daveopam

My Feedback: (9)

I have had a few props on my 1.25. I was starting to think I had a bad one. The APC16x6 would pull the plane around but the spool up was terrible and the engine sounded over loaded all the time. A 15x6APC would be just OK on a profile but I had this on a 10lb bipe it it was lacking. The 16X4W APC is pretty good on it. But again it is a better 3D prop than a sport prop. I took the 1.25 off of the bipe and put it on a 67" Fusion from OMP. After searching Tower for all the different props that would run on the 1.25 I decided to try the 16x6 Scimitar Series. The 1.25 really came to life. It had the familiar Saito pop in the exhaust it did not have before. Spool up was instant.
This is THE prop for the 1.25 IMHO.

BTW I am running the stock plug and muffler and use 15% PowerMaster with syn/castor blend. If you want to run 30% the 16x6APC is a good choice. I just don't want to run 30 all the time.

David

Ken6PPC

David, I run an APC 16x6 on my Saito 1.25, and I have been pretty happy with it. However, I wouldn't mind trying another prop that might make me happier.

What company makes the 16x6 Scimitar you are using?

Ken6PPC

Never mind - I think I found it....

http://www3.towerhobbies.com/cgi-bin...?&I=LXAA48&P=7

Flyboy Dave

My Feedback: (21)

.....amazing, isn't it....

....another Member finds out how much better the Master Airscrew is over
the APC plastic prop....no kidding ?


FBD.

daveopam

My Feedback: (9)

Ken let me know if your 1.25 reacted the same way as mine.

In my excitement Sunday. I forgot to say I also ran a MA 15x8 on this engine. On the bipe it was actually the best of the bunch. I just felt a 8" pitch prop was way to much for a profile. I want it to hover and have the best spool up possible. I never got the chance to run the Scimitar on the bipe.

flyboydave, That is the one. I wish they made a 18x6 I could run on my 1.80 Saito.

David

blw

My Feedback: (3)

I haven't tried a Scimitar prop on my 1.25 yet, but the APC 15x6 is a good one right now for pattern on a 60-90 CA Models Epsilon that I'm flying. Thanks for the info. I need to start looking at other props to settle in on the right one for my style of flying this kit. My estimate is that the Epsilon is around 7 lbs, so maybe the 12x6 does better with a lighter model. There are a lot of variables to take into account when looking for the right prop for a particular model/engine setup. Cowl shape is a major consideration due to the effects of symmetrical/non symmetrical effects on the prop disc.

Interesting that 30% gives that much more performance. I only run 15%.

daveopam

My Feedback: (9)

I have run both 30% and 15% in all my Saitos. As a general rule. The 30% gives only a few hundred RPM more but gives much better spool up. As of now I only run 30% in the 82. It is on a Funtana and runs a 15X4 Zinger Pro. On 15% it will not turn the Zinger. I would have to step down to a 14x4.

BTW the Fusion comes in at 7.5lbs.

David

rexracer

Dave, have you ever tried any of the MA Classic series? I have a MA Classic 18x6 on my 1.80, and it turned 8800 rpm with 15% wildcat on a 45 degree day. It's in a GP Super Stearman, which hasn't flown yet, but I'm sure it will fly great with this combo. Came in at less than 15lbs.

daveopam

My Feedback: (9)

I have not tried one on the 1.80. I bought a Top Flight Power Point 18x6 for it but have not tried it yet. I have tried APC18x6W and Zinger Pro 18x6 with no luck. The APC is way to heavy. The zinger is just to much of a load on 15% nitro. Right now I have a APC17x8. It is fine for general flight but stinks at hovering. It's just to much pitch. If the TF isn't right I will try the MA. I have $60 worth of props for this thing right now and am still not happy with it. I even thought I would try a CF prop. It is a last resort.

Thanks,David

blw

My Feedback: (3)

I have an APC 15x6 on my Saito 1.25. It is pulling a CA Models Epsilon built for pattern, and it pulls it with a lot of power. I've never had to wait on any revving up as power is instantaneous. I guess the whole model, with fuel, weighs at least 8 pounds. Power is there in an instant, and I rarely fly past 2/3 throttle as it is a monster with the 1.25.

Iflyglow

My Feedback: (79)

Blw,
I thought the 1.25 was made to turn a 16-6, not a 15-6.

blw

My Feedback: (3)

The recommend range is 15x6 to 17x6. Max RPM is 11,000. I measured somewhere around 9500, and that should give me plenty of room once the prop unloads and becomes efficient in the air, which it sounds like it does. If I'm actually around 10,500 in the air, that is just right for me.

I would like to see what a similar prop from Graupner and Bolly would do.

jaka

Hi!

A 15x6 is way too small for a 20cc four stroke engine (1.20).
15x8 or 16x6 is the size to use for most airplanes.

