himagain

Lucky escape!!!!


Well my P70 clad boomer is finally ready. This weekend is its maiden. I gave it a final check over last night and this happened [&:]

[link=http://www.youtube.com/watch?v=oyn4Q5JMy9w]hitec digi failure[/link]

The servo is a hitec 5625 digi. Seems to have worked fine on the bench fo weeks, but the first time i leave it switched on for about 10 minutes, this happened. The servo did this about 5 times then it locked up and stopped working at all

I just cant believe how lucky i've been in catching this on the ground.

Anyone else had obe of these go down like this

David

cap10b

Himagain,
Been there done that got the crashed planes to prove it. Sold all my hitech digitals and switched to JR. In fact all the guys in the club that fly expensive jets and prop planes switched. Love their analog servos run hitech in all my small electrics no problem but digitals are another story. Don't mean to start another servo war but change before you fly, you'll feel better after a sucessfull maiden.

Good Luck.

JDS

MikeMayberry

My Feedback: (1)

While any servo can fail at anytime (no brand is immune to this,) typically if it is defective it will fail within the first few minutes of it's life. The 5625MG uses a 3-pole motor which helps keep the cost down but they are not as reliable as the coreless motors used in the 59XX series servos. That's not to say these servos are not perfectly adequate as there are tens of thousands in service. Hitec in the UK is Amerang and has a one year warranty; they should repair or replace the servo at no charge if you send it in to them.

cap10b- To simply say "Hitec digitals" as if they are all in one category is a unfair statement; Hitec makes standard sized digital servos that range from $35 -$115 with the HS-5955TG being our flagship which has 333in/oz of torque but more importantly uses Titanium gears that simply do not wear. This servo is well proven and to indicate that anyone would pull 5955TG's out of their plane in favor for JR's is simply nonsence! Search on this servo on you see it is more likely the other way around since people are fed up with wearing out JR gears in a few dozen flights!

Mike.

rmh

I hate to say it but -I have seen at least two 40% setups switch out the top end Hitechs for JR's -recently. not a cheap exercize!
the reason in both cases was the servos changing settings - in the air .
These guys were not encouraged to do it -they simply were unable to hold settings with the HiTechs
Personally - makes no difference to me what anyone else uses --

dirtybird

My Feedback: (5)

The Hitec 5955 is the best servo available for a lot of reasons but, I don't know why you continue to insist that it is capable of 330 oz-in of torque. Its not. The best I have ever been able to get out of one is about 220 oz-in. You are just undermining your credibility.

NdFrSpeed

My Feedback: (1)

Not sure about others but everybody I know fly ing 33% and up here use Hitec's,,,,you talk about servos going bad,,,ive seen Jr's not even last a season,,,im talking the 8611A's,,you use cheap servos of any brand in a expensive plane and your asking for trouble,,Hitec 5955's are the only way to go,,theres a diehard Jr guy here,,but guess what he put in his 37% Yak,,they werent JR's...


NdFrSpeed

Flip and Fly

I have had HiTecs go bad on me but like Mike said they all went bad almost within the first few minutes. One went bad in the air and did damage the plane, rudder servo locked hard over. It was an new 5475, 6th flight. The others were 5645s.

However I have had other servos JR, go bad too. So I still fly with my 5645s, 100s of flights, and now 5955, getting up there. No problems. I guess any failure is a bad thing but thats the nature of the hobby.

cap10b

Mike,
Your right all my experience has been with the 5945 and 5925. While Hitech repaired the servos for free I lost two expensive planes and two good motors. That cannot happen in my world. While NdFrSpeed is right we have seen 8611a's recently fail on a very expensive Comp Arf 40% that one plane is not enough to deter me from my opinion and that's all it is My Opinion.

I continue to use Hitech analogs, most recently some 225MG for flaps on a scale job. I continue to use Hitech crystals in my Corona receivers for my e-flite planes. Large Aerobatic planes are very complicated sometimes and while the professional flyers have no problems with equipment (mainly because they don’t pay for it) I must fund all my planes without factory support. While I appreciate Hitech Service and appreciate the price break on the rebuild I cannot afford to tempt fate nor to risk injury over flight controls.

The large-scale aerobatic scene is dangerous enough with the way individuals handle their planes in public. I just don’t want to risk going out of control over something so simple as a servo. If Collins Radio or King Radio made servos for model planes I may be tempted to switch. If the industry were to adopt the FAA FAR rules and regulations for PMA certification on parts that may be a different story. If that were to ever happen your $500 .40 size fun fly machine would cost well over $10,000.

As I see it we continue to be at the mercy of the current equipment manufacturers.
As to who is right or wrong that's up to the individual flyer to decide for himself.

Thanks to everyone in our sport who try to make things right.

