When I was assembling CS I follow Larry's advise according his DVD instructions in the part of the motor vertical alignment procedure. I even made some marks on booms for easy re assembling if something happens. .... and something happened Just little crash. And my marks on booms are removed, so I can not just look at the markers. So, the questions are: 1. Is the strictly vertical alignment of the motors so critical, or it may plays +/- some degree from vertical (how much?) 2. How to re-align motors axes strictly vertically, without disassembling half copter. 3. Is their any simple trick how to make all motor axes all strictly vertical. Thank You in advance David
David there are a number of posts on the forum on the various ways folks do that alignment. Personally I eyeball it and occasionally check with a bubble level.
Gary, Thank You. As You just eyeball it, it means for me that alignment strictly 90 degr+/- 1 or 2 is not necessary and at the end of the day it will be compansated by the system itself. David
Being slightly off is okay. You want it to be as close to 90 as possible but it's very difficult for anyone to locate them perfectly every time in a timely manner. I'm in the process of using some extra boom clamps to make a depth and locating pin to make mine perfect every time. I'll post some pictures once they're finished.
At first I was trying to glue 6mm nuts onto the bottom of a bubble level but it just didn't work. I highly recommend buying a cold shoe mount and a hot shoe bubble level. You can get both at B&H for around $25 (special thanks to Mike Magee for this idea). The cold shoe uses a 1/4 thread which is very close to the 6mm thread on the motors. Just don't tighten very hard, you only need about a full turn into it. It's extremely easy to use with this method. Instead of unbolting the fasteners at the hub I slightly loosen the 3mm bolts at the motors as this will allow you to turn the motors ever so slightly. Then I tighten the botls as tight as possible and recheck to see if they moved at all. Here's the thread you want to check out http://forum.freeflysystems.com/ind...otors-and-checking-for-runout.334/#post-13296
If you're comfortable yawing the bird around in a full 360 at low altitude and six to ten feet in front of you, bring it down to eye-level and just look horizontally at the "discs" formed by the rotating props -- you can easily see if one of the "discs" is angled with respect to the others. If you need to stay more or less nose-out you can still get a pretty good idea for most of the motors -- I was surprised how easy it was to spot a slight "out of vertical" displacement. Andy.
One of the things I found is that you can have the motor perfectly level. Once you start torquing down screws the motor will go off alignment. The only way to precisely mitigate this is that you have to account for how many turns each nut gets. Even then it is not perfect. I agree with Gary 100% on this. You get them as close as you can get and accept it. As Andy stated you can get an idea if all motors are close by comparing adjacent blades. It is frustrating as hell, I know I spent hours in my lab going around and around trying to fix it. As long as the offset is not gross you should not have an issue. One of the things I noticed was that the motor mounts will twist as you are tightening down screws. This is something to keep in mind. As you are cranking down the bolts you eventually apply force to one side more than another an induce a slight rotation in the mount. This causes the motor to be counter rotated a little. The way to mitigate this is to crank evrery thing down in a very tedious star pattern. 1 half rotation for every bolt when you start getting notable tension. Andy's insight is great as well.