Goodbye shell cracks !

bernek · Jun 1, 2016

I was a little upset because one of the arms had developed a few minor cracks between the motor and the surrounding mounting holes. Bought some Bison Universal Epoxy and reinforced the motor arms

I think this will never fail ... maybe the arms will break from other points but between the motors and the surrounding holes not a chance

Here are some pics:

I also used some nail paint on the screws to make sure they wont drop. I was afraid before to tighten them because of these annoying cracks but I think now the problem is fixed.

Valkster · Jun 1, 2016

bernek said:
I was a little upset because one of the arms had developed a few minor cracks between the motor and the surrounding mounting holes. Bought some Bison Universal Epoxy and reinforced the motor arms

I think this will never fail ... maybe the arms will break from other points but between the motors and the surrounding holes not a chance

Here are some pics:

I also used some nail paint on the screws to make sure they wont drop. I was afraid before to tighten them because of these annoying cracks but I think now the problem is fixed.

Was it hard to split the shell? I have a crack on my P3 Advanced and my Standard and would like to try stopping any further cracking.

Prairie Pyro · Jun 1, 2016

bernek said:
I was a little upset because one of the arms had developed a few minor cracks between the motor and the surrounding mounting holes. Bought some Bison Universal Epoxy and reinforced the motor arms

I think this will never fail ... maybe the arms will break from other points but between the motors and the surrounding holes not a chance

Here are some pics:

I also used some nail paint on the screws to make sure they wont drop. I was afraid before to tighten them because of these annoying cracks but I think now the problem is fixed.

What is the age of the AC? I know there is some reinforcing plates available and would rather head off the problem than try fix it.

bernek · Jun 2, 2016

Valkster said:
Was it hard to split the shell? I have a crack on my P3 Advanced and my Standard and would like to try stopping any further cracking.

If by split you mean taking it apart it was very easy you only have to remove a few screws and put them back. English is not my native so I had to ask

I just wanted to show you guys what I did to prevent a motor loss or a crash because of these cracks. I think they will stop appearing and even if they do the whole assembly is much stronger now !

bernek · Jun 2, 2016

Prairie Pyro said:
What is the age of the AC? I know there is some reinforcing plates available and would rather head off the problem than try fix it.

I bought it with maybe 20 flights on it and 1 single crash that only showed some scratches. I applied maybe 30-40 flights on it after I've seen the first small cracks. These are only assumptions and estimates based on history tabs from app and the charge cycles on the battery I received it with. I would say its still in quite condition and flies really good since its a 2-3 year old machine with around 50-60 flights on it (maybe more).

I will further check for cracks but at least for now I know that I won't have an engine taking off in a different direction

My future plan is to change the motors to 2312 from the older ones I have and also upgrade the ESC to ver. 2.1 since the old ones won't support them (hence the reason I wasn't too careful spreading a little epoxy on them when I reinforced the shell).

Also those reinforcement plates in my opinion only distribute the stress on all screws but if you already have cracks the problem is only mildly being taken care of ... you can eventually end up with a motor with the plate in your hand

bernek · Jun 2, 2016

Valkster said:
Was it hard to split the shell? I have a crack on my P3 Advanced and my Standard and would like to try stopping any further cracking.

I'm sure you can find the US better glue and you should look for a two component epoxy based one. Few of the proprieties that I've found to be important are:

- plastic weld (make sure it will bond the Phantom plastic type)
- gap filling (this really helps it to enter all the existing gaps from inside out - like in my pics)
- higher resistance to external force (higher the rating better for the bonding)
- slow drying time (this will allow you with a screwdriver or something to even out and spread the glue and even remove parts from it after 20-30 minutes)

You can remove the top shell screws and only twist the upper shell and reseat it on the bottom one - you don't have to remove the gps cables and such.
Also you need to remove the motors to be able to spread epoxy evenly under them. (here make sure the axis location is glued but still allows shaft movements - you could check for any motor resistance spinning by hand before and after operation)

The epoxy based glue can be remove mechanically with sand paper (to even out any mistakes) and with a nail polish machine or small drill of some kind. Just make sure you don't block any motors while doing this ! even any small mechanical resistance can lead up to motor heating (even burning out) or severe flight time reduction since the motor is pulling much harder.

Where I have the ESCs you only have a few LEDs so it shouldn't be a problem if you epoxy them down

If you have any other questions for me just drop me a line

Prairie Pyro · Jun 2, 2016

I was thinking of using a UV activated bonding agent. It goes on depending the grade you get in a very liquid state and you hit it with UV light to set it. A bit more expensive but very easy to use and fast. Just scuff up the surface before application. The medical version of the stuff is used for gluing caps on teeth etc.

bernek · Jun 2, 2016

Prairie Pyro said:
I was thinking of using a UV activated bonding agent. It goes on depending the grade you get in a very liquid state and you hit it with UV light to set it. A bit more expensive but very easy to use and fast. Just scuff up the surface before application. The medical version of the stuff is used for gluing caps on teeth etc.

Sounds good I would like to test that myself but it's a little complicated now

Multicoptertec · Jun 2, 2016

Another option is to add removable prop guards. The guard kit I use has plates that attach to all 4 screw points for each motor, and lock the whole area together. You then have the option of flying with the guards if needed, they just snap on and off, but the plates stay put.

Prairie Pyro · Jun 2, 2016

aerialpix over at ebay has a set of carbon fiber motor mount reinforcement plates for $14.95

Prairie Pyro · Jun 2, 2016

bernek said:
it's a little complicated now

You've cemented in your choice

bernek · Jun 2, 2016

Multicoptertec said:
Another option is to add removable prop guards. The guard kit I use has plates that attach to all 4 screw points for each motor, and lock the whole area together. You then have the option of flying with the guards if needed, they just snap on and off, but the plates stay put.

I honestly think that fiberglass or epoxy or even uv adhesive is the "best" way to fix it. The guard kit it holding them together but if you have cracks already its not sure enough imho.

My solution is cheap and durable in time and you can see nothing on the outside. It might be complicated for some but I don't think there is a person that can't do this small repair.