Wood vs carbon fiber propellers?

[DannyShadow]

I've read online that wood props are stronger than plastic. However, from what I understand, carbon fiber is very strong as well.

So I wanted to know what's the pros and cons of each material?

[Larry3215]

Wood props are generally less $$ than carbon props. The fact that they are not as strong can save your motor shaft in the case of a prop strike. They generally require user balancing and can be subject to moisture/humidity issues and aging issues.

Carbon props - if made by a reputable mfg - are quieter, lighter weight, stiffer and can have a more accurate airfoil. All of that adds up to more efficient transfer of power to the air, which is where you want it to go. The better ones are factory balanced.

They are also more consistent from one prop to the next - there are fewer mfg issues to cause variance that you can see in wood props just from the quality of the wood alone.

[solentlife]

As an old scale hand ... used wood props where scale dictated ...

as an old pylon hand ... used CF / GFN where speed was needed.

They each have their pros and cons.

One area that I will touch on ... if you damage a wood prop it is usually quite evident ... but you can damage a CF prop and not know. I agree that generally you will see damage, but I know of many cases of damaged CF props and they looked fine - till put under load and then shredded. One guy I know ended up in hospital with shards of CF in his hands .. very difficult situation for hospital ..

Which is best ? neither as each is intended for diffferent purpose. Which is best for general use ? I would say the CF ... but I would usually go for a lesser format prop ... the Glass Filled Nylon ( GFN ) prop ... stiff, usually reasonably balanced and cheaper to buy than a true CF prop.

Nigel

[kyleservicetech]

Originally Posted by DannyShadow

I've read online that wood props are stronger than plastic. However, from what I understand, carbon fiber is very strong as well.

So I wanted to know what's the pros and cons of each material?

I've been using those APC-E electric props in all of my electric models now for many years. They do outperform the same sized prop designed for the glow engines. Because these APC-E props are not as massive as the glow version, they are more likely to shatter on a severe prop strike. Those props are quite strong for electric use. Their instructions indicate they are NOT to be used on a glow/gas engine. If you follow APC's RPM published RPM restrictions on their electric props, you will be OK. (Note these are the APC-E props, not the APC slow flyer props.)

That said, a straight in crash will still bend the shaft of a big motor. I've done it on a Hacker A40-10L motor when the aileron came completely off on an ARF model that used foam inside the wings.

Also have a Hacker A60-16M motor that pulls 2950 watts on a 19X12 APC-E prop. That same motor drops down to 2300 Watts on a 20X10 wood prop. That wood prop has significantly less thrust. That same 19X12 prop has been on my model for two years now with over 200 flights on it.

[JetPlaneFlyer]

My thoughts...
Personally, for my applications, I like wood. For these reasons:

• Much lighter than any other types
• Much cheaper than carbon
• Stiffer than most nylon/plastics
• Motor shaft protected in event of prop strike/crash
• Wood looks nice

I think though to a great extent it depends on your application. I'm flying mainly 3D aerobatic models these days and with their big diameter props and light overall weight then the weight saving of wood is a big selling point. Wood not only saves a few grams but gives the motor better throttle response.

For high very RPM props on speed models then carbon is probably the ultimate material followed by glass reinforced nylon. For general fun/sports models nylon props may win out purely on cost and durability.

[CHELLIE]

IMHO, I dont care what the prop is made from, as long as it works good and is safe and does not cost a lot Because I am Cheap, Thats good enough for me LOL

[Glacier Girl]

Least in my experience, with wood props, you need to check them often for tightness of the prop nut. Especially on a new one.
Wood compresses, what was tight yesterday is often loose today.

[solentlife]

Originally Posted by Glacier Girl

Least in my experience, with wood props, you need to check them often for tightness of the prop nut. Especially on a new one.
Wood compresses, what was tight yesterday is often loose today.

That is why it's advisable to use a knurled backplate for wood prop to sit against. Using plain smooth is not a good idea with wood. If a backplate is smooth as some are - then a knurled thrust washer with the nut instead of the usual plain washer is advised.
Also repeated tightening up of a wood prop can lead to weakening of the prop centre.

