300x servo's

[JonProphet]

So I aquired a couple of 300x air frames. I want to convert to the 300cfx geometry so I'm going to upgrade the frame to the microheli CF/Au frame.

I've looked through this forum for some upgrade information but I came up empty on a couple of the sticky's. I'm thinking of going with the Hitech 5065mg's but I'm also looking at a cheap alternative (Hey! I'm a cheap bastige! ) and I'm looking at the Turnigy MG90s. Its digital and can go to 6v if you choose. But will they fit?

Thanks.

[jmtyndall]

Double CH is a big fan of the Corona 919mg I think. Thatd what I bought on his recommendation

[Dustin Mustangs]

I have the 5065's on mine with no complaints but not sure I'd go that route again due to price. A lot of cheaper options now that seem to yield good results. A popular one with the CFX crowd is the 5055.

Here is a good thread that goes over many of the options:

https://www.helifreak.com/showthread.php?t=492617

[KiloXray]

Originally Posted by JonProphet

So I aquired a couple of 300x air frames. I want to convert to the 300cfx geometry so I'm going to upgrade the frame to the microheli CF/Au frame.

I've looked through this forum for some upgrade information but I came up empty on a couple of the sticky's. I'm thinking of going with the Hitech 5065mg's but I'm also looking at a cheap alternative (Hey! I'm a cheap bastige! ) and I'm looking at the Turnigy MG90s. Its digital and can go to 6v if you choose. But will they fit?

Thanks.

Jon, converting a 300x to a Microheli frame will not give you the 300cfx geometry. Have a look at these two pics. The top one is the CFX and you can see it uses a configuration in which all three servos are placed at an equal interval around the radius of the main shaft.

The second pic is of a Microheli frame. It places one servo in the front and two servos in the rear, which is similar to a stock 300x layout and identical to the Lynx CF frame layout.

[JonProphet]

what about the Turnigy servos I listed and what about the links frame as opposed to the micro he lynx frame?

am I barking up the wrong tree to try to achieve the 300 CFX servo geometry?

[KiloXray]

Originally Posted by JonProphet

what about the Turnigy servos I listed and what about the links frame as opposed to the micro he lynx frame?

am I barking up the wrong tree to try to achieve the 300 CFX servo geometry?

I don't see any reason that the Turnigy MG90S servos would not work. Just remember, you get what you pay for, for the most part. If you buy cheap ass servos, they will be likely more prone to early failure. Not guaranteed though.

When you say you want "300cfx servo geometry", what exactly are you trying to achieve?

The "servo geometry" refers specifically to the placement of the servos in the frame, which then gives a specific "line of motion" of the servo rods as they move up and down with the servo horns.

The only way to achieve the same servo geometry as a 300cfx is to use a 300cfx frame. That is illustrated in the pictures above.

It is a physical impossibility to have the same geometry as a 300cfx using any other frame.

The are no problems with the Lynx frame in regards to geometry. The layout more closely resembles the stock layout of a 300x. The design of the MH vs. the Lynx frame is slightly different, but they have the same component layout. IMO, the Lynx is more robust in the bearing block area. This keeps you from needing the support "hoops" around the areas where the servo links are. (yu can see them in the MH frame pic I posted earlier).

Here is a pic of the Lynx frame.

[JonProphet]

Yes, I'm trying to achieve the servo placement of the CFX. I've been told that the CFX uses a more common 3D type of geometry that allows for better symmetry by placing the servo vertically rather than horizontal and stacked like the X.

So I can just get the Lynx frame and presto chango, 300 CFX geometry. No need to change the swash assembly? From the pics, it looks as if the swash plate is the same between the two other than maybe being made of different metal or quality.

Thanks.

[vtown nick]

Originally Posted by JonProphet

Yes, I'm trying to achieve the servo placement of the CFX. I've been told that the CFX uses a more common 3D type of geometry that allows for better symmetry by placing the servo vertically rather than horizontal and stacked like the X.

So I can just get the Lynx frame and presto chango, 300 CFX geometry. No need to change the swash assembly? From the pics, it looks as if the swash plate is the same between the two other than maybe being made of different metal or quality.

Thanks.

The lynx frame won't give you the cfx geometry. But I doubt most if any pilots on her would even notice the difference in flight anyways. The lynx frame is very well built, I owned a microheli one for a few weeks too and wasn't a fan of the hardware and a few other things.

[jmtyndall]

Originally Posted by JonProphet

Yes, I'm trying to achieve the servo placement of the CFX. I've been told that the CFX uses a more common 3D type of geometry that allows for better symmetry by placing the servo vertically rather than horizontal and stacked like the X.

All three frames use "vertically mounted" servos. The 300x uses a delta shape and it matches the blade 700x. But it's not that common

[KiloXray]

Originally Posted by jmtyndall

All three frames use "vertically mounted" servos. The 300x uses a delta shape and it matches the blade 700x. But it's not that common

You mean the 300 CFX uses the delta shape.

I agree with vtown, new pilots will absolutely not be able to tell the difference, in flight, in servo placement between a stock 300x, a Lynx frame, an MH frame or a 300cfx frame. Chasing that geometry is a waste of time, especially when a person doesn't even understand what they are chasing.

[jmtyndall]

Originally Posted by KiloXray

You mean the 300 CFX uses the delta shape.

I agree with vtown, new pilots will absolutely not be able to tell the difference, in flight, in servo placement between a stock 300x, a Lynx frame, an MH frame or a 300cfx frame. Chasing that geometry is a waste of time, especially when a person doesn't even understand what they are chasing.

Right. 6am typo haha

Agree entirely. If you don't understand why they do it, and if you're asking questions like this, you probably aren't at a level that you would need or notice any improvement over standard servo geometry.

With that said, I can't figure out one way that the delta servo layout is "better" than what lynx uses. Provided that the pivot point of all the servo horns are coplanar, and that they are all 90° when setup, there shouldn't be any swash interactions anyways.

[Dustin Mustangs]

Pretty sure the idea is that the mainshaft is in the plane of travel for all three servo horns. So, regardless of servo position, the linkages always remain parallel to the mainshaft in that axis. This helps keep the swash as level as possible as the wash moves away from center.

Given that is actually what this optimized geometry is all about, it really is splitting hairs. My stock frame 300x has aftermarket servos that I made no attempt to space out for linkage alignment so it is kind of a worst case scenario. My Spirit FBL has a parameter to correct for inconsistencies here and even with a cnc swash leveler there was maybe a 0.25mm deviation only at one end and only on one servo. We are talking in the area of a half turn on the linkage or even less. Not exactly worth loosing sleep over but it sure is a big selling point, lol.