Carbon fiber props
- Thread starter Brian Mackey
- Start date
I think now that drones have been around awhile people are over the carbon fiber prop thing after people began to realize the physical danger of knives spinning and the destructive nature they have on motors. OEM props were specifically designed for the machine they are being used on and I have found that the more experienced I have become it is a rare occurrence that I lose a prop anymore, knock on wood!!!
Argue all you want buddy, been using carbon props for 15 years from 5" upto 34" on a variety of planes and helis, I know fine well how they stack up against plastic and the reality is both will hurt. If the wooden bat weighs less than the plastic one then it won't hurt as much using that very crude analogy. Sure it may bend a little more but both will hurt, just in different ways.
Look on YouTube at H V 4 review and you will see the plastic prop embedded in a tree, don't kid yourself plastic is much safer in every aspect, it isn't quite that simple.
Plastic is more likely to throw a blade so you could argue the other side of safety there. It isn't an apples to apples comparison but all else being equal, carbon props make sense if of good quality and I emphasise that again.
If you get jello it is out of balance or shape, doesn't matter what prop it is or what it is made out of. Unfortunately people who balance props normally only balance the blades and forget the hub itself, huge difference.
Anyways, I have not read of anyone throwing a prop so from that point of view no need to change but please don't kid yourself the plastic is safe, it is safe some ways and not in others so you take your pick. Doesn't matter if you use plastic, wood or bouncy balls as props, flying in a safe place and within guidelines is obviously good advice.
For the record, I don't believe these props will be of good quality given the price so I won't buy them. You can't get "good" carbon props for chump change.
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The analogy should be that of a plastic bat vs a steel bat. The definination of carbon fiber is that of being light like plastic but having the properties of steel. Carbon fiber props will conduct electricity, If anyone believes in Murphay's Law have fun with the CF props but leave the kids at home.
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I agree a plastic prop, for example an APC MR (which I find are very good props), is very sharp and will cut like a knife. I don't find them any safer than CF.
I also agree considering I have many (as in dozens) el cheapo CF props sitting around, so called "TM style" knockoffs that quite frankly are cheap junk. The worst are Tarots in my experience. The cheap ones flex from the hub out causing oscillations resulting in z axis vibration. On a heavy Y6 I couldn't keep it from bouncing using the Tarots. My rule of thumb is limit the thrust to those at no more than 400g (IIRC). Good quality plastic props are designed to flex more out at the tip.
For 6 CF props, $48 or even $60 is dirt cheap and I question the quality but may try them for the heck of it. They look like a typical cheaply made low quality CF prop with claims of excellent factory balance only to find them horribly out of balance and the airfoil form is inconsistent from prop to prop.
Typically I only buy APC, TM and Xoar (excellent props, just not as efficient).
PatR
Premium Pilot
40" Xoar's work pretty good actually, but 8 at a time is pretty darn expensive
I've been flying model planes and RC for over 50 years and have used every type of prop out there. The typical plastic prop is weak at the hub/blade root and are quite prone to shedding a blade, especially if an earlier strike weakened them. They are life limited to an unknown number of flex cycles even without experiencing a strike. Props mounted in the vertical plane shedding a blade are much less dangerous than props mounted with blades in the horizontal plane because the direction of blade travel, or the "danger zone" is fairly predictable. This is not so with horizontal plane mounting, other than up and out in any direction.
Due to this wood or carbon props are much safer because they don't share the blade root weakness that plastic possesses. The most dangerous aspect of wood or carbon props is when making physical contact with them. In such situations it was not the prop that generated the danger but either the operator or someone putting themselves in a position to make contact with the propeller. That really comes back to the operator since they control both the throttle and where the prop is being flown. That so many blame a propeller for their lack of situational awareness or disregard for safe operating practices is amazing. Very few propeller incidents have occurred without first experiencing some level of human failure or inattention of the user, be that sticking their hand in a spinning prop, failing to inspect their equipment, failing to secure their equipment during an engine start, flying too close to people, or losing control of their aircraft. I'll add hand catching a drone to that list because the first mistake may well end up a medical emergency. An exposed and spinning propeller blade is always dangerous, regardless of what it's made of but the more dependable the materials used the more the risk of design and construction failure is reduced. The greater the rigidity of a propeller the more efficient it will be. This should not be confused with helicopter blades because the manner in which they flex is a large part of their performance design. Bear in mind that flex is what limits their life cycle.
