Hitec 5645 servos, Are they good servos?
11-09-2007, 07:29 AM
#26
RE: Hitec 5645 servos, Are they good servos?
Common now folks, this thread has all the makings of a good one. Let's try not to beat each other senseless. This can be discussed in a calm manner.
Not having Jr servos wear out is definitely not the norm. I've used 8611, 8611a and 8411 for a long time. I have a couple 8711 now on some of my rudders and I must say they are powerful. All the 84 and 86 series have had gear replacements and now the couple of 8711's are starting to get a bit loose. The 84 and 86 series are quite old and on a plane doing very mild 3D and mainly IMAC.
Now, what I have come to see is this.
The 8411's and 8611's and 8611a's when run by themselves (only one servo per surface) and minor 3D will last quite a while. Now add in some hard in your face 3D and do it often and guess what, they will get sloppy. So that's where the 5955's come in. If you want your gear train to last and you do lots of hard 3D with said plane, use the 5955's. The centering issues and not really gonna matter much as you are stalled most of the time anyway.
When you run multiple servos on each surface, it's important to get everything setup as perfect as you can make it. Here is where the 5955's really shine. You can be slightly off and not tear up the gear train though you will tear up the surface, you'll jsut kill your battery run time When the JR servo's are off, you will tear up the gear train, in short order I might add, and not likely to harm the surface plus kill your battery run time.
If the plane is gonna spend most of it's life doing pattern/IMAC/sport style flying, then the JR servos will suit you well. If you consistently pound on the plane in 3D get the 5955's.
Now the original question is about the 5645's. I have been reasonably lucky. I have 7 of them on a well flown 30% Ultimate. I pound on this plane without mercy. Yes they are getting worn, but when I programmed them, I set all deadbands to match the radio, not to zero. The programmer is capable of telling you the radio deadband so match the servos to it. I've been doing this for a few years now. Would I replace them, yep, they are getting sloppy and not centering well, were they centering well when new, yes they were.
As far as not using metal gear servo's on a GS plane, you can get away with it easier on multiple servo setups. Take a look at any Comp-Arf manual, specifically the rudder setups. They tell you in the 2.3M Extra manual to replace the plastic wheels on the recommended 8411's with the H9 aluminum wheels, BUT in the 2.6M (and above) manuals they tell you that you can safely use the nylon wheels when ganging servo's because the load is spread over them. BUT, they say that you must use metal geared servos or the warranty is no good. I would think most of the better manufacturers have tested with both nylon and metal geared servos
Personally, I would rather put the best servo's I can into a plane, it's a safety thing. I know nylon gears are more easily stripped than metal, I know metal gears where out faster, but I know that metal will be there when I need it most so I would never risk any plane 50cc and above with nylon, even if they were ganged.
Now, everyone knows Hitec's do have centering issues and JR's have gear issues, both have been proven time and again. So maybe someday both will wake up and in JR's case, make one with titanium gears and Hitec will use a better POT design. Then we will have nothing to complain about as we will have the best of both worlds.
Not having Jr servos wear out is definitely not the norm. I've used 8611, 8611a and 8411 for a long time. I have a couple 8711 now on some of my rudders and I must say they are powerful. All the 84 and 86 series have had gear replacements and now the couple of 8711's are starting to get a bit loose. The 84 and 86 series are quite old and on a plane doing very mild 3D and mainly IMAC.
Now, what I have come to see is this.
The 8411's and 8611's and 8611a's when run by themselves (only one servo per surface) and minor 3D will last quite a while. Now add in some hard in your face 3D and do it often and guess what, they will get sloppy. So that's where the 5955's come in. If you want your gear train to last and you do lots of hard 3D with said plane, use the 5955's. The centering issues and not really gonna matter much as you are stalled most of the time anyway.
When you run multiple servos on each surface, it's important to get everything setup as perfect as you can make it. Here is where the 5955's really shine. You can be slightly off and not tear up the gear train though you will tear up the surface, you'll jsut kill your battery run time When the JR servo's are off, you will tear up the gear train, in short order I might add, and not likely to harm the surface plus kill your battery run time.
If the plane is gonna spend most of it's life doing pattern/IMAC/sport style flying, then the JR servos will suit you well. If you consistently pound on the plane in 3D get the 5955's.
Now the original question is about the 5645's. I have been reasonably lucky. I have 7 of them on a well flown 30% Ultimate. I pound on this plane without mercy. Yes they are getting worn, but when I programmed them, I set all deadbands to match the radio, not to zero. The programmer is capable of telling you the radio deadband so match the servos to it. I've been doing this for a few years now. Would I replace them, yep, they are getting sloppy and not centering well, were they centering well when new, yes they were.
