Im getting ready to start putting together a T-rex. But Im seeing the 450XL in a CDE and HDE models. Whats the diffference between the two if any, the frame looks different I know but is that repositioning things like the gyro???

CDE- eccpm HDE- mechanical ccpm

Okay so now the next question, which is the prefered setup or whats the overall difference in characteristics between the two??

CCPM seems to be the way to go. the HDE mechanical linkage might have more slop. I hve the CDE and am very happy with it.
RickP

I prefer the HDE. The setup simply makes sense to me. If you have no experience it probably won't matter which. I have had a Raptor 50 for almost 2 years and the setup is the same on the HDE so it was easy. On the HDE 1 servo controls 1 function. On the CDE all 3 servos(pitch, roll, and elevator) work together to control the swash and in turn the rotor head.

From people who have flown both, most report that they fly the same when setup properly. I really like my HDE, and do not care for eCCPM.

for hard 3d the CCPM is the way to go... when you're throwing +11 deg to -11 deg on the collective rapidly, you want 3 micro servos pushing up and down on the swash vs just one with the HDE setup..... In other words CCPM is stronger, faster and more precise for those quick collective movements in 3d.... If you just plan on hovering around or "flying scale" then you'll be fine with the HDE

It's funny though how people talk about less "slop" in the CCPM version of the T-Rex, but in the T-Rex CDE there can't be any less slop that in the HDE. The linkage that is used in the CDE, I think, could allow for more slop than in the HDE. The lever setup on the CDE is convoluted as hell.

Now, if we were talking about the HDE, or the CDE verses the SE, I could see a valid slop argument there, because the SE actually uses true direct CCPM, and obviously allows less slop in the linkage to the swash.

I used to have both a CDE and an HDE, identically configured, and I couldn't tell a bit of difference in the way they flew.

Well since I posted this question I have scoured numerous forums checking out the differences. I have come to the conclusion that this is completely an opinionated topic. Each time I came across the subject it would be threads of pages of post each picking a side, some even saying that they fly their friends opposite set up and see no difference in response between the two and found some post that a pro flyer prefered the mechanical setup.
Needless to say Im not swayed eitehr way right now since I havent flown a T-rex yet, I'm just building one to get a more stable machine. Budget doesnt seem to be a problem since the hardware price and requirements are the same. HDE I think would be the better option at first just for the gained experience and but the market seems flooded with CDE versions.
Not sure which way I'll go yet, but thanks for replying.

I guess the bottom line is this......

If you want an easy setup and a great heli, the HDE is the way to go.

Well said.

I'd also like to add that somehow I got turned around while flying my Rex on Sunday. I was flying inverted and had been for a few minutes. Then all of a sudden it was upright, still not quite sure how that happened. Anyway Being upright with negative pitch and only about 10 feet from the top of a shed heading down fast, really fast I slammed the collective stick to full positive pitch and the heli just suddered a bit and went up. I was within 3' of the shed when it started back up. This was with my HDE Rex running DS281 servos. So I think the servos are plenty strong and the single servo doesn't seem to be an issue. I mean how much more violent a manuever are most of us gonna do.

Hitting the shed would have been more violent.

Yes of course, LOL . I'd bet my servos would not have survived that as well either.

The only thing I can figure is that I was turning a bit and the wind caught it and rolled it on me before I knew it. Course I was flying right over top of myself, which is a big no no, but I'm hard headed.

Well maybe I should take back what I've suggested. My only other experience was with a mechanical mixing helicopter that was a POS. I bought the CCPM on the advice of well experienced and trusted friend. since then I have been flying this exeptional wonder without regret.
Of course the prospect of upgrading to the CF frame with direct servo conncetions are brewing to a storm in my brain.
When I was setting up the CCPM interactions I noticed that it was difficult to get repeatable readings due to slop in the linkages - so indeed there is some.....
RickP