Enterprise/ft.rucker ,al- home of army aviation
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it is just too weird the many different questions i have been recieving by e-mail lately about the multibladed heads. seems many want to venture into this world but do not know enough and are affraid to spend the costly amounts they carry without a little knowledge first.
keep in mind, i am no expert with these but i have flown many types and have owned a few helos sporting multibladed heads so these answers are based on my experiences.
1) are they hard to fly?
not really, they are just different. they have different tendencies especially in fwd flight. in the hover on a clm day they almost feel like a flybarred head. they can be docile or touchy just like a flybarred head but atv or dual rates can determine that. hovering on a windy day will make you really see and appreciate what a flybar actually does for the model and the pilot's workload. in fwd flight, you find yourself holdingfwd stick where as with a flybarred head, you pull aft stick especially in turns.
2)are they hard to track the blades?
well they are no different to track than a 2 bladed head. there are more now so you will have to come up with your next few favorite colors to put on the extra blades to see which is which. it will just take a little longer now that's all. be sure to use bright color paints or tape. if your blades are to be scale, use tape that you can remove after tracking. also, just like the flybarred heads, you want to keep each blade in the same holder whenever you remove them so you can color cote the root of each blade with the grip it goes in so you dont change them. kepp in mind, if you do, this may cause a blade or two to be out of track the next time you fly.
3)how do you go about balancing the blades???
easy!!! if there are an even number of blades ie 2, 4, 6 etc, justbalance each opposing sets of two just like with a two bladed head and you are good to go. just be sure these two blades are mounted opposite of each other so as not to throw off the balance. other sets of two might have a difference in weight. again the importance of matching the blades to the grips. if you have an odd number of blades ie 3, 5, 7 etc, then it takes a little more time. see first you have to find the heaviest blade. you can do this with a gram scale or do like i do, use the process of elimination. i first pick two blades and mount them to my balancer. i keep the heaviest blade on the balancer til i have checked them all. then i make that blade the masterblade (hush with the wiseguy comments ) then i keep it on the balancer and match all the previous blades to it. as usual, each blade should be matched to the grips so they get mounted to thatsame grip everytime.
4)does a 3 bladed head feel different than a 4 bladed head or five or vice versa???
well, in my experience, the number of blades seem no different in how it feels, that all feel the same to me. the only differences i have noticed are in the different brand heads and blades. i have tried several different blades on one particular head and they all felt differently. some better, some worse.
5)are there any differences in the blades for a flybarless head and a flybarred head?
yes. the blades on a flybarless head are made heavier with the center ogravity chordwise located very far forward. also spanwide, the weight is out towards the tip just like a flybarred blade but usually more weight there.
6) can you use a flybarred blade on a flybarless head? i have used blades from a flybarred head on my flybarless head with good results. not great results but good. it also depends onm the blade. some do well while some are just horrible to use. i have done vice versa whic is use a flybarless blade on a flybarred head and it seemed to do fine. killer autos with the weight. just keep in mind the weight is probably more that the flybarred head is designed for at the speeds they turn. then what makes them okay for a flybarless head you ask?? well the flybarrless head turns much slower though it doesnt look it, but there are so many blades spinning now, it looks that way. the head on a jet ranger looks like it turns slower than that of a hughes 500, way slower but it is about the same. if you ever see a 4 or 5bladed head on a fullsize that has one of them painted white, you wuold be shocked at the rpm it turns.
well i hope i have answered any questions many of you may have been wanting to ask. feel free to ask ones i didnt cover. gotta get back to work now, i gotta fuel waffle house's G3.
drive a rotary, fly a rotorcraft