Need help from the experts out there, you have been a wealth of information in my quest to get off the ground with my Raptor.

The good news: I was able to fly and land without incident.

The bad news: It didn't happen as expected.

This is what happened....I slowly increased throttle watching the blades spin faster and faster but no lift. Increasing to almost full throttle caused the engine to almost start bogging down while still on the ground. I started to reduce throttle (and by the way, the throttle direction is correctly set for reverse on my Futaba T9CHP), while reducing throttle the heli zoomed up 30 feet into the air (@ about 1/2-3/4 throttle) where I then went to the 0 throttle setting which shut down the engine and it safely came down on it's landing gear.

Does this have anything to do with throttle pitch curve? If so is there an easy way to calibrate this on the 9CHP?

Am I the only bonehead that has experienced this or have any of you made the same mistake?

thanks all
Bud,

Sounds like you have your collective servo operating in reverse.

As you increased throttle, pitch was going negative holding the heli on the ground. At full throttle, you had maximum negative pitch therefore bogging the engine.

When you decreased the throttle, the pitch went through zero to positive and the momentum left in the blades lifted the heli off the ground.

A thorugh check with a pitch gauge is called for.

Yup, definately sounds like a reversed pitch servo. When you push up your throttle stick (engine off please) the leading edge of each rotorblade should move up. If it's moving down, then your servo is reversed.

I don't mean any disrespect but if you don't know the answers to these questions ... you shouldn't make any flight attempts.

Yes ... you have a throttle curve ... which YOU must ensure is set correctly for your heli
And ... you have a pitch curve ... which YOU must ensure is set correctly for you heli.

These two curves must cause the power and pitch of your heli to interact together to produce the most power efficient performance of the heli (ie hold a constant RPM at a good power output of the engine). The least problem is that your heli doesn't perform as good as it could ... and of course you've already figured out what the worst thing can happen ... out of control heli. Actually, the worst is someone getting hurt due to an out of control heli, second is just crashing due to an out of control heli.

You need to find a local heli person that can explain these things too you or at least sit down and study exactly what makes the heli fly and how the TX accomplishes this. It's not magic ... but there is a lot to figure out. Play with with these settings on the bench (engine off) and get to know your TX settings. You can't just flip the ON switch, move the sticks, and fly. Some amount of set up and measuring and testing and fine tuning is required.

Good Luck,
d.tipton

http://www.raptortechnique.com he has step by step setup for that radio (and others) on his web site.

Verify everything before you tear up your machine or hurt yourself or someone else.

I would like to thank you all for your advice and concerns.

In response, I would like to assure you that the Heli's construction was inspected and calibrated by an experienced flier, although it was winter time and we couldn't test at the time. Since then, I have purchased the T9CHP controller and this person is no longer available to calibrate it for me. During the previous instance that I described the copter flew very smoothly and balanced.

I have been very very patient with it, and this point all I want to do is attach training gear on it and hover. I do know what a throttle and pitch curve is but I have never adjusted them.

I performed a pre-adjustment test to see if the copter ran smoothly, I was hoping to only get it a couple of inches off the ground (not nearly a hover) a set it back down to make sure the mechanics were correct, I found out they were not.

Therefore I ask the question again. Based on no lift on upward throttle and experiencing the lift while bringing the throttle down.

One possible issue mentioned was a reversed pitch servo, does this require a reverse setting on the controller as does the throttle servo?

Thank you all again for sharing your knowledge, half the fun is learning about everything. I am not one who only wants to fly.

-Bud

I performed the following checks with the engine off, servos on. All appear to be correct.

Confirmed all linkages at 90 degrees
Mechanical throws appear correct
end points mechanically set

Aileron-functional
Elevator-functional
Rudder-Does the rudder servo need to be reversed on the controller? Although I don't believe it would cause this type of issue if it wasn't.
Collective Pitch- Swash-plate level with full collective
Throttle- is in conjunction with collective pitch (servo reversed)
Gyro- performed perfectly, heading held, no REVO mixing required

Pitch and throttle curves not yet calibrated, set to controller's default.

I notice the the main blades will loosely flop back and forth, I'm assuming that this is normal and that they hold their pitch with centrifugal force, and it appears that all linkage is in place as the person that built it last winter left it.

Any ideas???

No way should you try and fly with the default pitch curves and throttle curves. Without putting a pitch guage on it and setting it up right you would have no idea where anything is. That would also answer the question about your pitch servo being reversed!

Get a pitch gauge..attach it.. with transmitter on and reciever powered (ENGINE DEFINATELY OFF!!) start with your tx controls in their nuetral positions and check the pitch. if it is not correct ajust it as per your manual. now with the pitch guage removed push your throttle up and take note of which way the stationary blades move. the leading edge should move upwards as throttle increases. (Important note: make sure your tx is not set in 3d mode as if it is then you have to set neutral pitch at 50% throttle.) hope this helps but it sounds to me that you need to do a lot more study and gain a much better understanding of how things work before attempting your next flight. You are probably best to inlist the help of an experienced pilot. Look up clubs in your area. As stated by others with concerns here "this is not a toy you can just start up and go!!" I would suggest buying yourself a smaller electric heli and becoming totally familliar with flight characteristics before jumping straight into something that can easily cause major injury to yourself or others near by. Hope this has helped

Oh and yes the main blades should be able to flop but not to freely. they should stay where they are and flop slowly when you hold the heli and turn it to one side to loose creates excess movement and vibration and to tight will do the same and not allow the centrefugal force to centre the blades

Thank you Steve, that is the answer I was looking for. Yes, I have much reading and have much more research to do, but this provides me with a starting point. And by the way, I do own a pitch gauge but wasn't sure on the correct procedure on using it, Thank you again.

Just about everything you need to know about setting up a Raptor is at http://www.raptortechnique.com

The Raptor tech page helped me out. I was able to set up my 60 and futaba radio no problem (took some time but got everything right)
I am located in Woodstock and I know there are some other pilots in the area (pilot locator) that would be willing to look over your setup.

I don't see what size your Rap is? remember a 60-90 size the swash moves backwards to the 30-50. On the big birds down with the swash is up with the blades.

Thanks Barn and Cudda, if you're ever near the Addison Heli field (although I haven't made is there yet) , look me up, [email protected]. Of course Steve will never make it since he's in Australia.