IMaflyer

My Feedback: (1)

I am assembling a Hangar9 Showtime 50 with a Saito .82 FS engine. I have seen a predominance of the 14x6 prop recommended for that engine. My question is: what style of prop should I choose and why? Scimitar, K-series, pattern-style, there are several options out there and I don't understand what the purpose of each design is. I checked on the packaging of each of those styles at my LHS, but there is no information available there.

Thanks for your consideration!

And thank you God for Mr. Bernoulli, for lift and for blue skies.

flygilmore

I would use a Xoar 14x6 for your application....won't be sorry!

jaka

Hi!
A 14x6 prop might be too large as it is mostly used on .90 engines, but it might work for a .82 four stroke too so try one.
APC , RAM or Graupner Cam prop are considered the best props today. Avoid Master A black with white tips props as these are no good (Loud and no performance). Scimitar series is a little better though.

IMaflyer

My Feedback: (1)

My question is not about prop sizes or brands. [:@] I am asking about prop styles and why one would choose a certain style over another. What are the design benefits or purposes of the scimitar style vs. k-series vs. standard, etc. I hope this will clarify the purpose of this thread.

@flygilmore: Why? I am interested in the 'why' behind a choice for xoar.

carrellh

APC uses all sorts of descriptive terms but they only have one offering in most of the sizes (exclude pusher and 'electric only' versions of some sizes). I know they have some models that are available with "wide" or "narrow" blades in addition to the standard blade.

The 14x6 (part number LP14060) is listed as a "sport prop" now but I have several at home that carry the "Pattern" description (same part number).

w8ye

My Feedback: (16)

The Saito 82 will pull a 14 X 6 of whatever style just fine

Some use a APC 14 X 4W for 3D and others use the APC 15 X 4W for the same purpose but use 30% nitro.

The Vess props are very nice looking and should be worth considering for they have a unique airfoil and tipe design


http://www.horizonhobby.com/Products...ProdID=VSS1406

daveopam

My Feedback: (9)

I run a Zinger Pro series 15x4 on mine. The Xoar sounds like a good choice in the 14x6 size. Either way pick something wood. The spool is soooo much better.


David

ro347

My Feedback: (13)

Agreed!

Augie11

Same here. Can't beat a good wooden prop, except on a seaplane. I use the MA wood scimitars on my WWI because they look 'scale' and perform better than the MA 'K' series. The APC's generally give you more rpm, size for size than the MA 'K''s but I really haven't had any problems with the K's. Some folks just don't like 'em

IMaflyer

My Feedback: (1)

Thanks a lot for your replies and consideration everyone. [8D]
What do you mean when you say that the wooden props spool better?

Tarasdad

Engine revs and slows more quickly. I've always favored Zinger wood props (standard sport type) for my FA80.

w8ye

My Feedback: (16)

The wooden props weigh less and therefore have less flywheel inertia effect. So the engine will speed up and slow down faster

flygilmore

Spool up and performance in the air is why I choose Xoar or Vess props....they have always proven best in my applications.

IMaflyer

My Feedback: (1)

Any thoughts on the performance difference between the square end props versus the rounded, scimitar-looking design? For instance, compare the Zinger Standard 14x6 (square) and the Pro Zinger 14x6 (sword-like rounded). Feel free to chime in here, Zinger/Xoar reps!!!

w8ye

My Feedback: (16)

Forget the regular Zinger

jaka

Hi!
Being a race pilot I can say that prop tips has nothing to do with performance...It's the overall shape and thickness of the prop that counts.
Thats why APC , Graupner Cam-prop and RAM are the best plastic props today.

Charlie P.

Surprisingly, wood is also stiffer and it doesn't deform at speed like the plastic, Nylon or composite props can. I like wood on the models I hand start because they break when they hit bone and are not as sharp. Sobering thought, but a 20" APC scares the crap out of me.

Back to the .82 on a Showtime 50 - I'd use the APC Sport style. I use ProZingers on my os 70S II four-stroke. It can depend on the overall looks of the model and certainly what you want to do with it. Speed, aerobatics; IMAC vs. 3-D, pattern, warbird, etc.

w8ye

My Feedback: (16)

The speed guys like the regular Zingers in the appropriate sizes

But for sport flying or 3D, we are better off with the Pro Zingers

IMaflyer

My Feedback: (1)

WHY?

