Testing a 3 Blade Prop
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- čas přidán 18. 04. 2019
- It's supposedly common knowledge that 3 blade props produce less vibration than 2 blade props so I stole Owen's off the Chinook and I tried it out. It didn't go completely as planned...
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Aircraft: 1987 Spectrum Beaver RX 550
Engine: Rotax 582 Mod90 (Grey Head)
Prop: 64" 2 blade Warp Drive with 12° of pitch
Stall Speed: 35 mph
Cruise Speed: 60 mph
Max Level Speed: 75 mph
Never Exceed Speed: 95 mph
Rate of Climb: 1000 feet per minute
Fuel Capacity: 18 US Gallons
Fuel Burn: approx. 5 gph
Range: 200 miles (no wind)
Take off and landing distance: 100-250 feet
Empty weight: 540 lbs
Max take off weight: 1000 lbs
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For similar style videos, be sure to check out:
Owen flying the Chinook:
/ llywelynapolywn
FlyingAirsickAdventures
/ @airsickadventures1252
glassdogangle:
/ glassdogangle - Auta a dopravní prostředky
Tie it down to test. Set blades with digital protractor for most accurate setting and least vibration. I did this recently on my 3-blade PowerFin which I set previously with the old pin and feeler gauge method resulting in blades being about 1 degree different worse case. After setting with digital protractor, got them all within 0.2 degrees. Noticeably smoother running.
What is different 2blade or 3blade, can i put my rc plane, what is I feel different
lovely machine ,take fan,enjoy
Should have swapped out Owen's engine while you were at it ... he would never suspect his best buddy.
Nice beaver!!
Matt this has always been the way that I shut my two strokes down whether it be bike boat or aircraft makes no difference a lot of people want to cut the fuel off and run all the fuel out the carburetor so that it won't come up when you do that you not only have removed the fuel you have removed the lubrication so I think you are doing it right by flooding them down.
When you run them out of fuel to shut them off they always speed up just a little bit before they die starve them for fuel they run lean right at the end starve for fuel starve for lubrication
I ran a 3 blade ground-adjustable Ivoprop. Flatten the prop until you get the desired rpms. He's getting more rpms bkz his prop is flatter. Takes fine tuning.
Allen didn't you see he removed the prop from the other aircraft and put it on his aircraft same pitch same prop not just same type prop but same exact problem
Every video, I like that steering. Maybe inspect the sidewalls regularly. I don't know if the duty of that tire was engineered for such side loads. Is it tube type?
I don't think it normally comes with a tube but I specifically requested that it get one. I give it a good look before and after each flight.
Then there is that stuff you can spray into them to make them semi-solid. I don't know if that would be good or necessary.
the extra blade absorbs power, To get the RPM, need to reduce the prop pitch.
given all that vibration, strongly suggest balancing the prop until the blades are within a very few grams of each other
The blades are balanced as perfectly as the scales will allow. The vibration issue isn't a problem with the balance, it's the way a 2 blade prop throws air compared to a 3 blade prop. The RPM issue was solved, it was a gearbox ratio difference although what you're saying is also true. Thanks for the comment!
Nice ski slope.
Engine. How much is it. Where can i buy?
You mentioned a different drive, are they they same ratio? I'm not familiar with these engines at all (I fly model airplanes with electric motors... lol) so forgive me if it should be common knowledge. If they're geared different maybe that explains the different max RPMs?
You figured that out much faster than I did! LOL! The next video (to be released Sunday morning) is where I finally figure it out.
Different gear ratio?
Hi, amigo matt Cual a sido el mejor avion ultralight que has tenido?
Éste. El CGS "Hawk" también es bueno.
Forgot to ask u did u notice any difference in ur aircraft and wat was ur max rmp
There was definitely less vibration with the 3 blades. I didn't re-pitch the blades to match my gearbox so I only got 4800 RPM at full throttle. Once I put my prop back on, I got the full 6500 RPM.
If your two blade that vibrates is supposed to be better for the gearbox, and now the three blade vibrates way less, I would take that chance and stick with three blades.
The RPM is a mystery if his gearbox is the same as yours. I'm curious to see what you find out. My challenger had a blue head 582 with a belt drive, no vibration at all. Is the non-blue head less HP? I don't remember the difference anymore.
The Rotax Certified Tech I spoke with said that there is no difference in power between the Blue and Grey head engines.... but..... if you look at the published power graphs for the 582, you'll see two lines; one for the 48KW (65HP) engine and one for the 40KW (54HP) engine. Also, I think I once saw a muffler for sale that was listed as being for the 54HP 582. I'm not exactly sure what the real deal is but I'm quite certain mine is the full power version now that I've figured out that it was just the difference in the gearboxes.
