APC 10.5 X 4.5 ...... The 'WONDER ' Prop ?

[Robin_Holden]

I'm picking up a lot of good reports about this prop.

Anybody out there with their own opinion / experience regarding this propeller ?

Would appreciate what engines you'd consider suit this prop best ?

Much obliged ,

Robin [ ex-pat Brit in the Charente full of ex-pat Brits ]

[Mark Scarborough]

Heck since I seem good at stirring things up, let me be the first. Same idea as I wrote over there, but lets see if someone else will jump on here, maybe I can learn more myself?
In my experience, I have heard it touted as a prop for everything from an FP 40, to an LA 46. I personally havent found it very substatial on anything over an LA or FP 25. It doesnt have a lot of blade area. The LA 46 seems happiest running around 9600 to 9800 and this is just not enough diameter, and to much pitch. the APC 12.25 x 3.75 being my prop of choice on the LA 46. as for FP 40, I again dont think there is enough blade area there to do the job. The FP seems to want just a touch more pitch than the LA but still in the 11 to 11.5 range, anything less and it wants to play race plane.
I have heard all the claims about this prop, and I have played with it, I personally believe it gives away the one KEY ingrediant that we need, that is *traction* As I said you may like it on an LA 25.
my experience,, your mileage may vary
One other factor to keep in mind is the density altitude you fly at. at lower altitudes, you may get away with it, here, at 3000 ASL on a warm day it just dont cut it!

[Dennis Vander Kuur]

Robin,
I use the APC 10.5x4.5 prop on my LA.40 powered Pathfinder (kit built) and love it. Originally I used a RevUp 10x6 Extra wide. However, after a couple years of flying and a couple minor "impact incidents" I found that the nose of the plane vibrating badly when I started the engine(yes the props were carefully balanced). I tried the APC 10.5x4.5 and the vibration went away. The engine was turning a higher rpm that apparently got the engine/fuselage out of the resonance frequency causing the vibration. With the vibration gone, I flew the plane and it flew better than ever. The engine was happy turning about 11,400 rpm and the flying speed was pretty consistent through the pattern maneuvers. This prop/engine/plane combination has served me well flying in the P-40 event on the Midwest contest circuit. Your results may vary depending on your plane/engine combination.
DennisV

[Dennis Moritz]

In the Philly Flyers we use the 10.5x4.5APCs on FP40s and 35s. Almost always the best choice. It often helps to balance the running characteristics of these engines, providing excellent power without runaway. Most of our FP40s and 35s are stock. The prop will work well on LA40s, but those engines are usually more flexible, handling a wider range of props without runaway issues. Same goes for the Brodak 40s that we've run. For the LA46 we try the 11.5x4apc first. Of course, every engine/airplane combination tunes differently. In many 40s the 10.5x4.5apc can be an excellent choice, with 40 and 35FPs they are often part of the "magic" tune. IMHO that's too much prop for a 25.

[Joe Yau]

The APC 10.5"x4.5 was indeed the magic prop for my ST C.35 powered flapped Flite Streak. I cut it down to 10"x4.5 and it worked great!  The first impression was it ran smoother, grooves better in round maneuvers, and the overhead line tension was also better.. especially comparing to the typical APC & MA 10x4, 10x5.

[Walter Hicks]

Try it on a Brodak .40 at about 11,000 rpm, this is not a typo it will 2-4 at that rpm and mucho power.

[Martin Quartim]

So far it is the best prop for my Enya SS30 / RingMaster.

Martin

[Joe Messinger]

I doubt there is any one "magic" propeller but, in my opinion, the APC 10.5 x 4.5 is a very good prop for a .40 sized engine.  I have several modified Twisters with LA .40 engines that perform remarkably better with the 10.5 x 4.5 prop than any of the many I've tried.  I think it's not enough prop for a .46 and too much for a .25.

Randy Smith sent me a new Super Tiger 11 x 4.5 prop which I installed on my Oriental powered by an LA .40 that he reworked.  On that combination, the S.T. prop performed much better than the APC 10.5x 4.5.  Really nice propeller. No flash on the leading and trailing edges and the balance was perfect stock.  I plan to order more of the Super Tiger props in other sizes.  By the way, it is spelled "Tiger" on the prop as opposed to "Tigre" on the engines.

