Originally Posted by i812

This may explain why it might be possible to strip a Servo Gear without crashing:

Good thought, but I have max positive pitch at 55% and negative at -20%.
TH pitch is straight line zero pitch.
The first on such in the up position and the one today stuck in the down postion.
I guess I'll just try so more and see how they fair.

AFAIK, the only things that can stop a Servo is mechanical binding (bound output, missing tooth, debri between teeth, etc.), or electrical (faulty input, bad wiring, worn Pot, etc.).

If you swap the Servo, and the problem follows the Servo, then it probably has something to do with that Servo.

Without knowing anything else, based off what you've posted, my bet would be with "space junk" floating inside the Servo intermittently being stuck in-between teeth, and stopping the Gears from turning. If any of the internal Gears were ever stripped (had a tooth break off and go loose), then IMO part of the Servo repair would be to locate, remove, and discard the missing tooth.

If the suspect Servo has never been stripped, then maybe "space junk" was introduced at the Servo factory? Maybe somewhere in the factory, a Gear tooth was broken, and somehow found its way inside that Servo, and it became a matter of time before it randomly fell in-between the Gears?

I vaguely remember a month or so ago, someone (mescaline dream?) reported having a Servo problem after replacing a RX. Later, he posted finding the new RX had a loose solder blob (or wire?) under a FQC sticker, and after removing the loose solder blob, everything was OK again.

Hey all

First little crash of my Mini CP ....and need advice.

At first I thought nothing was wrong but when I tried to fly it, it would not go more than a few inches off the floor on 100% power.

When I had a closer look the blades they seem to be at a weird angle but I am not sure what is broken and what I need to order in parts?

The shaft also moves a little bit up and down is that normal?

Thanks

No, the shaft should not move up and down, except for about a hair or two's amount.

First make certain the Main Gear is pushed up the Main Shaft as much as possible. On mine, when the Main Gear is fully pressed up the Main Shaft, the bottom of the Main Shaft is nearly perfectly even with the bottom of the Main Gear.

Then remove all except about a hair or two's amount of up-and-down slop by simultaneously pushing upward on the Main Gear and downward on the Main Shaft Collar while tightening the Main Shaft Collar. When complete, verify there is still a hair or two's amount of up-and-down slop.

Note: One version of a Servo Saver Mod is to only "snug" tighten the Main Shaft Collar Screw, so in event of a crash it loosens and slips instead of allowing the crash impact stress to force its way to the Servo Arm.

Originally Posted by i812

No, the shaft should not move up and down, except for about a hair or two's amount.

First make certain the Main Gear is pushed up the Main Shaft as much as possible. On mine, when the Main Gear is fully pressed up the Main Shaft, the bottom of the Main Shaft is nearly perfectly even with the bottom of the Main Gear.

Then remove all except about a hair or two's amount of up-and-down slop by simultaneously pushing upward on the Main Gear and downward on the Main Shaft Collar while tightening the Main Shaft Collar. When complete, verify there is still a hair or two's amount of up-and-down slop.

Note: One version of a Servo Saver Mod is to only "snug" tighten the Main Shaft Collar Screw, so in event of a crash it loosens and slips instead of allowing the crash impact stress to force its way to the Servo Arm.

Thanks hope this will fix it....I will this change the angle of the blades back to neutral on the grips?

Originally Posted by i812

No, the shaft should not move up and down, except for about a hair or two's amount.

First make certain the Main Gear is pushed up the Main Shaft as much as possible. On mine, when the Main Gear is fully pressed up the Main Shaft, the bottom of the Main Shaft is nearly perfectly even with the bottom of the Main Gear.

Then remove all except about a hair or two's amount of up-and-down slop by simultaneously pushing upward on the Main Gear and downward on the Main Shaft Collar while tightening the Main Shaft Collar. When complete, verify there is still a hair or two's amount of up-and-down slop.

