Micro-jet owner for EDF experiment.

[$h@d0w]

No excuses start building your F-18 and FLY !!!

He's flying all right, but the real ones, not the RC ones.

[Warbird]

Even less of an excuse – Ridz you are 1/2 there already

[chewy]

SFM= Super Flying Model EDF from MTH and distributed by J-hobby.
It is 68mm EDF with a 65mm impeller.

I am not advertising for J-hobby but here is the link for the SFM.....

http://www.jethobby.com.sg/cgi-bin/ezsite/prod/manager.cgi?action=show&pid=147&cid=37&idx=1

I hope this will help.

Cheers

Hi Babylon5,

The fan in that thread only has a recommended rpm of 25,000. How many rpm did you manage to get up to? What is the max motor diameter it can take? If it takes a 400 motor, I think it would be around 28mm, isn't it?

Regards,

Chewy

[Babylon5]

Hi Chewy, the bad plate of the 68 mm is one of the most important component that keep the blade from flying off or breakage.
So far I have balance the blade and make sure the blade does not come into contact with the shroud at high rpm.
Also make sue the prop adaptor fit well to the motor shaft.
There are some motor shaft that are 3mm and not 3.2mm. If you try to fit this type of motor to the prop adaptor design for 3.2mm it is not going to have a good grip and likely to come loose at high rpm.

The highest rpm I have run to-date is about 32,000rpm on 3 blade.

As I have said before do this very carefully with safety consideration to others.


When I test ,I place a big carboard box fill with soft materail like some cloth or sponges and some distance infront of the fan. You don't want to suck the cloth or sponges during power test. The purpose of this box is to catch the rotary fan should comes off.
Make sure the rotary fan is well secured.

Once you setup and run properly, the improvement to the flying characteristics of the jet is very signifant. It would fly faster at lesser power.

All the best to you

[chewy]

...There are some motor shaft that are 3mm and not 3.2mm. If you try to fit this type of motor to the prop adaptor design for 3.2mm it is not going to have a good grip and likely to come loose at high rpm.

The highest rpm I have run to-date is about 32,000rpm on 3 blade.

Hi Babylon5,

From the above, I gather the fan unit take a motor with a 3.2mm shaft? Is 3.175mm ok? Btw, you did not mention the max motor diameter. I do not mean the shaft dia, but the motor body itself.

Cheers,

Chewy

[Babylon5]

Hi Babylon5,

From the above, I gather the fan unit take a motor with a 3.2mm shaft? Is 3.175mm ok? Btw, you did not mention the max motor diameter. I do not mean the shaft dia, but the motor body itself.

Cheers,

Chewy

Hi, Chewy, Correct that "bad" plate should be "Back" plate.
The original fan prop adapter was design for motor with 2.3mm. shaft diameter.

I was using the 28xx which has a motor shaft of 3.17mm so I have to replace the prop adapter that was design to fit the motor with a shaft dia of 3.17 to 3.2mm. However, I also came across some motor with 3mm dia. The prop adapter that was used to fit the 3.2mm shaft motor may appear to fit this 3.0mm motor but does not have enough grip.

The prop adaptor I use for the 3.17 to 3.2mm are from Align models . The 28xx motor are also from Align models so they are perfect fit.

Right now found another motor which is the 2025xx 3.2KV which matches the 3 blade modified EDF. It takes in about 16 amps but runs at 32,000 rpm almost 2000rpm higher at the same current as the Align motors.
In another words, this combo is a better match and more efficient.
The motor weight about 65grams just 5 grams heavy so C.G of my plane remain unchanged.This motor has a 2mm shaft diameter so I have to change to another prop adapter that fit this motor shaft.



Cheers

[Babylon5]

This Micro-jet is awesome

Hi take a look at this link of this microjet picture....did I say micro...opps

http://image.rcuniverse.com/forum/upfiles/35977/Ay75128.jpg

[Babylon5]

Micro-jet on modified Kamdax EDF

Hi, here is a close up picture of the experimental Multiplex Micro-jet . Managed to make two good flight with this setup before the crash.

This plane is fitted with= Kamdax 60mm EDF +3 blade 9-7 GWS prop cut to fit+ Himark2025-40-4.2kv motor.

The Kamdax EDf is about 10 grams lighter than the SFM setup so battery have to shifted away from the nose to get a C.G. balance.

The plane is repairable. She will fly again


Cheers

[Babylon5]

micro-jet-EDF-near miss

Hi, here is a short clip of the micro-jet missing the tree the first round...I say first round but then there is this second round ... no so lucky ...picture tess all .Good news is this plane is one tough cookie.
It can be repair and will fly again.
Cheers