You guys had me scared on HS-605BB  
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All Forums >> Radios, Batteries, Clubhouse and more >> RC Radios, Transmitters, Receivers, Servos, gyros >> You guys had me scared on HS-605BB
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You guys had me scared on HS-605BB - 9/24/2002 10:10:48 AM   
ilikeplanes


 

Posts: 1058
Joined: 3/30/2002
From: portland, OR,
Status: offline 		So I put a brand new one through some subjective bench tests. Here's what I found:
* Centering seems pretty good. Within one trim click, both free and under load.
* Resolution good. Within one trim click dead band.
* Slight overshoot in one direction (under-damped) slightly slow to center in other direction (over-damped).
* Completely quiet even with drag torque.
* Very powerful.
* Slight heating of case when worked.
* Mabuchi motor
* Almost zero back-lash
* Typical surface mount amp
* Typical looking pot
* Motor not totally tight in mount but never moved even when output shaft was locked and stick was hard-over.
* Excellent value.
* Worlds better than my Cirrus sevos of equal cost and much better than a futaba standard.

All my tests were with futaba radio and 6v unregulated rx battery.

The fears I had learned from this forum were unfounded for this particular unit. I am going to use it on my CG Sukhoi without hesitation.
       Post #: 1

You guys had me scared on HS-605BB - 9/24/2002 12:22:45 PM   
easymoney


 

Posts: 82
Joined: 9/3/2002
From: Fort Smith, AR
Status: offline 		ilikeplanes

* Typical looking pot *... What is the brand name of this potentiometer manufacturer and whats the mechanical fitting/support for this pot... :

Just observe these 2 things and show these to an electrical and mechanical engineer... and hear the comments.

(in reply to ilikeplanes)
       Post #: 2

You guys had me scared on HS-605BB - 9/24/2002 12:39:53 PM   
WreckRman2



Posts: 1495
Joined: 5/13/2002
From: Indianapolis, IN,
Status: offline 		The recent inquires are not with all Hitec servos, just the digital ones and a 605 isn't a digital servo.

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David Smith

(in reply to ilikeplanes)
       Post #: 3

You guys had me scared on HS-605BB - 9/24/2002 11:09:00 PM   
ilikeplanes


 

Posts: 1058
Joined: 3/30/2002
From: portland, OR,
Status: offline 		I am a Mechanical engineer. The pot is not marked with a brand name, nor are the components on the pc board. My experience is that "brand name" potentiometers are only used in instrument grade products. A single pot of this type can cost more than an entire servo. The pot is mounted in a cavity molded into the top portion of the servo case. Other details and materials appear adequate for a product of this cost.

If I had the extra time and cash, I would do a full blown lab test showing peak torque, peak speed, speed at 1/2 stall torque, step response in both direction, minimum resolution, centering precision, dead-band, and mechanical slop. Of course, the test would have calibrated instruments with a population of components and a statistical analysis of the gathered data. It could also be done with "green" and "burned-in" servos.

BTW, I have used servo hydraulics in machinery that I designed for industrial processes. We did a structured test program to determine the difference between Parker and Moog servo hydraulics. The Moog servo valves were far superior to the Parker. In this case, price and a good name does buy you something. I'm not sure if the same applies to model servos.

WreckRman2, there is also quite a bit of discussion on the 605BB.

(in reply to ilikeplanes)
       Post #: 4

You guys had me scared on HS-605BB - 9/25/2002 2:18:22 AM   
can773



Posts: 1654
Joined: 1/25/2002
From: Calgary, AB, CANADA
Status: online 		Testing a new servo does not have a lot of merit, it shows new condition results, which only last for a finite period of time.

Fly that servo for 100 flights, pull it out and repeat the same tests.

Then do it with a 9402 Futaba for instance, you will see the difference.

Not trying to knock the Hitec, but you need to remember that it is not a precision servo. With servos I have found that you do get what you pay for.

Ya the equivelent Futaba will cost more, but in the long run it will be worth it.


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Chad Northeast

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       Post #: 5

You guys had me scared on HS-605BB - 9/25/2002 4:03:34 AM   
MikeMayberry



Posts: 2864
Joined: 1/15/2002
From: Poway, CA, USA
Status: offline 		Do the same thing with the 925MG which is in the same class as the 9402 and you will definately see a difference. The coreless motor servos are much more precise.

