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HelicopterBlades and Night Flying › Lighter, wider = more pop, papa, PLUS photo of swept blade made years ago
07-16-2017 03:00 PM  66 days agoPost 1
icanfly

rrElite Veteran

ontario

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If I made a blade that was 1/3rd the weight of all other manufacturers, and made it generally 109% wider would it not have an appreciable increase in pop and floatyness? and increase flight and lipo time? Sure it would because there would be less parasitic drag from the sheer weight for starters, then there would factor in the increase in planform/profile of it, there's no mystery about it.

Let's look at the 70mm wide Maveriks I had to shorten to use on my 550 shuttle, lighter, more floaty, more pop, and agility. They are 550mm long and 70mm wide, have no 25gram balast, and weighed somewhere like 145gr after being altered,

The chopper sound they made was awesome and they were never a problem flying.

then we look at the same with what were 380's for a Spirit pro in wood reduced to 325's and beside those what began as a 425 reduced to a 375mm and tapered in toward the root of 35mm. The fattest part being 43mm and the root was 6mm thick for what could have fit on a 380/420 sab.alz heli (with widened grips).

and lastly the slick production of Mikado in the VTX,

notice any similarities?

My blades were shaped back in winter of 2015 and I messed with blade designs since 2005.

I just recently perfected a new template that is unlike the others in many respects and may be the "ULTIMATE" in rotor blade design, bold statement of course and I don't kid about these things. Any existing blade manufacturer looking for something new and would like to invest in a business venture with capitol feel free to contact me.

My motto is "Be prepared to be outdone".

VTX has a design oversight (I call it) with the thin tip, it would have been BETTER to round the leading edge around while it tapered to the trail edge in a smooth fashion rather than the thin leading edge it has. The tip has a square end which doesn't look like it fits with a round PETAL or Paddle design like a plane prop.

Moral of the story is lighter blades will equal more efficiency, more pop, more floatyness, longer flight times, all those good things and it won't hurt to make them a little wider chord than what's offered as standard fare, and they can be ruler straight or look like plank prop blades make almost no difference.

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08-20-2017 10:09 PM  31 days agoPost 2
Mark Ryder

Administrator

Ann Arbor, Michigan

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To all concerned I need feedback on the safety merits of this topic's opening post. Please post reply your thoughts.

Mark Ryder

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08-20-2017 10:59 PM  31 days agoPost 3
Pistol Pete

rrProfessor

Seffner, FL

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Honestly, I saw this post way back when posted.

First off...
Kudos to the OP for the time vested in research. Given claims of more pop, longer flight, etc are yet to be seen.

This quote seems to be the cats meow
Any existing blade manufacturer looking for something new and would like to invest in a business venture with capitol feel free to contact me.
I can tell this is not Paul M.(hate to bring that name up,but...)

There are manufacturers that presently do not use an embeded safety wire attached to the lead weight. To those buying such is at their own risk, just like purchasing a heli. There was a time such added safety feature did not exist.

Given OP is not pushing to sell to innocent bystanders, Id say Im still waiting on a manufacturer to pick it up and their reps to test them. THEN, I will make an informed purchase.

The lack of others posting until you brought it to attention may also be indicative of interest.

The ignore list, on the other hand, is personal to many for whatever reasons.

Best of luck to OP on his quest. I see no harm. Everyone has a dream.

~~Enjoying the hobby one flight at a time~~

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08-21-2017 03:54 AM  31 days agoPost 4
EEngineer

rrProfessor

TX

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It seems to me that airfoil design would need wind tunnel data or something to determine precisely what the pros and cons are.

"More pop" is subjective, rather than quantitative.

Randomly modifying blades because it "seems" to be better, etc. is not good engineering practice, imo.

How would the results be quantified?

One thing is certain. The blade inertia is proportional to the blade mass x the square of the blade radius.

So, if the blade mass is reduced, the blade length would have to increase to have the same inertia.

If you shorten the blades, don't they rotate faster?

Like a smaller prop on a plank engine.....

Doesn't mean you have more thrust, but it sure sounds louder...

Logo 600SXs, 700XX, 800XX

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08-21-2017 12:54 PM  30 days agoPost 5
icanfly

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ontario

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more "pop" is really a way to suggest more lift. after many years of trial and error there have been a few discoveries made which were influenced from all things full scale and from all schools of thought where air screws and circulatory fans are concerned.

VTX will be out done that's a guarantee, not to be angry or have a fixation or in any way "hate on" for them. It takes a lot of money and balls to put a design out there knowing it may fail and or not last or plainly be outdone.