Note: One version of a Servo Saver Mod is to only "snug" tighten the Main Shaft Collar Screw, so in event of a crash it loosens and slips instead of allowing the crash impact stress to force its way to the Servo Arm.

The collar screw...is that to be tightened in a set position or is it free to move where u want to tighten it?

If you're asking if the Main Shaft has a "D" shape where the Main Shaft Collar Screw is to be tightened, then the answer is yes. no. The Main Shaft has a 100% round diameter along its entire length except where the Main Gear fits.

After the Main Gear is fully installed, and the Main Shaft Collar is properly installed, then the Links should be adjusted for 0* Main Blade Pitch when the TX is commanding 0* Blade Pitch.

Indoorheli has posted a video in this thread and other (mCPX? and Nano) threads showing how to adjust the Links for 0* Blade Pitch. I'm not sure what the quickest way to find that video would be, but it would probably be faster than me typing the procedure.

In case you have problems finding his video, here's an outline of how I would do it:

1. Servo Arms at 90*
2. All 3 bottom Servo Links adjusted to exact same lengths positioning Swashplate to be in center of the Pitch travel limits.
3. Top 2 Blade Grip Links adjusted for 0* Blade Pitch (see your photo below), and 0* Blade Tracking Error.

Originally Posted by i812

If you're asking if the Main Shaft has a "D" shape where the Main Shaft Collar Screw is to be tightened, then the answer is no. The Main Shaft has a 100% round diameter along its entire length except where the Main Gear fits.

Wonderful I did what you said and tightened it in a postion were the blade became neutral and she flys great again!!!!......the screw doesnt really tighten too much and I can keep screwing it but it will not screw to a tight fit?

I know how it feels to have a loose screw.

I'd rather have a tight fit.

I've had success repairing a cracked Collar by carefully widening the crack, applying CA inside the crack, and squeezing the crack closed overnight while the CA dries.

Sometimes even with stripped screw threads, the Collar is so tight on the Main Shaft, that a screw is not required.

Many people have different preferences. Mine is tight Collar, with ease of maintenance.

There have been a few Collar mods posted. CA it to the Shaft, Delrin, Metal.

I installed the Walkera full brushless kit yesterday.
It works pretty good other than the main motor won't start on its own. It just jiggles ans tries to start, but on it's own. It is the same whether installed on the Heli or not. I resoldered the motor connections, but that was not the issue.
I think the connections in the PCB must be not good.
Other than the poor quality control, I did get it in the wire several times and was impressed with the increased power and flight time. I had it up over 5 minutes and never saw a drop in power. Head speed is a lot higher as hover in normal mode is lower stick position than before.
All in all, the kit would be a great, easy mod if only they put some effort into quality control.

The first few posts in Tom Z's "Mini ... Review" thread is a good newbie read. If I remember correctly, he has tried and reviewed many of the BL mods.

Also, Tom Z recently created an "Asteroid ... Genius ... Mini ... BL... Review" thread which has video of a very capable Mini: http://www.rcgroups.com/forums/showp...4&postcount=48

Originally Posted by i812

If you're asking if the Main Shaft has a "D" shape where the Main Shaft Collar Screw is to be tightened, then the answer is no. The Main Shaft has a 100% round diameter along its entire length except where the Main Gear fits.

I changed a main shaft recently and it has a D shape where the collar fits.

Thanks

Yes, it's been a while, and I just checked and confirmed you're correct.

Sorry for the mis-info. FWIW, I'll edit my incorrect post.

Just watched a video on youtube and the guy says that the blade tension on the CP should be so that it does not move on its own and should only move if you give the heli a little 'jerk'.

My blades flopped around straight out of the box but I dont have a problem with flying it?

What is the best?

Mini CP and V120D02S Setup (Pitch Zero/Swash Zero/Blade Tracking) with Telemetry View (20 min 9 sec)

Originally Posted by i812

Thanks

Yes, it's been a while, and I just checked and confirmed you're correct.

Sorry for the mis-info. FWIW, I'll edit my incorrect post.

Cheers anyway for putting me on the right track