rckowal

I find the following statement from Hobby City to be confusing. I presume that "export" means USA. Do these servos come with standard Hitec/Futaba, etc. type connectors?

"WARNING These servos can be found on eBay and other asian sellers at close to this price, however be warned, they do not contain Taiwan/Japan components. HexTronik (the manufacturers of these servos) have two standards, one is for local sale, and the other is export quality with imported connectors and resin gears from Taiwan and Japan. Our HXT500 and HXT900 are export only, and not built for the domestic market."

Murocflyer

They do come with Hitec/Futaba connectors.

What that warning is saying is that the servos sold in China are made with "cheaper" parts.

I had some HXT servos given to me and they seemed to work pretty well. I believe they are still going strong. I have not heard anything otherwise.

Frank

Twmaster

If HXT are the actual manufacturers then TowerPro must be getting their SG-90 from HXT. It's the same servo.

And I have to agree Frank. They are terrific little servos. The super price is just a bonus!

ministeve2003

I believe the statement is that the hxt900's are made with much higher quality nylon resin gears for a more demanding "world market"... some of the cheaper towerpro ones sold elsewhere only use plastic gear sets...

As for the quailty of the hxt900's... they are a fantastic servo... I use them on everything from 42" balsa 3d models to 8oz foamys.... and with over 60+ servos used, I've only damaged 2 from hard crashes... I've never stripped the others...

Here's a video of my eflite minifuntanX using those servos on it.... its a 42" balsa 3d plane with a 35x36x910kv motor running 12x6 jxf Prop on 4cell 1500mah rhino Packs and 40amp turnigy esc... and You can really see it being put through the ringer....

[media]http://www.vimeo.com/1943406[/media]

CHELLIE

Steve is right, the HXT 9 granm servos are a awesome servo, very very strong, I have them in a FunJet doing 103 mph and a 42" wing Span Funtana and a 49" Katana, I damaged one in a crash, but that was my fault, Dumb Thumbs

http://www.youtube.com/watch?v=lTbir0Uc6Q8


http://vimeo.com/1782940

rcers

My complaint with them is they are VERY power hungry (2x+ than Hitec). Make sure your BEC is up to task.

Mike

rckowal

Thanks to all of you for the very helpful replies. They're really appreciated. Just about all of the comments I've seen on these servos have been very positive. I'm going to get some for my next build project. Too cold to fly here now so I build for the spring.

Richard

Bill G

That's really the issue. Especially with the 2.4G reboot issues, as 2 of these servos will likely draw the same as 3 HS55 servos, where 3 HS55 servos is taxing the average linear BEC on 3s. An article here talks about how you do get what you pay for in efficiency, even if the low dollar servo performs well. It actually shows results for HXT900 servos, being on topic with the thread:
http://homepages.paradise.net.nz/bhabbott/Servo.html

Twmaster

And that is quite the truth Bill.

I lost a plane with a cheap chinese ESC and 4 HXT900 servos on board. We determined the cause to be a Spektrum brown out. Of course this was not Spektrum's fault but the use of a weak built in BEC on the ESC.

One of the regulars on RCG posted his data recorder info from a Stevens Aero SHAFT 400 with 4 HS-55's the current drawn from these and the RX was only 700mA. Double that with cheap servos and you are exceeding the capacity of the built in BEC in many ESCs.

Murocflyer

Airtronics' Rx's will operate fine down to 2 volts, well past servo failure voltage. Just thought I'd throw that out there.

Frank

Twmaster

Too bad just about nobody uses Airtronics...

Bill G

You know I think that makes the point, that if folks would have known ahead of time of all the Spektrum problems, I think a lot more would have stayed with 72MZz. I've never been shot down. With 72MHz and a shortened antenna, I once had severe glitching on a GWS Pico due to interference. Still landed ok. I also have pretty much proven that with the longer version antenna, the problem would have been much less.

TWMaster, don't be so easy on them, they may have caused your crash, in the sense that you may have gotten away with the low voltage BEC output on 72MHz:
Spectrum is likely fully responsible for at least 1 brown out crash. With 72MHz, it would have very possibly just shown up as a glitch, or at least come back on before crashing. This is especially true since Spectrum is known to SLAM controls on their way out. That's real good guys. Nice going. Can't even have a chance for auto-glide. I had a beautiful circling auto-glide landing once on 72MHz, when the ESC lead disconnected.

All said, I've been buying Bergs, and only buy Spektrum when I need channels 5 & 6, or the programmable features, and then I have to use an external BEC if I'm driving anything more than 2 sub-micro servos. You can drive 3 of them if they are lower draw good brands (see my link posted previously) , but not with anything you really care about.

groundrushesup

Brilliant bit of research on the part of that Kiwi gent - Thanks to you Bill for posting the link.

GRU

rcers

Bill great chart..... Good data there...

I can say that I have been "converted" to 2.4GHz since the dx6 days. No small task to get a 20+ year Airtronics guy away from both Airtronics and 72MHz.

I HAVE been shot down - not fun. Thankfully the guy fessed up..... I have almost shot someone else down (even worse!). But that is not why I switched.

The 2.4GHz is simply THE most reliable RC system I have used. I use quality servos and BEC's - including switch mode separate and Jeti Spin built in switch mode BEC's. I have never had a "brownout" with Spektrum and to be candid - I think many MANY times since there was nothing to blame Spektrum with "brownout" becomes a large cause for crashes.

