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O.S 1.20AX Owners. Post your tach readings

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O.S 1.20AX Owners. Post your tach readings

Old 03-06-2006, 10:38 AM
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vlado
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Default O.S 1.20AX Owners. Post your tach readings

My 120AX run at

8400RPM , APC 16X8
7700RPM , APC 10X10

10% nitro , sea level
Old 03-08-2006, 10:35 PM
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seanychen
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Default RE: O.S 1.20AX Owners. Post your tach readings


ORIGINAL: vlado

My 120AX run at

8400RPM , APC 16X8
7700RPM , APC 10X10

10% nitro , sea level
Try Master Airscrew Classic 16x8. I got 9400 with that prop.
Old 03-09-2006, 08:59 AM
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vlado
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Default RE: O.S 1.20AX Owners. Post your tach readings

i got 9400rpm with APC 15X8 10% nitro , but i think is better to know the thrust.
Old 03-17-2006, 08:24 PM
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Default RE: O.S 1.20AX Owners. Post your tach readings

I just started breaking my 120AX in last weekend... only 1 tank so far:
APC 17X6, Byron 10% nitro / 20% oil, Sea Level
8800 RPM
9100 RPM peak (cold)
Old 03-17-2006, 09:13 PM
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Default RE: O.S 1.20AX Owners. Post your tach readings

I'm using the same prop and fuel on mine and have about one gallon through it so far. Hopefully I'll maiden my Laser in a couple weeks to see how this engine runs and pulls the plane.
ORIGINAL: chrisri01

I just started breaking my 120AX in last weekend... only 1 tank so far:
APC 17X6, Byron 10% nitro / 20% oil, Sea Level
8800 RPM
9100 RPM peak (cold)
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Old 03-18-2006, 03:56 PM
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seanychen
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Default RE: O.S 1.20AX Owners. Post your tach readings

chrisri01

How did you photo the thermal map of your 120 AX, as in your avitar?
Old 03-18-2006, 11:59 PM
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Default RE: O.S 1.20AX Owners. Post your tach readings

I used a Flir E25 infrared thermal camera that I was able to borrow. I posted a few more in my gallery. Can't wait to fly it!
Old 03-20-2006, 07:28 AM
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vlado
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Default RE: O.S 1.20AX Owners. Post your tach readings

hi , i got 8500RPM on Zinger 16X6 , 5% nitro , sea level
Old 05-15-2006, 04:41 PM
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malcolmm
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Default RE: O.S 1.20AX Owners. Post your tach readings

Running very rich, with 3 or 4 tanks through it, I got 9600 RPM , APC 16X6

10% nitro , sea level

Malcolm
Old 06-02-2006, 07:28 PM
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RoughLandin
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Default RE: O.S 1.20AX Owners. Post your tach readings

Update on the OS 120 AX in the H9 Showtime.

Amazing engine, still only have about 6 full tanks through it but very happy. I'm spinning an APC 17x6 prop.


Exhaust report:
I was using a shortened Bisson muffler specifically made for this engine I then chopped down the expansion chamber about 2 inches to make it fit in the cowl, then narrowed the exhaust diameter to replace the lost of back pressure. With this combo I was getting about 8400 RPM far less than the reported 9200. This combo will hover at about 3/8 throttle and has great pull out even at these lower RPM numbers.

I then switched to the stock Powerbox muffler with the pitts adapter and immediately got 8900 RPM. I figure this will improve closer to the 9200 as the engine completes break-in phase. The sound is improved (quieter but deeper), at lower RPM it now doesn't have that irritating 2 stroke rattle/ratatattat sound that it had with the Bisson though full throttle does not sound as impressive. I figure the increase in backpressure will help transition performance (still breaking in) but I'm really excited about the extra 500 instant RPMs. I have not flown this combo yet.

All figures are using 15/15 PowerMaster fuel at sea level.

I may also try the APC 16.5x5W prop and switch to a plastic spinner to reduce weigh and improve transition performance. How are every one elses transitions, last several engines were 4 strokes which seam a little better in this area... [&o]
Old 07-05-2006, 05:08 AM
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Default RE: O.S 1.20AX Owners. Post your tach readings

New reading

Mertz wood 16x10

10% Nitro, 20% syntetic-castor oil

1800 ft

RPM 7,550

Regards
Old 07-29-2006, 02:36 PM
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Default RE: O.S 1.20AX Owners. Post your tach readings

8900 with APC 17X6, muffler baffle in, coolpower 20/20, sea level, 90 degrees, 6 tanks through it. I have the idle set at 2250 and the transition is good.

Aaron D.
Old 08-04-2006, 06:17 PM
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Flyer95
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Default RE: O.S 1.20AX Owners. Post your tach readings

APC 14x12, 10% Nitro 20% oil, peaked @ 9000rpm, richened down to 8700rpm for flights.
Old 09-07-2006, 07:37 AM
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vlado
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Default RE: O.S 1.20AX Owners. Post your tach readings

¿ anyone with APC 18x6 ?
Old 09-17-2006, 05:16 PM
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Flyer95
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Default RE: O.S 1.20AX Owners. Post your tach readings

I added a four chamber quiet pipe to my 120AX and now it is turning that same APC14x12 @9800rpm[sm=thumbup.gif][sm=teeth_smile.gif] The plane is going like crazy[sm=wink_smile.gif]
Old 09-18-2006, 08:54 AM
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vlado
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Default RE: O.S 1.20AX Owners. Post your tach readings

WOW , what pipe do you have ?
Old 09-18-2006, 09:39 AM
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Flyer95
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Default RE: O.S 1.20AX Owners. Post your tach readings

I have the flatdisk pipe made by the Just engines for the 160-180 engines. It is called "Purple Pipe" but is also available in aluminium finish.

