Changing out an EDF motor & fan

[Hernthehunter]

Just tried taking a fan and motor out of an 50mm edf and fractured the fan and housing. How do you safely remove the motor and fan from an EDF? What tools do you use? I was thinking, in the future, of removing my 64mm EDF motor for an upgrade to my foam jet at some point too. Thanks for all your help

GOOD FLYING!!

[E-Challenged]

I'm no expert but it would be wise to make EDF units removable during the assembly stage if possible. For example, when assembling a GWS ME-262 make hinged clamshell doors in the nacelles and tack glue ducted fan units in place so that they can be easily removed to make acccess and removal of fans, hubs and motors easy when needed.

[PerlAddict]

Hern, are you talking about removing the whole assembly, or taking apart the actual EDF assembly itself? I'm going to assume you mean the latter. It depends on the fan setup sometimes, but generally the rotor is held onto the motor by screw that goes through the center of the rotor and screws into a rotor plug (a little metal cylinder with a threaded hole in one end and a smooth hole in the other end, typically). The rotor plug itself is held to the motor shaft by loctite and/or a grub screw(s).

Getting the whole thing apart usually involves a lot of swearing and crying for me, and a healthy amount of patience and elbow grease. First I take out the rotor screw (with some fans, there will be a domed-cap over the center of the rotor that hides the screw. Those are usually just glued on and can be popped off with your fingernails or a small screwdriver). After that, the rotor may or may not come off depending on whether it was actually glued to the rotor plug along with being screwed in, as well. If it was glued, your best bet is usually just to get your fingers around the center of the rotor (as opposed to the outer part of the blades themselves ... they'll bend too much and be rather hard on your fingers if you don't get your fingertips up under the center of the rotor), and then start pulling and twisting. It takes some effort, but eventually it ought to come off. Emphasis on the "ought to." I've had a couple before I just gave up on for a while, but I eventually did get them to let go.

Once that is off, you'll need to see if the hole in the fan housing that the motor shaft sticks through is big enough for the rotor plug to go through. If it is, then just unscrew the motor from the fan housing and slip the whole thing out. If it's not, then you'll need to get the rotor plug off. If any grubs screws are in the rotor plug, use an allen wrench to get them out and see if the plug slides off. If it does, you're golden. If it doesn't, it's probably loctited in place, which means more crying and swearing. I've grabbed the plug with a pair of vice grips before and just tugged and wiggled it until it eventually came loose, but you have to be careful not to put too much pressure on it as you wiggle around - you don't want to break the fan housing where the motor screws onto it, and you definitely don't want to bend the motor shaft. Sometimes you can get a piece of thick piano wire down inside the rotor plug from the threaded side you removed the screw from. Then you can tap it with a hammer so that the wire is hitting against the top of the motor shaft, and it will slowly push the motor (and EDF housing that the motor is screwed onto) out from the rotor plug, which you can then wiggle free more easily. The problem there is finding a way to hold the rotor plug steady while you're tapping at that piece of wire.

All in all, it's usually a heck of a lot easier to get an EDF assembly put together than taken back apart. Time, patience, and making sure you don't use too much force when things are glued/loctited together are the big factors.

[tarheal63]

I can sympathize with PERLS statement, I broke 2 rotors trying to get them off of my GWS A-10s 55 mm. I think they were glued on at the factory. I did see in one post on a forum which shall not be named here about a guy who use 2 paint can openers and slipped them in the duct to hit below the impeller hub and worked them off that way.