Me ? Wood props are too expensive for me now ! I used to use them on my IC powered stuff years ago ... I prefer GFN now (Glass Filled Nylon) .... very nearly as stiff as CF, cheaper, usually well balanced as they come from a standard mould, easily modified ... available LHS, Ebay, HK ... everywhere. (To the uninitiated ... Master Airscrew and other usual stiff black props are GFN ....).

Nigel

[FlyWheel]

I hope y'all don't mind if I piggyback on this thread (it's not really a hijack because it's the same subject ) I have an AeroCraft 1911 Eastborne kit that is next in line for the build table, and since it is a scale aircraft I was thinking maybe a wood prop would look really nice on it. RPM is no big deal as this is going to be a slow flier simply by design; the undercambered main wing pretty much assures that.

I will be going brushless, probably an inrunner with a gearox. Noisy, I know, but another builder of this bird mentioned the right one can actually give it a reasonably good "scale" sound.

Given the parameters mentioned above, what would be the best wood prop for this bird?

Posted via Mobile Device

[JetPlaneFlyer]

Best for a pre WWI vintage model that I can think of would be the Xoar PJWWI Scimitar: http://www.xoarintl.com/props/model-...tar-light.html

[CNY_Dave]

I think the APC-E props are an excellent value and since they are thin and light waste little energy in spinning up, and slice through the air very nicely.

They seem to break just easily enough to save motor shafts while being able to take a pretty good punch.

I shorten them just a little when I rash the tips (not common on my taildragger, but on my trike gear plane while learing how to land well I rashed a number of 'em).

[kyleservicetech]

Originally Posted by CNY_Dave

I think the APC-E props are an excellent value and since they are thin and light waste little energy in spinning up, and slice through the air very nicely.

They seem to break just easily enough to save motor shafts while being able to take a pretty good punch.

I shorten them just a little when I rash the tips (not common on my taildragger, but on my trike gear plane while learing how to land well I rashed a number of 'em).

Agree on those APC-E props. The few glow engine type wood props I've tried in comparison to the APC-E props, IMHO, they are noteably better for electric power than those wood props on the same motor.

[solentlife]

Originally Posted by kyleservicetech

Agree on those APC-E props. The few wood props I've tried in comparison to the APC-E props, IMHO, they are noteably better for electric power than those wood props on the same motor.

i would hazard a guess the need for stable wood such as Beech or Elm makes the wood prop an unlikely best for E power ... with synthetic / composite materials - the likelihood is better ...

For Glow power ... a good wood prop is a different beast all together ..

Nigel

[kyleservicetech]

Originally Posted by solentlife

i would hazard a guess the need for stable wood such as Beech or Elm makes the wood prop an unlikely best for E power ... with synthetic / composite materials - the likelihood is better ...

For Glow power ... a good wood prop is a different beast all together ..

Nigel

For the newbies, don't ever put one of those APC-E props on a glow engine!!!! Those electric props have a warning about using them on a glow engine for a reason.

[rcers]

Originally Posted by kyleservicetech

Agree on those APC-E props. The few wood props I've tried in comparison to the APC-E props, IMHO, they are noteably better for electric power than those wood props on the same motor.

+2 - I too agree.

I always find it interesting that many don't do testing with propellers. On one stubborn model - I actually found my best prop after trying almost a full dozen in flight. In this case it was an APC sport prop that was the ticket.

I have found MAS absolutely stink - they take more amps and give less in flight performance.

I also found a gem of a prop that many should consider for lower power models those are the GWS "HD" series propellers. I don't use them over 250-275 watts but they are magic. They draw less amps than many comparable propellers yet give more thrust and in-flight performance.

Some of them draw almost 30% less power and give MORE performance - that is amazing. On my Alfa models using the APC-SF type 8x6 will draw almost 30% more juice and give less speed than the 8x6 GWS HD. And to boot they are also very light weight like the SF series when, on those small planes I don't want to use APC-E type (too bulky on the small models with tiny spinners).