Trust me when I say what I've got to come after several years experimenting and testing has only recently been perfected in plan shape and foil which I know you're going to like, maybe more than anything else out there, no bull shyt whatsoever.

EE, a lot of info is readily accessed on the net even new info I never saw a year ago. It's only up to one who has skills in "intuitive engineering" to put all the important pieces of the puzzle together. If you go to rcgroups and search my "Safer Blades with 220" read my last entry for my explanation of tip dynamics we're interested in.

I didn't write the book on aero, just made some educated assertions and engineered a design for the market albeit with many years of exposure to all things hydro and aero. It's in my blood so to speak.

Now to find some money.

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08-21-2017 03:04 PM  30 days agoPost 6
EEngineer

rrProfessor

TX

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Sure you did.....

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08-22-2017 05:44 PM  29 days agoPost 7
icanfly

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ontario

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the louder part is correct, the blades require less power to turn them due to reduced drag and mass. Parasitic drag from inertia and weight is less and if the rpm is higher they will change pitch quicker.

All good point EE, appreciate the feedback.

I finally template'd a 710mm blade with my new plan form (it may have 56 in/2 area). Now on to make so actual ones with foils.

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08-22-2017 05:53 PM  29 days agoPost 8
EEngineer

rrProfessor

TX

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"Parasitic drag from inertia and weight is less "

Not so, but you're entitled to your opinion....

The drag is less due to the blades being shortened....

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08-22-2017 06:17 PM  29 days agoPost 9
icanfly

rrElite Veteran

ontario

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"opinion", maybe it was a description of the same order with different terms, your saying less actual area. Good point actually.

I neglected to say the 710 was scaled up from an original 425 template. Root size for that would be 6mm so it could be used on most every 500 and would need a sab 420 grip swap to 6mm root or a machined original, or upgrade, to fit them on.

I have now been designing and testing blades for over three years with many lessons learned. One aspect of the final product is it will have no wire but will stay with the root and will not have lead ballast. I'm also trying to get the weight down to half of the average 700 while not loosing auto ability. they will be tested to 5000 rpm as well, yes I said 5000 rpm (why not, it's only a fan blade).

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08-22-2017 06:22 PM  29 days agoPost 10
EEngineer

rrProfessor

TX

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"testing blades"

What test equipment are you using?

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08-22-2017 07:55 PM  29 days agoPost 11
Chris Bergen

rrElite Veteran

cassopolis, MI USA

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If I may,

You're reducing profile drag with your design, not parasitic drag as stated, If I understand your intentions correctly.

But even that doesn't explain the statement of reducing drag by reducing weight. You reduce the inertia, both in the phases of spooling up and spooling down, by that I mean decreasing the amount of power needed to spin the blades up, at the same time making it easier to slow the blades down when power is taken away. Once the RPM is attained that you require for flight, having lower weight will probably require more power to MAINTAIN that RPM than if weight was added in the tip, in effect using the inertia that you build to spin them up to help maintain it.

Not necessarily desirable if auto-rotations are to be performed.

Rotor blades are all about balance (Pun intended ), in lift, drag, inertia and overall performance.

Unfortunately, making a blade perform better in one area will most likely take away performance in another area.

But I always applaud experimentation and testing, even if you are the only one who learns something...

Subscribed and hope to see your progress...

Chris D. Bergen

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08-23-2017 01:59 AM  29 days agoPost 12
icanfly

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ontario

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thanks Chris for putting it more clearly.

Test equipment?, there's a university in town with a wind tunnel and cfd if a couple of thou are available.

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08-23-2017 02:36 AM  29 days agoPost 13
jbjones

rrApprentice

Columbus, Mississippi

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icanfly : ...and cfd if a couple of thou are available.
CFD software is cheap if you know where to look. Most modern desktops are plenty powerful to run moderately useful CFD simulations, provided you know how CFD works to start with. Most home users don't mind waiting the extra time that it takes to complete, so a massive HPC installation isn't required anymore to perform decent CFD simulations.

OpenFOAM is free software. There are 2 "forks", so your search will turn up a .com and a .org domain. We have both at my installation.

Our CFD group is trying to transition from Fluent (an expensive Ansys product) to OpenFOAM. They seem to be fairly pleased with it. If it couldn't do the job for this group, there is no way they'd even attempt to use it.

$.02 and all of that. I toiled for a very long time on the early releases of OF, trying to get it compiled. It's much better now, and their general compilation instructions are pretty good.

