Mini Heli Blog

Trashed my TREX 450 Plastic Head and Ordered a Metal CopterX Head from China

A couple of weeks ago I had my first huge crash in my TREX 450. It’s a shame I don’t have it on film, since the crash was so spectacular. I was attempting a role too close to the ground, and the bird met tera firma blade first almost completely inverted. Damage to the head was total. The SA has a mostly plastic head and therefore I broke mostly every piece of it. Since I was in stunt mode, the gear was chewed up pretty badly since it took me a second to kill the motor. The main shaft was bent at almost a 100 degree angle. Amazingly the wooden blades were just fine, since the bladegrips and the rest of the head took all the impact I guess.

I priced out replacing the pieces for the head, and decided to just replace it with a full metal CopterX head. The one I ordered was only $40 shipped from China, and reading reviews on helifreak.com it seems that it’s almost as good as the Align setup (at a fraction of the cost). Having ordered R/C stuff from China in the past, I know that it can take up to 20 days to receive it, but I need that time to fly no the simulator and get this last crash out of my system. I’m also going to spend a lot of time making sure that my head is setup perfectly this time. helifreak.com has great videos by “finless bob” that show the proper way to set up the collective and pitch of the head. My SA came fully assembled, so I pretty much just put in the servos and started flying. Looking back, it seems that if I had had more negative pitch available during my role that I would have been able to pull it off. Although I really have no idea where it was.

Once I get my new head on and setup, I’ll write up a review of the CopterX head compared to my plastic Align head. I’ll also be sure to catch my next roll attempt on video.

My First Crash with the Align TREX 450

So it was bound to happen sooner or later. I hadn’t been doing any flying for the last couple of weeks with my TREX 450 (or any helicopter since I got rid of the Axe CPv3), but on Saturday morning, since it was the first day it hadn’t rained in a while, I went to a local park with my wife to hover around. I affixed some training gear to the landing struts just to be sure I wouldn’t tip on the uneven ground in a landing, but I ended up crashing it anyway.

I’m not exactly sure what happened, but it seems that my elevator servo in the collective failed and that’s why I lost control and landed on my side. It actually wasn’t too bad of a hit, as both blades flew off (breaking at the blade grip), and the landing gear struts snapped off. The elevator servo is also ruined, but I think that was what failed, although it might have been something else and the servo could have just died in the crash.

In either case, I’m getting rid of these jenky E-Flite S75 servos that I have. They have a terrible time centering, and just seem really weak. I’m contemplating between the JR Digital 285 or the Hitec HS65 servos. The JR digital servos obviously will do a better job at centering and keeping their position, but they’re relatively weak and slow (and expensive at $35 each). The HS-65 servos seem to be the most commonly used servo in the TREX 450, with a decent speed, the most torque in a micro servo, karbonite (or metal) gears, and a ball bearing on the top. I originally had thought about the HS-65 servo, but it seemed that the mounting holes wouldn’t line up and I would have to drill custom holes for them. Well the new version of the HS-65 has 3 mounting holes, so they fit fine in the 450 without any modifications. I found the karbonite gear version on ebay for only $21 each, so I think I’ll pick them up and try them out. I’ll write up a post about them once I get them in and fly them around.

Before the crash, my wife took a minute of digital video on my new Sony MHS-CM1 HD camera that I just got. The video isn’t very interesting, I’m just hovering around before I start flying (and crashing which isn’t on the video).