mcpx wierd problem... hope its not my board

[Rahulgaba]

Hi guys

I have this mcpx since a while now.. this is exactly how its life has been --- first day out of box, i had issues with the board. the gyro was glitchy.. HH was kind enough even after a month to change it... yeah thats how long it took me to figure out that gyro was a problem..but anywaz.. new board came in... and I put it in with a new servo caus ei superglued my servo.. u might find my post about that here somewhere.. it was embarssng and frustrating at the same time.. lol.. anywaz... now that i had that all in, i flew.. but right in time my dx6i busted... some battery issue. sent it in.. 4 weeks later i have have it back... in working state. now.. I am not exactly sure whats happening to my mcpx.. 4 weeks i know that the batteries were fully charged and inside the box.. so i donno if they are going bad.. on did... (why?) well my servos even couldnt pull enough juice from it and charger showed it was full... anywaz..

now.. I am trying to get it in te air.. the batteries fully charged.. it start going up in throttle, and all of a sudden bogs down (its not pitch, as i have checked and double checked all pitch settings.) i have almost equal positive and negative pitch with travel 70perc both ways.. anywaz.. now that when I try to get it flying, it bogs , come back up, bogs again, like there is something switching it on and off... heli jumps up and down because if loss of throttle.. and the blue light is solid on all this time, no chage.. not even dimming.. its buggy.. I thought the battery is not able to pull the load. I started marking the batteries to see which oned do that.. 2/3 did.. one didnt... and again i charged them all back u.. 2/3 did at first.. third one did at first but then it went stable.. And then one of the earlier two i tried back on, and it did perfectly fine too.. By saying testing.. I mean pitch pumps... in the air or in my hand.

I have tried just about every iteration, and there is no pattern to the batteries. I am not exactly sure what's the problem here. Its just so erratic.. How do I check if its the board? Can you suggest a series of tests or something to help me out here. I can probably buy a new battery and see if that works at all.. but i am doubtful somehow.. I am sorry this was long but i had to explain everything.. Thanks y'all..

are all my batteries bad? is my board bad? HELP...!!

[TheQuixote]

Sounds like there is play in the main shaft and you need to make sure the main gear is pushed all the up. In crashes it's designed to slip off and after every crash you need to check to make sure it's pushed all the way up.

[Rahulgaba]

Originally Posted by TheQuixote

Sounds like there is play in the main shaft and you need to make sure the main gear is pushed all the up. In crashes it's designed to slip off and after every crash you need to check to make sure it's pushed all the way up.

I checked that too... it is definately not the main shaft.. i have hovered it on idle up on one full battery in the middle of all this happening.... There was a time when my main motor wont even turn on after those glitches, only the tail... BUt I really appreciate your reply..

[Ampdraw]

If you left the batteries charged for four weeks they could be cactus.

Amp

[jchandler]

Could it be the main motor?

[Rahulgaba]

Originally Posted by Ampdraw

If you left the batteries charged for four weeks they could be cactus.

Amp

Agree!! I am planning on buying a new battery and doing flights on it. But does a lipo or any battery supply spikes of voltage? Doesn't it just die? I mean these were like serious throttle and then nothing at all.. I'll see if I can make a video to.. Just for good measure..

[Rahulgaba]

Originally Posted by jchandler

Could it be the main motor?

Honestly I doubt it! But u know... You never know!! Lol I donno how to check that though.. Any ideas?

[jchandler]

not sure how to check, other than replacing it. I just went through a "needle in a haystack" situation finding an issue with mine. Replaced a bunch of parts in the process It ended up being a nearly invisible crack in the main shaft, and a twitchy servo.

[cgriffith]

just throwing this out cause it sounds similar to someone else. Check to see if the power cables from batter to 3-n-1 board are soldered securely. I have heard that this joint can be a weakness.

[markb50]

Sounds like motor to me, as long as your main shaft bearings are ok. I had to replace mine and it flys better now then it had for a while.

good luck..

[Rahulgaba]

Hey guys..
Thanks a lot for the ideas . Here is the update:

I am gonna do a full autopsy of this birdie. I am starting by checking the 3in1 connections, and making sure they are OK.. Then I have another battery and my old main board, I might see if the new battery still gives me issues, I might then see what other hardware is messing up. I will go to the main shaft and the bearings then... I can see how all this can definately cause the esc to think its getting overloaded and shut down again and again and act screwy.. But, I am sure I will inspect everything very closely... and see if i can pin point something

The bearings seems very plausible, because the last area I flew was loose mud and lots of dirt... it might have gotten dirt in bearing from it. I am gona clean every dang thing and will give further updates..

More Ideas welcome.. seems like this thing is coming apart on the bench now.. lol

[Paka]

i had a similar problem. motor would spool up lift off the ground and then bog down and noisy. I tried 3 times and it kept doing the same thing. I changed the swash plate and still the same.

Took off main gear and just ran the motor by itself. Ran for 20 secs and then bogged down.

Put in new motor. Runs great.

Paka

[Rahulgaba]

Hi.. I tested this thing.. I saw a bearing had some red stuff on the outside. inspected.. RUST.. that was interesting... i sae if a we bit gritty. so there is 1 ..


second the motor, it was noisy.. like it wsa just mentioned above (thanks for that sir!! ) , I made a video which i will be adding very very soon...

3rd.. in the video i mention that there is no cracks in the main shaft.. well... i triple checked, and finally found a hairline going from the hole to the top... so i have vibrations because of that too...

after that, I turned the heli on, and tried to start the motor without the head. NO bogging. tried to hold the main shaft with hand to make it pull current.. NO BOG.. its was running fine... Then i decided to put on the full head system, and there it started... but then, i thought about setting the whole heli up and then starting again... BOG... (on the new battery).. SO no the batteries arent bad...


Then i went by doing elimination... rmoved tail motor.. still bogged.. so its not the tail motor pulling too much current.. or blown tail motor. . [ame]http://www.youtube.com/watch?v=nKgnhdioWDI[/ame]

Then i removed the gear... now moment of truth... MOTOR BOGGED even without having the head connected to it.. now the only thing i have left to make sure its motor is to connect it to the new main board i have lying around (which i might sell here on helifreak soon) , and see if it bogs there tooo..

That'll confirm the culprit.. I will change the main shaft and thebearings too for having a beautiful new heli, but atleast i know that they were not the main cause. lets c... video :


thanks!

[Rahulgaba]

I think I pinpointed it now. I changed the board, the battery , and every thing... the motor still bogged.... I had forgotten for some reason that it is a brushed.. and then i remembered the HBFP v2 days, and its tail motor. how it had similar issues... exactly similar respnse after a while... Well, if and when i can rub two pennies together. i might upgrade to a brushless.. but today is not that day...


QUESTION : How are the metal main shafts for the mcpx? Recommended? not ??? the one i have obviously has issues now. Its not making it die in the air, but hey might hurt the new motor.. so, any suggestions? should i upgrade main shaft or stick to stock? do they ben easily? will i have to upgrade all and everything with it?

LET ME KNOW!!