I forgotten to attach the link to the JE, here it is now.

http://www.justengines.unseen.org/pipesjen.htm
Old 10-21-2006, 10:27 PM
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Default RE: O.S 1.20AX Owners. Post your tach readings

Graupner 15x8, Fox 5% fuel/20% castor=9,475
Old 04-27-2007, 07:10 PM
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Default RE: O.S 1.20AX Owners. Post your tach readings

APC 16x6 on Powermaster 5% with the new version of the Bisson pitts which has been changed to deliver more pressure to the tank. I got an easy 9600 but didn't want to push it any more. I tuned it to fly at 9200. I would like to try a lighter wood prop to see if I can get closer to a 4 stroke transition but it wasn't bad. Does anyone know what the upper RPM limit of this motor is?


ORIGINAL: RoughLandin

Update on the OS 120 AX in the H9 Showtime.

Amazing engine, still only have about 6 full tanks through it but very happy. I'm spinning an APC 17x6 prop.


Exhaust report:
I was using a shortened Bisson muffler specifically made for this engine I then chopped down the expansion chamber about 2 inches to make it fit in the cowl, then narrowed the exhaust diameter to replace the lost of back pressure. With this combo I was getting about 8400 RPM far less than the reported 9200. This combo will hover at about 3/8 throttle and has great pull out even at these lower RPM numbers.

I then switched to the stock Powerbox muffler with the pitts adapter and immediately got 8900 RPM. I figure this will improve closer to the 9200 as the engine completes break-in phase. The sound is improved (quieter but deeper), at lower RPM it now doesn't have that irritating 2 stroke rattle/ratatattat sound that it had with the Bisson though full throttle does not sound as impressive. I figure the increase in backpressure will help transition performance (still breaking in) but I'm really excited about the extra 500 instant RPMs. I have not flown this combo yet.

All figures are using 15/15 PowerMaster fuel at sea level.

I may also try the APC 16.5x5W prop and switch to a plastic spinner to reduce weigh and improve transition performance. How are every one elses transitions, last several engines were 4 strokes which seam a little better in this area... [&o]
Old 04-30-2007, 08:06 AM
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Default RE: O.S 1.20AX Owners. Post your tach readings

From the Tower- OS specs. Practical RPM: 1,800 - 9,500
Old 07-13-2007, 01:37 PM
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Default RE: O.S 1.20AX Owners. Post your tach readings

APC 17x6
Omega 15%
Stock Muffler
600' ASL
8900 rpm

Best prop I've found yet for my 1.20. The prop-braking on downlines is just about perfect for my taste. Would like to try a 17x6 Xoar though.
Old 07-13-2007, 07:06 PM
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Default RE: O.S 1.20AX Owners. Post your tach readings


ORIGINAL: Berwyn Bill

APC 17x6
Omega 15%
Stock Muffler
600' ASL
8900 rpm

Best prop I've found yet for my 1.20. The prop-braking on downlines is just about perfect for my taste. Would like to try a 17x6 Xoar though.
Hi Bill,

I am running a Menz wood 16x6 and getting 10K on 10% with the pits muffler. I find that the spool up is really quick with the lighter prop and the performance is really similar to APC's. I tried Zingers and they were really bad. Do you get a super strong hover pullout with the 17x6. I was going to try it but thought it might kill off too much speed. Wood is definitely the way to go on this engine though.

If you check out the new OS 200 four stroke it puts out 2.9HP at 9000 RPM. Were getting the same on a much lighter and less expensive engine. I love this thing.
Old 07-16-2007, 07:14 PM
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Default RE: O.S 1.20AX Owners. Post your tach readings

ORIGINAL: rino


ORIGINAL: Berwyn Bill

APC 17x6
Omega 15%
Stock Muffler
600' ASL
8900 rpm

Best prop I've found yet for my 1.20. The prop-braking on downlines is just about perfect for my taste. Would like to try a 17x6 Xoar though.
Hi Bill,

I am running a Menz wood 16x6 and getting 10K on 10% with the pits muffler. I find that the spool up is really quick with the lighter prop and the performance is really similar to APC's. I tried Zingers and they were really bad. Do you get a super strong hover pullout with the 17x6. I was going to try it but thought it might kill off too much speed. Wood is definitely the way to go on this engine though.

If you check out the new OS 200 four stroke it puts out 2.9HP at 9000 RPM. Were getting the same on a much lighter and less expensive engine. I love this thing.
Rino,

I like wood props on a lot of my planes but the APC is available at my LHS and not too pricey (club discount is nice too). The hover pullout is astounding on my Fusion 90 (7# 7 oz), Estes rocket-like. With the 17" dia. the surfaces really come alive and it smooths out everything. As far as killing off speed, iot does have considerable braking power but I like that for practicing IMAC and keep my figures smooth and clean.

I'm sure the Menz is great but the APC is damn good too, wood or not. Spool up on the APC is very nice and overall transition is smooth and linear.
Old 08-07-2007, 07:02 PM
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Default RE: O.S 1.20AX Owners. Post your tach readings

9,500 dead on, cool power 5%, really owns, apc 17x6, stock muffler, lovin it.
Old 08-11-2007, 10:50 PM
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Default RE: O.S 1.20AX Owners. Post your tach readings

Malcolmm--What muffler are you running ???

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