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OS 120FS X OS 95AX

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OS 120FS X OS 95AX

Old 01-12-2013, 05:30 PM
  #1  
mjunior
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Default OS 120FS X OS 95AX

I don't exactly where to ask but I will try here since I'm looking for 3D flight.

I have just bought a Funtana 125 and I have to engines, an OS 120 FS (pumped) and an OS 95AX, both almost brand new.

Which one would be the best choice for the TANA? Which one would produce more thrust considering large props with small pitch?

Regards
Old 01-14-2013, 11:18 PM
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nitro wing
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Default RE: OS 120FS X OS 95AX

I wrote a lenghty reply but RCU crashed..
Use the 120 FS
Old 01-15-2013, 01:59 PM
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Dave McDonald
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Default RE: OS 120FS X OS 95AX

The 95AX engines around my local club haven't proven to be very reliable. For that reason alone I would avoid using the 95AX in a 3D plane.
Old 01-15-2013, 03:36 PM
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mjunior
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Default RE: OS 120FS X OS 95AX


ORIGINAL: Dave McDonald

The 95AX engines around my local club haven't proven to be very reliable. For that reason alone I would avoid using the 95AX in a 3D plane.
While the 120FS are extremelly reliable....
Old 01-15-2013, 07:45 PM
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nitro wing
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Default RE: OS 120FS X OS 95AX

5 years ago
120FS on X100
http://www.youtube.com/watch?v=SkjRGPsyI54
Old 01-16-2013, 12:02 AM
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ameyam
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Default RE: OS 120FS X OS 95AX

The FS120 will offer lower power than the 95ax but will offer more torque. Based purely on displacement, 4C 120 would be equal to 2C 85 or so. If you intend to do a lot of 3D, I feel the 95ax would be advisable. Its a ringed engine, so run it richer. Adjust the tank heights and setup properly and there is no reason why it shouldnt be reliable. Only consideration for the FS120 would be that it is pumped.

A fellow flier has the same airplane on field with a DLE20. To keep weight down he used metal gear hi-torque servos. His airplane is slightly tail heavy but still ok for an experience pilot and does 3d quite well

Regardless of what you do, post a video here for people who are going to follow in your footsteps (me), OP

Ameyam
Old 01-16-2013, 06:33 AM
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Default RE: OS 120FS X OS 95AX

ORIGINAL: ameyam

... To keep weight down he used metal gear hi-torque servos. His airplane is slightly tail heavy but still ok for an experience pilot and does 3d quite well

Ameyam
Aren't metal gear hi-torque servos generally heavier than nylon gear hi-torque servos? I believe that is why people complain that their model turned out tail heavy when they installed 3 metal gear servos in the tail.

ORIGINAL: Dave McDonald

The 95AX engines around my local club haven't proven to be very reliable. For that reason alone I would avoid using the 95AX in a 3D plane.
Many people find the OS 75AX, 95AX and 120AX to be finicky to adjust and unreliable. When you get lucky and stumble upon the correct settings you will have a powerful and reliable performer. They're just not as user friendly as the older FX series of OS engines.
Old 01-16-2013, 12:52 PM
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Default RE: OS 120FS X OS 95AX

Watch nitrowing's video and read the comments: 16x4W or 16x6 prop, adequate pullout from hover. Not gonna be a rocketship. Two local clubmember's here have Funtana 125's: one with a Syssa 30, the other with a DLE30. These gassers pull the Funtana around very well. Of interesting note, one of them originally had a YS1.10 that apparently was fairly comparable in punch out to the 30 gassers, but a CRRC 26 was tried in between the YS and the DLE, and it would barely hover it, with no pullout whatsoever. Your 1.20 would probably be the best bet...
Old 01-16-2013, 01:43 PM
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Dave McDonald
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Default RE: OS 120FS X OS 95AX


ORIGINAL: Rocketman_

ORIGINAL: Dave McDonald

The 95AX engines around my local club haven't proven to be very reliable. For that reason alone I would avoid using the 95AX in a 3D plane.
Many people find the OS 75AX, 95AX and 120AX to be finicky to adjust and unreliable. When you get lucky and stumble upon the correct settings you will have a powerful and reliable performer. They're just not as user friendly as the older FX series of OS engines.
I have two 120AX engines in 3D planes, and they have proven to be 100% reliable.

We just haven't had much luck getting the 95AX engines to run as good as the 120AX, even in non-3D planes.

As for this thread, I would skip both the 120FS and the 95AX and install a 120AX instead.

Old 01-16-2013, 10:04 PM
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nitro wing
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Default RE: OS 120FS X OS 95AX

I my video I barely ever pushed the FS, just putzing around.
It actually did pull out well from a hover, could stop, hover and pull out again..
If messing up and the plane went sideways and you had to "goose" it with full deflections, it was a bit white knuckled and challenging.
Nice thing, as you can tell per video, is that alot of power and torque is available straight on from idle, two strokes always seem to have just a bit of lag to get into their powerband.
3D flying needs immediate throttle response from idle.
The FS has a similar power curve to a gasoline engine.

