TRex Building Tips and Tweaks by Charles Rosario (rchover and Align sponsored pilot )
Thanks Charles for the great tips!!!!
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Here is my lipo battery break in procedure.
I fully charged the pack and for the first flight hovered for only 2 minutes. I then did the same thing for my second battery just after the first flight. I fully recharged the batteries and then made 2.5 minute flights, recharged, then made 3-minute fights, and then recharged. At this point I started to fly around and do full 3d. I did give full throttle at times and didn't care about temperatures, as the flights were still short. I continued watching the flight times until I reached 8 minutes and I was done.
I did make two or three extra flights per pack at 3 minute, 5 minute, and 7-minute points, or something close to this. So that makes 13 flights from 2 to 8 minutes plus an additional 6 flights for a total of 18 break-in flights per pack.
Recharge time is low when you only fly 3 minutes on a pack. I think I took three flying days to break in the packs.
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TRex Tip 1: I suggest you look at the main blade holders and note they are oriented where the link control is on the trailing edge of the blade. I reversed mine to have leading edge control. If you note the head design of the other model helicopters in production most heads are made this way. As a result I had to switch other things in the head to match the main blade holder change such as washout, flybar control arms, seesaw, servo direction, and pitch direction.
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TRex Tip 2: I use three O rings on each side of the head block to tighten the damping on the spindle. This helped with inverted hovering and tracking (maintaining direction) if I flew in the wind or just trying to do precise maneuvers. Blade tracking was improved as well.
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TRex Tip 3: Take off the tail blade holders from the hub and apply grease. Make sure screws that hold the tail blades to the hub are clean and have loctite. Check for 1mm endplay in the blade holders to hub as a pre-flight check. If more than this then recheck screws. Also, every 20 flights or so reapply grease. I find if I have the tail setup very good but after a time the tail starts to hunt or oscillates in flight I just need to re-grease tail hub.
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Problem and fix for the TRex tail slider mechanism and links. The balls and links on the tail blade holders bind at the full right stick position. If the screws going into the blade holders for rudder control are out of plane (90 degrees) to the blade holder rotation there can be an extreme amount of throw used with no binding. If you look at the tail of any Miniature Aircraft heli you will see how they avoid binding. Align has upgraded the tail slider and blade holder assembly and it allows full throw without binding.
TRex Tip 4: Here is what I did to get 'almost' maximum movement of the older slider. First I kept the shorter links on the tail pitch slider on the output shaft but left about 0.2 mm endplay in the screws. I didn't fully tighten the screws holding the links on the slider. I'm talking about the two screws that hold the two links (to the pitch slider) that connect to the two balls on the tail blade holders.
I also looked at the holes for screws in the slider and if I made the holes larger on the blade side, by using an exact knife to cut a funnel shape, I could get a little more right stick throw before binding.
TRex Tip 5: I moved the hub further out on the output shaft to give more mid stick or starting blade angle. This also helped in having an even amount of right and left throw in the blades. Remember you need to have the blades at the proper angle when the Gyro has the tail servo centered. Checking the heli in Gyro Normal mode will confirm the nose doesn't turn for one specific rotor head rpm. I'm also using a ball and link on the servo side of the tail control link. If it does turn in normal mode then adjust the tail servo linkage length not the transmitter trim. You're changing the pitch on the tail blades with the tail servo centered.
Now go back and check the slider movement by disconnecting the link at the tail servo and while adjusting gyro limits make sure you have max and even throw without binding. In my setup I have a little binding at full right compared to left stick but I have more tail pitch than before.
The tail holds very well and I can have very high pirouette rates if I turn up the ATV on rudder. Even 100 ATV is very fast.
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TRex Tip 6: I use program mixes for hard 3d flying so moving aileron, elevator, or rudder will increase throttle. You'll need to set the +- values to increase throttle. Test each direction to make sure rotor speed is increased if not then you have to reverse the +- value. This can be done on the ground by just not applying throttle and moving rudder, the rotor will start to turn. For cyclic to throttle I use 30 and for rudder I use 20 but you will need to set the values based on your motor and speed controller. If the rotor over speeds too much then reduce the values.
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TRex Tip 7: Another thing with respect to the spindle. Check to make sure the bolts with washers go all the way into the spindle ends. I found the threads in the spindle didn't go deep enough for the screw. I had to cut down one of the screw ends to make it work.
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rchover team pilot Charles Rosario check him out flying his Trex VIDEO
