Spent a couple more hours working on the 450 last night. It’s coming along nicely. Today I didn’t need to grind anything.

A couple of the many tasks required to get this thing in the air, is balancing the main blades and applying Loctite to all metal to metal fasteners. To accomplish this I needed some very small metric hardware and a new tube of low-power Loctite. A lot of people are using Blue Loctite 242.

I don’t think it’s the proper compound for fasteners of the size we’re using, so purchased a large bottle (all they carried at the store) of the Purple Loctite 222.

The place I like to go for such things is Tacoma Screw (there is one local in my town, about 35 miles from Tacoma itself – for this I’m glad). It’s a jobber style shop with top-notch customer service, curious people behind the counter (by that I mean they like to talk about what you are working on) and always friendly. I picked up a pair of German Philips #0 and #00 screwdrivers:

Also picked up 100 2mm washers:

And finally, a long 2.5mm bolt and nylocks for making a home-brew pour-boy blade balancing rig:

I ran one of the nylock nuts down on the screw, about 2/3 of the way. Placed the blades on the bolt and ran down the other nut, just making them snug. I chose the nylock nuts because I knew that they would stay put once I achieved the snugness wanted. A few extra pennies spent to save a lot of potential frustration later. You learn these sorts of things being a gearhead for nearly 4 decades.

The frame on the EXI-450 Plastic V2 is made of a stamped metal (you know, I think it’s aluminum, but I’ve not confirmed that), so some of the edges are rather sharp. To prevent the cutting/chaffing of wires where they exit the frame, I placed a small bit of high-strength tape (red) on the frame and then places a heavy duty heat shrink tubing over the wire bundle and applied heat to shrink with a heat gun, which works orders better than a lighter. You can get a cheap heat gun at Chinese places like Harbor Freight for around $10.

Here is the reciever I plan to use for this helicopter. It came with the Spektrum DX6i transmitter I purchased last month, and have been using with the ParkZone P-51 and Blade CX3. Not in this photo is the 2nd remote antenna/receiver that provides a very long range capability.

Installing the linkage balls on servo horns was next. The idea here is to make sure the link bars are as perfectly vertical as possible when installed on the servo, so some trail and error is required to select the correct hole to mount the balls. In this case both of the forward servos were able to use the last hole. You’ll notice that the balls are mounted in ‘reverse’ so the ball is on the servo’s side of the arm. Once they are all installed and photos taken, the reason for this will be clear.

Unfortunately, not all servo placements allow for such cut-and-dried installations. To get as close to pure vertical actuator alignment, you sometimes have to get a little fancy with the servo hardware. Once again, out comes the cheap Harbor Freight heat gun to apply some ‘persuasion’ to the nylon horn. After determining how much offset I needed, it was made very hot and then adjusted.

I think this makes it a little clearer why the adjustment was made and how it all turned out. This is the pitch cyclic primary servo.

The fly bar on a Bell-Hiller head is critical to smooth and stable flight. To get the fly bar properly setup, the first thing that has to be done is make sure it’s absolutely centered. Measuring with a caliper seems like a pretty accurate method.

Larger photo of the Bell-Hiller rotor head, typical to R/C helicopters.

Unlike yesterday, I placed the ‘calling it quits for the day’ photo at the end of this post.

It’s looking a lot more like a helicopter now! I still need to get some important things before I can go much further, the most critical of which is my batteries! I think I mentioned it in the last post, being unable to source a suitable battery at the local hobby shop, soooooooooooo yet another package of stuff is on the way. I’m sure I could have save $30-40 on shipping if I’d spec’d out my needs better ahead of time. For someone that is such a stickler for planning, I didn’t do a very good job of it for this project so far! :p