For anything 3D I would always choose a 4 stroke nitro or gasoline 2 stroke.
Never compare HP figures from 4 strokes to 2 strokes, its very misleading.
You want the the best spool up from low rpm, swinging the biggest or ( most thrust producing) prop the engine can safely handle.
Old 01-16-2013, 10:15 PM
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nitro wing
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Default RE: OS 120FS X OS 95AX

The 120 AX had pretty good reviews on Funtanas when they where more popular.

After my 1.20FS busted a con rod, I stuck a YS 1.40 in it.

Honestly, the thing flew horrible with it. Such a big torquey prop and massive throttle response, it crabbed all the time and would never trim right.
The YS 140 would easily finish this airframe in an afternoon if one let it rip full hot doggin..
Someone stuck an OS 1.60FX in it, brutal..I have one, dont do it.

If I had another I would likely go OS 1.20FS again or YS 1.10, third choice would be gas, as its not a robust airframe, beefing it up just defeats the purpose of light wing loading.
Old 01-16-2013, 10:39 PM
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nitro wing
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Default RE: OS 120FS X OS 95AX

My 1.20 was a late 90's model, no pump.
I asume yours will have just a tad more power and even better response all around, Put light adequate servos all around, and a smaller flight pack such as a 1200 -1600 mah 6v, thats it, no extra junk. Or an 1100 A123 battery.
Old 01-17-2013, 05:54 AM
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Default RE: OS 120FS X OS 95AX

so... I'll go ahead and say it ..


am i the only one seems out dated ?? the 30cc planes have really blown up and really fly so much better then a 100 size funtana ...
Old 01-17-2013, 07:54 AM
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Default RE: OS 120FS X OS 95AX

True, but the OP already HAS a Funtana 125 AND both the 1.20FS and 95AX, so we're just trying to help him figure out which one might work better by comparing it to similar planes and powerplants....

I personally would power it with a DLE35 on a single 2300 size LiFe/A123 pack with an IBEC kill on the ignition to keep it light. Not sure if the OP wants to spend more money or not...
Old 01-17-2013, 08:43 AM
  #15  
mjunior
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Default RE: OS 120FS X OS 95AX

To all of you buddies I thank you a lot for all the replies. As wyo69cowboy said I would like to avoid buying a new engine for my funtana. This would avoid additonal expense. Also in my country gas has 25 per cent of ethanol so people how flies gassers here had to remove the ethanol since they usually promotes premature wearing of the gaskets.

I have a clubmember flying a Funtana with a DLE 20 and looks a very good combination. Any extra CC sounds an overpowered combination that could lead to premature end of the airframe that is very light (and fragile).

My perception is a pumped 120FS will be very close in torque to a DLE20. I have considered the 95AX because it is 8oz lighter than the 120FS.

I might be end with the 120FS.
Old 01-20-2013, 10:03 PM
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Default RE: OS 120FS X OS 95AX

i had a 95ax and it was very reliable. The only strange thing i found about it was that I needed to use a four stroke glow plug to get it to run reliably. But once the plug was switched out, it was a monster performer and absolutely reliable. No dead sticks at all.
Old 01-21-2013, 04:36 PM
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mjunior
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Default RE: OS 120FS X OS 95AX

A buddy in our club did the same thing. OS F glow plug and no problem anymore.
Old 01-21-2013, 04:41 PM
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mjunior
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Default RE: OS 120FS X OS 95AX

I found that viseo http://www.youtube.com/watch?v=k0drw1sGQ3U .

The tester found the following numbers for 95AX:

Prop RPM Thrust
APC 14X8 9,400 9.6
APC 15X6 9,625 11.1
APC 15X8 8,600 10.3
APC 15X10 7,550 8.9
APC 16X6 8,700 11.9
APC 16X8 7,525 11.1
MA 15X6 10,175 11.4
MA 16X6 8,925 11.3
MA 15X8 8,850 10.1
Xoar 15x8 8,425 10.5
Old 02-28-2013, 06:08 PM
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SharpProp
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Default RE: OS 120FS X OS 95AX

+ 1 on the 120 AX. Never used a 95AX but if it's anything like it's big brother, it's a monster.
I did find that my 120 likes the OS F plugs better.


ORIGINAL: Dave McDonald


ORIGINAL: Rocketman_

ORIGINAL: Dave McDonald

The 95AX engines around my local club haven't proven to be very reliable. For that reason alone I would avoid using the 95AX in a 3D plane.
Many people find the OS 75AX, 95AX and 120AX to be finicky to adjust and unreliable. When you get lucky and stumble upon the correct settings you will have a powerful and reliable performer. They're just not as user friendly as the older FX series of OS engines.
I have two 120AX engines in 3D planes, and they have proven to be 100% reliable.

We just haven't had much luck getting the 95AX engines to run as good as the 120AX, even in non-3D planes.

As for this thread, I would skip both the 120FS and the 95AX and install a 120AX instead.

Old 03-06-2013, 02:56 AM
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Default RE: OS 120FS X OS 95AX

For 3D it's not about all out power but rather thrust generated at various rpm's and the throttle response. This is really needed during harriers and harrier landings.
In 3D flight I find myself bipping my throttle alot
That said the 120 fs would be better

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