Help! I have custom carbon blades for my Yuneec Q500 4K. But today, I flew about 35 minutes and I can’t remove both left blades anymore. They are stuck. I thought waiting an hour would fix it in case the metal augmented volume from heating but it doesn’t help. They were a bit grumpy to screw in and since the flight they are virtually impossible to remove, no matter if I use the plastic pinch or not. The plastic pinch bends and the rotor skids under its grip as well as under my hand. What’s a better system to keep the rotor in place so I can actually unmount the blades for transportation?
Sounds like the props are tightening down due to how the direction the shaft rotation and the propeller and motor shaft threads interact with each other. (I’m no guru here, especially for the set-up you describe - just voicing a possible solution).
In the metal-crafting world it is sometimes necessary to put a solid round shaft into a solid ring which has a slightly smaller inside diameter hole in it to form what’s called an “interference fit” (the shaft is meant to be in there very tight, but not rotate inside the ring when in use). To do this the shaft is dipped in liquid oxygen or liquid nitrogen to shrink its outside diameter sufficiently to insert it into the hole. The two are then allowed to stabilize back to room temperature and, wha-whooo, they are tightly joined.
You could try reversing this process with your props and their associated motor shafts. Metal has a higher coefficient of temperature change than does carbon, so what I suggest is possibly rapidly cooling the tip of the rotor shaft with something like liquid oxygen or liquid nitrogen, then using whatever prop removal tool came with your kit to remove the prop normally.
Where do you get such an item that could cool the prop shaft tip like that? Try a drug store! Look for a wart remover kit that has a small canister of pressurized air in it and a small fibrous applicator tip that attaches to the can. Set that up and then try discharging some of the contents of the can while holding that tip against the end of the rotor shaft for a few seconds.
Who knows… it may work!
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@Toohightofly @Jerald_Thompson
Hi
I don’t know which country you are in but if the UK, Screwfix sell a freezing kit for water pipes. It’s aerosol has very effective ‘freezing’ effect.
No doubt other plumbing supply shops have similar products
Cheers
Steve 
I looked online and some people in the same situation had some success hacking off the blades, unscrew the blades head with thick metal pinches and then redo the whole shaft with a tap and die toolkit. I’d rather avoid that, given the price of carbon blades.
Now is the next day, the drone is at room temperature and the blades still won’t budge. I think the carbon and metal melted together when the metal heated during yesterday’s flights. So I’m not sure an unfreeze kit would help.
The blade manufacturer recommended me to drop in some WD40 or metal cleaner product (the blades have a hole on top) but I don’t want it to leak in the engines. I might try that later tho.
Hi
I would not worry about a bit of WD40 getting into the motors you can mop up any excess with absorbant cloth.
Concentrate on getting the props of first then assess and address any secondary damage later
Cheers
Steve 
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Sorry to come across this way, but you should NEVER EVER use LOX (liquid oxygen) for anything but allowing it to form a gas and then allow it to mix with the air around you and then breathing it.
LIN (liquid nitrogen), unless you’ve been trained in the safe use of LIN, NEVER try using it, it can and will kill you if used incorrectly!
The easiest way to remove a ‘circle’ from a shaft is to utilise the ‘donut effect’ and warm/heat the ring and it will increase in diameter to allow removal.
Mark.
Daft question possibly but,
are you trying to remove the prop in the correct direction, (sorry, but it has to be asked), as they appear to be self tightening props.
Doyou have a phpicture of the prop/adaptor as it could help with a possible solution to removing the props (bth fitted and not fitted would be best).
Mak.
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I don’t know where my reply is gone, but anyway WD40 did the trick, took a few days / several flights to sink in tho. No harm done
Liquid oxygen (LOX) and liquid nitrogen (LIN) ARE hazardous items, to be sure, and any container they are sold in is (at least in the U.S.A.) required to have printed precautionary instructions as to the proper steps to follow when using the product. The kit to which I referred is designed to cool an porous applicator tip that is first attached to the aerosol can, and the amount of compressed gas that is actually used is so miniscule that the only precautions one has to take with it is to keep it away from flames and don’t allow the compressed gas to touch flesh (only the applicator tip should come in contact with the skin). Whats more, I found that I had mis-identified the contents of the can itself - it is neither LOX or LIN but is, instead, dimethyl ether and propane - a MUCH more dangerous aerosol than either LOX or LIN. This kit is FDA-approved for use in well-ventilated areas but requires no special training or certifications for use.
One precaution that it DOES mention is one which I believe applies to most any situation we adults often find ourselves in, but one which we should ALWAYS keep in mind:
KEEP AWAY FROM CHILDREN! (those little rascals are just too darn fast for us old codgers!)
Helli toohightofly
I had this problem yesterday. But being a stubborn person. I would not do anything till I had it fixed. I notice you used wd40. I have some. Not only do I have some but wd40 for elelictronics… Yes they make it. I ended up using a thick shoe string and a pair of channel lock pliers. The prop came off and no harm to the motor. 6