Iflyglow

My Feedback: (79)

Jaka,
I totally agree with you.

blw

My Feedback: (3)

Why do you suggest that this is too small for the 1.25?

Just picking a number like Jaka's suggestion of a 15x8 or 16x6 may be a good starting point for *some* models, but there is no way you can state that this is a rule. This leaves no room for the person who wants something to match his flying style or goals for a model. In my case, I do not want more speed and I do want effortless vertical for pattern flying. And, I do want the engine to be able to produce at least 10,000 RPM in the air. The 1.25 sounds incredible when putting out the RPMs!

It turns the engine just where I want it to be running with sufficient margin between unloading and max RPMs.

It performs better than I had hoped.

It is within the recommended range of Saito.

I admit to having thought of bumping up to an APC 15x8, but I'm not sure about the model doing well with more speed. I had some very bad flutter problems due to a bonehead mistake of mine when preflighting it for the first flight. I chased down the damage flight after flight, and am lucky it is still flying. It is now a pure pattern plane for flying without any snaps or spins. I think it will last a long time, but I'm not willing to push it at the present time. Maybe after 100 flights, or so.

daveopam

My Feedback: (9)

I have a small update on the Scimitar 1.25 Combo. I did few tach runs at the field on Sunday. Temp was 65 I am using 15% Power Master and the field is 2,000ASL.
First ran up the APC 16x6. 200RPM rich of peak was 8,200. Then ran up the MA Scimitar. Also 200 rich of peak. It turned 9,100. The difference in pull is night/day. The difference in spool up is also night/day. I have about 20 tanks through the Saito now. After another gallon it may even gain a few hundred.

David

Ken6PPC

I tried a MA Scimitar 16x6 on my Saito 1.25, and I went back to the APC 16x6. It did give me a few hundred more RPM's, but it seemed to pull less on my setup than the APC. I also had a less reliable and stable idle with the Scimitar. Go figure.....

Perhaps it has more to do with the plane than we realize?

My 1.25 is on a Seagull Edge 540.

daveopam

My Feedback: (9)

The idle difference is in the lighter prop. Four strokes will idle slower with a heavier prop.

David

Ken6PPC

Yeah, I agree. I'm sure the lighter weight prop does require higher idle RPM's.

The surprising part was that the 16x6 Scimitar didn't seem to perform quite as well for me on my plane, as the 16x6 APC. I fully expected it to outshine the APC.

I suppose "performance" is subjective?

daveopam

My Feedback: (9)

I guess your right. I do mostly 3D with mine. I would be afraid to hover on the deck with the APC. It just wont respond quick enough. With the MA it's not a problem at all. The only time I am full throttle is doing water falls or going straight up.

David

jaka

Hi!
Why!
Just my personal experience from 33 years flying R/C models.
30 years ago ...or 25, I don't remember exactly I bought an OS FS 1.20. I flew it in an "Old Tiger" Formula I racer built from plans in MAN (span around 185cm). I still have all my MAN, RCM, Model builder and Model-Aviation magazines from 1975.
A 16x6 Zinger or Top-Flite (Thinned down and slighly modified) was the prop to use in that airplane.
Since then I have run several other of all four stroke engine brands and helped a lot of people with their four strokes and I can say that if you fly at sea level in a temperate climate like ourswith temperatures from -20 - +35 degrees Celsius,then either a 15x8 or 16x6 prop is going to work best, this regardless of airplane size or weight. A 15x6 is going to make the engine rew over 10000rpm and this is to much if you want good performance. Better aim for a rpm in the range of 8500-9500rpm.

Spinning up will be instantaneous with a 16x6 or a 15x8, regardless of brand, if you set the idle needle correctly

Hobbsy

My Feedback: (102)

Jan, here are some numbers I got a few minutes ago with my 1.25 and WildCat 15%/18% lube
MA Classic 16x6===9,450
Graupner 15x8====8,795
MA K prop15x8====8,975
That's quite a difference. I don't have an APC in the 15x8 or 16x6 size.

daveopam

My Feedback: (9)

Jan I respectfully disagree with your last line. The MA prop I am using is wood. The APC is of course resin. The lighter weight of the wood prop helps with the throttle response. The wood prop can be accelerated faster. In sport or pattern flying both may perform similar. The way I fly 3D the throttle is used as much if not more than any other servo. Spool up is everything.


David

Iflyglow

My Feedback: (79)

Hobbsy,
I can report that my Ys 1.10S is spinning 10,200 peaked with a APC 15-8, and 10,100 with Master Airscrew K 15-8 on WC 20-20. I might have to buy a 16-6 Scimitar just for giggles. I have yet to touch anything other than the HS needle.

Hobbsy

My Feedback: (102)

Please remove, Thanks