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RE: Props-More Myths Busted - 12/20/2006 1:10:16 PM   
speedster 1919



Posts: 1466
Joined: 12/17/2004
From: Martinsville, IN, USA
Status: offline 		OK BOYS
Looks like this weekend will be a heat wave for December. I just got 2 more Top Flite sizes and MAS scimitar's coming in and some 11" . I will not touch my high speed needle on the mule engine so we will try to keep it the same. Temp will be colder by about 15 -20 degrees. Because this is a SUPER TIGRE tweaking the needles won't be nessasary.

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Hey Buddy -That was the most spectacular crash I've ever seen , That rolling cart wheel with parts slinging out was cool...

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RE: Props-More Myths Busted - 12/20/2006 7:50:42 PM   
jaka


 

Posts: 4348
Joined: 12/11/2001
From: Upplands Vasby, SWEDEN
Status: offline 		Hi!
Dar ...It's a Spitfire MK XIX PR version (Photo version of the Spitfire) that the we used in Sweden after the WW2.
The other is a picture of the most famous airplane of all time ...at least to me...flown by real hero. The GEE BEE R-1 flown by Jimmy Doolittle in the Thomson Trophy in 1932...Just picked those pictures as I have been building the R-1 in 1/4 scale since 1985 ...and just started to build the Mk XIX Spitfire (modified Brian Taylor Mk IX plans) in October this year. Nothing to do really with the discussion though.
Let me be frank...not rude...that's not my intention. But the fact is that every experienced flier knows that static tests don't say anything about how a propeller is going to perform in the air, so any test measuring static trust is worthless. And doing tests without adjusting the highspeed needle is equally useless...same as measuring rpm at mid throttle ...for what reason???

To measure prop performance you must follow the trail and error method and try them out in the air.When you get experience you know which prop that works best for which type of model. You also know that it's possible to modify all plastic and wood props so that they can perform better than standard props...this is something you can learn by being active in pylon racing or other competitive activities.

I have flown for more than 30 years and I know...don't want to brag but... that one of the best props on the maket, although not the best for every category of airplanes is the APC line of props.
It's also a well known fact that any 3 or 4 blade prop in the dimension ...let's say from 6" to 18" diameter will perform less good compared to a 2 blade prop. This is a pity to scale flyers because people that fly a P-51 Mustangs or Corsairs really want to have a 3 or 4 blade prop for looks. But to have best performance they must choose a 2 blade prop...preferable an APC prop. There are exceptions to this 2 blade rule and that is in F3A aerobatics where 4 blade APC 's sometimes are used along with 2 blade APC 's.

There are other good props out there than APC, like the British RAM , German Graupner (but not the old gray blunt-tip ones), Czech Mejzlic, Australian Bolly and German Mentz (Wood prop).
All the airplanes below use APC props...







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< Message edited by w8ye -- 6/23/2007 2:39:38 PM >

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RE: Props-More Myths Busted - 12/20/2006 7:56:01 PM   
proptop



Posts: 4426
Joined: 10/18/2002
From: Rome, NY, USA
Status: online 		Actually that's a PRU blue Mk. XIV Spitfire...but who's nit picking??? (not me )
It has the Griffon engine...not the Merlin...hence the 5 blade prop.

Edit: Jaka...it could be a Mk. 19...could be a 14...I believe they both had / have Griffon's ?...but it certainly isn't a Mk. 9 which is what you had before you edited your post...didn't you?

I worked on a Mk.IX (with the Merlin...)

< Message edited by proptop -- 12/22/2006 1:19:17 AM >

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RE: Props-More Myths Busted - 12/20/2006 11:59:35 PM   
speedster 1919



Posts: 1466
Joined: 12/17/2004
From: Martinsville, IN, USA
Status: offline 		JAKA - the earth is flat ! Do not leave Sweden . I repeat do not leave Sweden.

< Message edited by speedster 1919 -- 12/22/2006 11:54:35 AM >

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Hey Buddy -That was the most spectacular crash I've ever seen , That rolling cart wheel with parts slinging out was cool...

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       Post #: 54

RE: Props-More Myths Busted - 12/21/2006 4:39:49 PM   
jaka


 

Posts: 4348
Joined: 12/11/2001
From: Upplands Vasby, SWEDEN
Status: offline 		Hi!
Spitfire Mk XIV ?? how do you know? Mk XIX was the PR version...in PR blue uniform...

Well... that's the British F3A aerobatic team ...can't be wrong all using APC props do you think.
No one using a MA prop ...strange... or could it be knowledge got by experience???!


< Message edited by jaka -- 12/21/2006 4:40:21 PM >

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RE: Props-More Myths Busted - 12/21/2006 5:39:40 PM   
Flyboy Dave



Posts: 13307
Joined: 3/20/2002
From: San Bernardino County, CA, USA
Status: offline 		Jaka, of all those props you mentioned....show me one that comes close to the
performance of this 12-6 Zinger....I will guarantee you one thing....

....there is no 12-6 APC prop that will even come close.

http://www.rcuvideos.com/view_video.php?viewkey=4175610e5a00c1e221eb

An APC prop cannot even approach the performance of a Zinger prop in the sport line.
You are trying to fool the people that don't know you are using specialty APC pattern
props, and specialty pylon props on your small engines.