Regardless, as soon as I get some money saved up, I'm pretty sure I'm going to add a third blade to my Warp Drive. :-)
Thanks for making this video. It's gonna be interesting to see what you find. The different gearbox ratio is a good possibility and I hope that's it. I had a similar problem and actually observed what looked like tiny air bubbles in the fuel line only to find out late that one of my pistons was seizing. (wish I hope is not the case with yours). Strange as all this sounds please stay close until you have 5 hours or so on it. 2 blade vs 3 blade is just an excuse to spend money imho. I swear I'll never buy another 3 bladed prop again. Just doesn't chop the air like a 2 blade. Take a super hard look at those cylinders before you buy anything.
Cylinders are fine. I put my 2 blade prop back on and I got all my RPMs back. The difference was just the gearbox ratio. I think I'd rather a small decrease in performance if it meant a smoother ride. I haven't decided yet though so I guess we'll all just have to wait and see! :-)
Yes actually, I saw many examples of catastrophic b-box failure with people running three blade Warp Drives that forced dead stick landings. My business was on the field at Arlington Airport....which had one of the bigger ultralight parks in America.
It was due to these harrowing escapes from death I spent so much time trying to get the mass moment of inertia DOWN when designing Powerfin propellers.
I built every propeller WITHIN the limits set by Rotax for whatever box I was trying to put a prop on.
May be different ratio. I just replaced my 2 blade warp drive with a 3 blade Kiev. Which is lighter than my warp drive less gearbox wear. On 65 hp Hirth 3203 EFI. What a differance.
Tell me more about your 3203. I'm very interested in them and will probably replace the 582 with one once I wear this one out. ;-) What plane do you have yours on? What do you get for fuel burn? Are you happy with it overall?
@@mmatt I just installed it beginning of the year on my phantom x1. My fuel burn has been between 3 to 4 gph. Only have 12.5 hours on it. I take off at 6500 and 8740 feet msl. Need all the power I can get. Lighter than 582 by far being air cooled with nikasil cylinders.
Very nice. One of the main reasons I like it over the 582 is the fan cooling over the liquid cooling. Liquid cooling belongs in cars, not on airplanes in my opinion. lol
@@mmatt U r Instagram ID OR mail ID
czcams.com/users/mmattabout
Wouldn't you be better to go with the better RPM than the smoothness of the 3 bladed prop Matt?
Yes, but the props I use are all adjustable so I can get the RPM I need with just a bit of adjustment. I just didn't want to adjust Owen's prop because it's already all set up for the Chinook.
The more I think about this, the more it makes sense. Both engines being the same, running at full throttle for take off, will consume the same amount of fuel, as long as they are both tuned and running properly. So let's assume they are. That means that an engine that make 4800 bangs per minute will draw less fuel than an engine that is running at 5500 bangs per minute. (RPM) Now, if your engines produce maximum power output at or below 4800 RPM, that means that the energy going to drive the prop will be the same , and the prop spinning at the same RPM, with the same energy input, will perform exactly the same. Regardless if the engine is at 4800 or 5500, which is governed by the gear box! I'd say based on that, you would have the same performance, with less fuel consumption, running that prop with your gear box! I really do hope I'm making sense, if not...blame it on the cold winters here in Winnipeg freezing my brain! LOL (EDIT) OK...I just checked the power bands of those engines. I appears that they are not producing maximum HP until you get them upwards of 6500 to 6800 RPM, and can only run them that high for 5 minutes. So....4800 RPM is not producing as much HP as 5500 RPM, by a long shot. Sorry for the long reply...
I believe it's the mass of the prop not the number of blades on the gearbox. Check out e-props, they have half the rotational mass of many others.
czcams.com/video/zM5SP7XSv1s/video.html
You should have edited in a clip of dad saying bye
I know somebody's already said this but right at the end of your comment you switch from 582 to 503 worn out 503 I obviously that was just a mistake.
I know I am WAY late to this party but as a new ultralight owner I am watching a lot of videos and reading a lot of material to make my experience as a new unlicensed pilot as enjoyable and safe as possible. My Hurricane has a Rotax 503 duel carb, DCDI setup that is rated at 50 horsepower at 6800 rpm. It spins a 3 blade ground adjustable IVOProp. With all that said, there are two things that matter when it comes to which prop is right for your application. First, you have to know at what rpm range your engine makes its peak horsepower. Secondly, your engine has to be spinning the prop (any prop) within that rpm range at full throttle so the engine neither over-revs (spinning excessively fast) nor lugs itself (not spinning fast enough and not achieving its peak horsepower) when you are at full throttle take offs or full throttle flying. Full throttle here equates to max revs and max horsepower at the same time. These blades are made to be adjustable for a reason. You must take the time to experiment with different blade pitches to achieve the max rpm range of the engine at full throttle (thus max horsepower from the engine) with the proper blade angle. If the engine does not reach its max power rpm at full throttle then the pitch of the blades is too high. If the enginge over-revs at full throttle then the blade pitch is too low. Trial run ups of the engine at full throttle and the blade pitch at different angles of attack is the only sure way to achieve this balance of max horsepower and proper blade pitch. Running the engine any other way is damaging to the engine and dangerous for the pilot. Sorry for the long commentary.
