Venus 40 on a123's
#1

Thread Starter

I thought I would start a new thread with the info on my
Venus 40 on a123's.
A friend of mine donated this plane so we could test out an
inexpensive Turdigy motor and test out the A123 cells we have
successfully flown in our helicopters.
Being new to electrics I tried to decipher the Drive Calc findings
and choose a motor for this project.
This is what I ended up with:
Battery - 6 cell a123 pack
Motor - Turnigy TR 42-60C 500Kv Brushless Outrunner
Speed control - Hextronic HVT80 amp
BEC - TURNIGY 5-7.5A (8~42v) HV UBEC
Venus 40 on a123's.
A friend of mine donated this plane so we could test out an
inexpensive Turdigy motor and test out the A123 cells we have
successfully flown in our helicopters.
Being new to electrics I tried to decipher the Drive Calc findings
and choose a motor for this project.
This is what I ended up with:
Battery - 6 cell a123 pack
Motor - Turnigy TR 42-60C 500Kv Brushless Outrunner
Speed control - Hextronic HVT80 amp
BEC - TURNIGY 5-7.5A (8~42v) HV UBEC
#2

Thread Starter

To convert the Venus 40 to electric I was going to need a easy way into
the top of the plane.
I used an knife and followed the top of the lite ply removing the top half
of the fuse from the cockpit forward.
I also cut out some extra weight and made a vent hole in the front bulkhead.
the top of the plane.
I used an knife and followed the top of the lite ply removing the top half
of the fuse from the cockpit forward.
I also cut out some extra weight and made a vent hole in the front bulkhead.
#4

Thread Starter

After some testing on the bench I decided to try out a 14x6 and a 14x10 prop.
Flight #1 - 4 minutes
Prop - 14x6 APC
Max amps - 28
Max Watts - 475
mAh replaced on recharge - 690 - estimate 11-12 minute flight available.
Good for cruising around or light aerobatics. This would be good power for
a trainer or slow scale flying.
Flight #2 - 5.5 minutes
Prop - 14x10 wood zinger
Max amps - 43
Max Watts - 725
mAh replaced on recharge - 1490 - estimate 7-8 minute flight available.
More power for aerobatics but the plane will sag on long up-lines due to the
voltage drop of the a123's. Approx 130 watts per pound.
The plane flies nice, but not the way I want. I will be trying a 7s1p for my
next test.
Flight #1 - 4 minutes
Prop - 14x6 APC
Max amps - 28
Max Watts - 475
mAh replaced on recharge - 690 - estimate 11-12 minute flight available.
Good for cruising around or light aerobatics. This would be good power for
a trainer or slow scale flying.
Flight #2 - 5.5 minutes
Prop - 14x10 wood zinger
Max amps - 43
Max Watts - 725
mAh replaced on recharge - 1490 - estimate 7-8 minute flight available.
More power for aerobatics but the plane will sag on long up-lines due to the
voltage drop of the a123's. Approx 130 watts per pound.
The plane flies nice, but not the way I want. I will be trying a 7s1p for my
next test.
#5

Thread Starter

I tested the plane with several more props and so far the 14x10 wood prop
is the best but the plane was still just a little short on power for my taste.
I put together a 7 cell pack (one 4 and one 3 cell pack) and the plane really
came alive.
On a 7s1p and a 14x10 prop the plane was fantastic. 54 amps and 980
watts, about 178 watts per pound.
Final weight:
with 6s1p - 5 pound 5 ounces.
with 7s1p - 5 pounds 8 ounces.
The extra cell added 100 watts.
is the best but the plane was still just a little short on power for my taste.
I put together a 7 cell pack (one 4 and one 3 cell pack) and the plane really
came alive.
On a 7s1p and a 14x10 prop the plane was fantastic. 54 amps and 980
watts, about 178 watts per pound.
Final weight:
with 6s1p - 5 pound 5 ounces.
with 7s1p - 5 pounds 8 ounces.
The extra cell added 100 watts.
#6

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Join Date: Jan 2002
Location: Ossining,
NY
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Nice work. Adding a cell over the lipo equivalent is a good guideline. Try to match the lipo voltage. You can make it up with amps but with only 2300 mah capacity flight times get real short. I have seen some reports of people going to much higher voltages and still 1p to have enough watts on board for good flight times.
#7

My Feedback: (7)

I was wondering if you have any pictures of your finished electric project? I put together a venus 40 but this one i made a few changes as in that i installed pneumatic retracts. I recovered the entire wing and I first installed an O.S. 70 fourstroke but I sold the motor because I wanted to save some weight so I used an O.S. 50 SX so this weekend i will find out how it flies. Let me know what yall think. I named it Venus 40 Retracted and the letters are hand cut out of monokote and same for the stars. I even put a video on youtube with the retracts in action. http://www.youtube.com/watch?v=h2psCRLI-KY