I especially like the 8x6, 9x5, 9x7.5 and 10x8. Many are also finding the small ones 3", 4" and 5" WELL outperform the stuff used on UM stuff from Horizon - I too agree.

So finding a cheap prop (they are a buck!) from GWS in the HD line for my small stuff is awesome.

My advice - do some real inflight testing on props - you might be surprised!

Mike

[CNY_Dave]

Finding the best prop is like adjusting the fuel mixture on a carb- how do you know it's optimal?

Only after you've tried everything else and made it worse!

[kyleservicetech]

Originally Posted by rcers

+2 - I too agree.

I always find it interesting that many don't do testing with propellers. On one stubborn model - I actually found my best prop after trying almost a full dozen in flight. In this case it was an APC sport prop that was the ticket.

I have found MAS absolutely stink - they take more amps and give less in flight performance.

I also found a gem of a prop that many should consider for lower power models those are the GWS "HD" series propellers. I don't use them over 250-275 watts but they are magic. They draw less amps than many comparable propellers yet give more thrust and in-flight performance.

Some of them draw almost 30% less power and give MORE performance - that is amazing. On my Alfa models using the APC-SF type 8x6 will draw almost 30% more juice and give less speed than the 8x6 GWS HD. And to boot they are also very light weight like the SF series when, on those small planes I don't want to use APC-E type (too bulky on the small models with tiny spinners).

I especially like the 8x6, 9x5, 9x7.5 and 10x8. Many are also finding the small ones 3", 4" and 5" WELL outperform the stuff used on UM stuff from Horizon - I too agree.

So finding a cheap prop (they are a buck!) from GWS in the HD line for my small stuff is awesome.

My advice - do some real inflight testing on props - you might be surprised!

Mike

Agreed.
Those computer programs such as www.motocalc.com work very well, but you still need to tweak your model with a few different props in the general size recommended by motocalc to satisfy your needs.

Methinks that even with the same exact model and same exact power system, different modelers would be happiest with different props.

[JetPlaneFlyer]

Originally Posted by kyleservicetech

Agree on those APC-E props. The few wood props I've tried in comparison to the APC-E props, IMHO, they are noteably better for electric power than those wood props on the same motor.

What props were 'those' wood props? Wood props just like nylon ones come in many brands and types. Just like nylon, some types are good and some not so good, but you cant tar them all with the same brush just based on the material they are made from.

I've had great results from Xoar PJN electric props. Comparisons depend on the size you compare but for the size ranges I've used (12-15") the Xoar props in comparison with APCe pull about 5-10% more amps but make correspondingly higher thrust, so overall efficiency is about the same. APC score on durability but Xoar scores on light weight. What works best depends on what you are looking for but for me the light weight and the better throttle response it brings often wins out.

[rcers]

Originally Posted by JetPlaneFlyer

I've had great results from Xoar PJN electric props. Comparisons depend on the size you compare but for the size ranges I've used (12-15") the Xoar props in comparison with APCe pull about 5-10% more amps but make correspondingly higher thrust, so overall efficiency is about the same.

+1 - LOVE the Xoar propellers for the larger stuff.

And the Hobby King knock off (light electric wood) is pretty good too if you go that route.

Mike

[kyleservicetech]

Originally Posted by JetPlaneFlyer

What props were 'those' wood props? Wood props just like nylon ones come in many brands and types. Just like nylon, some types are good and some not so good, but you cant tar them all with the same brush just based on the material they are made from.

I've had great results from Xoar PJN electric props. Comparisons depend on the size you compare but for the size ranges I've used (12-15") the Xoar props in comparison with APCe pull about 5-10% more amps but make correspondingly higher thrust, so overall efficiency is about the same. APC score on durability but Xoar scores on light weight. What works best depends on what you are looking for but for me the light weight and the better throttle response it brings often wins out.

They were generic wood props designed for glow engines. This posting was changed to reflect that fact.