THAT is true.. but if a motor is even slightly out of alignment there is no more stability in flight. If the cracks go so far as to totally separate... I guarantee you its coming down, and fast! The only reason a MR is stable is because of the delicate balancing act it performs on its own. This is why there has never been a gas powered MR!
Anyone using the Strong Arm kit from UAVBITS for stress cracks?
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alokbhargava
Premium Pilot
I'm not sure how will this strong arm kit save the cracks. If cracks have to come, they will. If these plates get homogeneously bonded to the shell, they can strengthen the mounting area but then load will transfer to the neck of these arms and we will see cracks there.
Anyway I am not yet convinced about the benefits and thus will not use these lose pieces.
Anyway I am not yet convinced about the benefits and thus will not use these lose pieces.
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Are you using UAV Bits' Strong arms and.... | DJI Phantom Forum
Here is my response on a similar topic.
Here is my response on a similar topic.
Its clear in this post...
I have installed the kit a months ago and i dont know what i should think about the strong arm kit. There are a lot more cracking and crunching sounds going on when i slightly try to twist the end of the arms, i havent tested the kit in the air yet. The shells are just not as solid than before, they are slightly more loose. All screws are tight, so maybe this is normal but i have a strange feeling about it.
Maybe the plastic material of the kit is to flexible and thin, the plates are bending like hell.
That there is SIGNIFICANT streess being exerted where it shouldn't be. Notice the obvious disfiguring at the screw holes! The majority of that added stress is being applied exactly where those getting cracks are cracking. That image alone is proof enough that they are NOT a good idea!
I also believe cracks are random. I have a firm belief it's related to the mold process used by some of the injection mold vendors that DJI uses, or cheap materials, or a combination of both. Plastic injection molding is a science. I have a customer that make injection mold machines (Husky), they have told me lots of stories of how injection molding can go bad just in the process, temperatures, materials, timing and cool cycles. If you don't take the science seriously the formula can turn out crap that may look OK on the surface, but the integrity is brittle garbage.
It would be interesting to know how many vendors DJI buys their injection molded shells from. I haven't heard of anyone noting any kind of ID marks on the shells that might indicate who made them, or a code so DJI can ID who the maker is of the cracked shell so they eliminate that bad vendor. It's my "guess" that DJI simply has a bad injection mold vendor, and DJI doesn't know how to vet a new injection mold vendor and their process before they engage in business.
I bought the Strong Arms as protection against catastrophic failure with a motor dismounting itself during flight, which was reported. That story kinda made me pause, I decided $25 was pretty good insurance against that from occurring. It's obvious to me that using Strong Arm brackets spreads the pressure of the tighten screws over a larger area, relieving the specific areas that have failed around the screw cavity barrel areas. For those that use Strong Arm kits that have compared the twist flex of the motor pods, with and without the strong arms installed, it's clear there is less flex in the motor pod with the kits installed. They feel stronger.
Did the Strong Arms prevent me from getting shell cracks? I don't know, I never will, but I can say I don't have any cracks. Am I'm glad I bought them? Yes, it doesn't hurt to have some extra strength and insurance.
It would be interesting to know how many vendors DJI buys their injection molded shells from. I haven't heard of anyone noting any kind of ID marks on the shells that might indicate who made them, or a code so DJI can ID who the maker is of the cracked shell so they eliminate that bad vendor. It's my "guess" that DJI simply has a bad injection mold vendor, and DJI doesn't know how to vet a new injection mold vendor and their process before they engage in business.
I bought the Strong Arms as protection against catastrophic failure with a motor dismounting itself during flight, which was reported. That story kinda made me pause, I decided $25 was pretty good insurance against that from occurring. It's obvious to me that using Strong Arm brackets spreads the pressure of the tighten screws over a larger area, relieving the specific areas that have failed around the screw cavity barrel areas. For those that use Strong Arm kits that have compared the twist flex of the motor pods, with and without the strong arms installed, it's clear there is less flex in the motor pod with the kits installed. They feel stronger.
