Micro Blade 180CFX Tail Servo / Upgrade

[USAF_Ret]

Yesterday while flying my 180, the tail servo completely froze and when I removed it from the heli, I was unable to move the servo arm in either direction.

While I didn't have a 76T servo at hand, I did have a Lynx DS-895 and thought I would try that as it at least has metal gears. I had to reverse the servo through the transmitter, but the tail slider appears to be working properly.

Next I went to spin it up and the the heli started rotating clockwise. I reduced the throttle and gave full left rudder and the began rotating counter-clockwise. In either case, given full rudder to the opposite rotation had no impact on the initial rotation but after throttle down and giving opposite rudder the heli would again rotate uncontrollable.

This seems very odd to me.... As if the heading gyro is not working.... However, after re-initializing the FBL unit and manually yawing the nose, the tail slider appears to react as you would expect.

Just for fun I reversed the rudder servo via the transmitter again with no change....

Does anyone have any thoughts on how to resolve this?

I really don't like the 76T servo given the nylon gears but can't seem to find a replacement. Has anyone replaced the stock 76T servo with something with metal gears?

Your comments are welcome.

USAF_Ret

 

[Tony]

You have to reverse the gyro correction direction in the gyro in order to get it to work. If you can that is.

 

[USAF_Ret]

Any idea how to do that?

 

[Tony]

From what I'm reading, you can not reverse the gyro on the helicopter. You can adjust everything else, PID gains, tail gain, tail centering, but can't reverse the correction direction.

One thing that you could try (and it could burn up your servo!) is to reverse the red and black wires. As long as this is a brushed servo, it should work. But again, this could burn your servo up! The other method is to open the servo and reverse the wires on the motor as well as reverse the pot (this can take a lot of time). Best bet, just get a replacement servo lol.

 

[USAF_Ret]

Tony,

Thanks for the input and info. Not sure I want to mess with (and risk damaging the servo) so it may be just easier to get a new 76T for it. I just don't like the nylon gears in servos...

 

[Tony]

Take your helicopter to the LHS and see if they will let you test some servos. I'm with you on the plastic gears, they are horrible.

 

[USAF_Ret]

MY LHS really sucks. You might recall that I posted earlier some interest in getting into 250 class quad FPV racing. I had the cash in my pocket and asked them to set up the quad and FPV goggles so I could see how everything worked. I was informed that was against store policy. Right.... They expect someone to slap down a $1000 bucks without any assurance that it works. I asked about their return policy.... Again was informed that if I opened the box and there was no defect, there was no return / refund.

Needless to say, I left without the quad and googles and told them to tell their owner / manager that they just lost out on a $1000 sale and all of my future business.

It's way easier just to order online.

The help I get from this website is WAY, WAY more helpful than what I get at my LHS.

USAF_Ret

 

[Tony]

Copy that, and yes I do remember that post. Have you decided on what way you are wanting to go? I guess that question is for the other thread though lol.

 

[USAF_Ret]

Tony,

There is a local group / club that has scheduled racing events and they sponsor a 'build night'. I have been in contact with them and they have suggested that I build my own but before doing that, the group has suggested I come to their July build event and really get the details.

USAF_Ret

 

[Tony]

That is absolutely PERFECT! This way, you can see the quads, see the boards, you can see everything and how they work. No spending a grand on something that might not do what you want it to do. Take pictures and/or video of this event, I would love to see it!

 

[Admiral]

I have fitted an Align DS420MG servo to the tail of my 180CF , the servo rotates the opposite direction so I had to modify the tail push rod to get the servo & Gyro in sync.

The mod works well, the Align servo is not as fast as the Blade one, but that fast that I can't tell the difference.

 

[USAF_Ret]

Admiral, how did you deal with the reversed servo setup that I have been lead to believe is how the Blade 180?

USAF_Ret

 

[Admiral]

Admiral, how did you deal with the reversed servo setup that I have been lead to believe is how the Blade 180?

USAF_Ret

Hi I reversed the servo arm, but turning it 180 degrees the servo is working in the same direction as the original servo but the arm is no longer in line with the boom so you have to bend the tail push rod to suit.
Doesn't look great but it works and I haven't had to replace a servo since, I was replacing the tail servo about every 4 or 5 flights, the servo speed difference is not noticeable for sport flying you may notice it if your doing full on 3D.

 

[USAF_Ret]

I can't find a DS420MG servo anywhere on the web. It looks like the stock Align tail servo is a 426M. Would you please confirm the servo model for me?

Thanks.

USAF_Ret

 

[Admiral]

Yes I used an Align DS420, I assumed the MG as it has metal gears, it was an old servo out of a 450 Tail, Align changed to the larger DS520 when the 450 Pro was released but replaced the DS420 with the DS425M and used it as the T-Rex 250 Tail servo. The DS425M was replaced by the DS426M both servos are the same dimensions as the DS420 and slightly faster so either should work fine on the Blade180CFX.

Sorry if the MG confused you, but I got the I couldn't see the whole servo name because of the tail brace and guessed that it was suffixed with MG.