11T Pinion, TP CF 325 Blades

[skigolfmike]

I can't help it, I always seem to be experimenting. I guess I like being a test pilot.

I got the ThunderPower 325 blades at the Toledo show. I got them on Sunday and got in a few flights. Definitely smoother than stock and the heli flew nicely. I did notice it changed the gyro gain a little too. I flew it initially with the 10T stock pinion. Then I reprogrammed the ESC and I think I messed it up as I started bogging really badly on punchouts. Actually, I attributed that to a change I made to the ESC. (Long story)

Then I tried the 11T pinion. With this puppy I get almost 2800 headspeed at 75% throttle. 85% is close to 3000. It's singing. In governor mode though I have encountered some bogging on punch outs, so it may be too much gear. What might work better with this combo is a higher output 3700kV motor. It will take some more experimentation to see.

Also, I changed my O-rings in the head to pieces of fuel tubing. I cut about 10 thin slices of Prather fuel tubing and picked the best 2 slices. I put the head together and played with the spacers until it got notchy and I took out a spacer on each side. it's a little stiffer than before and very responsive. it's not unmanageable though and seems to be working great.

[sparx-]

There is no way the stock motor can handle an 11T pinion. To keep the headspeed in check you have to lower your thorttle/governor down too much and you pull the motor out of its power band. That is why you are getting boggin now. The motor just cannot recover to changes as well when running it that slow. Even the 10T is pushing it if you ask me. The motor just cannot put out enough watts to maintain the headpseed.

Brushless motors are best kept in the 85% and higher range. Anything lower then that and you are severly degrading its performance.

One thing you always have to remember about motors... Its always about the WATTS. More or less kv does not mean more or less power. The more Watts the motor can put out, the stronger it is.

SPaRX

[skigolfmike]

Even better, I'm not going to disagree with anything you said.

You are correct that if you overgear the motor it will bog. However, I am not running the stock ESC and therein lies the difference.

I have the Phoenix 35 ESC. One thing I have noticed with this ESC is that I don't get the same rpm out of it that I get with the stock E-Flite ESC. At 85% throttle with the stock ESC and 10T pinion the head speed was something like 2800-2900. With the Phoenix 35, I was only able to get about 2450-2500. Here's the thing, it was bogging really bad with the 10T and the Phoenix 35.

I called CC today and they told me to go back to the 1.55 firmware and crank up the gain. I got 2700 rpm at 65% throttle and 2900 rpm at 72% throttle. I bumped the gain up to high (80%) and gave it a test run. Most all of the bogging is gone and I have a little rocket ship. It's really strong in idle-up.

So, I don't think you said anything I disagree with. However, even with the stock ESC, I don't think a 9T pinion will be the way to go. I think the B400 likes the headspeed in 2600-3000 range and I don't like the way it flies below 2400 at all.

[buildem336]

On my blade I am running it with the 11 tooth and 100% throttle it tached in at 3120 headspeed and nothing bogs this heli Im running carbon blades so the stock motor can definitly handle a 11 tooth pinion with no problem

[SeaComms]

On my blade I am running it with the 11 tooth and 100% throttle it tached in at 3120 headspeed and nothing bogs this heli Im running carbon blades so the stock motor can definitly handle a 11 tooth pinion with no problem

WOW.....

Thats quick.. hows the tail response with the head turnin that quick?

[buildem336]

tail response was better