Propeller question for newbie?
 

I have a Hobbico Superstar Trainer. The prop that came with it is WOOD. And it's already got a small chip on it.

My question is this..........What is the best type of prop to get, another wood...or plastic...or whatever else is out there?

thanks Steve

RE: Propeller question for newbie?
 

When I'm teaching A student to fly I always go straight to the Master Air Screw props. These are not A great prop but they are almost bullet proof to things like small ground strikes and nose overs. Cheap too so that is also A plus.
There are way better props out there but for people just learning to fly these are what I have in my prop box.

RE: Propeller question for newbie?
 

What he said. Stay away from the wood props for now or you will be buying a lot of them. The Master Airscrews are far from being the most efficient but you can smack and bend them repeatedly and they'll stay together. This is exactly what you need as a beginner.

http://www3.towerhobbies.com/cgi-bin...crew&search=Go

RE: Propeller question for newbie?
 

Indeed what GrayBeard and Chuckw side. In the training environment stick with the master. Later when performance becomes more of an issue then APC is my choice with an occassional Bolly throw in for good luck, except for certain old timers where the 'look' is of major importance then yes wood.

John

RE: Propeller question for newbie?
 

I'll chime in and agree with the above. Stick with Master Airscrew. When training the propeller is going to take a pretty good beating. The Master Airscrew props can deal with prop stikes and keep on running. A wood propellor is going to shatter if you have a strike with it.

Ken

RE: Propeller question for newbie?
 

Thankyou everyone, looks like it's the master for me.

Also I saw a 3 blade master.

If my plane came with a 2blade, would it help with 3 blades or throw the whole areodynamics out?

thanks Steve

RE: Propeller question for newbie?
 

Don't go there yet!! ;)

RE: Propeller question for newbie?
 

3 bladed props IMHO are just for display, I have tried some of them (Master Airscrew) and they tend to loose power and thrust. There is a rule to use them, you have to go down one inch in size of the regular two bladed prop. That you are currently using. In the other hand there is a trainer system power sold by Horizon Hobby which consist on an Evolution engine and a three bladed prop combo. I have seen them work flawlessly but when they break the owners tend to go to the most common two bladed props. And how have been stated plastic fiber props. Are good for beginners.

RE: Propeller question for newbie?
 

I thankyou again for all the help. Looks like I'll stick with the 2 blade master.

Happy flying to all.

Steve

RE: Propeller question for newbie?
 

Ok I got 4 masters. That should be enough. But they are razor sharp. [X(] The hobby shop guy told me to sand them just a little to make them less sharp.

Does that sound like a good idea?

Thanks Steve

RE: Propeller question for newbie?
 

I have heard it recommended to use a metal edge (the back of an xacto?) to scrape off the sharpness from the production.

RE: Propeller question for newbie?
 

Just hit them with some sandpaper to dull the edge and then balance them. If it is out of balance, just use the sandpaper and take off some material on the heavy side.

RE: Propeller question for newbie?
 

I converted my trainer to a 3 blade prop. You will appreciate the additional ground clearance till you get the hang of landing.

RE: Propeller question for newbie?
 

I like APC for most applications and wood where weight is an issue. I'm currently flying wood on my Contender 60 with an OS 70II Surpass engine and both of my large(er) gasoline models. It's stiffer and lighter than plastic or fiberglass, and I can't see paying for glass fibre (plus they just lk right on some models.

Wood is not very forgiving, though. If you tend to slap & splat in the landings forget it.

RE: Propeller question for newbie?
 

Here's an interesting question along the same "propeller" line of questions that I just thought of:

When you change from a wood prop like an 11x8 Thrustmaster to a nylon glass-filled prop (on a .60 engine), should you change the size or pitch of the propeller to get the same flight characteristics? I know that an 11x8 wooden prop is going to weigh more than an 11x8 nylon and since the efficiency of the engine rpm/prop combination is affected by the weight/size of the prop it's swinging, wouldn't a heavier wooden prop have different effects on the engine characteristics than a nylon prop? And should it be substituted with a "sport" nylon prop or some other style of prop? What would be a comparable prop size/style?

This can be a convoluted problem with alot of different engine efficiency factors and aerodynamic issues to address.....

Incidentally, props are alot cheaper than I would have thought they'd be! (most nylons are under $3-$4 each! I can afford to keep a dozen around for the "just in case" situations ;) )

RE: Propeller question for newbie?
 

Wow, that's quite an impressive conversion! :)

RE: Propeller question for newbie?
 

You are making some asumptions that are just not true. In most cases glass filled props are heavier than wood in the 14 and under sizes. There are some exceptions but not many.

The way in which propellor weight can noticibly affect our engines is a heavy prop will allow a slower reliable idle slightly. On the other hand a lighter prop will allow better throttling characteristics (throttle response) slightly.

A more important differance between wood and various brands of plastic is flexing or flexability. A blade will flex forward with throttle application however it will tend to flatten its pitch also. This is very easy to see the forward flex visually but I hesitate to tell you to look because its horribly dangeous to be standing anywhere in the tip path plane of a spinning propellor. obviously this blade flex robs thrust and efficiency.

Wood props in many cases are quite stiff and APC props are similar but Master is most flexible of all which makes them great for trainers however they generally not quite as efficient.

Propellor design is a horribly complex science and there are many other factors beyond these simple assumptions as well.

John

RE: Propeller question for newbie?
 

you're right, I hadn't thought of the flexing! So, if nylons are slightly heavier in a 14 and under, would an 11x8 wooden still equal an 11x8 nylon? or is there a chart somewhere that lists comparable sizes?

RE: Propeller question for newbie?
 

You know an 11x8 APC may not even match another 11x8 APC. Charts are not going to do much good beyond just hopefully getiting you into the ball park. The very best chart you can use is a wall like in the picture. In other words a selection an do your own testing on your airplane, your engine, in your Wx and your flying. This is the only way to really fine tune your prop selection.