3D Flyer

My Feedback: (37)

Just wanted to pass along an experience my son had
this weekend with his 3DX:

My son was doing some flying yesterday in about 30 degrees
when all of a sudden, during a roll, the gearbox and motor came flying
off of the motor mount! My son quickly cut the throttle and the motor was hanging on
by the wires attaching it to the speed controller. Fortuantely he landed safely having
only damaged a prop.

The analysis is that the epoxy holding the gearbox to the wooden motor mount got cold
and cracked off. I examined my 3DX and the SAME thing happened! The only difference was mine did not
come off in flight.

I am going to reglue but in addition, add a metal pin or a zip tie or something else to hold the motor
on for cold flying conditions.

patternjockey

My Feedback: (1)

Hi Eagle

Just curious, what epoxy did you use? What set up time? What Brand?

I am about to put together a Foamtana and was advised to use 30 minute for all glued area's.

Thanks

Dave

H.Dale

My Feedback: (3)

I did not glue my motor on. I put a screw through the motor mount with a nut on it. It makes it easy to change from one plane to another and it has not come off. BVM Aeropoxy works well for everthing else.

We have had problems with bending shafts on the gearbox, but solved that by cutting off the shaft and using another type of adapter.

I have been flying a 3DX about three weeks and I am still amazed at the performance of electrics. I normally fly 20 minute flights with a 3 cell li-poly battery.

Hal
3D wannna be

3D Flyer

My Feedback: (37)

I used a Hobby Town USA brand 5 min

3D Flyer

My Feedback: (37)

Could you please expand on this? I have a bent shaft too and want to know what
to do rahter than buy another $18 gear box (we are using the GWS 6.6:1 ratio D gearing setup) Right now its only slightly bent and I am flying with it.

Any info would be greatly appreciated. Thanks

crashingagain

shafts are only $1.79 at my lhs

As far as the motor mount goes, I drilled out the wood stick and roughed up the carbon fiber tube and epoxied it in, its not coming out. On the older 3dx plans the motor stick goes under the carbon tube, the new ones hve the tube in the center of the stick which is better. Also, dont use 5 minute epxoy on this, use 30 minute and it will give a stronger bond.

Now how do you keep that 3dx elevator from flexing?

extra 33OL

I had the same problem with the bent shafts... The GWS 3mm shaft is made of very soft material. The shaft normally bends on the threaded portion and the un-threaded shoulder remains straight. I solved the problem by cutting/discarding the threaded bent portion of the shaft and replacing it with a Graupner (part #1326) prop adapter. This adapter is made for a 2mm shaft so it has to be drilled to 3mm. (not sure if Graupner makes a 3mm prop adapter) The prop adapter is the correct size for the the apc 11-7 slowflyer prop so you dont need the prop shaft bushing either.

Use locktite to secure the prop adapter set screws in place.

works great and no more bent shafts.

whopper1

Guys, Guys, Guys, to end these motor dramas simply drill a small (and I mean small) hole through the gearbox where it mounts onto the motor stick (on the side), through the stick itself and through the carbon tube and simply screw a short servo mounting screw into the assembly. The motor will never fall off again but you can just unscrew it when you need to get the gearbox off. Much easier than trying to debond epoxy to remove it. Note I said a SMALL screw so that you don't weaken the motor mount which would surely mean that the nose could break off if you crash. But none of us ever crash do we?[sm=lol.gif]
An MP JET prop adapter is 3mm and will go straight on. Fits APC props but you'll need to carefully drill out the GWS hub to fit. At the field you can straighten the GWS shaft with care but it may take a little patience. (A mate of mine can usually do it first go, don't know how he manages that!!)
Hope this helps, Matt.

3D Flyer

My Feedback: (37)

Here is another tip ... I kept having the taped hindges come loose on the elevator
when I landed and it caught on something ... solved this problem by using low temp
hot glue gun. Now its stay on really well. Work nice for the servos too.

3D Flyer

My Feedback: (37)

I have also found that if your GWS prop shaft is not bent too badly you can just bend it back
and it works really well.

Xlogic

Hey Guys,

Whopper1 is correct, I use a small wood screw to keep mine on. To keep the shafts from bending I also use a 3mm prop adapter here is a photo.


Mike
http://www.ncrcf.org

H.Dale

My Feedback: (3)

Mike where did you get the 3mm prop adapter? I went to Hobby Lobby and all they have is 3.2mm. Will that work?

Hal

zagibond

My motor seems to be breaking the carbon rod away from the Depron. Then it torques up.
I used 5 minute epoxy on the whole plain. Should I have used a glue gun?
The epoxy actually seems a bit hard and brittle/
Any ideas?

Xlogic

I got it from Sal at Northeast Sailplane http://www.nesail-online.com/detail.php?productID=2207
NESail has them cheaper than Hobby Lobby.
Mike

Xlogic

I used Elmers Probond on mine, it seeps into the fanfold/depron like a sponge and grips carbon rods tightly.

Mike

3D Flyer

My Feedback: (37)

What are you guys doing to keep the control horns from poping off?
I used strapping tape and that seems to work well.
My son uses hot glue and he is always fixing his control horns
(but I guess it is less likely he will strip a servo gear)

3D Flyer

My Feedback: (37)

I saw another instance of the motor popping off this weekend on a 3DX! A friend of mine has a 3DX and I forgot to mention to him about the motor poping off and it happened to him. Unfortunately it was not very cold. It was probably about 59 degrees out. Sooooo ... it may just be that you need the screw, cold or warm weather.

Stanoo

Hmm on the control surfaces I use cut down zip tie just drill a hole for the pushrod the same size as the wire take an exacto put a small cut on the hinge line just aft of the bevel expoy top and bottom where it sticks thru works great never had one come lose in about 10 planes.

Tape don't use it pain in the butt I have been useing 3.5 floppy disk cut down to small squares like a ca hinges (ca hinge work well too little stiff) but cut down the floppy disk material (the round disk inside ) get some foam safe ca and usem like ca hinges fast and simple work awsome I have had some come loose after a crash but a little glue and you ready to go again. also you can double bevel the control surface for extreme throws.

Another thing I have started doing is useing a soildering iron with the tip cut down and a metal ruler the iron has a lip and I use the ruler as a guide too meltin the carbon tube slots very fast but don't slip the iron goes thru the depron like butter.




THis last pic is the floppy hinges hard to see but theres only 2 perside I have to use activator on the foam safe ca I have or wait forever

patternflyer1

My Feedback: (11)

I have used a screw on the gearbox, 30 minute epoxy on the rod to motor block. and 30 minute on mpjett micro control horns. All on Depron though, with absolutely nothing losening up. Also used regular pin hinges on all surfaces with regular bevels and 30 minute epoxy. Everything is still very tight and holding through all of the abuse i put it through.