I've been flying model planes and RC for over 50 years and have used every type of prop out there. The typical plastic prop is weak at the hub/blade root and are quite prone to shedding a blade, especially if an earlier strike weakened them. They are life limited to an unknown number of flex cycles even without experiencing a strike. Props mounted in the vertical plane shedding a blade are much less dangerous than props mounted with blades in the horizontal plane because the direction of blade travel, or the "danger zone" is fairly predictable. This is not so with horizontal plane mounting, other than up and out in any direction.
Due to this wood or carbon props are much safer because they don't share the blade root weakness that plastic possesses. The most dangerous aspect of wood or carbon props is when making physical contact with them. In such situations it was not the prop that generated the danger but either the operator or someone putting themselves in a position to make contact with the propeller. That really comes back to the operator since they control both the throttle and where the prop is being flown. That so many blame a propeller for their lack of situational awareness or disregard for safe operating practices is amazing. Very few propeller incidents have occurred without first experiencing some level of human failure or inattention of the user, be that sticking their hand in a spinning prop, failing to inspect their equipment, failing to secure their equipment during an engine start, flying too close to people, or losing control of their aircraft. I'll add hand catching a drone to that list because the first mistake may well end up a medical emergency. An exposed and spinning propeller blade is always dangerous, regardless of what it's made of but the more dependable the materials used the more the risk of design and construction failure is reduced. The greater the rigidity of a propeller the more efficient it will be. This should not be confused with helicopter blades because the manner in which they flex is a large part of their performance design. Bear in mind that flex is what limits their life cycle.
Glider, PatR.......nicely said gents and nice to see fellow modellers are about the forum for the occasional reality check.
These drone guys haven't lived until you smack your fingers starting or adjusting the needles on a 40 nitro in a trainer.....that makes you respect props! Then the nitro or castor gets in the cut for a double whammy...ARGHHHHH
These drone guys haven't lived until you smack your fingers starting or adjusting the needles on a 40 nitro in a trainer.....that makes you respect props! Then the nitro or castor gets in the cut for a double whammy...ARGHHHHH
Hi,
Well this is a real debatable discussion. I have Carbon blades for all my copters including the Q500 but not the H to date. I do find good and bad points with carbon blades some of which have been mentioned in this thread.
I fly for an example an XXX-830 (one of a kind) ha.... and for the first time since the build in 2012 I installed the Carbon blades (13") replacements for the standard props just to see if eCal was correct first and second to see if there was any improvement in flight stability and flight time.
First I noticed a much firmer hover and as mentioned much quieter flight as to blade noise. Unfortunately the esc noise increased and out weighted the prop noise….lol.
Second the flight time decreased by 1-2 mins per flight. Why? Best I can explain it is because the copter being firmer in hover and flight required the controller to work a little harder in stabilization. I know that sounds odd but it is true. With the standard blades (also 13”) they would flex and give much more allowing a softer overall flight which dropped the esc noise very low in comparison and the controller didn’t work as hard to maintain stabilized flight. This I believe is why most manufactures put plastic blades on copters instead of Carbon fiber, well all but the high end copters and the other consideration price. But most high end copters have specially designed carbon blades for that motor/esc series etc…….
I also tried 2 different carbon blade manufacturers on the Q500. First I installed the Maytechs which IMHO are the cheap side of the carbon blade market. I also tried the upscale AeroNaut cam light blades. Both performed like any carbon blade and each lowered overall flight time. The Maytech cost less and the AeroNauts cost more and a better quality blade overall.
In the end I removed the CF blades from the XXX-830 after one flight session and reinstalled the factory blades. They look nice, they fly nice, but they work the controller and escs harder not counting the loss of flight. Another thing, the PID tuning needs to be readjusted for the CF at least on the XXX-830. The reason I bought CF blades for this copter was something you have not mentioned on this thread, weight carrying capability. The carbon blades will haul more weight. On the Q and H this is not a factor until later when the larger cameras come out or your own mods adding weight.