JDS

Nogyro

My Feedback: (10)

Funny how the brand wars will go on and on........ I've been running the 5945's for years with never a problem. Had close to 500 flights on one set and sent them into Hitec for gears.....One was just plum wore out so they replaced it with the new 5985. I've got close to 200 flights now on a set of 5955TG's and the gears are as tight as they were new. (on a 33% Hanger 9 Extra/3W80Xi). A buddy I fly with has been a die hard JR fan for several years. He's had 3 of the 8611A's lock up on him, and this last time it cost him a Comp-Arf Extra on the first day out. He's setting up a new 40% and he's giving the 5955TG's a try.....

Nothing can replace a good clean installation with ample power being delivered to the servo. Also as Mike said, if a new servo is going to fail, odds are it will be in the first few minutes of running. I'm a firm believer in burning in those servos for an hour minimum.....

Good luck to everyone no matter what brand of servos you use.

NdFrSpeed

My Feedback: (1)

Nogyro

Youve got the idea,,,i test run all my servos,,,actually all i use is 5955's..i fly 35% and up,,so far ive got 24 HS5955's,,,8 of those,are allmost 3 years old,,still tight as the day i put them in,,but its about time to send them back in just for a check up anyway,,,just gives a guy a piece of mind knowing there in good shape,,no matter what brand a person uses,,in my opinion,,you should be useing the top of the line,,its worth the extra money knowing your planes should have a better chance of liveing longer with the high end servos instead of middle of the road servos,,another thing,,i dont use your typical extenisions,,i make all my own,,all solder joints,,all the way to the reciever.

NdFrSpeed

mglavin

My Feedback: (31)

Dick

I think you'll find the issue you noted as in flight changes is likely explained by the fact that Hitec's digital servos develop power to react and or counter surface needs with less error signal, much less than the other big player. In laymens terms the other servos react like mucho expo is dialed into there control response while the Hitecs develop power sooner than later and live through use and abuse with much better results too. Other variables are linkage ratios and less than ideal TX programming and servo setups which favor poor system resolution. Properly setup we simply are not realizing complaints IMO.

XJet

The Hitec PR machine has *zero* credibility anyway but I seem to recal them justifying the over-statement of servo performance as being okay because everyone else does it.

It seems that two wrongs must make a right.

Having said this, Hitec's servos are great value and I've got a lot of planes that get flown all the time without problems.

I love their gear -- I hate their "there is no problem" attitude to denying things such as the Spectra/Optic glitch issue, the Fusion 9 recalls, the fatal Optic 6 firmware bugs, Optic 6 handle design flaws, the early digital servo lock-ups, the Karbonite debarcle, the Electron 6 temperature-related issues, etc, etc.

No honesty until their head is well and truly nailed to the wall by the facts.

Customers deserve to be told of product flaws as soon as they become proven -- not told that there's no such issue -- so that gullible customers end up crashing expensive models as a result.

I'll continue to buy Hitec but I won't believe a word of their hype and denials of problems with new products.

rmh

Having been only an observer in the debacles seen with my friends' programmed servos --I can only note that they were very unsatisfied with the experience.
The comparative servo response comment you make is a bit of a puzzle tho.
In actual use - the JR (and JRSport)servos I use, appear to have very tight dead dand and tx input to servo output is spot on -I use 70-80% expo and there is no discernable response delay.
Part of this is now due to the DX7 radio I use with all my models -
Having used some HiTec servos in the past -I personally had no problems with them but as far as superior response- I did not see that. I reallydo like (and use) the little bitty foamie model servos --

dirtybird

My Feedback: (5)

If you use 70-80% expo the superior responce of the Hitec 5955 would be lost on you. In fact, I suspect you would be just as happy with non digital servos. The responce of the JR 8611A is very similar to a non digital servo. The responce under a load can be very different than the no-load deadband.

rmh

-

rmh

have you run the 8611a on 6.6 volts with a DX7 radio? with 150% throws?
I really think you are missing what I am addressing.
the response is so fast with this setup -I need to run that much expo for non 3D maneuvers .
there is NO lag in response.
Today I was flying my 400sq in foamie (being charged in pic) at the flats - (75% expo all around) and doing repeat laps from me to about 600 ft out - all at about 1 foot altitude - the response was tight as a drum - I could hold the bank angle or altitude very easily- servos wer some little Bluebird or whatevers but even with that much expo the model was following inputs exactly
The exercize was a range test for my 6100rx.- as far out as I could see it and as close to the ground as possible.
perfect --also at 2000 ft out n up-just a tiny white blob--it never faltered. pic will give an idea as to the size of the circle area I was flying. great test flying area -flat as a billiard tabe -really- for 1/2 a square mile

Nogyro

My Feedback: (10)

Now that's flat! Over here in Tennessee, I'd have to drive 100 miles to Missouri before I found an area that large & flat.

