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4 pages [ <<    <     2      3     ( 4 )    >    >> ]7634 viewsPOST REPLY
Ron’s HeliProz South . Century Helicopter . MTA Hobbies

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e-Robbe Eolo > My Eolo Pro SE + badass Lehner
 
 
bawufa
Veteran
Location: Italy / Venice

in fact numbers are numbers : 35 A is false value registered in first half second by wattmeter meaningless to calculate power.
after one sec you are at 25 if you're lucky, better 20A.
After years of tests you will believe only in Bawufa Law .
03-24-2005 Over year old.
 
 
dnam
Veteran
Location: Herndon, VA - USA

No, this is not the case. I can measure the peak 35A value over and over as I bump up the throttle and pitch with the T-rex in my hand and looking at the amp meter real time. This is a peak value and not continuous, but for helis this is something to look at.
03-24-2005 Over year old.
HOMEPAGE  
 
 
bawufa
Veteran
Location: Italy / Venice

35 x 11,1 x 2 = 770W 2 seconds ?
03-24-2005 Over year old.
 
 
CustomPC
Veteran
Location: Sydney, NSW - Australia

Wow Gary, that is a fantastic explanation.

I've been playing with the KC spreadsheet for weeks now and i agree with everything you have said. I base my calculations on 175W hover, 350W average and 450W peak. Have you found that the 200W-700W to be more realistic.

I currently have a Twist37 with a 3S2P packs of Tanic 2450's. These are probably heavier than the TP packs but they are still lighter than the 8 cell Nickel packs they replaced.

Comparing the spreadsheets predictions with my actual data. With my ESC governor at 95% the spreadsheet predicts 1895rpm and 15.6min duration. I tached my rpms at 1950 and i've had several flights over 15 mins and still had 1000mAh in the pack. I have a Medusa Power Analyzer but haven't had a chance to check the current draw on my Eolo.

I've been looking for the ideal mild HV combo. I want to increase my headspeed to 2200, keeping the weight low and duration the same.

I almost went with the Twist33 and 4S2P combo but 4S LiPo's weren't readily available here and connecting four 2S packs in Series Parallel would have been a nightmare on the Eolo.

Which brings me to a small point that the Eolo is a smallish heli and there just isn't a lot of room in both size and weight to lug 8 LiPo cells around, so i'd like to keep the cell count at six cells max.

I then looked towards the Lehner 1920/8 as a potential candidate. I actually ordered it and waited 4 weeks and still no delivery. I contacted the vendor to hear they had not yet shipped it and promptly cancelled that order.

The Aveox is a recognized favourite but is way to hot for me (in both head speed and operating temps)

Finally i think i may have found a good motor in the Medusa MR028-056-1900 (1900kv, 1.7Io, 16mohm, 160gm). On 6S1P with a 15T - 16T pinion it gives me what i'm looking for. It's a 4 pole motor like the Aveox so should have a good deal of torque.

How do you think it will go Gary? Have i got my calculations right?

Too late now if i am wrong because I ordered the motor yesterday and have already recieved shipped notofocation from medusa. I'm looking forward to testing this motor.
03-26-2005 Over year old.
 
 
dnam
Veteran
Location: Herndon, VA - USA

Yeah, Lehners are so hard to get! Well, not hard actually but takes time. I was so lucky to get mine in just 2-3 days for $190.
03-26-2005 Over year old.
HOMEPAGE  
 
 
Reesy
Key Veteran
Location: In the doghouse ... Nottingham UK

I've just run the medusa numbers thru on 6S1P and they look very similar to my Lehner 1530 on 6S1P, that flew very well, it was jjust I wasn't too happy with the way the Lehner overheated. I don't have the figures for the Lehner but use the Aveox as the numbers are similar.
The Medusa being slightly larger should be OK?

I'm hoping to try the Neu 1506-3Y 8S1P combo (thanks Gary) once it becomes available.

Ting Tong
.... ...... ...from Tooting
03-26-2005 Over year old.
 
 
CustomPC
Veteran
Location: Sydney, NSW - Australia

I considered the Nuemotor as a mild 6S1P option and i thought it was a good setup. Someone else in these forums asked about the Nuemotors and i answered it a few days ago. I never even thought to go with 8S.

My supplier for Tanic's has some Feigao B40 3808417L 1700kv motors for only AU$90. Published specs are very close to the Nuemotors and i was going to test one before i discovered the Medusa. Heck, for $90 i might even try one for fun...er..... Research.

What turn was your Lehner 1530?. The 8 or 9 turn with the star wind would be closest to the Medusa but i don't have the actual Io and resistance so it's hard to tell. The Medusa is 5mm longer and the same weight. Did you have a heatsink installed? I'll be using a hacker b40 heatsink.
03-26-2005 Over year old.
 
 
dnam
Veteran
Location: Herndon, VA - USA

Gary at TP Packs is recommending 4S2P or 8S1P because he is thinking of the new Pro-Lite batteries. A 4S1P 2000mAh Pro-Lite pack is only about 10g heavier than the Gen2 3S1P 2100mAh packs.
03-26-2005 Over year old.
HOMEPAGE  
 
 
bawufa
Veteran
Location: Italy / Venice

nice thread
03-27-2005 Over year old.
 
 
CustomPC
Veteran
Location: Sydney, NSW - Australia

Do you have any TP distributors in Australia Gary? What is the C rating of the Lites? If the Medusa works out well, i may look at a 6S pack of TP's to reduce my weight.

Funny thing i just noticed with the Medusa numbers in 6S is that the Efficiency is lower at hover but increases by 5% as you start pulling 400W. Most other motor combinations seem to hover with 1-2% of the same efficiency across the current/watt range. Is this significant at all?

The other thing is the cost of an ESC when moving up to 8 Cells. I have the Jazz 40-6-18 now and it can just handle 6S. An ESC capable of handling 8S would be a considerable expense.

I have a Medusa 3.5A BEC coming too. Has anyone tried these?

Gary, i love the work you've been doing with the Raptor's and The Box. when i'm ready for a larger Heli you'll be getting an order from me.
03-27-2005 Over year old.
 
 
rdnardin
Heliman
Location:

Head Speed

Hi dnam,

I've a spirit Pro SE, with the same configuration as yours. Lehner 1930-6, 19t Pinon, 3S2P Bat. I'd like to known your head speed

Thank you Renato
07-18-2005 Over year old.
 
 
dnam
Veteran
Location: Herndon, VA - USA

MY HELI IS UP FOR SALE NOW!!

Please read the classifieds:
http://www.runryder.com/helicopter/t196658p1/
08-15-2005 Over year old.
HOMEPAGE  
 
 
Laurens
Key Veteran
Location: NL, behind my computer

PM sent
09-07-2005 Over year old.
 
 
gorn
Elite Veteran
Location: Western Australia

Custom_PC, I searched everywhere here in Oz and found no'one selling TP's.
I ended up getting mine out of Canada from RCtoys.com.
Good prices and fast freight. I think it was 10 days?
Pro Lites from memory have a 12c continuous and 20c burst.
IMore info is on the Rc toys website.
I know the name sounds dodgy, but they are in fact a TP distributer.
You cannot buy direct from TP anymore unless within the US.
Hope this helps mate.

If you bling it, they will come :D
09-23-2005 Over year old.
 
 
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e-Robbe Eolo > My Eolo Pro SE + badass Lehner
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