ORIGINAL: seanreit
I can't answer for both, but I can attest after running numerous tests that the Hitec 5645 is just about the worst servo I have ever seen when it comes to centering on a control surface.
I had bought a few of them a few years ago, and ended up using them as retract servos in my models till I was out of them. And it was questionable to me even in that application, I should have just thrown them away.
FWIW.
Sean
I found the same with the 5625. My trim was all over the place and would not center until I switched them out for 5945MGs. In contrast, the 5945MG, I considered one of the best servos out there when they were still manufacturing it.
The newer digitalis have a Karbonite gear, but I'm not sure if its a load bearing gear (please correct me if I'm wrong). Makes me want to take one apart and see...
After the fiasco Hitec went through with the Karbonite gears, I can't see any reason in them pushing for the use of that material in any servo, let alone using it for marketing new servo models. Strange... Now, I'm a Hitec servo user in all my jets and most prop planes, but to see a company tell everyone that their Karbonite servos are really strong, but change their tune completely once a bunch have been sold and failed, then not offer a metal gear retrofit option; that's really disappointing. I hope the story isn't going to repeat itself, since I have a pair of the new 5985MGs on a shelf looking for a project.
Kelly