Prop Strike in Sport Mode

[NastyNate]

This AC should be still under warranty and should be returned to the seller

OP why are you trying to fix this yourself , get DJI to give you a new AC ?

I've called DJI - who insists this is normal and classifies the above condition as a "design limitation."

I'm a cheapo and didn't buy the refresh. when I asked about warranty, they offered an RMA but id be grounded for 2 weeks for the process and hopefully DJI will own up and replace. There's still a chance I'd get my claim denied and then be without a bird for 2 weeks and still have to make repairs.

I like to tinker and upper shell removal doesn't seem like it's too hard. I plan to fly hard and this is good crash course in intermediate level repair.

 

[smusk]

Check out the tear down videos

Thank you, perfect.

 

[lolo780]

makes sense. did you use 2mm or 3 mm stock?

Closer to 2mm.

 

[NastyNate]

Very interesting reading...So what is the prognosis?
Prolonged flying in sport mode will cause arms to flex?
or
Mavic was refurbished and not assembled correctly?

bird was factory new so my investigation concludes that repeated operation under sport mode conditions will introduce stress at the rear rear prop arm guards or butterflies. Said stress will eventually cause the butterfly to fail and crack and compromise structural integrity. Once cracked the rear prop arms are now allowed to flex farther and during a full descent at full yaw, in either direction, prop arms will flex up and props will strike upper shell.

take your bird and attempt to fold rear prop arms up into body. if you're butterflies ate intact , you shouldn't be able to complete the exercise.

if you're butterflies are damaged, your arms will flex upward and props will scrape upper shell.

make sense?

Maybe this thread will shed some light on the DJI limitation and 1. DJI will own up and remedy affected birds
2. they will reinforce MP2 butterflies

 

[Anthony Viscomi]

bird was factory new so my investigation concludes that repeated operation under sport mode conditions will introduce stress at the rear rear prop arm guards or butterflies. Said stress will eventually cause the butterfly to fail and crack and compromise structural integrity. Once cracked the rear prop arms are now allowed to flex farther and during a full descent at full yaw, in either direction, prop arms will flex up and props will strike upper shell.

take your bird and attempt to fold rear prop arms up into body. if you're butterflies ate intact , you shouldn't be able to complete the exercise.

if you're butterflies are damaged, your arms will flex upward and props will scrape upper shell.

make sense?

Maybe this thread will shed some light on the DJI limitation and 1. DJI will own up and remedy affected birds
2. they will reinforce MP2 butterflies

Thanks for the follow up answer.

 

[NastyNate]

Just my opinion, but if the arms did that kind of damage to the body, I would replace the whole arm including motor because there is a very good chance the motor became damaged or possibly motor shaft bent. It's just as much work to replace the joint as it is to replace the whole arm.

agreed. I'm gonna swap both sub assemblies while I'm at it
where do you guys get your parts? I've seen the best prices on eBay and Amazon but wanna make sure there isn't an inside line to parts here.

 

[NastyNate]

I see no one has asked you if you are using real OEM stock props.

DJI props. The dimensions and composition of props however is not the issue here.

 

[NastyNate]

Wow...I think I must have limited mine in the settings anyway when I got it, so I have not seen it run at that speed yet...but ok, so it’s Sports and steep yawing/decent that will place the force on it in the corners - mmm...will keep that in mind...I’m a gentle pilot with my bird

I like to live dangerously. I ran mine in beginner mode for about an hour to pop my cherry. been in SM since then got everything but take offs.

 

[NastyNate]

Closer to 2mm.

just ordered some 2mm stock.

 

[Davzone]

Cold weather might have caused the butterfly parts to break more easily!
Plastic is rigid in cold, so maye the same stress on the part is fine in the summer, but not at winter time.

 

[NastyNate]

Cold weather might have caused the butterfly parts to break more easily!
Plastic is rigid in cold, so maye the same stress on the part is fine in the summer, but not at winter time.

maybe but...

I live in the Southern California sunshine. it's all of 65F here right now.

I'm leaning more towards this is just a junk design that they are aware of and have reclassified as a "limitation."

 

[Mike4884]

How many flights did you say you had on that thing? I have over 200 flights on mine and it has been hacked since day 1 so i am constantly doing 52 to 53 mph (sport + mode) super fast ascents and descents about double what stock is..... Those pieces on my mavic look like they're brand new still. maybe you just got a crappy one or a Friday build LOL

 

[Mike4884]

Cold weather might have caused the butterfly parts to break more easily!
Plastic is rigid in cold, so maye the same stress on the part is fine in the summer, but not at winter time.

Been flying in 15 degree weather here in philly ..... Maybe not the case here

 

[NastyNate]

How many flights did you say you had on that thing? I have over 200 flights on mine and it has been hacked since day 1 so i am constantly doing 52 to 53 mph (sport + mode) super fast ascents and descents about double what stock is..... Those pieces on my mavic look like they're brand new still. maybe you just got a crappy one or a Friday build LOL

55MpH? please share a link to the tutorial.

I agree that this isn't normal but DJI insists that it is. my solutions are now:
1. $70 and some bench time
2. RMA bird and hope they fix it and not just send me a bill for repairs nd shipping I could have done myself and probably made better with reinforcements.

I'm gonna go with #2 because I will most likely learn something and off the top looks to be the cheaper and faster route.

 

[Mike4884]

I cant its forbidden here but if u google "digdat0" u will find what u are looking for... Anyway here is mine after 200 flights

 

[NastyNate]

I cant its forbidden here but if u google "digdat0" u will find what u are looking for... Anyway here is mine after 200 flights

thanks Mike. I gotta remedy my prop clearance issues but right after, this ***** is picking up some more speed.

 

[JohnC]

I've called DJI - who insists this is normal and classifies the above condition as a "design limitation."

I'm a cheapo and didn't buy the refresh. when I asked about warranty, they offered an RMA but id be grounded for 2 weeks for the process and hopefully DJI will own up and replace. There's still a chance I'd get my claim denied and then be without a bird for 2 weeks and still have to make repairs.

I like to tinker and upper shell removal doesn't seem like it's too hard. I plan to fly hard and this is good crash course in intermediate level repair.

Not normal, that sort of impact requires considerable flexing up of the rear arm. as others have mentioned the rear folding mechanism is secured inside the body and the top clips into the top of the mid shell. crashed Mavics sometimes 'pop out' of this clip and allow the rear arm to flex upwards. It also gives the impression the shell is cracked when it isn't.

Check that the rear arm support posts have not snapped inside the mid shell as this would also allow the rear arms to flex.

I have flown aggressively in sport mode using original and the more flexible low noise pops and have never had any sort of prop strike.

 

[NastyNate]

Not normal, that sort of impact requires considerable flexing up of the rear arm. as others have mentioned the rear folding mechanism is secured inside the body and the top clips into the top of the mid shell. crashed Mavics sometimes 'pop out' of this clip and allow the rear arm to flex upwards. It also gives the impression the shell is cracked when it isn't.

Check that the rear arm support posts have not snapped inside the mid shell as this would also allow the rear arms to flex.

I have flown aggressively in sport mode using original and the more flexible low noise pops and have never had any sort of prop strike.

thanks. I've got new arms on order. will advise once I receive and break her down.

 

[Smecky]

Mine is fine when doing that.
Get on to dji pal that’s shocking cutting into the bird like that.

 

[NastyNate]

Mine is fine when doing that.
Get on to dji pal that’s shocking cutting into the bird like that.

I thought so too. my first course of action was to contact DJI who then advised this is normal when in Sport mode.