Hitec fans what do you think about this?

[airborneSGT]

OH snap we got some new servos. No wonder why the 5955's were being discontinued.

[50%plane]

Thanks for bumping this thread!

Good stuff

[MattyMatt]

Well.. it seems that the aluminum case on the 8711 is a very large heat sink, which will allow it to take on more and disapate the heat faster. I will be using these in my new Dalton 300.

The big change to come in servo tech will be the brushless servos... speed, tq, less heat, and hopefully can take a Lipo/Lion voltage.

[Edge 540]

	Quote: Originally Posted by exeter_acres
	Ummm..this thread is 5 months old

Sorry. I recycled an old thread. My post is new and the discussion is still relevant with the new servos I mentioned in my first post.

[caurimare]

where did you get that info I can find anything on the hitec site, are they really discontinium the 5955

[Edge 540]

They had literature and displays at I-hobby. This is all coming straight off the flyer. I dont think I'm telling any secrets. Maybe I'm just the only one to pick up their paper? I searched the internet last night for each of the model numbers and found nothing in english.

The 2x resolution is intriguing.

[jonkoppisch]

I hope they have some new stuff coming out. I'm pro hitec but the 8711 is kicking their butt!!! Bad part is, if their 5955 was up to the advertised specs it would be in the running... According to tbm, aren't they about 1/2 the advertised power?

[AHP]

Here's another interesting article:


http://www.servotestsite.com/page5.html


The tests in 2005 were performed primarily to determine the best servo out of the top three servos currently manufactured. The three servos to be tested were the Hitec 5955, the JR 8611A and the Futaba 9152. Several other servos were tested as they were available, provided by Michael Glavin.
The JR 8611A tested as the strongest. I managed to get about 320 oz-in out of it. It didn’t last long at that load. I burned out two of them. The third one that I tested broke its gear train trying to lift a weight of 300 oz.
Both the Hitec 5955 and the Futaba 9152 tested lower than their specification. The Hitec 5955 tested nearly 1/3 less than their specification .Hitec claims 330 oz in on 6V. I could not get more than about 220 oz-in out of any of the three 5955 I tested or the 5995. The Futaba 9152 tested about 15 % less than its specification. The difference in my test and the test Futaba performs probably explains the difference between my results and theirs, but I am at a loss to explain why the Hitecs test so low. Maybe Hitec can explain that.
In spite of the maximum torque test results I think the Hitec 5955 is the best overall servo. The Futaba 9152 is a good servo but its quite a bit larger.
Why do I say that? The maximum torque is little used by the flier. To develop the maximum torque there must be an error signal of more than 125 us or about 10 degrees. Thus the servo will lag behind the stick 10 degrees if the maximum torque is required. This is usually never the case.
Most flying is done with the servo very close to the neutral point with small error signals. That is where the 5955 shines. It develops more than twice the torque at small error signals than the 8611A. It will make you seem to have better control over the aircraft.
Lets look at an example:
Suppose you have an airplane with a 15” by 6” rudder with a 3 by 3” aerodynamic counterbalance. Using the calculator at coloradogliders.com for servo torque I got 78 oz-in minus 4 oz-n for the counterbalance or 74 oz-in required for a 30 degree deflection of the rudder at 60 mph. A condition probably required for knife edge flight.
Looking at the chart (6V)for the 5955, 74 oz-in requires an error signal of 20us. The chart (6V)for the 8611A shows it requires an error signal of 37.5 us to produce the same torque. Thus you would have to move the stick about 1/2 the movement required with the 5955 than you would have to with the 8611A. You would feel like you had better control.
There are other reasons I would prefer the 5955 over the 8611A. They are:
1) The 5955 is programmable. I have been flying the 5955 on a rudder with a current recorder. It shows there are 100ma current spikes occurring throughout the flight. This caused by the servo resisting vibration caused minor deflections of the rudder. The deadband needs to be increased to reduce the current drain on the battery. You can do this with the 5955. You can also reverse the servo and match its travel with another servo in tandem installations.
2) It has titanium gears. This is bound to wear better than other metal in the gears.
3) It has greater resistance to burn out than the 8611A according to my tests.
4) Service. I burned one 5955 out by trying it on 7.4V. I sent it in and it was replaced with no questions asked



5955 all the way for me; that is, until Hitec releases a new iteration. Titanium gears that never wear and programmability put them significantly ahead of the rest, IMO.

[3DBatixkid]

I think it is misleading to compare the amp draw of a GS power system to that of your house. This number should be observed in watts, not amps, since the voltage difference between house power and a 40% is drastically different. Other than that, the information is great to have published.

[Edge 540]

Apparently the new servos are compatible with the old programmers but you lose the overload and resolution functions. If you want to "have your servos, and program em too" you need the HFP-20 programmer.
Maybe they will do upgrades?

[jonkoppisch]

'05 is an old test as there are new servos out.. 8711 of course. Now don't get me wrong. I am NOT a jr fan. What ticks me off is that you're not getting what's advertised!!!! Let me explain.

There's a guy in our club with a 35% carden extra that he just put together. Of course, everyone including me was telling him about the high torque and advantages with the hitec servos (& there are some advantages, servo reversing etc). He decided to go with hitec servos and with the 5955 on his rudder. Well, he was having a hard time keeping it in knife edge. It would be ok for the first knife edge then not be able to hold after that. He gave up and put a 8711 on the rudder and now he can knife edge + climb all day. Yes, 87's also sag some in power, but the point is that if the 5955 would have put out a majority of the power that they claim (the power that we paid for!!) it would have been plenty for his plane. Instead, his choices were either to go with a 2nd 5955 or switch to a jr.... Either way, he had to spend his $ twice...

[Edge 540]

I dont think 300oz is enough on a 35% rudder no matter which brand is supplying it. Two servos from either company is the way to go. Take your pick.