Espritmodel.com Telemetry Radio
Reply
Thread Tools
Old Apr 09, 2013, 02:52 AM
MightyG
MightyG's Avatar
Joined Mar 2013
598 Posts
Help!
SCM-9A causing other servos to clitch!

Hi All,

Don't know what the hell is going on here, but I was flying my Wasp yesterday and suddenly (just as I was landing) the main motor stops and all the cyclic servo's (3 of them) are glitching (servos moving slightly up and down non stop). Heli comes down really quick with a thud on the concrete and I destroy my:

1. tail stabiliser
2. tail blade mount's
3. Main blades are dented on the tips (sanded off)
4. pitch shaft in rotor head is bent
5. main shaft is bent
6. Waaahhhh!


Here are the steps I took to resolve the issue:

1. rebind TX to RX - Fail
2. swap out ESC - Fail
3. disonnect all the connections to the RX and try each in turn.
3.1 throttle (motor disconnected!) - ok!
3.2 Ailerons - ok
3.3 Elevators - ok (by now I have full cyclic control)
3.4 Rudder - Fail!!!

4. disonnect all the connections to the RX and try each in turn again
4.1 throttle (motor disconnected!) - ok!
4.2 Ailerons - ok
4.3 Elevators - ok (by now I have full cyclic control)
4.4 Pitch - ok
4.5 Rudder - Fail! all servo's glitching again!

So I've swapped out the rudder servo with the one from by "spare" wasp and all controls back to normal!
After swapping out the obviously damaged parts & then the not so obvious after a test flight I'm now finally back with 1 flyable machine, 1 not so flyable machine, and long list of more spares to purchase

Any Ideas as to why? Why would the rudder servo cause the others to glitch, and do they often just go like that? The machine is only a few weeks old with only about 20 flights on it! My google foo revealed another person with a similar issue but no answers were forth coming.

Any idea's and help appreciated!

Cheers

Simon
MightyG is offline Find More Posts by MightyG
RCG Plus Member
Last edited by MightyG; Apr 09, 2013 at 02:57 AM.
Reply With Quote
Sign up now
to remove ads between posts
Old Apr 11, 2013, 01:25 AM
United States, MI, Auburn Hills
Joined Dec 2008
852 Posts
Quote:
Originally Posted by MightyG View Post
Hi All,

Don't know what the hell is going on here, but I was flying my Wasp yesterday and suddenly (just as I was landing) the main motor stops and all the cyclic servo's (3 of them) are glitching (servos moving slightly up and down non stop). Heli comes down really quick with a thud on the concrete and I destroy my:

1. tail stabiliser
2. tail blade mount's
3. Main blades are dented on the tips (sanded off)
4. pitch shaft in rotor head is bent
5. main shaft is bent
6. Waaahhhh!


Here are the steps I took to resolve the issue:

1. rebind TX to RX - Fail
2. swap out ESC - Fail
3. disonnect all the connections to the RX and try each in turn.
3.1 throttle (motor disconnected!) - ok!
3.2 Ailerons - ok
3.3 Elevators - ok (by now I have full cyclic control)
3.4 Rudder - Fail!!!

4. disonnect all the connections to the RX and try each in turn again
4.1 throttle (motor disconnected!) - ok!
4.2 Ailerons - ok
4.3 Elevators - ok (by now I have full cyclic control)
4.4 Pitch - ok
4.5 Rudder - Fail! all servo's glitching again!

So I've swapped out the rudder servo with the one from by "spare" wasp and all controls back to normal!
After swapping out the obviously damaged parts & then the not so obvious after a test flight I'm now finally back with 1 flyable machine, 1 not so flyable machine, and long list of more spares to purchase

Any Ideas as to why? Why would the rudder servo cause the others to glitch, and do they often just go like that? The machine is only a few weeks old with only about 20 flights on it! My google foo revealed another person with a similar issue but no answers were forth coming.

Any idea's and help appreciated!

Cheers

Simon
Do you have the X303v or the X302 receiver?

Evidently the servo developed an electrical or electronic or physical problem like stripped or jammed gears. This happens; while not common, it happens to all RC Equipment eventually. The postings about the person you linked to with a similiar problem was with a completely different servo on a completely different helicopter.
If you feel you got a unit that is a factory defect, contact your dealer for replacments or repairs

Max
www.parkrcmodels.com
www.skyartec-usa.com
Parkflying is offline Find More Posts by Parkflying
Site Sponsor
Reply With Quote
Old Apr 11, 2013, 08:49 AM
MightyG
MightyG's Avatar
Joined Mar 2013
598 Posts
Quote:
Originally Posted by Parkflying View Post
Do you have the X303v or the X302 receiver?

Evidently the servo developed an electrical or electronic or physical problem like stripped or jammed gears. This happens; while not common, it happens to all RC Equipment eventually. The postings about the person you linked to with a similiar problem was with a completely different servo on a completely different helicopter.
If you feel you got a unit that is a factory defect, contact your dealer for replacments or repairs

Max
www.parkrcmodels.com
www.skyartec-usa.com
Hiya Max,

On my "spare heli" I have a X302, an on the one I regularly fly I have a X303v. The servo is causing glitches on both heli's. Thanks for the info regarding the possibility of a physical problem. I'll pull the servo gears apart to check it out. Spare parts (again!!!) are on the way. Now... if I could only figure out what is now causing the heli to bob up and down in idle up mode... Everything seems straight (pitch axis, main shaft) and the blades track nicely in normal flight mode, aaahhh the joys of this hobby!

