jh4db536
Posts: 530
Joined: 5/22/2005
From: Monterey Park,
CA, USA
Status: offline
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the 90 degree plate and 120 degree plate accomplish essentially the same thing: phase the swashplate for aileron, elevator, and collective.
90 degree - usually MCCPM Mechanical mixed (denoted as HDE in trex) has 1 servo for each control surface. analogy = 1 servo for both ailerons in the middle of the wing.
120 degree - ECCPM computer mixed (denoted as CDE[indirect levers] or SE[direct control]). you have the power of 3 'Matched' + computer mixed servos moving the swashplate. analogy = 2 servos on each wing for ail/flap for a total of 4 servos in dual or push pull format accomplishing the same thing. mixed Vtail to accomplish rudder/elev, etc
the upside of 120 degree ECCPM direct (i only refer to direct style) is the simplicity IMO worth it if you set it up correctly. the whole system has few linkages and mechanical mixing to save weight and SPACE on a small heli. you MIGHT lose some accuracy in the mixing depending on the setup/hardcore/software. the argument used to be that servos take too much damage in a crash, but HS65MG's have pretty much solved that disadvantage.
the proper mixing of the swashplate is VERY important. Some radios do it better than others *controversial*. I seriously believe there are radios that shouldn't even be used for a ECCPM heli ie. a DX6 and the derivative JR maybe even some of the budget futaba6 series. the futaba 9CH has the best mixing i have seen so far...i have built hundreds of trex and unfortunately other undesirables, i have seen everything almost.
Think about the geometry of a servo arm movement, linkages, and the swashplate points 90,120 when you are trying to move it in a SYNCHRONIZED manner without INTERACTION.
you need inverse trig functions to compensate during mixing or the swashplate is going to be whacked. it's already proven the dx6 has the brains of a +-*/ calculator. it is using some stuff like 1 to 1 mixing that is okay to do with a delta wing or vtail wing setup on a parkflier/flying wing zaggi. it makes the trex cde/se fly like a pile of crap but no one believes me lol.
they sell standalone Computer programmable mixers that are very complex IE the CSM cylock in order to get perfect ECCPM mixing.
< Message edited by jh4db536 -- 9/5/2007 3:56:29 AM >
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Printable Version
All Forums >> RC Helicopters >> Electric RC Helis >> T-Rex heli >> RE: Is it really Necessary to Have an SE? 
RE: Is it really Necessary to Have an SE? - 
Especially the diablo red. But come on, in a common sense thinking, metal would be more weight and a slight disadvantage. like iron vs aluminum heads on a small block chevy.....the iron heads make more power, always do.......so its a double edged sword when asked which is better? 
Or maybe, I GOT better AT flying.