As noted earlier by others, something might work well for one person and another has the opposite experience.  As an example, Mark mentioned that his LA .46 is happiest with an APC 12.25 x 3.75 prop.  I tried that prop on a couple LA .46 powered Cardinals I have.  Not good for me.  APC 12 x 4 props worked the best.  Who knows?  Lots of reasons, I suppose.  You just have to try different things until you find something that works for you, I think.

Joe

[Mark Scarborough]

Joe,
exactly right
****Lots of reasons, I suppose.  You just have to try different things until you find something that works for you, I think.*****
there are so many other variables that without attempting to at least duplicate the remainder of my setup, the odds of my prop working for you would be slim. I think one of the reasons the 10.5 x 4.5 works well for  many is that it doesnt tax the motor, its not really using all the available power so you are effectivly regulating your setup with the prop, as opposed to my setup that attempts to regulate it more with fuel mix, as in amount of oil, prop diameter, and mostly venturi bore. Differences in philosphy and comfort with your setup affect the whole result. not to mention, altitude, temperature, fuel tank system and the size and weight of the airframe. So your statement about trying things, is extremely valid. I know that for Pat Johnston and I, and a few others in the northwest, we have found the APC 12.25 to be  a very effective tool on and LA 46, our venturi bore typically is in the .275 range with a ST needle. of course then Pat also does the pattern with this setup on about 3.5 oz, whereas I need more like 4.25, same setup, same airplane within an ounce of his, same rpm, just something about his magic touch I guess, lol,,

[Scott B. Riese]

MARK....when are you going to move over to the other side......

Of the mountains. Then you can fly almost everyday. 

[Mark Scarborough]

lol, Scott, when my job moves over there, or the girls graduate from school, or ,,,,,
well who knows what tomorrow brings,,

[Joe Messinger]

I was just out in my workshop looking at some propellers and noticed that the "Super Tiger" prop I commented on in my earlier post on this thread is really a "Thunder Tiger" prop.  I either only read the "Tiger" and assumed the first word was "Super," was trying to read the name without my glasses or had another senior moment.
Whatever the cause for my blunder, it is a good prop and performs well on my Oriental, powered by a Randy Smith LA .40.  Sorry for the mistake.  Hope I didn't cause too much confusion.

Joe

[keith sandberg]

Having been beaten by DennisV and his Pathfinder several times I can attest to how well it works, Keith Sandberg

[Ralph Wenzel (d)]

It turns out I was using almost exactly this same prop about 2 years ago on a B.40-powered Cardinal. I made mine from an old Rev-Up 12-5, which became sort of a 10˝-4˝EW. Launch rpm around 9800; excellent 4-2-4; fair economy. Unfortunately, I'm running real low on the Rev-Up's


Ralph

[Mark Scarborough]

GOod point, however the APC 10.5 x 4.5 is a narrow blade, free flight prop, not much blade area at all really

[FLOYD CARTER]

Those APC props are very popular.  I cannot bring myself to use one.  Even with an electric starter, they scare me unless I'm several feet removed.

When it comes to experimenting with props of slightly different diameters and pitch, available wood props are almost altogether absent. 

I would like to find wood props in 11" , 11.5" or 12" with low pitch, say 4 or 4+"

Floyd in OR

[Steve Helmick]

Maybe Dr. Sparks wouldn't be scared of the Thunder Tiger 11 x 4.5? Also, don't overlook the Graupner props, if they have the pitch you need (nothing as low as 4" pitch in diameters over 9"). The APC's are really good if you find the correct one for your application. All of 'em hurt if you stick your hand in the way, but I've found no stock wood props that are the equal of one of the above stock plastic units. APC does offer buku sizes...a real nice selling point.