In general use use the APC's are junk compared to the Zingers.

FBD.

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RE: Props-More Myths Busted - 12/22/2006 11:53:23 AM   
speedster 1919



Posts: 1466
Joined: 12/17/2004
From: Martinsville, IN, USA
Status: offline 		LHS forgot to order my props ,so this weekend will be a bust. I should check my 12" supply to see if I have them covered.

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Hey Buddy -That was the most spectacular crash I've ever seen , That rolling cart wheel with parts slinging out was cool...

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       Post #: 57

RE: Props-More Myths Busted - 12/22/2006 12:50:06 PM   
skiman762



Posts: 1166
Joined: 12/1/2005
From: Nashville, NC, USA
Status: offline 		Well here's 2 more cents for what it's worth
I have a ASP 52 and run a APC 13x4 that works great on my magic 3d I tried a zinger 13x4 and the engine just can't turn it so I'll take that to mean the zinger is bitting harder
then the APC I also have a APC 13x4w and it seems to bite as hard as the zinger but is much heavier and takes longer to wind up so I'll give the nod to the zingers
I haven't looked to see if zinger makes a 12x4 if so I might try one or cut the 13 down and re balance it

I know there's chatter about thrust and 3d in fairness to the 3d guys there looking for static thrust because they spend so much time in stalled flight and static thrust is the key to hovering the planes, speed is not really a concern on my magic most of my flights are in a 150 box and not much faster then 25mph so the larger dia. lower pitch, higher static thrust works well in that application on a prop jet that prop would be worthless
so I guess prop choice depends mainly on application and type of flying being done

look at a 40 foot tug boat it turns a huge low pitch prop and a 40 foot ocean racer turns a small high pitch prop both are a perfect match for there application

Happy landings


< Message edited by skiman762 -- 12/22/2006 12:51:08 PM >

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RE: Props-More Myths Busted - 12/22/2006 4:02:09 PM   
jaka


 

Posts: 4348
Joined: 12/11/2001
From: Upplands Vasby, SWEDEN
Status: offline 		Hi!
Proptop!
Here is a picture of the Swedish Mk 19 Spitfire...I'm building two 83"models ... one Mk 9 (fullsize powered by Merlin 61) from Brian Taylor plans and one Mk XIX with longer nose (Mk XIX, Griffon powered) also from Brian Taylor. Both powered by MVVS 26cc engines (perhaps watercooled).






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< Message edited by jaka -- 12/22/2006 4:03:38 PM >

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RE: Props-More Myths Busted - 12/22/2006 4:03:51 PM   
RVM


 

Posts: 1975
Joined: 3/12/2006
From: Sacramento, CA, USA
Status: offline 		Speaking of Zingers... I recently bought a Zinger Pro 15x4 on a friend's suggestion. He said on his Saito .82 it didn't load the engine as much as the APC 15x4w, but that it spun at higher RPMs and obviously spooled a lot faster. I tried it and the engine could barely turn it, and spun the APC about 600 RPM higher.

Go figure.

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RE: Props-More Myths Busted - 12/22/2006 5:29:27 PM   
JettPilot



Posts: 1149
Joined: 4/18/2005
From: Paradise, USA
Status: offline
quote:

ORIGINAL: Flyboy Dave

An APC prop cannot even approach the performance of a Zinger prop in the sport line.
You are trying to fool the people that don't know you are using specialty APC pattern
props, and specialty pylon props on your small engines.

In general use use the APC's are junk compared to the Zingers.

FBD.


You are very wrong about this Flyboy Dave, but I would be willing to do a test. The static thrust measurements done at the beginning of this thread dont mean much, because no plane flys at zero airspeed. The only good way to measure the performance of the prop is to check how the plane performs with each prop in the air.

I have sevaral UAV's that sends live video with speed, and altitude back to the ground with the following engines - Evolution .46 Saito .82 and Zenoah G-26 and Zenoah G-45. I am not going to spend a bunch of money to test Zingers larger props, but I will buy one Zinger of the smaller ones ( Evo .46 and Saito .82) and do a test of speed, and rate of climb and compare it on those airplanes to the same size APC's that I always use. I will post the videos and results so that everyone can see the numbers for themselves. I bet you a case of beer that APC wins hands down, but I need all the performance I can get on my UAV's, and if Zinger does perform better, I will have all my props switched over before you can drink those beers If anyone wants me to test any other prop, they can send it to me and I will test and post a video and results... If it is an expensive prop, I will be happy to send it back after testing is done.

JettPilot

To see one of the videos with data feedback, click on this link.

http://www.youtube.com/watch?v=F42iBPOPCr0



< Message edited by JettPilot -- 12/22/2006 5:33:28 PM >

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RE: Props-More Myths Busted - 12/22/2006 6:02:11 PM   
djlyon



Posts: 1874
Joined: 12/10/2001
From: Castaic, CA, USA
Status: offline 		Great video JettPilot

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RE: Props-More Myths Busted - 12/22/2006 6:06:16 PM