Why does one prop spool up better than another?
Why do speed guys prefer the wooden standard, but other guys prefer the Pro Zinger?
Why are K-series props particularly well-suited to 4-stroke engines?

I have read that 4-stroke engines are higher torque engines whereas 2-strokes operate more on higher RPMs, so naturally a larger diameter prop will be more efficient on a 4-stroke (less RPM and more torque) and a smaller diameter prop will function better with a 2-stroke (less torque and more RPM). For you scientists, I know I'm over-simplifying, but I'm a music pastor. Give me a break.

Charlie, thank you for the answer to: Why wood over nylon? (Wood is stiffer and doesn't deform at high speed.) As for the rest of your post, I'll clarify that this airplane's main purpose will be aerobatics (possibly 3D, but mostly IMAC)

Jaka, what is it about the overall shape and thickness that makes a prop count?

W8ye, Thank you for your elucidation of the wooden prop's spooling characteristics. Why forget the regular Zinger? Why are we better off with the Pro Zingers? I am not doubting you; I'm just curious about the background that led you to that conclusion. Until today (and with all of your help), I had no way of intelligently choosing one prop over the other outside of apparently random suggestions.

Thank you all for your information and for helping to educate me! [8D]

To further muddy the waters, any opinions out there (duh!) about why I would lay out $10 for a Vess prop instead of $5-$6 for a Master Airscrew? Is Vess the Ferrari and M.A. the Yugo here? Is there a significant enough difference to warrant the price or am I just paying for the smarmy logo and shiny varnish on the more expensive prop?

w8ye

My Feedback: (16)

If you lay a Vess and a MAS prop side beside and take a good look. you would be willing to pay more for the Vess

The pro Zinger has superior airfoil and blade shape compared with the standard Zinger

w8ye

My Feedback: (16)

Props are a personal thing.

One flies better because it looks pretty?

You need to get some of these different brands and types and decide for yourself what you like and then you can tell us "WHY"

IMaflyer

My Feedback: (1)

w8ye,
True, true. Although what you are suggesting sounds a lot like homework.

I'm not trying to avoid thinking for myself; I simply want to drink from the fountain of accumulated knowledge and experience here at RCU. I also don't have the discretionary funds to just go buy a bunch of different props to test, so I'm trying to narrow down the wide field of choices with all of your help.

w8ye

My Feedback: (16)

Most of us will eventually try a couple brands and settle on the one we like best

With me it was rather on-going for years

Charlie P.

I must say after trying a couple of the Xoar (Beechwood, made in Germany) sport version that I am very impressed just on the looks and finish alone. They are very well crafted and were perfectly balanced at the factory; as is their promise. Run about 10% more $ than ProZingers for like size.

A few more tidbits for IMa: APC are quieter than, as far as I know, any other prop. They use the same parameters (and engineers) as they did to develop props for military submarines. At our field they are good for a few dB noise reduction.

Pattern props are designed to allow a down line of equivalent speed to an upline in pattern planes. (i.e.: a square loop that does not slow down much going straight up or speed up going straight down!) They are designed more for torque than flat-out speed. Also, for four-stroke glow engines or gasoline 2-stroke, pretty much. Pylon props are designed for flat out speed. Sport props have a wider envelope but excel at neither.

Wood props are usually beech or maple. Maple is heavier, so beech would be the choice if you are a throttle jockey. Believe it of not - some pilots fly level at half throttle mostly and compensate for the model's changes in attitude by adding or reducing engine power. I know several flyers who don't know of this technique. ;-)

IMaflyer

My Feedback: (1)

Wow, Charlie P., you are the prop master. Thank you for the excellent information, buddy; that's exactly what I was hoping to learn.. I resonate with what you said about APC props. I use one on my Magnum 1.20 FS, Goldberg Ultimate 10-300 and it certainly is quiet. I read about attitude adjustments using throttle management, but I've not tried it yet. Again, thanks for taking the time to explain!