Alpha A4 Pusher

[NUTS]

I thought to myself "why not". I installed a little 2500KV motor I had for a while. Maidened it with a 5.5x5 prop but found it just wasn't enough. Stepped up to a 6x4 on the second flight. Great vertical and plenty fast for me. I acually like it better as a pusher. The AUW came out lighter than it did as an EDF. It's only 13.4oz with a 1320 3 cell in the nose.

Regards,
Nuts

[rcers]

Nuts - I have been thinking about doing the same with my Alfa A-4. The 3s 3blade setup is very lathargic - even with the LittleScreamers motor.

APC-e makes a 5.25x6.25 prop - if you motor can handle it - that will give you MUCH better speed ....

Mike

[The Don]

Nuts - I have been thinking about doing the same with my Alfa A-4. The 3s 3blade setup is very lathargic -

You just need a hotter EDF motor:) Here is my A-4 on 3S lipo wihtthe Wicked Extreme and 5 blade alfa fan.
.
http://media.putfile.com/Alfa-A4-DonsRC-Wicked-Extreme-3Slipo

I dopplered it at 105mph. With the 3 blade fan you will most likely be in the 90 mph range.

Don

[rcers]

But how many amps Don?

I don't need 90mph especially at the cost of amps! I like to use light packs to keep the landing speeds down a bit....

EDF's are ultra cool - I have a number of them, but at the end of the day I do get pretty bummed at the inefficiencies of fans overall. That 200w/lb that make me smile on EDF is attained by a pusher at 125w/lb. But you lose the cool factor.

Mike

[NUTS]

I agree. I too have a few larger EDF's and they always pack a lot of "cool factor". My little set up on the A4 draws 14.3 amps. On a full pack it's around 140watts. I can fly it for 12 minutes on a 3 cell 1320. Could not ask for anything funner than that.

Nuts

[The Don]

But how many amps Don?


Mike,

For 90 mph you need about 270 watts. For me, I like my EDFs in the 100 mph range as they look more jet like to me but they do eat up the watts :D

Don

[rcers]

Yep - for 270w (25-27amps on 3s) you are talking about a large 2100-2200 pack. Now you make a nice light flyer 4oz heavier....

But speed takes power....unless you do a pusher :)

Mike

[The Don]

I use a 3S 2200 lipo and my AUW is 18.5 ounces and I get about 22 oz thrust.

Don

[rcers]

I am at about 14.5oz with the 3s 1320 pack.... So about 4oz more is right - Don't know what my thrust is, but I am at 180w.

Those 4oz are precious however.... A 4s 1320 might be the ticket for me with the 3 blade fan and LS motor. That should only cost me an ounce. Might try that first as the spin 22 ESC can handle that - with the BEC....

Mike