Cheers

Simon
MightyG is offline Find More Posts by MightyG
RCG Plus Member
Latest blog entry: Introducing Ruby
Reply With Quote
Old Apr 14, 2013, 03:08 AM
MightyG
MightyG's Avatar
Joined Mar 2013
598 Posts
Quote:
Originally Posted by Parkflying View Post
Do you have the X303v or the X302 receiver?

Evidently the servo developed an electrical or electronic or physical problem like stripped or jammed gears. This happens; while not common, it happens to all RC Equipment eventually. The postings about the person you linked to with a similiar problem was with a completely different servo on a completely different helicopter.
If you feel you got a unit that is a factory defect, contact your dealer for replacments or repairs

Max
www.parkrcmodels.com
www.skyartec-usa.com

Hiya Max,

Well... I decided to really try and figure out why the heli was bobbing up and down in idle up mode... removed the main shaft, and the pitch axis rod, they were the tinyest bit out from straight, evident by rolling them on my glass dinning room table. With the patience of a saint I worked them ever so slowly to as straight as I possibly could, and put the bird back together. Wooo hoo! the bouncing is significantly reduced, but then disaster!

The moter cuts out and the heli comes crashing down! Fortunately I was only a meter in the air and over grass so no damage except for dirt on the main blades! What is is going on here I think... and once more I have no tail control and all the cyclic servos are glitching like crazy! Disconnect the tail servo and all is good! Bloody hell am I having a bad run of tail servos or what!

What do I do now? Wait for a couple of weeks for the new one to arrive or try to investigate the issue of the buggered up tail servo now... I decide to investigate and here's is what I found:

1. No stripped gears - yay!
2. Voltage out of the circuit to the motor is oscillating between +5V and -5V as I manually rotate the gears back and fourth - so that is good.
3. Voltage feed back test on the motor at certain points in the rotation is appearing to be resulting in a short!
4. Pull the motor apart and voila! One of the bushes has a bent up arm which I guess is shorting the circuit...
5. Straighten out the brush and, put the motor back together and voila! All is good with the world!

So, I decide to pull apart the originally buggered tail servo, and once more I find the exact same problem, I straighten the brush out and now that servo appears to be in good nick. Put the heli back together, take it outside, idle up, and all is good again! Yay!

So should I raise this with skyartec directly (I bought off a simple ebay distributor so ho help there!)? Or is this just something I should come to expect from this hobby! 2 servo's in a row with the exact same problem and me thinks that something might be either amiss or I've just had a really bad run!

Cheers

Simon
MightyG is offline Find More Posts by MightyG
RCG Plus Member
Latest blog entry: Introducing Ruby
Reply With Quote
Old Apr 14, 2013, 08:24 AM
United States, MI, Auburn Hills
Joined Dec 2008
852 Posts
Quote:
Originally Posted by MightyG View Post
Hiya Max,

Well... I decided to really try and figure out why the heli was bobbing up and down in idle up mode... removed the main shaft, and the pitch axis rod, they were the tinyest bit out from straight, evident by rolling them on my glass dinning room table. With the patience of a saint I worked them ever so slowly to as straight as I possibly could, and put the bird back together. Wooo hoo! the bouncing is significantly reduced, but then disaster!

The moter cuts out and the heli comes crashing down! Fortunately I was only a meter in the air and over grass so no damage except for dirt on the main blades! What is is going on here I think... and once more I have no tail control and all the cyclic servos are glitching like crazy! Disconnect the tail servo and all is good! Bloody hell am I having a bad run of tail servos or what!

What do I do now? Wait for a couple of weeks for the new one to arrive or try to investigate the issue of the buggered up tail servo now... I decide to investigate and here's is what I found:

1. No stripped gears - yay!
2. Voltage out of the circuit to the motor is oscillating between +5V and -5V as I manually rotate the gears back and fourth - so that is good.
3. Voltage feed back test on the motor at certain points in the rotation is appearing to be resulting in a short!
4. Pull the motor apart and voila! One of the bushes has a bent up arm which I guess is shorting the circuit...
5. Straighten out the brush and, put the motor back together and voila! All is good with the world!

So, I decide to pull apart the originally buggered tail servo, and once more I find the exact same problem, I straighten the brush out and now that servo appears to be in good nick. Put the heli back together, take it outside, idle up, and all is good again! Yay!

So should I raise this with skyartec directly (I bought off a simple ebay distributor so ho help there!)? Or is this just something I should come to expect from this hobby! 2 servo's in a row with the exact same problem and me thinks that something might be either amiss or I've just had a really bad run!

Cheers

Simon
I can only chalk it up to these servos are inexpensive digital servos, without the best manufacturing QA. As far as the Ebay Seller; I wasn't aware that just because you bought a product on Ebay, a buyer shouldn't expect 1st Class customer and dealer service.

Max
www.parkrcmodels.com
www.skyartec-usa.com
Parkflying is offline Find More Posts by Parkflying
Site Sponsor
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Question DLG servos that FrSky causes to chatter? GaryO Hand Launch 39 Jul 26, 2014 06:26 PM
Sold New Futaba Replacement Servo Gear Sets & Other Parts pnman Aircraft - General - Radio Equipment (FS/W) 0 Mar 28, 2013 07:38 PM
Discussion DX5e DSMX version causes servo jitter - HELP! TheLeabres Electric Plane Talk 0 Feb 21, 2013 11:07 AM
Discussion Throttle servos frying - cause unknown grosbeak Fuel Plane Talk 48 Jan 26, 2013 11:23 AM
Help! Clitching and you. Butters Motorcycles 32 Oct 15, 2006 05:07 PM