Another Prop Chart
 

I hope this will work.
Prop Chart for 2-Stroke Engines (cu. in.)

......... Starting Propellers........ Alternate Propellers

.049.......6-3____________ 5¼-4, 5½-4, 6-3½, 6-4, 7-3

.09........7-4____________ 7-3, 7-4½, 7-5

.15.........8-4____________ 8-5, 8-6 ,9-4

.19 - .25.9-4____________ 8-5, 8-6, 9-5

.29 - .30. 9-6___________ 9-7, 9½-6, 10-5

.35 - .36.10-6__________ 9-7, 10-5, 11-4

.40.........10-6__________ 9-8, 11-5

.45..........10-7__________ 10-6, 11-5, 11-6, 12-4


.46..........10-6__________ 10-6, 10-7, 11-5, 11-6, 11-7,12-4

.50..........11-6__________ 10-7, 10-8, 11-7, 12-4, 12-5

.60 - .61...11-7__________ 11-7½, 11-7¾, 11-8, 12-6

.70...........12-6__________ 11-8, 12-8, 13-6, 14-4

.78 - .80...13-6__________ 12-8, 14-4, 14-5


.90 - .91...14-6__________ 13-8, 15-6, 16-5


1.08........16-6__________ 15-8, 18-5


1.2..........16-8__________ 16-10, 18-5, 18-6

1.5..........18-6__________ 18-8, 20-6

1.8..........18-8__________ 18-10, 20-6, 20-8, 22-6

2.0..........20-8__________ 18-10, 20-6, 20-10, 22-6

RE: Another Prop Chart
 

You left out .25

RE: Another Prop Chart
 

25 ?,as soon as i find it i'll post it,i had enough problems with the first ones. :)

RE: Another Prop Chart
 

On .15 size engines,
7x4 is my normal prop.
8x3 is also good.
9x4, no way would I put a 9x4 on a typical .14

On .25 -.30 size engines,
9x4 is useable (what I run all the time),
9x6 more typicalf for sport flying.
10x4 is ok.
8x5 is a bit small for the hotter .25's.

You skipped right over .32

No mention of .061 either. I use a 5x3 on mine

a .45 and a .46 are close enough to be the same thing. (most engine companies round a bit anyway, so really, a ".46" from one company could be smaller than a .45 from another. And certainly the power output, and approprate prop could vary quite a lot.

Fwiw, I'm generally not in favor of such charts. They usually over-simplify and over-limit the prop selection for your application. In part because different engines in the same size class are often very different in performace. The OS .40 LA for example, is not a terribly powerful engine. I run the same prop on my OS .32F as on my .40LA, and frankly, I think the .32F turns it to a higher RPM. While an OS .40FX would be a differnet story entirely.

Also, the larger the engines seem to run well with a larger range of props.

RE: Another Prop Chart
 

Ok,i get it,YA'LL (texas talk) are just picking on me but that's ok,i posted this for some "newbies" like myself.I copied and printed it along with another from Power Point,i also put them in plastic sheeting so they should last a lifetime,i might need a quick reference. :D

RE: Another Prop Chart
 

In graphical form: http://www.top-flite.com/accys/topq5000a.html

RE: Another Prop Chart
 

Ok,look at this one,it includes the 4 strokers to.
Try this :D

RE: Another Prop Chart
 

While I applaud your efforts, it is not easy to chart what prop goes on what engine. Diffs in engine power, fuel used, and even altitude and temp play a large part in what prop the engine can turn. Beyond that, the plane type and one's personal flying style also effect prop selection. Taking it another step, a Zinner 10x6 won't turn anything like a Master Airscrew 10x6 which won't turn like a APC 10x6. While you have laid out a good starting point, I found it interesting that I don't have any of the sizes you list for my engines.

Not trying to steal any thunder, but if I may, I'd like to suggest another method. Using your chart, or the engine directions, start with some reasonable prop. Tach the prop. Then download the following free program

http://freespace.virgin.net/barry.ho.../thrusthp.html

Using this calculator, punch in you data. This will give you a starting point for knowing the load your engine can deal with. Then you can play with different props in the calculator. Based on your initial measurement, you can easily find out at what RPM your engine will probably turn different props.

I've used this calculator for several years on everything from a YS45 2s spinning a 10x10 to YS140DZ 4s spinning 18x6 to DA100 twin spinning a 28x10. The calc seems to predict performance fairly well across this broad spectrum.

RE: Another Prop Chart
 

Try this one.
http://www.geistware.com/rcmodeling/prop_charts.htm

It has the .25ci engine listed

RE: Another Prop Chart
 

5_spot,

Not picking on you at all. Listing a prop or two for various engines as a "place to start" is one thing, and can be useful. For that purpose, you can just check the engine instructions, or just list one prop for each size as a starter.

But the problem with charts and such is they tend to be interperted by beginners as "listed props are ok, not listed props are not ok".

When what a beginner should be learning is that our engines can actually run with a rather wide variety of prop sizes, and you want to pick your prop to match your engine (not just displacement/size, but the make and model), airframe, and the way you expect to fly it. It sounds complicated, but it's actually not a big deal.