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-   -   what prop do i need (https://www.rcuniverse.com/forum/beginners-85/8476428-what-prop-do-i-need.html)

jsteiner 02-14-2009 03:39 PM

what prop do i need
 
i have a hobbistar 60 trainer with an os 61fx engine that is broke in already. what size prop should i use. i am a beginner..thanks for your time..jim

skippyspad 02-14-2009 03:46 PM

RE: what prop do i need
 
Looks like a 12x6-8 should work. A copy of the manual is below.

http://manuals.hobbico.com/osm/50sx-...1fx-manual.pdf

bonebreak 02-14-2009 03:53 PM

RE: what prop do i need
 
I am running a 12 X 7 on my OS .61fx.

Edit: You will need to pick up a prop reamer also as the hole on a standard prop is too small for the shaft of the .61. Do not try to make the hole bigger with a drill bit. The reamer has a slight taper on it, and will make the prop seat alot better on the shaft.

jaka 02-14-2009 04:01 PM

RE: what prop do i need
 
Hi!
If in a high winged trainer ...a 13x4, 13x5 or even a 13x6 APC or RAM if flying from sea level.
12x6 will work too but not as good as the above sizes

jsteiner 02-14-2009 04:48 PM

RE: what prop do i need
 
what would be the difference in a 12-6 prop verses 13-5?

Jetdesign 02-14-2009 05:42 PM

RE: what prop do i need
 
12-6 is a little faster top speed, takes slightly longer to reach top speed. 13-5 has more pull; shorter take-offs, better vertical performance, a touch slower top speed but better acceleration.

Trainers tend to be 'dirty' designs, meaning they have lots of drag (largely due to the fat, flat bottomed airfoil). They also are not the most graceful aerobats, so I would go with the 12-6, but it's probably best to try them both and see what YOU personally like.

LuftwaffeOberst 02-15-2009 02:42 AM

RE: what prop do i need
 
Jstiener, in your trainer arf kit you should have a os 61fx manual. Evolution and O.S. has a graph near the back of the booklet showing what prop size that is recommended. It's hard to find... but it's in there. ;)

w8ye 02-15-2009 02:52 AM

RE: what prop do i need
 
I used a 12-6 with mine. I thought it was perfect

jsteiner 02-15-2009 09:11 AM

RE: what prop do i need
 
i do see the list and it says you can use about five different props, i was just asking which one i should use and why...thanks for your input......:)

carrellh 02-15-2009 03:32 PM

RE: what prop do i need
 
I like the Master Airscrew 12x6 K Series on a trainer with a .61 two stroke. These are the black props with white tips. They are more flexible than APC props which means they do not break if the prop touches the ground when landing.

chopper man 02-16-2009 09:59 PM

RE: what prop do i need
 
I'm going to run a OS.61 on a TF Piper Arrow that I built. Some thoughts were that engine is underpowered for that plane. In your opinion can you use a different size prop to make up for an engine that may be underpowered for a plane? I oringinally had a 11x5 prop but after reading through this thread that may be way to small both in pitch and dia. Tell me what you think as well.
Thanks

chopper

w8ye 02-16-2009 10:09 PM

RE: what prop do i need
 
The minimum prop for the OS 61 is a 11 X 7

The standard everyday prop for the OS 61 is a 12 X 6

OzMo 02-18-2009 12:18 AM

RE: what prop do i need
 
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