-JB

J. B. Jones

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08-23-2017 03:27 AM  29 days agoPost 14
EEngineer

rrProfessor

TX

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"wind tunnel and cfd if a couple of thou are available."

Sounds like that is not an option for you....

So, what test equipment will you use instead?

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08-23-2017 03:54 AM  29 days agoPost 15
icanfly

rrElite Veteran

ontario

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a real rc heli, 700. Don't worry I've already tested some 550 blades done from about a year and a half ago that went too far but showed promising results. Further experiments with inexpensive 325's were very positive. The design I want to introduce now is a step back into the present vein of offerings, nothing super radical but futuristic and the method of choice in materials and fabrication may have to be in wood like the old days, except covered in cf to get things like molds started. I am a sculptor.

As far as funds are concerned the only thing lacking would be a big cash outlay for first run for sale volume. I should be able to take care of some small stuff for now and the University access could be arranged as a partnering of sorts perhaps. I was in conversations with the professor of the engineering dept a year ago about costs but nothing was definitive. NDA LATER folks.

thanks for that jbjones, searched it and got the site simflow, probably beneficial to experiment and get familiar with the free version before buying the real deal.

Much of what the design will include is from what already exists only tweeked to more optimal results and like Chris B said there will be trade offs. One blade may not do all.

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08-23-2017 04:20 AM  29 days agoPost 16
EEngineer

rrProfessor

TX

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"a real rc heli, 700."

And how will you quantitatively determine the results on such a heli?

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08-23-2017 01:03 PM  28 days agoPost 17
icanfly

rrElite Veteran

ontario

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very good question, press on, you aren't the only one asking for the mathematics (at least I understand what the math tells of and some inkling of the formula). I think in aero the math is a device used to leave the general public in a cloud of confusion. Plain old "feel" and acute observation has been very effective as is screening and gleaning from the many graphs, drawings, charts, cfd pictures, articles, etc from the www, based on Nasa articles too. So.

It should be duly noted the wire in your standard rc heli blade offering of late is to prevent the lead ballast at the near tip outer leading edge of the blade from becoming dislodged and acting like a slow moving bullet, not to stop the cf from shredding apart. anything attached to the lead ballast will be carried with it if it had no wire. I have some older Thunder Tiger blades which had a ballast but no wire, the ballasts were removed and substituted with great success.

Moments ago I just took my balsa 710 template and tested a small leading tip ballast to test how much it would calm the fluttering it suffers without. This is on a 1/16 thickness balsa sheet that was waved through the air quickly like a wand, A single 1'5" screw reduced the flutter by a half or more weighing all of 2.2 grams on a sheet of balsa non reinforced whatsoever about 2 grams itself. If I work on this ratio and multiply by 25 or 30 it will net an end result of 100 to 130gr.

Now to go separately weigh everything involved in the final equation were it that the blade is a cf one looking like the ones bought readily.

I'm not some wunderlust child who got a kite for the first time, lol. A lot of what I eschewed very early in my rc heli experience regarding blade qualities and manufacturing has now come to be favored. I have to thank GreyEagle for enlightening me with some cryptic reply containing hints on fabrication of mock ups and full run blades.

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08-23-2017 02:26 PM  28 days agoPost 18
jbjones

rrApprentice

Columbus, Mississippi

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icanfly : ...searched it and got the site simflow, probably beneficial to experiment and get familiar with the free version before buying the real deal.
To heck with that. We use Paraview for postprocessing. It's free too. Matter of fact, OpenFOAM ships with its own version that will build the FOAM module for it. Lots of OF tutorials out there.

You don't need a fancy/expensive GUI to do your work. There's all kinds of free enterprise-class tools out there.

J. B. Jones

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08-23-2017 03:19 PM  28 days agoPost 19
EEngineer

rrProfessor

TX

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"I think in aero the math is a device used to leave the general public in a cloud of confusion."

Huh?

" I have to thank GreyEagle for enlightening me with some cryptic reply containing hints on fabrication of mock ups and full run blades."

GreyEagle science, too.....better than math....

And "acute feel", too.

So that's your "test" equipment?....

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08-23-2017 03:59 PM  28 days agoPost 20
icanfly

rrElite Veteran

ontario

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so maybe I have to send you EE a pair for beta testing and you can throw all the numbers out there?

What is your looking for EE? You have to remember the guys who designed the vtx had to go back and forth between the cfd's and real life testing and feedback before settling on the final iteration, all math aside. Haven't you read the VTX engineering topic on hf in the Mikado forum yet?

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HelicopterBlades and Night Flying › Lighter, wider = more pop, papa, PLUS photo of swept blade made years ago
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