As far as not using metal gear servo's on a GS plane, you can get away with it easier on multiple servo setups. Take a look at any Comp-Arf manual, specifically the rudder setups. They tell you in the 2.3M Extra manual to replace the plastic wheels on the recommended 8411's with the H9 aluminum wheels, BUT in the 2.6M (and above) manuals they tell you that you can safely use the nylon wheels when ganging servo's because the load is spread over them. BUT, they say that you must use metal geared servos or the warranty is no good. I would think most of the better manufacturers have tested with both nylon and metal geared servos
Personally, I would rather put the best servo's I can into a plane, it's a safety thing. I know nylon gears are more easily stripped than metal, I know metal gears where out faster, but I know that metal will be there when I need it most so I would never risk any plane 50cc and above with nylon, even if they were ganged.
Now, everyone knows Hitec's do have centering issues and JR's have gear issues, both have been proven time and again. So maybe someday both will wake up and in JR's case, make one with titanium gears and Hitec will use a better POT design. Then we will have nothing to complain about as we will have the best of both worlds.
11-09-2007, 09:14 AM
#28
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RE: Hitec 5645 servos, Are they good servos?
Just a quick response to the what they did 15 years ago... yes did gang multiple servos together because they didn't have any other option.
They also didn't fly 3D
They also didn't have huge engines and the power to weight ratios we have today. It wasn't uncommon to see a G-62 on 23 pound plus plane.. today that plane gets an 80, 85, 100, or even a 115 in some cases.
They also didn't fly 3D
They also didn't have huge engines and the power to weight ratios we have today. It wasn't uncommon to see a G-62 on 23 pound plus plane.. today that plane gets an 80, 85, 100, or even a 115 in some cases.
11-09-2007, 10:57 AM
#29
RE: Hitec 5645 servos, Are they good servos?
This has been a good thread so far. I've enjoyed reading both sides of the the issues: brands and types of gears.
It is okay for the differing opinions. That is how we learn, imo. Let's not get our feelings out of whack if someone disagrees, okay? I'm reading a lot of things here that I think are very good from both sides. If we keep our feelings in check, we may have a good thread going for a while.
It is okay for the differing opinions. That is how we learn, imo. Let's not get our feelings out of whack if someone disagrees, okay? I'm reading a lot of things here that I think are very good from both sides. If we keep our feelings in check, we may have a good thread going for a while.
11-09-2007, 01:09 PM
#30
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RE: Hitec 5645 servos, Are they good servos?
While nylon may indeed "work" in many applications where people opt for metal... all it takes is one to strip to ruin you whole day! I always tell our customers it's better to be safe than sorry.
Yes, metal gears will wear over time (some brands worse than others
) but it's easier to replace gears than build or rebuild a model anyday. FYI: Titanium gears have shown zero signs of wear since their release three years ago, so if you never want to worry about gears breaking or wearing (not to mention get ultimate performance) then opt for the 5955TG. While it may be overkill for a 50cc model, it can be used in larger models down the if (when) you move up.
FYI: It's not the pot... the Hitec 59XX series servos use the same pot as the JR8XXX servos, it's the I.C. that affects the centering (deadband and resolution) Hitec sacraficed this for programmability but the next generation 79XX series digital servo will improve this aspect of our digitals. But that discussion is for another thread.... remember we are talking about the 5645 in this one
Mike.
Yes, metal gears will wear over time (some brands worse than others
) but it's easier to replace gears than build or rebuild a model anyday. FYI: Titanium gears have shown zero signs of wear since their release three years ago, so if you never want to worry about gears breaking or wearing (not to mention get ultimate performance) then opt for the 5955TG. While it may be overkill for a 50cc model, it can be used in larger models down the if (when) you move up.FYI: It's not the pot... the Hitec 59XX series servos use the same pot as the JR8XXX servos, it's the I.C. that affects the centering (deadband and resolution) Hitec sacraficed this for programmability but the next generation 79XX series digital servo will improve this aspect of our digitals. But that discussion is for another thread.... remember we are talking about the 5645 in this one
Mike.
11-09-2007, 01:20 PM
#31
RE: Hitec 5645 servos, Are they good servos?
ORIGINAL: mrbigg
"So maybe someday both will wake up and in JR's case, make one with titanium gears and Hitec will use a better POT design."
Somebody set the alarm clock.
"So maybe someday both will wake up and in JR's case, make one with titanium gears and Hitec will use a better POT design."
Somebody set the alarm clock.
11-09-2007, 02:43 PM
#33
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RE: Hitec 5645 servos, Are they good servos?
ORIGINAL: nonstoprc
I thought the type of motor plays an important role on centering. The coreless motors are always better and used in high-end servos (e.g., 59XX).
I thought the type of motor plays an important role on centering. The coreless motors are always better and used in high-end servos (e.g., 59XX).
Mike.
