CAUTION: Before actually mounting propellers make sure to test the motor operation to assure they run in the correct direction, else swap two leads on the specific motor to reverse its rotation direction until all match the picture. Wait with installing propellers until you see that the IMU and transmitter calibration look ok. Once propellers are in place they represent powerful aviation stuff that can accomplish considerable lifting force, so unless you have everything looking right prior to propeller install, then motors running havoc in an unintended way could hurt both you, the ArduCopter and others. So take care and double-check your setup prior to running with propellers.
Propellers come as pairs in two sealed plastic bags. One pair is intended for running clockwise (front/rear) while the other pair backwards (left/right). Make sure you install them as shown in the following picture (the + orientation shown. Same rotation direction principle applies for X orientation as well) :
By rotating them in the shown direction make sure they are oriented to drive air downwards. Once you come as far as arming motors and applying some throttle, then double check rotation directions before attempting flight.
How to mount propellers on each motor axle:
The washer shall go into that hub recess.
You place it on top, then press it into the opening....
And here is how it looks with the spacer in place.
Now install the axle using both aluminium parts.
Propeller with the mount ready to go onto the motor axle.
This type of 2mm shaft screwdriver proved handy for tightening the nut
* Put a small drop of locktite into the nut and start it onto the thread.
* Consider also to put some locktite onto the motor axle but make sure it does not leak down to the bearings.
* Position the prop adapter with prop onto the axle and carefully tighten the nut. Don;t use a very long-armed wrench. These aluminum thread's don;t like too much force. In addition excessive force can also negatively impact the strength of these EPP prop hubs. The adapter has to tighten onto the axle so that it sits tightly and the prop cannot turn on the axle. If the nut is also a spinner, that's all. If it is a normal nut and there is room, then consider adding a 2nd nut and tightening that onto the first. This provides additional security against the nut working itself loose in flight.
A great replacement part:
I had a crash yesterday from a propeller coming lose mid-flight and I was hoping someone here could help me with some tips to avoid another scenario like this. Luckily I was over grass so I only lost a couple of props. I have a 3DR frame with the 850 kV motors and 10x45 EPP props. I install the props pretty much like shown here but I have been using a paperclip to tighten the spinner on the shaft. Maybe this doesn't provide enough force. As the picture below shows, the threaded shaft which goes on the motor shaft was bent at the point where it grabs on to the motor shaft. There was medium wind when I was flying so it may be possible I was putting a lot of strain on the props. But I still think it's odd that this happened and made me think it wasn't just from the fact that I didn't tighten it enough. It seems like it would take a lot of force to do this. Also, I haven't wanted to use loc-tite yet because I am still making a lot of PID adjustments and I want to be able to take off the props easily for testing and transportation. Anyone have any ideas why this may have happened and any tips as to what I can do to avoid it from reocurring?
That spread joint looks like a result of the crash. Do not try to re-use this particular axle as this joint could break in flight. Paperclip is way too soft for tightening. You need one of those japanese screwdrivers that come in cheap sets, the size that just about fit in the hole of the nut. But not so tight that you strip threads or worse.
Another important ingredient is locking fluid such as Permatex or Loctite ThreadLocker, the Blue variant.
That prevents the joints from unscrewing. When mounting this way where the mount tries to hold on solely to the smooth surface of the chromed motor axle it needs both a tight fit and some help from the threadlock fluid. There seems to exist propeller mounts that also screw into the additional threads on top of the "outrunner" motor housing and that would add additional safety I guess. I am surprised that is not the standard application. Grabbing smooth motor axles this way may not be the safest solution seen so I will look at other ways myself. Some in the community here may have expertise on this as well as on the ultimate thread locker fluid usage recipe.
If you use loctite can you still remove the propellers at the end of a day of flying? Or do you just normally keep the props on there and just remove them when you are doing maintenance?
A couple of people seem to be having problems with prop adapters coming loose. Here is one way to prevent this that has worked for me for many years.
In the US, Loctite sells a "Green" formula retaining compound similar to their Blue & Red thread lockers. Green is intended for securing pinions and such on smooth surfaces like shafts. Loctite formula #603 and #609 will both work. You can get it at McMaster-Carr online or at most local industrial supply houses. A 10ml bottle is about US$13 and will last you a lifetime if you store it in the freezer. If you are outside the US, look for a "retaining compound for close fitting parts" rather than "thread locker". With the exception of #641, which I do not recommend for this application, Green is intended to be permanent.
Before you attach the adapters, turn the copter upside down to prevent the Loctite from contaminating and freezing the motor shaft at the bearing which will render the motor useless. And be careful not to use too much Loctite or it will wick into the motor, even upside down! 'nuff said...
Motors tend to have an oily film on their shafts which makes the retention problem worse. So first you must clean everything with isopropyl alcohol to remove any contaminants from manufacturing. This includes the motor shaft, collet, adapter threads, and spinner nut. Then put a very thin film of Loctite Green on the end 10mm (3/8") of of the shaft, and also a tiny bit in the collet. Insert the collet on the shaft as far as it will go and immediately wipe away any excess Loctite from the shaft with a soft cloth. Then quickly mount the prop, put a small amount of Medium Strength thread locker like Loctite Blue #242 (NOT Loctite Red!) on the top 6mm (1/4") of the threads, and tighten the spinner nut with a hardened metal rod through the tightening holes in the spinner. A miniature screwdriver works well. It needs to be firmly tight, so don't use a paper clip, nail or other soft tool. Don't over tighten or you may deform the prop, strip the threads, or fracture the shaft leading to an in-flight failure.
You need to get everything tight before the Loctite sets up, say 5 minutes or less, so mount the prop quickly since it's the spinner nut & prop bearing on the collet washer that tightens the collet on the shaft. Then let it all sit for an hour before you turn the copter back over, and don't fly for at least 24 hours to alllow it to cure.
If you need to replace a prop, the spinner will come off without any trouble as long as you used Medium Strength thread locker. If you need to remove the prop adapter from the motor shaft you will probably have to sacrifice the adapter since Loctite Green is not intended to allow removal, and the usual way to get it off - heat - is definitely not recommended this close to the motor windings.
after dealing with a broken prop at the field. i found out that when using the supplied props you end up with one dia of thread engagement. when using apc props you have 2 dia's which is better. went to my local hobby store and got a E-flight adapter. after putting it on its real nice. sits down on the motor farther, has more thread and has a built in raised section so you dont have to use the spacers. im converting the other 3 soon.