Miniature Aircraft's
August 5th, 2002:
Installing the Servos:
It's been a busy couple of weeks for me and I haven't had as much building time as I would have liked. This installment will cover the radio gear. I am using a Futaba GY401 Gyro and a 9253 Futaba Digital Servo to hold the tail and Futaba 9252 Digital Servos for the CCPM. I am running a lowly Futaba 3003 BB servo on the throttle and I am running a GV-1 governor. I may find it necessary to replace the 3003 with a faster servo but I will see how well it works as is. My thoughts are the OS91 has so much HP and torque that I won't be working the throttle servo as hard as a 60 size engine might be while being controlled by a governor.
Here's a shot of the left frame showing the 9253 servo at bottom and one of the CCPM 9252's at the top. Notice the large Futaba Servo Wheels are cut away on the right side. This is required if you use a wheel and you should on the Futaba system in order to clear the servo support arms that are installed over the servos.
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I have to tell you that I am Extremely impressed with the quality of the servo linkage, pushrods, balls, links and support arms. You just don't normally get this kind of quality and engineering with your average kit. The Fury is special and the Extreme is... extreme! The photo to the right shows the right side of the heli with the servos and wheels in place. These large wheels also must be cut down to clear the support posts that are installed later (See photos below). There is a template in the owners manual showing how and where to cut the servo wheel for clearance. Use a dremel with a sanding drum to cut it out, it takes just a few minutes to do,. |
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Here's a shot of the left frame with servos mounted and all pushrods are installed and the servo support plates are in place. I can't speak highly enough about the control system in this heli. I especially liked MA's approach to the tail servo rod. They include a special carbon sleeve to slip over the metal pushrod and you just tighten the links up until they are tight against the carbon sleeve. This makes for an extremely rigid control system that has zero slop and is very well thought out.
Here's a picture of the right side. I used a regular servo arm for the throttle servo. This is the only servo that doesn't need the large wheel. You can see in the photo a Futaba GV-1 Governor and just above that a Futaba GY401 Gyro. I decided to mount my gyro on a piece of flat Lexan, I had some spare 0.030 Lexan sheet and cut it out to the same size as the gyro tape. The Fury Extreme has a split gyro tray which I really don't care for so I decided to put a sheet of 30 mil Lexan down first and tape the gyro to the lexan sheet. It's probably overkill but I wanted to further isolate the GY 401 from any un-necessary shock or vibration.
The GV-1 is held on with two one inch squares of Scotch Double Sided Foam Tape. I am planning on running the Fury with a Normal Headspeed of 1500 RPM, 1650 in IdleUp1 and 1750 in IdleUp2. I think I'll break the engine in without the governor at first. Then after several tanks start to fly in Normal mode (GV-1 Controlled-1500RPM) and start getting the engine broken in. I won't use the governor until I am comfortable with the motor performance and have it tuned properly.
Below is a picture of the scratch built optical sensor that drives the GV-1 instead of the magnetic Hall-Sensor type that comes with the GV-1. It works great, on this particular fan, I am getting 4% background and 91% spike on the reflective strip, this is plenty of signal for the GV-1 to work properly.
Here are a few more shots of the mechanics:
The Tail Boom Supports:
Here's a peek at the tail boom supports hardware set. Notice the large plastic ball-links are actually rotating balls except they are plastic. This allows the supports to be properly seated and tightened to the hub and frame without binding. Pay attention to the height of the movable centerpiece. You always want the taller side facing the surface you are mounting the balllink to.
Here's the supports mounted on the heli. It was strange. I already had screws holding the landing gear on to the frame from a step much earlier. There were two long shouldered bolts included so I had an extra set of bolts. Anyway, you can also see in the photo above the round spacers under the ball-links. flat washers go on top and bottom. I chose slow CA to mount the ball-links to the carbon rod. I am pretty confident it will hold quite well.
First look at the canopy:
I got this canopy in a trade, I hope it won't be to hard to see in the air, I still have my unpainted canopy that came with the kit. It sure would be nice of MA to pre-cut the canopy holes and fill the center seam so we dont have to deal with it.