Did the Strong Arms prevent me from getting shell cracks? I don't know, I never will, but I can say I don't have any cracks. Am I'm glad I bought them? Yes, it doesn't hurt to have some extra strength and insurance.
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THAT is a statement cant disagree with! No emotional connection. No following a whim.. or doing it because the cool guys are. Well stated!
I had time to think about it and its people like you that convinced me to stay the course. I will continue to asked questions and avoid responding to negative members.I am sorry to hear that. The forum has a lot to offer and I am sure that if you were to hang around you would benefit. This is an internet forum like most and are made up of many people from many places. Statements get challenged sometimes so you have to be prepared for that with facts to back up your statements. Everyone who follows the guidelines here are welcome to participate including you. Give it a chance and see how it goes.
Best Regards,
William E. Burrows Jr.
Glad you are staying with us. Every group has a few bad apples. I think the majority of members on PP truly want to help each other. I've learned a lot from other members.
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I have a P2 and wondered if the P2's have this same problem?
I would imagine they do, seeing as the shell is pretty much the same material.
I would also imagine that these would be a wise investment for my P2.
I will write a note to uavbits, but wanted to get some opinions.
sorry if I hijacked this thread.
I would imagine they do, seeing as the shell is pretty much the same material.
I would also imagine that these would be a wise investment for my P2.
I will write a note to uavbits, but wanted to get some opinions.
sorry if I hijacked this thread.
alokbhargava
Premium Pilot
Interesting point. Look at the P2 forum and figure out if many are complaint about cracked shells. If not then either they were sold in very low numbers or P3 has gone through major change. Only comparison of both can help us.
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Thank you for your suggestion!
I have looked and searched for cracking on a P2, and the only hits have been for P3's, but I will investigate further, thanks!
I was just thinking that it MIGHT be because the motors are different in a P3 versus P2, and the mounting method used, power of the motor is higher, operating temperature of the motors, etc., might be what is different?
Don't really know as I don't have a P3, but this kind of thing HAS me a little concerned.
I watch my motor mounting area for cracking and bolt hole pullout, and haven't seen anything YET...
I will keep my eyes open however!
I have looked and searched for cracking on a P2, and the only hits have been for P3's, but I will investigate further, thanks!
I was just thinking that it MIGHT be because the motors are different in a P3 versus P2, and the mounting method used, power of the motor is higher, operating temperature of the motors, etc., might be what is different?
Don't really know as I don't have a P3, but this kind of thing HAS me a little concerned.
I watch my motor mounting area for cracking and bolt hole pullout, and haven't seen anything YET...
I will keep my eyes open however!
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Well call me a liar!!!
I did another search an YES the P2's have this problem as well.
Need to do MORE research though....
Just thought I would let you know....
I did another search an YES the P2's have this problem as well.
Need to do MORE research though....
Just thought I would let you know....
John's post is spot on. I have also been involved with injection molding and I would guess that DJI and its vendor are not ISO9000 companies.
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The strong arm kit is now $15. Given the way it is mounted I think it is safe to say that it adds additional structure as well as bigger area to distribute pressure leaving the neck potentially the weak spot.
To me, even if the shell rack at its usual spot, this provides additional insurance against the entire motor separated from the craft with obvious catastrophic result. So why not? I dont see a down side. Worse case I wasted $15. Best case I save $1200.
No brainer really.
To me, even if the shell rack at its usual spot, this provides additional insurance against the entire motor separated from the craft with obvious catastrophic result. So why not? I dont see a down side. Worse case I wasted $15. Best case I save $1200.
No brainer really.
Basically the same thing-- I would want the lighter ones if there is any difference-- the strong arms have been out since the first week of the cracking scandal
I looked into making them out of aluminum, like those, but they are heavier and there did not seem to any interest from PhantomPilot members. Also, don't use Locktite like they recommend. It weakens the shell.
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