Is there a reason for using these non harden, pot metal screws that are more decor than functional. The machine shop that tap and die/removed the original one noted that the screw was very soft and not meant for this use. Said the inconsistency of the material wouldn’t allow it to have a consistant tensile strength or rotational capacity test. Just letting them know that if they say it is suppose to be a certain grade that it couldn’t be graded. I realize my warranty is void since I broke the seal. But I feel in the current situation with the popularity of the Inspire 1 and the all the troubles of this growth hitting DJI at one time that the turn around time and availability of parts make this the best decision. To be honest I haven’t heard of any people talking about things that have been covered by the warranty? I am a huge fan of DJI and will continue, but thought that this information might be valuable. I am planning on having the second one drilled out and replaced. Might just replace the rest to elimanate this problem.

                  

Thank's for sharing , I  will take your advise as regular inspection point.

What is the actual size of these if we need to get spares from other sources ?

GB44 Posted at 2015-3-9 03:29
What is the actual size of these if we need to get spares from other sources ?

I will find out Monday from the machine shop. The first one I replaced had to be drilled out and retreaded one size larger. I will find a replacement for the original that is hardened and post the link.

Just HOW tight did you try and torque these little screws?
I have tightened mine pretty tight but not enough to sheer the head or thread!

I knew people would think I wrenched them but I PROMISE not that tight. But I did go over it every two weeks to tighten any loose screws due to vibration. My old Phantom taught me that lesson and some of the screws do loosen after a lot of fly time.

skip@interactiv Posted at 2015-3-9 04:46
I knew people would think I wrenched them but I PROMISE not that tight. But I did go over it every t ...

That's what threadlock is for
The blue is not too aggressive and saves having to re toque everything periodically.
The problem with these small hex head screws is that every time they are loosened/tightened the thread stretches slightly and ultimately they will fail (as you have discovered). Best to torque them once with loctite and then forget them.

markjacobs.talk Posted at 2015-3-9 04:31
Just HOW tight did you try and torque these little screws?
I have tightened mine pretty tight but no ...

I wasn't tightening the second one it was just gone but broken off right where it goes into the other piece. And it is the quality of the screw that concerns me. I have never crashed mine or even broken a blade. I do put tons of hours on it... I have flown it over 1,612,764 ft. or 305 miles.

OK, I will keep a close watch on mine. I do go over my airframes regularly in any case as part of my general maintenance.
You have me paranoid now that one of mine will sheer

markjacobs.talk Posted at 2015-3-9 04:54
That's what threadlock is for
The blue is not too aggressive and saves having to re toque everyt ...

I am a little hesitant on threadlock since I used it on my Phantom after a motor upgrade and found out the next day it ate threw the plastic and I had to replace the entire shell.

Be very careful using threadlocker on or near plastics.
The anaerobic compound softens plastics.
While these screws thread into bushings molded in the plastic, any excess liquid could wick out onto the plastic.
DJI pre-applies a dried blue thread locker to many screws to provide a good grip, but not endanger plastic.
The stuff seems to only be available in bulk...

Thanks..... I'm well aware of what threadlock can do to some plastics. Whenever I apply to this kind of situation it's always via toothpick to the end of the thread to prevent wicking.
Another alternative if people are nervous about using threadlock for this kind of situation is some PTFE tape. It's just got to be enough to prevent the screw turning under vibration.

These fasteners look very similar to some polished aluminum screws I used to deal with a lot.  The beveled hex heads.  I only ever saw them in aluminum or Stainless Steel, and I doubt the head would break off of a stainless one.  Anyone know if they are indeed aluminum or steel?

Has anyone tried the solid blue threadlike compound to see if it has less affect on the plastic? Same material and vendor, presumably without the liquid solvent...

and speaking of stripped screws...the genius from DJI who worked on my PT2V+ tightened one down so tight it spins now and is most likely stripped...any ideas on how to extract it??

dbeck@promobox. Posted at 2015-3-9 13:56
and speaking of stripped screws...the genius from DJI who worked on my PT2V+ tightened one down so t ...

Couple of ways depending on the size. An "easy out" if it breaks of flush and no way to grab. It is a drill bit  type device that goes in but has barbs so it will not unscrew. That is how you back it out. Or if it s to small I would take it to a machine shop that has the equipment to tap and die it.

Thanks.  Seen them. I know what this guy did.  He over tightened it and now its spinning in the 'nut' thats holding it in the plastic inside the arm.  I can get the 2mm driver on it but it just spins...ughghghggh