You are absolutely correct in all you say as far as I can tell. The issue here was I had borrowed the 3-bladed prop from a friend and so I didn't want to adjust the pitch just for this test. I didn't realize that our gearbox ratios were different until after and so despite having the same engine, his prop wasn't pitched correctly for my set-up.
If both props are the same pitch and both engines are identical,you would get a drop in rpms due to the extra blade the engine has to rotate,however it would be smoother and a 4 bladed prop would be even smother still.To compensate for the 3 bladed prop you’ll have to use a smaller diameter prop,maybe 1-1.5 inches,but no more.
Unless your engine is so wore out and compression is not what it used to be,loading it with 3 blades will show in Rpms,not that simple,lots of variables play a big role here.
what about noise?
I didn't notice any difference.
Is the reduction gear box the same ratio
If you have a 2.58:1 gear box, and get 4800 RPM. Your buddy has a 3.0:1 gear box and is running 5500 RPM. That translates to a prop RPM of 1833 for you buddy and 1860 for you! So close I'd say they were spinning at equal rates. You should have been developing nearly the same thrust as he does, or maybe a touch more in fact. Also, you are probably developing the same horse power, based on the prop RPM and thrust produced. Energy can't be increased with gear ratio, and that's proven by the fact that the prop develops the same RPM at full throttle. Hope this makes sense.
You say RPM. Is his engine is same as yours? Perhaps the tachs are calibrated slightly different. Put his tach on your engine and check RPM again. That might eliminate tach errors as long as they are getting the same power voltage.
I see I'm late to the party, and it looks like you've zeroed in on the gearbox. I can only say that Gillette touts there three bladed razor as an improvement over their two bladed one.😎
I'm no expert at flying, but I *DO* have a good working knowledge of sailing & boating. Let me say what I think is going on with the three blade...
Would it make sense that more blades catch more air to push with, as more sails on a boat catch more air to drag the craft through the water? More blades catching more air makes the engine work harder to achieve the same goal. On the other hand, less sails on a boat catch less air & won't travel as fast? I'll bet that the engine will reach full RPM 'without' a prop because of no air resistance. The two blade catches less air than the three, hence higher RPM. And yes, pitch will make all the difference too!
It's just physics. And yeah, the same motors with the same props reaching different RPM's (on different aircraft) could very well be a difference in engine build & tolerances being slightly different, engine wear, aerodynamics on the craft...etc, etc.
/Edited because I accidentally a word out! :)
It was the difference in the gearbox ratios, that's all.
But thanks for the comment! :-)
@@mmatt NO...Not the gear box.. Scott Meister is 100% correct.. Do not worry about the prop RPM.. 2 bladed prop or 3 bladed prop is really doing the job... But lastly 3 bladed prop will don some thing much better... Just use the 3 bladed prop...
Didn't read all the comments., so maybe someone else mentioned this. The 55 HP 582 was a single carb engine. I've found that 3 blade props do run much smoother, but performance is not as good as two blade prop.
Matt, incase you are still thinking of going with the 3 blade warp, I have an extra 3 blade warp drive hub I will part with for way less then new. Jim
Ahhh... single vs. dual carb, that makes sense. With the performance I'm currently getting, I'd be ok with a slight reduction in performance if that meant a smoother ride. :-)
Well three blade will be smoother. Your static RPM should be from 6000-6250. If you are set there, the prop shouldn't unload much and over rev on climbout. Surprised your engine didn't bog down completely with the low rpm you were making. Jim @@mmatt
I like my static RPM at the top of your range. I actually aim for 6300 since that gives me a little better climb performance. Not like I'm going anywhere fast anyway so I might as well pitch it for climb! ;-)
Some props unload more then others, that's why I started at 6000. A warp taper tip 3 blade on the yellow Avid Flyer in my picture comes to mind. With most other props I found 6250 was a good place. More of a load helps keep the EGTs lower. Did you ever go to a 3 blade? Jim@@mmatt
Different gearbox
What does an aircraft like yours cost? Does anybody know? Please let me know send me a message
Anywhere from $5 - 50K depending on what you want. If you're in the US, check out:
barnstormers.com
Aaron Eckhart
maybe even though the engine is the same you may have a different gear reduction
The chinook has an E-gearbox, likely a 3:1 gear ratio, you are running a B-box, probably with the 2.58:1 gears. If so, there is your problem. ;)
You win. :-)
3 blade carbon fiber would give you extra thrust, greatly reduced weight, and returning your RPM's...maybe?
Maybe air resistance increased by 1/3.
Hence the blades are shorter and the chord is a bit narrower
Too much pitch will give low RPM.
more power less rpms
"Dave's not here man", is that a Cheech & Chong reference?
Yes it is Dave.
Too much pitch.