Anyone using the Strong Arm kit from UAVBITS for stress cracks?

Joined
Jul 10, 2015
Messages
208
Reaction score
92
Age
55
I saw this idea mentioned on the DJI forum and I'm wondering if anyone is using this kit? It basically seems pretty simple by stiffening the ends of the arms with another piece of plastic. I have detachable prop guards on my P3P so the base on my prop guards essentially does the same thing. Just wondering if this Strong Arm kit would be worth using?

http://www.uavbits.net/store/p28/Strong_Arm_reinforcement_plate.html
 
Yeah I have the detachable prop guards too, not that I'm using them a heck of a lot.

These look good. I'd just have concerns about that lack of thread lock on the new motor screws.

I'd actually like to just see a more compact solution for the two screws where most of the cracks seem to be happening, rather than replacing all the screws. I don't see issues with cracks on my motor mounts. Yet.
 
Motor mount screws are coming Scotty. This happened to me today. How bad is it? This crack allows maybe twice as much movement from the motor in comparison to the cracks we've already expericed. Sucks. These shells are too thin period. These quads should definitely be weighing a little more and having a lot more strength.
20150728_182233.jpg
 
Last edited:
  • Like
Reactions: Chris Vedeler
I ordered the strong arm kit to try out on my P3. Mine has about 6 hours flight time and already has a small crack starting on one of the rear arms. I got the kit yesterday looks like a decent kit and should work. Im going to sand them down a little smoother they still have the machining marks in the plastic but with a small amount of work should work well. Gotta be better than the eggshell thin plastic around the screw now. I will post back with my results after i put them on.
 
Just ordered one myself after noticing tiny cracks just starting to form and stressed plastic that is just about to start cracking. Certainly a design flaw by DJI. My Phantom will be grounded for now until the reinforcement plates arrive.
 
I ordered the strong arm kit to try out on my P3. Mine has about 6 hours flight time and already has a small crack starting on one of the rear arms. I got the kit yesterday looks like a decent kit and should work. Im going to sand them down a little smoother they still have the machining marks in the plastic but with a small amount of work should work well. Gotta be better than the eggshell thin plastic around the screw now. I will post back with my results after i put them on.
Those aren't machining marks. Uvbits 3D prints their parts. Those are print marks. I'm interested in this kit and would like your opinion on the fit. Do they fit the curvature of the bottom of the motor shell good?
 
Those aren't machining marks. Uvbits 3D prints their parts. Those are print marks. I'm interested in this kit and would like your opinion on the fit. Do they fit the curvature of the bottom of the motor shell good?
Yeah I knew they were 3d printed I just couldnt think of the word for them not being smooth. They seem to fit the shell fine, Ive got 2 of them sanded down already going to get some silver paint and paint them to match my p3a. But they seem like a decent solution since dji wont give us one. I almost sent my p3 back since it was only like 6 easy flights in when i noticed the first crack but a new one will do the exact same thing and mine flies great with no other issues. I figure eventually dji will redesign the shell then I will just change it out.
 
So, if you have detachable prop guards, will those also act like the strong arm supports?
 
So, if you have detachable prop guards, will those also act like the strong arm supports?
I think nobody knows that and nobodys knows about experiences with the strong arm kit. It maybe makes everything worse etc.. I will send my Phantom3 in if it develops cracks and will sell it before the warranty is over. Maybe they come out with a new version.
 
I think nobody knows that and nobodys knows about experiences with the strong arm kit. It maybe makes everything worse etc.. I will send my Phantom3 in if it develops cracks and will sell it before the warranty is over. Maybe they come out with a new version.
One of the reasons I have not yet installed the detachable prop guards is because I don't know what those 4 screws are attached to. I suspect the motor and I'm just a bit weary of unscrewing the motor and then screwing a different set of screws into it.

If those screws are attached to the motor and seat against the thin plastic then I can certainly see how a thicker piece of plastic would prevent the cracks. As long as the motor isn't compromised then it seems like a good workaround.
 
More weight?
Not sure what you mean but I would doubt that the very small weight addition would even be noticed.

I'm thinking that those motors produce a lot of stress on the screws holding it in place. That's translated to the surrounding plastic as vibrations and torquing forces. To me, and this is only my opinion, having a sturdier support for those screws would be a big plus. Spreading the vibrations and torquing forces away from 4 single points of contact on the frame sounds like a good idea to me.
 
Not sure what you mean but I would doubt that the very small weight addition would even be noticed.

I'm thinking that those motors produce a lot of stress on the screws holding it in place. That's translated to the surrounding plastic as vibrations and torquing forces. To me, and this is only my opinion, having a sturdier support for those screws would be a big plus. Spreading the vibrations and torquing forces away from 4 single points of contact on the frame sounds like a good idea to me.

I purchased the kit a few weeks ago and returned them because I could not get one of the arm brackets to mount correctly, screw kept spinning.

I received my refund and to my surprise, days later a package from them. Another set, but this one at no cost...I thought...Amazing! Great customer service!

So time permitting, Im happy to report this set fits. Only time will tell or the next time I take off brackets and see what lies beneath if it truly works.

Things I noticed: The arms feel stronger more secured. You don't hear or feel the creaking plastic movement sound(if that makes sense). There is no change in birds flight characteristics with them on-I flew with them on this morning... 7000 plus ft...

I also notice in flight hover the phantom doesn't wobble or shake as much as it did without them on.

and for the most part, I get a piece mind...

ImageUploadedByPhantomPilots1438630296.817778.jpg


I want to thank Uavbits for sending me the free kit.
 
I purchased the kit a few weeks ago and returned them because I could not get one of the arm brackets to mount correctly, screw kept spinning.

I received my refund and to my surprise, days later a package from them. Another set, but this one at no cost...I thought...Amazing! Great customer service!

So time permitting, Im happy to report this set fits. Only time will tell or the next time I take off brackets and see what lies beneath if it truly works.

Things I noticed: The arms feel stronger more secured. You don't hear or feel the creaking plastic movement sound(if that makes sense). There is no change in birds flight characteristics with them on-I flew with them on this morning... 7000 plus ft...

I also notice in flight hover the phantom doesn't wobble or shake as much as it did without them on.

and for the most part, I get a piece mind...

View attachment 26456

I want to thank Uavbits for sending me the free kit.

I suspect they would be tickled to death if you would consider paying for them if you really like them, but are probably just glad you gave them another shot and verified they work. :)
 
  • Like
Reactions: Bigdz
I put mine on and they seem to fit well and make it feel much sturdier. To one of the posters above yes the 4 screws go through and directly into the motor. Ive had a few flights with them on and flies great with no issues. I actually sanded down my kit to make them all smooth and then painted them a silver aluminum color to match my stripes on my p3a. Ill attach a few pics to show them installed and before and after sanding and painting. They look much better than the zip ties I had on there.
20150805_204140.jpg
20150803_192601.jpg
20150804_093536.jpg
 
I have a set and like them a lot. I got a little nutty filling cracks with super glue during the install so they are now a permanent addition:). Not really an issue as the only reason to remove them would most likely to replace the shell. I have a lot more confidence with them on.
 
I have a set and like them a lot. I got a little nutty filling cracks with super glue during the install so they are now a permanent addition:). Not really an issue as the only reason to remove them would most likely to replace the shell. I have a lot more confidence with them on.
Are you going to be able to remove them because motors actually do go bad
 

Members online

No members online now.

Forum statistics

Threads
143,066
Messages
1,467,354
Members
104,933
Latest member
mactechnic