Hi Everyone,

I saw some posts that I cannot re-use my old screws on a re-installed propeller on my drone without applying a Loctite.

Quick question, how important is the Loctite, and How risky it is to fly without it on re-used screws

Thanks,
Jann

I would not risk using the screws without the Loctite. The original Loctite blue is a bit pricey here, but it is still nothing compared to the price of the drone

Why not thread locker is readily available.

Maybe I have been lucky but I have never use that unapproved substance with my props. Just saying...

GaryDoug Posted at 4-9 20:41
Maybe I have been lucky but I have never use that unapproved substance with my props. Just saying...

As far as I know that is the exact thing on the new screws!  So you recon it is something else, not the Loctite Blue threadlocker?

The thread lock is needed but its a non issue as the new props come with new screws with the thread lock pre applied.

CemAygun Posted at 4-9 22:27
As far as I know that is the exact thing on the new screws!  So you recon it is something else, not the Loctite Blue threadlocker?

Use the new screws.  Blue locktite will degrade plastic if it comes in contact with it.

Rob

DAFlys Posted at 4-10 00:06
The thread lock is needed but its a non issue as the new props come with new screws with the thread lock pre applied.

So, just for my peace of mind. You are saying that if I require to change my props with the spares supplied in the FMC, the screws already have the loctite on the threads?

You can reuse screws if the thread is fine, just apply a little dot of strong threadlocker, like the liqui moly or the loctite ones.

The thing is that each blade comes with a new screw, so there's no point in reusing them, but you can save the old ones for spares if you want.

Why the threadlocker is important?

Because small screws like the prop ones doesn't support a lot of torque when they are screwed, so they end up unscrewing themselves when vibration and centrifugal force is applied. So for small screws like the prop ones, no thread locker means a high chance of loosing props while flying.

I always check that the 8 screws are tightened before flying (just a little check with the screwdriver without aplying force).

New props from DJI come with screws that have the thread lock already on it.  The threadlock ensures that the screw doesn't vibrate loose.  

CemAygun Posted at 4-9 22:27
As far as I know that is the exact thing on the new screws!  So you recon it is something else, not the Loctite Blue threadlocker?

He doesn't use it because he doesn't know what it is!
It is pre-applied to the prop screws I have seen.
Loc-tite is only a brand for a thread locking chemical. One can find other brands that are less expensive.
When in doubt Blue thread locker is perfectly acceptable.

TP-FPV Posted at 4-10 04:52
He doesn't use it because he doesn't know what it is!
It is pre-applied to the prop screws I have seen.
Loc-tite is only a brand for a thread locking chemical. One can find other brands that are less expensive.

I know exactly what Loctite is and have used both types on automotive and marine engines when needed. I just have never used the new screws and never applied new threadsealer to my drones. If you want to use it, ok, but know that putting it on screws for props that turn counter-clockwise is not needed or desirable.

DowntownRDB Posted at 4-10 04:34
New props from DJI come with screws that have the thread lock already on it.  The threadlock ensures that the screw doesn't vibrate loose.

That's good to know!

Just slightly away from the main thought for a second, I have used Loctite on a four foot helicopter because the first time I Removed and Replaced the screws for the blades, I revved it up to test it,
then shut it down,  on inspection, I found them to be loosening, I applied the Blue stuff, and they held till I gave the ship away years later.  Yes, true - the new props DO come with their own screws,
as someone said, why not use them and keep the old ones for if you ever need one.

yogi053 Posted at 4-10 03:20
So, just for my peace of mind. You are saying that if I require to change my props with the spares supplied in the FMC, the screws already have the loctite on the threads?

Yes thats right.   the come pre applied.

DAFlys Posted at 4-11 02:09
Yes thats right.   the come pre applied.

Thank you DAFlys!

yogi053 Posted at 4-11 02:14
Thank you DAFlys!

You're very welcome.

I just felt like I should throw a word of caution into this Loctite discussion.
Yes, the new screws have the proper amount and "formula" on them so if the screws are replaced with the props, no worries.
There are a few different colors/grades of Loctite and are used for different fastening scenarios and if the wrong color/grade is used, the threads can be damaged.
Red Loctite is designed for things that are not removed like a bearing race, etc. It requires heat to remove....NG for the delicate things like on the drone
Blue is the standard "removable" formula but that can be a problem when using on aluminum and the old stuff must be removed before re-applying.
There is a Purple color that is a lighter duty formula specially made for aluminum/softer metals but again, careful and proper use is key. More is not better for any of them.
So, I guess I was just looking to warn of the "willy-nilly" use of Loctite

JMB63, thanks for that, I forgot.

The substance on the screws is not loctite, it’s a type of patch lock which goes under different names such as torqlok, nylok and others.
It is a nylon based product that creates a friction fit it, is not an adhesive.
Once applied the screw can be reused with acceptable holding/vibration resistance but since you get new screws use them.

Loctite, mentioned in this thread, is anaerobic adhesive so you will have to wait for it to set, it will also stay a liquid in air so it will wick and get in places you don’t want it to get into.

To be honest, the mistake I did is I bought and installed something like the below on my drone (motor covers).


And upon reviewing it before I start flying once again, I saw a post here that it's not recommended as it may create heat upon covering the motors. the same thing is I used the same propeller that I removed (because it's still new) but basically the Loctite on it was already removed.

So most probably I'll just use the supplied new propellers with the new screws packed with it to be on the safe side

JannEarlTV Posted at 4-11 16:09
To be honest, the mistake I did is I bought and installed something like the below on my drone (motor covers).
https://img.sunsky-online.com/upload/store/product_l/EDA00992101A.jpg[/img]

The covers can help keep foreign particles out of the motors but at the expense of less cooling. If it is hot where you fly, I would leave them off. Otherwise keep them on. I will not use any thead-locker on my drones because particles of it can fall into the near-microscopic spaces between the motor's moving parts on removal or installation. I always hold the drone upside down when removing new prop screws to lessen that possibility. Some of these drones can still fly (poorly) with a prop missing but they will not fly with one motor jammed