On the Q500 the blades also flew nice but dropped flight time by a good 2 mins. Also you could see same issues as my test bed XXX-830 copter with working the copter harder and more jerkiness when using follow me etc. I also removed both sets of CF blades after testing finding no significant improvements to copter and less flight times overall vs standard blades.
So…… IMHO carbon fiber looks great if you are just showing your copter at a copter meet. In real life flying CF blades are not worth the outlay of money. Why? Carbon blades need to be designed and built around a particular motor and esc they will be used on. The most important part of the blade is the inner 1/3 of blade for designing around a motor/esc combination.
Oh, and if you talk about accidents, a plastic blade cuts and might break on contact, a CF blade will cut break and splinter with toxic results to affected area. You may never get all the splinters out. OUCH!.... no not me but seen pics.
Cheers
Batfire
Well this is a real debatable discussion. I have Carbon blades for all my copters including the Q500 but not the H to date. I do find good and bad points with carbon blades some of which have been mentioned in this thread.
I fly for an example an XXX-830 (one of a kind) ha.... and for the first time since the build in 2012 I installed the Carbon blades (13") replacements for the standard props just to see if eCal was correct first and second to see if there was any improvement in flight stability and flight time.
First I noticed a much firmer hover and as mentioned much quieter flight as to blade noise. Unfortunately the esc noise increased and out weighted the prop noise….lol.
Second the flight time decreased by 1-2 mins per flight. Why? Best I can explain it is because the copter being firmer in hover and flight required the controller to work a little harder in stabilization. I know that sounds odd but it is true. With the standard blades (also 13”) they would flex and give much more allowing a softer overall flight which dropped the esc noise very low in comparison and the controller didn’t work as hard to maintain stabilized flight. This I believe is why most manufactures put plastic blades on copters instead of Carbon fiber, well all but the high end copters and the other consideration price. But most high end copters have specially designed carbon blades for that motor/esc series etc…….
I also tried 2 different carbon blade manufacturers on the Q500. First I installed the Maytechs which IMHO are the cheap side of the carbon blade market. I also tried the upscale AeroNaut cam light blades. Both performed like any carbon blade and each lowered overall flight time. The Maytech cost less and the AeroNauts cost more and a better quality blade overall.
In the end I removed the CF blades from the XXX-830 after one flight session and reinstalled the factory blades. They look nice, they fly nice, but they work the controller and escs harder not counting the loss of flight. Another thing, the PID tuning needs to be readjusted for the CF at least on the XXX-830. The reason I bought CF blades for this copter was something you have not mentioned on this thread, weight carrying capability. The carbon blades will haul more weight. On the Q and H this is not a factor until later when the larger cameras come out or your own mods adding weight.
On the Q500 the blades also flew nice but dropped flight time by a good 2 mins. Also you could see same issues as my test bed XXX-830 copter with working the copter harder and more jerkiness when using follow me etc. I also removed both sets of CF blades after testing finding no significant improvements to copter and less flight times overall vs standard blades.
So…… IMHO carbon fiber looks great if you are just showing your copter at a copter meet. In real life flying CF blades are not worth the outlay of money. Why? Carbon blades need to be designed and built around a particular motor and esc they will be used on. The most important part of the blade is the inner 1/3 of blade for designing around a motor/esc combination.
Oh, and if you talk about accidents, a plastic blade cuts and might break on contact, a CF blade will cut break and splinter with toxic results to affected area. You may never get all the splinters out. OUCH!.... no not me but seen pics.
Cheers
Batfire
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Wow that was a two beer post i had to read through. I love my Carbon Fiber props on my Q500. Best investment I ever made. Balance them and don't look back. No more chip blades. I can not see why they would not be a great addition to the Typhoon H. The price is really good also.
