For those of you who don't enjoy breaking your piggy bank to buy a propeller balancer (like me). This may be the instructable for you. This propeller balance device is used for reducing dangerous vibrations on an rc aircraft. It is most important on multirotors because not only does it get rid of the "jello effect" when filming, it can also greatly improve the way your multirotor flies by reducing the vibrations reaching the sensitive equipment on the flight controller. The construction of this device is very simple. It took me 10 minuets to complete after I had all necessary parts of course. In addition this was basically free for me, but if you do not have all the parts the cost would be super cheap.
****A 3-d printer is required for best results****
Step 1: Parts
Here are all the parts you will need.
1. a few pieces of erector set (pretty much anything will work my design is not the only useable design)
2. some all thread (make sure it will thread into your grommets and fit into the hole in your prop)
3. 2 grommets (I 3-d printed mine special for my all thread, but 3-d printing is not the only option)
4. 2 small neodymium magnets (other magnets may work depending on the weight of your prop)
Step 2: Assembling the frame
Get a couple pieces of erector set, assemble them similar to this. Also bend the arms sticking up outward a little bit, this helps reduce friction and makes it more simple to put together.
Step 3: Prepping your all thread
Cut a piece of all thread that is slightly smaller than the base of your frame. Sharpen the ends (I used a grinder to do this) Also the sharper they are the less friction your balancer will have, but the less weight it will hold. For most propellers this is not a problem.
Step 4: Grommets
As mentioned earlier I 3-d printed mine. If you do not have access to a 3-d printer... buying grommets may be your best option. When the print was complete I tapped the holes in the grommets to the appropriate thread. The stl file for printing is included in this instructable.
Step 5: Finishing up
Okay here is the hardest step ready? put the two magnets on the tips of the arms of the frame. When done thread a grommet on the all thread, then put a propeller on so the grommet is poking into the propeller hole. Put the other grommet on the same way, then suspend it all between the magnets by attaching one of the sharp points on the all thread to one magnet on an arm of the frame, then pull the other arm to the other point of the all thread.