Now I have seen a reboot - I know it exists, but again it is very convenient for pilots to "blame" brownout for their issues.

At any rate - glitch free for me since Mid 2005 (I had a pre-release Spektrum system for a few months prior to release! ). I had many glitches bumps and hits on 72MHz - while fine the majority of the time, 2.4 is better IMHO.



Mike

Murocflyer

It is a shame. There would be a lot less drama out there in RC land.

We are getting sidetracked.

Frank

CHELLIE

Good Point, but thats what makes them so strong, I use a 40 amp Turnigy ESC and bigger in my planes, because the turnigy ESC form 40 amps up, have a 3 AMP BEC, most are only 1 1/2 to 2 AMPS, so use the Turnigy ESC or a UBEC for cheap insurance, just My 2 cents worth, Take care, Chellie

Bill G

I agree that some of these issues are not directly Spektrum's fault, but they were part of the equation. As long as the user was well informed of the differences and different vulnerabilities compared with the 72MHz they used before, they would have a good chance of success. I'm convinced some users did not respect the reccomendation to set antennae 90 deg apart, and not pack them into a mess in a corner. Those are probably the folks who experienced the rf shielding from a large outrunner, that still would have not been a problem, had the arranged the antennae properly.

I'ts not necessarily that brownouts are Spektrum's fault, but many rc flyers leaned about the increased sensitivity to voltage drop of the pure digital electronics, when it happened to them in flight. Running ESCs in a high power EDF app, where the ESC is in the fuse and poorly cooled is not good, BUT, the Eflite Airliner was setup like this I believe, and many found their supposed plug-and-play setup to be plug-and-crash, due to BECs dropping voltage from overheat, thus brownout. Had it been on 72MHz, the receiver would likely have kept working if the BEC had not shut down entirely, but the real point is that people were not well informed of this issue that they had not encountered with such sensitivity to voltage drop in the past. Granted, the info is well out there now, about using external BECs depending on the app.

ministeve2003

there we go again, People love to compair apples to oranges.... hs55's are weak 8 gram servos check the specs... hxt900's are comparable (in specs) to hs65hb's which according to those charts are 100mah more.... not 2x more... please stop compairing 900's to 55's....

I have never had an issue with 4 hxt900's on an knockoff/noname/cheap esc with 3 amp built in bec, however, I have seen a few people crash with 4 hitec 55's and/or 4 hxt900 servos on a Castle Creation esc/bec due to brownout.... that was a compatiblity flaw between spectrum and CC... and doesn't seem to be prevailent with any other brand that I'm aware of... of course if that Eflte airliner has issues then Eflite esc's might be suspect too....

SK

CHELLIE

Oh Goodie, More Drama

CHELLIE

There is a Good Reason for that but i wont get in to that, might Cause more Drama

rcers

Well - I can tell you the Nylon gears on the hxt's are not in the same class as the karbonite. Never stripped a karbonite or had one fail.

So you are comparing apples to oranges in quality and durability.

Again we all get to pay our money and take our chances.

I think Hitec Servos - are FAR better quality - use less power, and will last longer and have the BEST warranty and support in the business. I have not had the same results with Hobby City many others share that in the same result.

The Hitec HS-65 is the best servo (in it's size class) I have ever used BAR NONE. Again my choice and I pay my $20 each and smile all the way!

Glad you like the hxt's but again don't compare apples to oranges.

I can compare 55's and hxt's all day long - they are in the same class in my mind. Actually - the quality on the 55's is better!

You don't have to change my mind - nor I yours. Be happy - I am!

Mike

CHELLIE

If A person is happy with the Hitec 55 Thats great, they are a good servo Period, they have there limitations, but they are a great servo, so is the HXT 9 Gram servos, they are a great servo too, period, I have both and like both, So There LOL ,Take care, Chellie

Murocflyer

I'm sure you are right about the Hitecs being better quality. I didn't have the HXTs long enough to see if they were any good or not. I used them on a GWS foamie plane that looked like a cub (the real name escapes me) and that was a sloppy flier so I couldn't tell much about them. I then moved them to a MM Tyro 100 and that plane flew sweet! The servos seemed to work well with that plane, but I sold it after about 15 flights. So no long term experience for me with them.

On the other hand, I've used HS-55s in about every plane that needed them since 2005. Very good servo.

Frank

ministeve2003

seen too many 55's strip out... seen bad centering on them too... not worth $12... thanks....

have only stripped 2 hxt900's out of 60+ on crash damage...

Seen 65hb's stripped out too.... but those were on heli's and were crash damage...

I like how we are now compairing gear sets on servos and not size/tork rating... yes, carbonite gears are stronger... but the servo can only take so much tork, and I was compairing the same tork specs... hs55's are like .5kg the other two are around 2.2kg... quite a difference.... if I was going to compair the $25 price I'm sure I can find hs65 size/tork rated servos in metal gear digital servos at hobbycity for less....

if you put hs55's on a funtana and did the tumbles I do... they would snap like a twig.... 65's hold up and so do 900's... both servos are nice... I own both... I would not take out my 900's out of any model even for free hs65's... they do their job, and it wouldn't be worth the effort...

SK

CHELLIE

I would not dare to use a hitec 55 servo on this 49" W/S Plane, thats why I used a HXT 900 servo, much much stronger, I use the Hitec 55 in my smaller foamies.

[media]http://www.youtube.com/watch?v=lTbir0Uc6Q8[/media]