Will J hooks work as booms and landing gear?

The humble J hook 

A couple days ago, my dad challenged me to replace the poplar booms and standard FT landing gear with J hooks. This was mostly because he didn't want to get more landing gear after he broke one.

So, excited by trying something new and curious to see if it would work, we went to ACE to pick up some J hooks

We chose to use 2 inch hooks as they had similar height to the original gear, and didn't seem too bulky. Since we were curious as to what weight gain or loss would occur, we decided to weigh them.

As you can tell by the images, there would be no loss or gain in weight because of this modifacation. So, we had the parts, we just needed to prepare them and install them.

I began by pulling all the motors and escs off the arms and took the arms off.

I then removed the nails that come with the J hooks by simply pulling them out.

Next, since the J hooks were slightly over 1/2 inch tall, I ground them down slightly on the beltsander after marking them using one of the old booms.

That left me with this:

Next, I marked out and drilled the holes for the booms to mount to the electrohub, and promptly mounted one. After I was satisfied with the fit, I mounted the other three.

The next step was to drill the holes to mount the motors, as the screws I had were too small to use with both the booms and the old motor mounts.

As is evident by the extra hole, I need to learn to drill in the right spot the first time!

After doing that to the other three booms, the quad is complete and ready to test!

Now, at this part, I forgot to grab the camera and document what happened, but needless to say, it wasn't pretty.

Well what happened?!? If you take a closer look...

You see that break occured right where there was little support from the frame, the boom was thinned, and there was a factory drilled hole. 

This was extremely discouraging, and drove home a point I made to my dad early on in the challenge, and that is that we should use thinner, more solid J hooks that can flex less and arn't of I beam construction if you want to make it work. An example of such a thing: 

Sadly, I have actually tested these other kinds of J hooks, and forgot to get a record of what and how I did it. What I ended up doing is taking these hooks and using them to replace the broken style of hook. When tested on my dad's quadcopter, they STILL ended up breaking. However, that was after an 11 foot drop straight out of the sky due to electric faliure. So, we decided to give it one more go. Finally, SUCESS! The J hooks we ended up using have a special feature where the hook can actually rotate around the main shaft. This, in turn with a unibody construction, has finally given us the strength and give needed to be used on our multicopter.

To anyone interested in trying this, make sure that you get unibody hooks, and not I beam, as I beam hooks become weak when you drill into them. As well, when you do drill, make sure you drill in the right spot the first time, and perpindicular to the shaft of the hook. This will ensure better fitting, and will make it so you dont have to drill more holes, which only further weaken the hooks. And finally, be prepared to spend some time making sure you have the right hooks and that they are mounted properly and strongly.

I hope you enjoyed the article, and than you for reading!