I’ve had a few good flights, and few bad flights with the N450V2A. After locating a nasty wobble and some incorrectly manufactured parts, I’ve torn the bird down to just about the bare bones and have started a re-construction.

Starting here with this picture, I have already performed the following.

Replaced the Main bearings in the main bearing blocks. One of the old bearings had a bit of a ‘notchiness’ to it so I tracked down some replacement parts, including two pairs of original Align factory main bearings (5x11x5mm). $6.49.

They are installed at the top of the frame, and in middle, just above the main gearset (in blue). The main gearset has already been replaced with at genuine factory Align part AGNH1218 $22.99

The original Pentium 30A ESC (Electronic Speed Control) was showing signs of overloading and causing in-flight resets! In defense of HobbyWing, it looks like I was running too steep a pinion on the main motor (I’ll get to that later). Regardless, I wanted to make SURE I did not have to learn auto-rotation landing in my first few weeks of flying. So I purchased a new genuine Align 35A ESC with Governor, PN 35ABLESC GOVMD5VBEC RCE-BL $53.99. It’s installed high on the frame now, where the battery would normally be located. I did this to help ensure good air flow along it’s heat sink.

As mentioned, it turns out the that original 13T pinon which came with the EXceedRC Alpha 400 63N18 motor is not an appropriate selection. It was suggest that I run either an 11T or 12T pinion by several people online. The local hobby shop had a pretty knowledgeable flyer behind the counter, and suggest a 12T would make a big difference. It’s also the suggested pinion for the factory Align Trec450 V2 (of which mine is a clone). Having already ordered an 11T pinion, I purchased the 12T. Original 13T is on the right, new 12T Align part on the left:

The motor itself might be OK. I’m going to re-use it for now. Another is on the way from Hobbypartz.com price about $20.00. The pinion is only firmly mounted on the shaft, since it will have to be precisely adjusted for main gear engagement once I re-install the motor in the frame.

Next I went about trying to get the main bearings and main shaft running as true and consistent as possible. The bottom bearing has some manufactured in lateral play, nothing I can do about that. But I did manage to snug up the shaft to bearing interface with some very light knurling of the main shaft where it contacts the lower bearing. Additional play looks like it will come out with a slight ‘cocking’ of the upper bearing. Just enough to produce a natural tendancy to run straight. I have plenty of bearings now. One of my next objectives will be to take the extra bearings I have to an expert bearing distributor and see if a higher-quality bearing is available in the same dimensions.

After all that work, the main shaft finally looks like it’s running true. The dial indicator is still picking up some movement, but it’s about 1/2 or perhaps less than it was originally. I think I managed to take at least a little play out of the main drive system, and that makes very hopeful for some major flight improvements.

Taking all these parts off, I think it wise to re-check the swash plate level, just in case it something got bent, twisted or otherwise tweaked. Placed the 450 swash leveling took on the plate, and it was dead on! I ordered the tool from XHeli.com (it’s an EXI too) for around $3.50. Well worth the investment. When I checked my ‘by eye’ leveling with the tool I found I was pretty far out. Sure it’s a fair bit more labor to tear down the head to use the tool, but having such a core component as close to perfect spec as humanly possible seems like a wise use of one’s time. Maybe it’s not, but I did it.

Having conquered my fears of the main shaft, time to rebuild the rotor head from the swash pate up. First thing I want to tackle is the top of the head, sort of going in reverse order. It turns out my latest blade grip purchase, to replace the broken grip, wss of the WRONG PART. My model is a Version 2, and the parts I got, unbeknown to me, were Version 1. Barely close, certainly not the cigar. Now today I did pick up a full compliment of Version 1 parts. Combined with the plastic Version 1 head ($7.99) and 2 pairs of grips($13.99) from the other day, I should be able to assemble a very tight and very functional main rotor head. My ideal scenario would be to re-use the original allow EXI head (left) instead of the new Align plastic Version 1 head (right).

It turns out the the V1 head (right) and the alloy V2 original head (left) are identical in width, and the ID of the feathering shaft ($7.99 for three) holes are also identical. The only difference (beyond material) is a more pronounced shoulder in the V1 head. Fit wise though, they tested out (to the best of my abilities) the same! This is very encouraging! All I need to do now is figure out how the V1 head systems is supposed to go together!

It’s about 1:00AM now. No need to work all night on this thing. I’ll pick this another day, maybe tomorrow, maybe I’ll go ride a motorcycle instead.

Setting Re-duex.

When I thought I had it all figured out, I learned (in a rather painful way) that I in fact did not. At least no blood was spilled.

So, after a lot of testing with the heli double duct taped to the floor, I have some new settings that visually agree with my very limited understanding of how these things really work. One mental hurdle was figuring how how the Swash mixing really worked. A simplistic view of individual servos on the swash was getting me into a major logic box. It was when I looked at it from a conceptual standpoint, instead of the discrete mechanics, that it made sense. Confused? Join the club!

Not many photos were taken today since this was mostly transmitter programming, a little out of control flying and working on dialing in the Gyro. Still spent more than a couple of hours hacking away at understanding all there is to creating a BASIC setup for a good hobby helicopter. Now I have a better understanding of why RTF helis like the MadHawk typically don’t ship with an BNF (Bind-and-Fly) version. The amount of customer support they would have to deal with would quickly consume the fairly narrow profit margin.

Perhaps I’ll have the bird in the air this next week. For now I need to call it a night and get ready for another exciting week of computer programming, project management and cat wrangling.