty old post you resurrected there... hehehe

you might want to take things appart and check your bearings. gears dont usually make a rattling sound so it has to be one or a few bearings that are making that sound... keep in mind that the Concept 60 is a pretty old machine and the last owner probably didnt replace any of the bearings during his use.

another thought is that the mesh between the pinion and main gear is not set correctly. cut a small strip of paper the same width as the main gear and place it between the pinion and main gear. then tighten everything up and then remove the strip of paper.. this will give you the perfect mesh. to tight, the gears will wear out... to loose and they will wear out so you gotta get it just right.

all helis are usually tail heavy (my experience), this is corrected by sliding the battery as far forward as possible or swapping it for a heavier one.

just a thought....

orlee

Flying in Miami, FL (Kendall Area)

Problem located

Thanks orlee008

I think your right about it being the plastic pinion thing that sits on top of the main plastic gear at right angles and drives the tail rotor.

If this is loose in some way it will bounce up and down as the main gear is rotating round (but i cant see if this is happening due to all the gears being encased in a plastic housing

I wonder weather i will have to strip this baby down in order to tighten this gear up?

thanks for you time helping me out