L
LOL! Yep get carried away sometimes. I may sit down again and revisit putting them on the XXX-830 and re-tune the PID's on that one to see if I can get it into a sweet point. The Q to my knowledge will not allow PID tuning unless there is some app I do not know about. That would be nice. Just don’t have the time... I'm sitting here at work now following you guys on the forum.... lol
Cheers
Batfire
LOL! Yep get carried away sometimes. I may sit down again and revisit putting them on the XXX-830 and re-tune the PID's on that one to see if I can get it into a sweet point. The Q to my knowledge will not allow PID tuning unless there is some app I do not know about. That would be nice. Just don’t have the time... I'm sitting here at work now following you guys on the forum.... lol
Cheers
Batfire
If a carbon prop, different plastic one, wooden one or whatever is using more power than the original then it is down to them being a poorer design in some form, no more, no less.
I say again, you can't buy good carbon props for chump change and until the good model prop companies make them you are stuck with original or a compromise with cheap carbon ones.
I say again, you can't buy good carbon props for chump change and until the good model prop companies make them you are stuck with original or a compromise with cheap carbon ones.
PatR
Premium Pilot
Or break a 16" wood prop on your hand during a Saito kick back.... I try not to remember the feeling of nitro-methane making contact with open wounds on my hands and fingers. Of course, I would not have had the open wounds had I not been using an APC or Master Airscrew propeller. Some of that was part of why I gravitated to gas engines.
PatR
Premium Pilot
Indeed, and many don't understand the many variables that are involved with propeller design. Blade shape, chord, taper, tip shape, thickness, rigidity, stall speed (propeller blades do stall), all influence how well a propeller works. It's been mentioned before but a flat ruler will provide thrust if the AoA and RPM is just right. It just won't provide a lot of thrust.
Some years ago I performed a long series of propeller tests to establish performance levels of propellers from various manufacturers, having different compositions for 50cc gas engines. Buying that many 22" propellers was rather expensive but I found the cheapest propeller provided the most RPM but the least amount of thrust at any RPM level. Blade flex was terrible. Some carbon props in a medium price range worked quite well, while some of them functioned better in a vertical or horizontal plane but not equally in both. The carbon propeller least well known and most expensive performed extremely well. The carbon props typically provided more RPM over wood propellers, but sometimes that RPM took the engine out of it's best torque band. Of significant interest was that one wide bladed wood propeller provided less RPM than any other, but provided better flight performance in every aspect over any other propeller except the one expensive carbon. The wood prop was extremely rigid and visible flex of the blades or tips was almost nothing.
From what I've seen thus far there is not a lot of work taking place designing good propellers for multirotors. Only a couple of companies are doing this and a lot of other companies are roughly copying their designs. Most are not good copies, leaving important features out of their products to reduce material and production costs. The smaller propellers being used for the racing quads are actually terrible designs but the RPM is so high they get the job done. Square propeller tips are terrible for energy transfer and make a lot of noise as well. What we are provided for the H is an adequate design, not a good one. A lot more performance could be obtained with a better propeller but the manner in which they are affixed to the motors severely limits our experimentation options.
I'm willing to venture that a redesigned propeller could provide much better performance for the H at lower RPM, which would extend flight time and provide more lift capability without putting additional stress on the motors and ESC's. Doing that would likely require a change in the way the H functions with a motor out, but with a well designed propeller there is no need to be reversing motor direction when you have a motor go out with a hex.
Yes, break proof, the props don't break the typhoon H arm will break(when H flip on to the ground the stock props give way to protect the arm and motor, but the CF props don't break the motor keep turning motor burn or the arm break)
Yuneec spent a lot of time engineering the blade for the H and no accident that they use plastic. There is a really good reason that no consumer grade drone comes with CF blades (although I am sure there is one somewhere). Just make sure to leave the kids home when using them.
PatR
Premium Pilot
Indeed. A quick comparison of the cost of plastic injection molding to carbon pre-preg laminates and auto clave processes makes that quickly apparent.
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I beg to differ. I've been hit with a plastic prop on one of my racers. The room looked like a crime scene with blood even on the ceiling. Shaved a finger to the bone. So yeah, it doesn't much matter what it's made of when it's spinning 10K RPM. The blade itself, while covered in blood and meat, was just fine.
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