" some one has to explain the blade shape to me. "
This is the Evolution 12x4 Alpha 60 3-Blade Propeller. The Evolution Engines Alpha 60 three blade propeller was designed to fly at slow speed while maintaining excellent thrust for climb and aerobatic maneuvers. Engine sizes from 50 to 61 can easily spin this 12x4 three-blade propeller. This prop will control the top speed of your model within a 52 to 70 mph range, which is very practical for training purposes. However the high thrust at low speed is perfect for 3D flying in models designed for maneuvers at slow speed.
They look HEAVY which wouldnt help . But in very thin air , the could , maybe .
Im thinking , as Late Lancasters ran props with blades winder outward for better high altitude cruise ( The probly ran at lower pitch in the climb than the standard prop ) that theyre a ; air grabber .
So in cool / dense / low altitude air , theyed load the motor , so youd need a lot of turque to spin them . As in a big motor or a small prop . As there a lot of blade out there going a long way - Which
would do nasty gyro precession nose swing scary stuff . Also slow the 2-4-2 bit . not being light .
Some Vickers Viscount - a early Turo Prop mainly intercontinental ( Is England a Continant
) well inter country ! so Those flights wernt LOW . Presurised so 20.000 feet , where the Airs Thinner ,
So you want more grab .
There were late Mustang experimental & development props , some found their way onto Reno P-51's . Some hollow bladed . Square Tip ones .
The Evo props mightve been done by someone with P 51's on the brain , or they just wanted to be differant - marketing .
BARTON forum a few years back , ha a big debate on nylon props and AGEING . Here in Australia where its hot and dry . Sometimes . when its not freezing or raining ! , Big Place - climates vary throughout .
Drying Out - Ive had Yellow Tornados , Twist in hands - Start to & they go .Ping . A 11 x 4 yellow howevers Flexi and just bends . Maybe it never dried out . ( I twisted it again the other day - its twistable )
Barton - tthe scientist or two lectured on Moisture Content in Plastics . The proposal was 45 minutes in 80 degree water - would re hygroify !? it . Correct the humidity vital to flexure .
Having debritalised crash pads , ( a extremely dry and a bit faded / greyed one ( uncracked ) in a 67 Corsair outdoors shut parked , nose into sun , for 5 years or more ,
soaked up the first dose late afternoon in a hour - another -vernight ,dry next morning . 4th - next started to revive it , and slowed absorbtion . Sixth & it was pliable . so there you go .
Re thingo the moisture percentage . IF it hasnt been damadged WHILE it was ' dry ' . ( You armoualled - when it would stay wet for a few days , then it was back in service .
So all the nylon props get soaked & bagged overnight - Glared at - observed - then Twisted . BEFORE USE . Wait till it STOPS absorbing it , before the Twist Check , If it was trashed before hand , youve lost out .
A Crankshaft crack tested before regrindings better than ground before crack testing . You loose either way if its cracked . BUT a 51 BSA one I Then threw out still ' RUNG ' So I Shouldnt have . Work that one out .
Tornado , the purple bubble pack silver were stiff ( From the 60's ) the bagged yellow lablel perhaps not - usually theyre flexi yuk . Not on a HOT day , thank you . Late White are polypropolene , white Not Nylon .
White Nylon 2 blade are stiff and need there thermal bath or suclike , if to be trusted .
The Black Ones similarly . All mine have been aggresively Armouralled . Then They Flex , a little . ( The black ones were the last of the line ) But Cottage Industry to the rescue . theres TWO I think blokes here
Doing Glass Tornado 3 Blade 10 inch props , 20 or 25 bucks , if I recall right . the 10 x 4s quite usefull , and the 10 x 6 ( 5 true ) will have yore G 51 at its best .
So THERE you Go .
The Grish - tornado is thin high efficency ! blades ( Dosnt load a motor a great deal ) . so not overly heavy , either . OS max . 35 on 70 feet of 12 thou at a slow airspeed , keeping on keeping on .
Frightning the neigbours and the pilot on a FSR 45 , or at home on a F P 40 etc , underpropping gruntier motors - Yet to perfect THAT , but dint try , or start - to . But the attempt was spectacular and not horrifying .
just scary .
The Big Black Blades on those Evo's look like theyed be prone to ' strike ' damadge .
Ran G 15s on Taipan grey props . Combat . O.K. , might survive a vertical arrival . When they came out with the G R P ones . The Black - Glass ( F'Glass !? ) Reinforced Plastic ones . Superb .
But the prop impression in the field usually contained a propellor blade or two ,
So the G R P Black props , do not , have a high elastic limit . ( Keep them hygroified - Moisture Content - for ANY . ) and they DONT deform - they break . Fibre Glass would be way more durable & youd see any irregularities .
Brief and to the point .
Topic: Evolution 10x4 3-Blade Prop (Read 1450 times)