For wood props, I'm not interested in using something that is not replaceable, at least if I don't have a bag full in stock! I have not yet flown the RSM props, tho have a few. I'm not at all sure that those sizes would work on anything I'm currently flying. The Pro Zingers give some hope, but they do appear to need a good bit of hand work to correct the airfoil. They come in 11-4, 5 & 6, and 12-4, 5 & 6, but you may not find those in the Tower Catalog. Look online at Hobby People, instead. I tried an 11-4 Pro Zinger (reworked) on my Olympic in Salem (Friday) but buzzed the tips on takeoff,  so it wasn't a good test. Gonna make a new set of LG struts this Winter.  Steve

[Steve Holt]

Another nice prop for engines like the Magnum 36 and EVO 36 is the Bolly Clubman 10.5X5.  Wider blades than the APC and a bit lighter.  I've got one now on my Leo 37 powered Primary Force and it flys the airplane better than the APC 10.5X4.5 did.
Steve

[Robin_Holden]

So far it is the best prop for my Enya SS30 / RingMaster.

Martin

Martin , just got back from the field and have tried this APC prop on my Enya 30 powered model.

Transformed ! It's never run so well.........Thanks for the tip !

I'm very much obliged.

Kind regards , Robin.

[Martin Quartim]

Robin,

Glad to hear that.  What model do you have ?

Martin

[Clint Ormosen]

Another nice prop for engines like the Magnum 36 and EVO 36 is the Bolly Clubman 10.5X5.  Wider blades than the APC and a bit lighter.  I've got one now on my Leo 37 powered Primary Force and it flys the airplane better than the APC 10.5X4.5 did.
Steve

That Bolly Clubman 10.5 X 5 works great on Brodak 40's as well. Spun at 10.4 K.

I used the APC 10.5 X 4.5 on my FP 40 with good results untill I had to fly in really HOT weather. Then there was no bite to it at all. Had to switch to something with more blade area.

[Robin_Holden]

Robin,

Glad to hear that.  What model do you have ?

Martin

Martin , I'll do my best to answer your question.

The model is nothing spectacular ! It's one of my own concoctions using the moments etc from a Lightening Streak with a slightly longer nose. I tend to always have something on the building board so if there's balsa going spare I tend to build someting . I'm a big Enya fan and bought one of the re-manufactured Enya 35's from Enya Direct.

That said , I'm a 'returnee' [ about 4 years ago ] to Stunt after retiring to France in '97 so my skills with the handle leave a lot to be desired.

My favourites are my 'quality' models i.e. The ones NOT designed by me , Brodak Cardinal [ G51 mod'd by Tom Dixon ], a selection of Sig Twisters [ OS 35Fp also mod'd by Tom and a  Magnum 36 ] and the Sig Banshee which housed my Enya 35 before it decided to have a row with the field where we fly ! The field won !

Better go before I bore you to sleep ,

Kind regards from S.W.France and thanks again for the prop tip !

Robin.

 

[Clayton Berry]

Tom Hampshire gave me one (insisted, is more like it) at the Brodak contest of 98. 

I've been using it exclusively on Tower 40's ever since, both with Twister renditions and a Cardinal.  It just works great.  Looks a little mean, but it builds on my macho image, and I need all the help I can get with that.

Had a couple of K&B 40's that liked it, but I finally gave those boat anchors away.

[Phil Spillman]

Such a timely post! This afternoon, 11-1-08 Pat Rowen and I were out flying. I had had a superb running LA .40 on another ship which just wasn't the same world beater on a Brodak Hellcat profile. Pat suggested that I try an APC 10.5 X 4.5 in place of the Pro Zinger 11 X 4 that I had been using. Fortunately I found one in my flight box and it solved my problem! I prefer a high four cycle run with a touch of two every now and then. This prop gave me what I had been missing.

I used to run these on my FP's but had gotten away from them! Nice to "rediscover" this prop!
Phil Spillman

[Allan Perret]

I was just out in my workshop looking at some propellers and noticed that the "Super Tiger" prop I commented on in my earlier post on this thread is really a "Thunder Tiger" prop.  I either only read the "Tiger" and assumed the first word was "Super," was trying to read the name without my glasses or had another senior moment.
Whatever the cause for my blunder, it is a good prop and performs well on my Oriental, powered by a Randy Smith LA .40.  Sorry for the mistake.  Hope I didn't cause too much confusion.

Joe

What material are the Thunder Tiger props?

[Jim Oliver]

Some sort of plastic or nylon.  The color/material looks similiar to the gray Graupner props.

Jim