A go at a Foamie

The folding props I ordered have just arrived.
I seem to remember Q shortening the prop shaft but I cannot find the post at the moment.
There is about 8mm gap between the back of the prop spinner & the motor. Is it necessary or advisable to cut it back? The only reason I can think for doing it is to avoid the prop wallowing on the end of the shaft & causing vibration or bending the shaft.
The distance from the motor mounting face to the tip of the spiiner is about 50mm.
 
 

I did cut the motor shaft.
I do not like the prop running so far ahead of the front motor bearing or that the motor mount is only glued to the fuselage foam.
I arranged the length of the motor cowling and shortened the motor shaft such that the folding prop driver was up against the front of the motor.
 
The flat on the motor shaft will be in the wrong place for the prop driver grub screws but they still hold plenty firm enough for such a low power installation.
Just do not over tighten the grub screws as they are only threaded through plastic!
You can remove those big screws on the motor. They do not hold the motor onto the shaft. They are to hold a prop on using O rings to allow it to knock off.


Very true about weight. My FX707 at 320g ready to go is a lighter conversion than any I have found on web sites and You Tube! 
  

It definitely sounds like a good idea to shorten the shaft.
To paraphrase Klippy, having the prop so far away on the shaft reminds me of Baby Poo off a stick.
How did you cut the shaft? Grinder or hacksaw? Is it hardened?

My props have a collet clamping them on with a screw tightened up from the tip so the flat isn't used.
I'd assumed the big screws were for a spinner so they aren't needed.

Does the flat motor mounting plate glue onto the foam securely enough? Would threaded inserts (such as from ModelFixings)  glued into the foam be an advantage?
 

I have just added up my weights, it totals 367g.
The model out of the box weighs 210g (less its balls).
Fuselage 66
Canopy 5
Wings 80
Tail 21
Fin 6
CF 16
Fixings 16
Battery 67
Prop 18
6 Servos 24.6
ESC & Motor 40
Tx 7
Total 366.6

How do you get to six servos?
Even my flapped XF707 with 5 servos only weighs 340g. 

I printed a motor mounting plate. It had two parts so the nuts were enclosed and permanently retained but it does allow the motor to be removed. 
 
 
 
Note the mount has to be about 3mm thick to give clearance for the rear of the motor shaft. 
The smooth flat rear surface of the motor mount gave plenty of glue area. After cutting off the fuselage nose the foam surface was pretty "open" giving the glue something to grip to. 

Six will cover all the options, all six may not be fitted but they are for:
Rudder, Tail, 2 x Aileron, 2 x flaps.
Where did you save one on your flapper?

Cutting off its nose is the next big one. Getting it square vertically & horizontaly!
 

That's even more difficult!
With the nose's curved shape an ordinary mitre block is no good, I intend to make a longer trough shaped jig out of some 4x1 & 3x1.
If I cut the nose off square I can put washers under the motor fixing screws, it'll be as accurate as sawing off-square in two dimensions.

As a hand launched glider with modest power I agree to some down thrust (big wing gliders are particularly sensitive to changes in thrust level) but with a long tail, generous fin area and low motor torque side thrust is unlikely to be needed.

As a belly lander with limited wing tip ground clearance my advice to avoid a serious ground loop is a "glide" approach & touch down, wings level and always directly into the wind.
www.youtube.com/shorts/qHh7thPHkr8
Note the good glide angle of the FX707 particularly when its prop is folded.  

I've cut the nose off & quite pleased with the job I made of it. Here's a photo of the drawing of the mounting plate I've done for it pinned on.

 
 

I had decided to cut the nose with abit of down-thrust but no side-thrust so I cut the side walls of the jig with my chopsaw at 2 degrees. When I assembled the jig the cuts in the tops of the sidewalls didn't quite line up so I had to coax them abit & in doing so made sure they veered more to give some right thrust, not measurable but more to the right than the left.

I've painted the fuselage, fin, underside tips to the wings & underside of the flaps/ailerons to help visibilty. I'd noticed on the flying field that the white models disappeared when the sun was behind them.
The blenderm came so I used that for hingeing on the wings.
It certainly sticks to the paint well, so well in fact that it sticks better to the paint than the paint does to the EPO & if I didn't get it right first time & tried to adjust it, it peeled off the paint. On the four flaps/ailerons I had to repaint & restick three times!

I've got the snakes in for the tail & rudder but the clevices will foul the underside of the wing so I've got to refit the servos lower.

I've ordered the screws etc for the motor.
While I was on the site I added some Swann Morton blades. These increased the delivery from £2.20 to £6.80 because of the new regulations. They were charging £16.00 for a pack of 100. I managed to find them elsewhere for £12.59 plus £3.99 delivery, quite a difference.
The first site had a warning notice that the delivery required age verification on delivery so an adult had to be present to sign for them, they couldn't just be dropped through the letter box.
The second supplier sent them via ordinary first class, we didn't happen to be in so the postie just left them in the usual place.

I mounted the LE2204 1800Kv with the 6 x 4 folding prop on my test rig to run it.
Initially I hadn't shortened the motor shaft & at about 75% on the throttle stick it started to vibrate quite badly so I powered down, removed the motor & prop & shortened the the shaft so the prop was back at the motor housing & set it up again.
Again at 75% stick the vibration started again & I just had time to read the current as 5.4A when the rotor tore itself off the mounting.
So the question is what to do?
It's the same motor as Quorneng is using. Its obviously not possible to balance a folding prop.
Was I driving it too hard?
At 1.5A the input power was 20W so that works out at 72W at 5.4A