Servo thoughts

[Wheels]

I've seen alot of negative responses whenever someone posts about using hitec 5645s on 35%+ models, and I'm wondering why?

Many of us seem to have no problem with the idea that 2 5955s were enough for a 40% aileron, and 1 was enough for an elevator half. Independant testing (TBM) showed that the real world torque of a 5955 is 214 oz/in, and a 5645 is 144 oz/in. So if we put 3 5645's on an aileron thats 432 oz/in and two 5955s is 428 oz/in. Similarily two 5645s on an elevator half is 288 oz/in and that's substantially more than one 5955 would provide.

I know that some of you have had centering issues with them, but I flew 10 of them regularily this year with 0 issues, so I can only think that these are isolated problems. So, they are metal geared, reasonably priced, and provide more torque than many have allready decided their planes need............................. what's the problem with 5645s again?

[Altavillan]

Issue 1, a while back, 4 years or so, HT servos were having problems with the signal when an analog servo was in the plane. Newer versions or updates cleared up the problems. So did using Power Expanders. 5955's didn't seam to be affected but 5945's and 5645's were. So they got a little knock there.
Issue 2, It's not that much more money to get 5955's.
Issue 3, Lots of 35% ers will fly fine with 1 5955 on the rudder but not 1 5645.
I agree 5645's can be used in place of 5955's on the wings and tail if thats what you have. Just not on the rudder.

[Wheels]

	Quote: Originally Posted by Altavillan
	Issue 1, a while back, 4 years or so, HT servos were having problems with the signal when an analog servo was in the plane. Newer versions or updates cleared up the problems. So did using Power Expanders. 5955's didn't seam to be affected but 5945's and 5645's were. So they got a little knock there. Issue 2, It's not that much more money to get 5955's. Issue 3, Lots of 35% ers will fly fine with 1 5955 on the rudder but not 1 5645. I agree 5645's can be used in place of 5955's on the wings and tail if thats what you have. Just not on the rudder.

We completely agree about the rudder, by the time you had the power you need you'd have half a dozen servos ganged. I think that a couple 7955s and maybe the hardly used 5955 have sitting here will work nicely though.

I agree about it not costing SO much to buy the 55s as opposed to the 45s (even though the are just about double here, I'd go all 7955 if I was buying new now). But when your hangar includes only one giant scale at a time, and you're looking at using what you've got and $200 to toss in a couple extra rudder servos V.S. completely filling a 40% airplane with all new 55 series servos the price deosn't look so similar. As you said, if you're using what you've allready got, I don't think there's anything wrong with them.

[dbcaster]

The 5645's have a three pole motor the 5955 has a coreless motor. The 5645's also have metal gears. They will develop slop much quicker than a 5955 plus they will also not center as accurately. They will work but with the cost of a 35% plane paying a little more for a better servo is worth it.