Why can't I go vertical with my mIFO? - RC Groups
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Dec 21, 2003, 09:27 PM
Registered User
isaac-bees's Avatar

Why can't I go vertical with my mIFO?

I have been flying my mini IFO for a while and have always thought I couldn't go vertical because of my motor or battery. But now I have a newish motor and a great battery and it still won't perform like I would wish.
What I have.
GWS A drive motor with a 1080 prop.
Kokam 1200 2 cell pack.
It is a pretty light plane I am not sure exactly what its auw is. I'll have to weigh it soon.
Any suggestions?
I would prefer to avoid 3 cells b/c then I have to build a charger
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Dec 21, 2003, 09:34 PM
Only nerd in the village
Why not try to use 2x340mah cells - that will save some weight. It would be nice to know the weight so someone who knows what kind of thrust can be had from GWS drives can give advice.

Dec 21, 2003, 09:43 PM
Registered User
This doesn't give your prop size but,will give an idea of what happening.

IPS-DX-A (M0.3) 82 / 14 = 5.86
PROPELLER Volts (v) Amps (A) Thrust (g) Power (w) Efficiency (g/w)
EP9070 6.0 1.26 86 7.56 11.38
7.2 1.65 110 11.88 9.26
EP1047 6.0 1.28 101 7.68 13.15
7.2 1.67 129 12.02 10.73
Dec 21, 2003, 09:49 PM
Registered User
Or don't even bother with it and trade in your small block for a big block with aluminum heads

CN12-124X2 (M0.3) 82T / 14T = 5.9
PROPELLER Volts (v) Amps (A) Thrust (g/oz) Power (w) Efficiency (g/w)
EP1080 6.0 2.7 151 5.29 16.20 9.3209
7.2 3.4 195 6.83 24.48 7.9656
8.4 4.3 244 8.54 36.12 6.7552
EP1147 6.0 2.6 172 6.02 15.6 11.0256
7.2 3.3 226 7.91 23.76 9.5117
8.4 4.2 286 10.01 35.28 8.1065
EP1180 6.0 3.1 180 6.30 18.6 9.6774
7.2 4.0 231 8.09 28.8 8.0208
Dec 21, 2003, 09:57 PM
Registered User
Try a 10x4.7 a finer pitch will be better for hover .
Dec 21, 2003, 10:06 PM
Registered User
Marked's Avatar
I run the following and can hover.
IPS DXa 10x4.7 prop cirrus CS-10s GWS rx 4 CH....FMA ESC 5A...a 750 mah lithium 2s 1p...weight.....4.9oz
A savings in .4 oz(I was running a heavier battery) made all the difference in this plane.
I also found it will fly a little better WITH the spinner.Air flow or something.....not C/G,,Mark
Dec 21, 2003, 10:26 PM
Only nerd in the village
Good point guys, the 10X8 prop could very well be stalled when static and would not be suitable for vertical manouvering.

Dec 22, 2003, 03:01 PM
Registered User
isaac-bees's Avatar
I weighed it this morning and it came in at 5.5 oz. Seems when I tried the 10x47 I had to be on full throttle to motor around nicely without descending.
I suppose I could go to a dual drive but isn't there another option?
Dec 22, 2003, 08:33 PM
Registered User
If you use the stock GWS A drive, as you are, it all comes down to weight. 5.5 ounces is not bad for a Mini, but the A drive will only pull so much weight straight up. You can either use smaller, lighter cells, like the 340's, or add power thru a dual IPS or small brushless. The lighter battery will be the easiest way to achieve vertical, but remember, it will still be a slow vertical. You can, of course, do both, and use smaller cells and a brushless motor, like the Nippy 0508, and you'll get good vertical, but you'll have to throw some money into the system to get this. Even the tiny DC1524 coreless will take a Mini straight up, but we're talking under 4 ounces here. It really does come down to weight, at least with the smaller powersystems.
Dec 22, 2003, 11:23 PM
Registered User
For hovering I use either 3 cells, or an E or an F gearbox on 2 cells with a 13" prop. For my faster planes I use the lower A or B ratios with 9070 or 1047 props.

I've also done my own static thrust tests and confirmed that the GWS published thrust/power figures are roughly in the ball park, although it appears that they use a constant voltage supply to get their figures which does not really model real life conditions where battery voltage sag can be significant.

Dec 23, 2003, 12:11 AM
Crash Master
Gene Bond's Avatar
If you want to stay with the lightweight IPS, I'd take DeanInMilwauke's advice, and use an IPS-C with a 1047 and 3 cells. Personally, I'd try the ET250's, or the K340's. Seems like there should be a cell between these, since the 340's are almost as heavy as the ET700's...

Personally, I gave up and went to a Wattage 180 in an EPS-C box with an 1147 prop on 2xET700. It's 1/2oz heavier than the IPS, but lots more speed and thrust. A 1047 gives more speed, and just enough thrust to climb vertically (if you can hold it). AN M-100 in the same box is just about the same.
Dec 23, 2003, 01:01 AM
Registered User
The 500ma irate cell from CBP is the same weight as the 340ma at 10 grams each and can handle 10C contiuous and 15C in short bursts.Probably the best IFO battery out there.Matt
Dec 23, 2003, 11:14 PM
Registered User
isaac-bees's Avatar
Appreciate your advice guys. I am thinking of the dual IPS since I am running 1200 HD kokams. They sure are more money though. I would love to go to the brushless but they cost too much for a college student or at least for this one. I saw a friend fly a mini max(?the purple small ones.) motor today. It was IMPRESSIVE! full vertical on dual 3cell 1300!
My only problem to going with 3 cells is a charger. Any ideas for that problem?
Dec 24, 2003, 09:19 PM
Registered User
Nowell York's Avatar

It's all about thrust to WEIGHT

Use an A drive, 10x4.7 with 2s 340s.

My mini with rudder weighs in at about 4.1 ounces and will climb vertically like a slow elevator. If you build light and more importantly select light componets you'll be fine on 2 cells.