RE: Art-Tech Diamond 2500- initial impressions and question about CG.
Hi. Just got the Art-Tech Diamond D2500 glider last week. Looking at it in the box it appeared to be a pretty good quality model, and the design is very much like the Multiplex EasyGlider (only bigger) which I had flown before and liked. So I decided to spend the big bucks and get this "receiver only needed" monster. However when I got around to building the glider this week, good old "Made In China" lived up to it's reputation. Here it is in a nutshell.
I'm not sure if that Servo Slower is supposed to be included, but it wasn't in the box with my glider.
Out of the box the rudder clevis and one of the flap clevis were broken.
As mentioned by Bob below, attaching the wings to the fuselage is a painful experience (and my spar rod is not bent or dented). It's hard not to damage the foam wings with the amount of pressure that needs to be applied to slide them together. I still haven't managed to get one of the locking pins in!
One of the two screws used to hold the horizontal stab to the tail is bent and can not be used (try finding another one of those!).
To get the CG as specified in the manual with the battery they supply, the battery has to be put so far back you have to dig some foam out at the back of the cockpit.
With everything wired up on the bench, it looked (and sounded) like a few servos were struggling. (all the servos come pre-assembled). Within five minutes one of the Aileron servos stopped working, and on further testing I found the servo had blown. With the servo arm disconnected from the aileron I had to fight to manually move the aileron surface! Full sized servos would have a hard time moving that surface, let alone these 9 or 10 gram servos. The problem is a design issue with the foam hinge, it's far too thick to allow for easy movement. After checking all the other control surfaces I found the same issue with both ailerons and the elevator. I have since heard that other D2500's have had servos fail in flight.
I have ordered six new quality servos, and I'll do whatever is needed to get all the other bits working properly. I still like the design and I'm sure it will fly great, it's just so damn frustrating having to spend even more money and countless hours to get an RTF ....well RTF!