We get pretty good at dodgin' trees though. [X(]

dirtybird

My Feedback: (5)

I have not run the 8611a with a DX7 radio but I did load test the servo on 6V. I burned out two of them trying to get reliable readings. I found I had to shut them down in less than 10 sec at high loads or they would burn out. You can look at my test results at www.servotestsite.com until April 4.
I repeat. If you use high expo you have lost the advantage the 5955 can give you. Except that it don't burn out when you load it hard.

rmh

I hate to sound negative - but I simply have not seen burnout problems with the 8611A - A number of us fly them on 40% setups and problems are almost nil. - but personally I have watched others smoke a few of the top end Hitecs -but these were all "programmed " setups Perhaps operator error -but they were very unhappy campers ..-- as for the expo - I don't think we are looking at same performance criteria
many other radios at 80% expo have extremely poor performance. Likely this is what you have seen.
totally different ballgame.
My setup -at 70% expo - will follow the stick bounce-if you let it fly from full throw to center .-- as an example only.

dirtybird

My Feedback: (5)

I am not looking at the expo performance of any radio. I am only looking at the performance curves of the servos. The advantage of the digital servo is that it produces more output at less error signal. The 5955 is better at this than most other servos. Almost twice as good as the 8611A. When you use expo on any radio you negate this advantage.
I am not surprised that you have not burned out the 8611A. Its performance curve shows that for you to get it to produce maximum torque you need an error signal of nearly 200us. Thats almost never going to happen in operation. If it does, you are not likely to have the airplane for 10 sec. due to other considerations.
As for the 5955 smokes you have seen, when you put control in the hand of the operator you risk failure of the product due to operator error. I have subjected the 5955 to 7.4V ( out of specs) at full load for 3 minutes without burn out. The 8611A will stand 6V at full load for only about 10 sec. I have to wonder how long the 8611A would last in the hands of the clods that you have seen burn out the 5955's

rmh

actually the same guys have not burned up any 8611A servos
The reason -to me is that both of these guys showed up with their Hitech programmers and proceeded to show me how they could correct for linkage differences with the programmer
I doubted it -but they were both adamant -so I bowed out.
they also both smoked em all-- .)
when they recovered from these debacles- both installed 8611A servos and did the setup right .
The other guys who tried the high end Hitechs simply complained about "in air" changes. They also changed over (at a dozen servos at a time they did not do this without first giving the original servos a fair shake
Personally I use no matching or other electronic devices - rather -I get linkage to match . some kits on the market show mismatched linkages but -I don't fly those setups .
My favorite servo - is the JRSPORT 126 --a very inexpensive, 3 pole non digital with the best gear train I have ever seen -cheap (35 bucks?)but puts out 140 (adv)in ounces .
why is it a favorite?
the gear train capabilities far exceed power limits and it is extremely accurate and inexpensive. maybe Hi tech makes it -(?)-it is made in Maylasia.
I have servos ranging in size from a few grams on up to the 8611A's but for the job these little guys do - I am amazed. I have a set eith over a year onem (125 version) and geartrain is still tight
All flying using em has been with gassers -including 33% EDGE.

camss69

My Feedback: (46)

I also don't believe the Hitec hype, I went against myself saying I would never again buy a Hitec product and bought a 5955 for the rudder on my 27%, again I am not impressed. (the promises were just too tempting) The thing just doesn't center for crap, I'm not buying a programmer to make my $100 servo center like it should. WHY IS IT that I can swap it out with a JR 8411 and the JR centers every time, EVERY SINGLE TIME. Same setup, same push rod, same everything, just the servo swapped out. Why can I move the trim switch on my radio ONE click and the JR's move with every click and the Hitec, even the FLAGSHIP 5955 doesn't do the same? Let me guess, "we've never heard of that before" or "your setup is bad" or "you need the programmer to narrow the deadband" freekin please. I will say this though they did get one thing right the titanium no slop gears rock. Hitec should make a gear set for the JR servos, I would buy that from them since JR isn't making the ti gears. Ah well there still is no perfect servo.

I also don't think their speed ratings are correct but I won't get into that one.

I just bought all the servos for my 35% and none of them say Hitec on them. I'll deal with the gear wear as I have to, on my 27% I've only had to change one set of gears in 300 plus flights.

dirtybird

My Feedback: (5)

I don't know who makes it but I am told both the 5955 and the 8611A use the same motor. If you want the Hitec gears put on the 8611A you might just as well buy the 5955.

himagain

I still have the dilema, after having the servo swapped out by my model shop do I replace it in the model and trust them not to fail in flight. I bought expensive servos for reliability my confidence in them is now tarnished. Is this a case of you have to pay more for reliable digi's

David

tkilwein

I had hs5645mg in the tail and elev on a 36%Katana they had some small amount of slop. The ailerons have hs5955tg's and they are great!!. now 5955tg all around. They center dead nuts every time, have enough power, four of them to lift the plane when the flaperons are deflection down.
I have a futaba 9zhps and 14mz, let me tell you they are blazing fast with the 14mz and 5014rx setup. I have no matchbox or programmer, two servos per surface, as the 14mz does it all. I have NO buzzing when center and endpoints are set in the tx.
I had the 8611's and they do not compare to centering and power of the hs5955TG. I don't care about the numbers advertized, just the results they give me. Even if the numbers are off the 5955tg's are sweet.

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