Glow to Electric Conversions Discuss glow/gas conversion to electric here.

1/4 scale Electric Piper Cub

Reply

Old 04-30-2004, 01:59 PM
  #1  
pardus
Junior Member
Thread Starter
 
Join Date: Jan 2004
Location: JohannesburgGauteng, SOUTH AFRICA
Posts: 4
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default 1/4 scale Electric Piper Cub

Span - 2.54m / 100 inch
Wig Area - 101dm2 / 1574in2
Weight - 6kg / 13.2lb /211oz
Motor - Model Motors Axi 4130/16
Cells - 20xGP3300's (2x10 cell packs in series)
ESC - Castle Creations Phoenix 60A
Prop - 17x6 Airflow Wood
Static current and power - 35A & 700W
Tx - Futaba 9CAP
Rx - 6ch Futaba PCM

This cub was swapped for an old .46 that I had lying around. It had aparently been powered by various engines including a .60, .90, a 1.20 and a 23cc petrol. I felt that it would make an ideal conversion as the original full size cub didn't have a lot of power but did have a huge wing area.

The aircraft was covered with fabric but that was in a bad way so that was stripped off and replaced with Solarfilm (5 full Rolls!). An additional 600g excess weight was also removed from the airframe. Flying is lovely, very docile with no tip stalling at all, holding full up elevator causes a controllable descent.

Motocalc's predictions regarding current and rpm were spot-on, however the performance predictions proved to be wrong. At the moment I only have large 2 props, a 14x10 APC and a 17x6 Wood. Motocalc predicted that with the 17x6 the pitch speed would be too low and would provide a too narrow band between it and the stall speed. Yet the plane flew extremely well with power and speed to spare. Predictions with the 14x10 were that the prop would be stalled until about half the stall speed and then would provide good performance from there on and yet the aircraft hardly got off the ground with that prop.

It flies really well and takes off in about 30m (100ft)and will cruise around quite happily on 50% throttle.

Standard servo's allround except for the elevator which is a JR591 Hi-torque servo. Rx battery is a 4 cell 600 mAh.

This was a surprisingly easy conversion and the results are better than I expected. Cosmetic details are being added with the cub stripes now completed.







pardus is offline  
Reply With Quote
Old 05-01-2004, 10:15 AM
  #2  
Hannu Vuorinen
Senior Member
 
Join Date: Aug 2003
Location: Helsinki, FINLAND
Posts: 122
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: 1/4 scale Electric Piper Cub

Gongrats, Pardus!

I have been also more than happy with my 1/4 Cub, flown it over 25 flight hours now.
Its powered by Actro 40-6 and 10s2p Kokam 3270mAh cells with Menz 19x8", flight time around +40 minutes.
It was also earlier glow powered by Saito 1.20 twin
Hannu Vuorinen is offline  
Reply With Quote
Old 05-01-2004, 02:22 PM
  #3  
pardus
Junior Member
Thread Starter
 
Join Date: Jan 2004
Location: JohannesburgGauteng, SOUTH AFRICA
Posts: 4
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: 1/4 scale Electric Piper Cub

Thanks Hannu, if I may ask, what ESC are you using and what is your static current / watts

(p.s. black cub stripe has now been added)
pardus is offline  
Reply With Quote
Old 05-01-2004, 05:53 PM
  #4  
Hannu Vuorinen
Senior Member
 
Join Date: Aug 2003
Location: Helsinki, FINLAND
Posts: 122
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: 1/4 scale Electric Piper Cub

Hi,

I use Actronic 70-32 ESC ( this Actro´s own ESC) wich is using 32Khz high frequency, it is very good and reliable combination.
Well, normal scale flying I use 19x8" prop at 5700 rpm at static 29A, for aerotowing 42A 20x11" Menz prop at 5300rpm.
Under load voltage is apprx 34-35 volts, so by 29A it gives 1015W out, at efficiency closer 90%. Scale-like cruising is much less,
average consumption is roughly 9A through flight . By those average low amps it gives only 1,4 C disharge, whereas meaning keeping higher voltage. By this way its endurance is so long
Attached Thumbnails Click image for larger version

Name:	Bz78527.jpg
Views:	13
Size:	48.8 KB
ID:	128186   Click image for larger version

Name:	Xt60295.jpg
Views:	15
Size:	32.3 KB
ID:	128187   Click image for larger version

Name:	Xc78564.jpg
Views:	16
Size:	54.4 KB
ID:	128188  
Hannu Vuorinen is offline  
Reply With Quote

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service