If you want to compare Futaba servos to Hitec then lets compare apples to apples below.

http://www.futabarc.com/servos/futm0029.html
http://www.hitecrcd.com/Servos/hs925.htm

Mike.

(in reply to ilikeplanes)
       Post #: 6

You guys had me scared on HS-605BB - 9/25/2002 4:07:46 AM   
ilikeplanes


 

Posts: 1058
Joined: 3/30/2002
From: portland, OR,
Status: offline 		can773, I hear you loud and clear. I'm trying to figure out the value equation for my personal servo needs right now. An $80 servo is a hard pill to swallow though. But, like many products, a high initial cost can pay dividends down the road.

I think for now, I'll give the 605's a try. If they don't last a couple of seasons, I'll probably go with a top-shelf Futaba servo.

(in reply to ilikeplanes)
       Post #: 7

My kind of thread - 9/25/2002 5:05:16 AM   
TheEdge



Posts: 483
Joined: 12/29/2001
From: Chula Vista, CA, USA
Status: offline 		This was in my opinion a brilliant thread. Good subject and supporting results.
Very enlightening but not too much of a surprise.
I personally thankyou for going to the trouble.

Thanks Mike

I use the 605's and 615's on the majority of my planes, all of which are Non precise
No more than I am

For those that I am attempting to be precise with, I do splurge into the digital market, and do see a difference.

Mike Mayberry, help me out, I am thinking of putting 4 mini servo's in the ailerons for my DP Ultimate. What would you put in yours ?

< Message edited by TheEdge -- Sep 25 2002 12:24AM >

(in reply to ilikeplanes)
       Post #: 8

You guys had me scared on HS-605BB - 9/25/2002 5:14:12 AM   
can773



Posts: 1654
Joined: 1/25/2002
From: Calgary, AB, CANADA
Status: online 		ilikeplanes

I hear ya, give em a shot they might suit your needs. If you are looking for the ultimate in precision and reliability sooner or later you are likely going to spend some big $$$.


Mike

Unfair comparison I know, I was just pulling a number off the top of my head.

In my experience though the Hitecs just dont hold up as well to the abuse I put them through as a Futaba does, nothing against Hitec, I feel the same about JR stuff as well, just my experience.


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Chad Northeast

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You guys had me scared on HS-605BB - 9/25/2002 7:49:31 AM   
Kevin Greene



Posts: 2580
Joined: 3/28/2002
From: Jackson, TN, USA
Status: offline 		ilikeplanes,

That small amount of degrees of non-centering at the servo can equate to a large amount at the control surface. I had a 605 on the rudder via a pull-pull cable. The cables were attatched to a metal pull-pull tiller and not to the servo itself. The servo drove the tiller via a 4-40 rod with tight Rocket City hardware. Due to non-centering the rudder was off by 1/4 of an inch when it went back to neutral!!!

I have used Hitec servos in other applications and I've been happy with them. I use HS-81's to operate air valves. I have a couple of the new thin digital wing servos mounted in the verticals of my HotSpot and they center wonderfully. I do have concerns with other Hitec digital servos locking up and I will not use them on ANY critical control surface until Hitec sorts this out. Besides, JR digi's are only a couple of dollars more and the bugs seemed to be worked out with them. I can't afford to loose a $6000 jet not to mention possibly killing someone over servos that may or may not lock up. Hitec knows that there is a potential problem with some of their digi's---If someone gets killed or injured I wonder if Hitec could withstand the potential financial mess that they are exposing themselves to. Just my .02 Kevin

(in reply to ilikeplanes)
       Post #: 10

You guys had me scared on HS-605BB - 9/25/2002 7:40:50 PM   
Volfy



Posts: 3227
Joined: 1/4/2002
From: Houston, TX, USA
Status: offline 		I really think people bash the 605BB unfairly. It's a $29 servo, ferchrisake! It's a 3pole motor - of course it's not going to center as well as a 5pole or coreless motor. Within it's own limits, however, it's a very nice high torque stardard size BB servo.

It's hard to compare to other brand servos mostly because many other brand don't make 3pole high torque servos.

As far as durability goes, I don't see Hitec as being any less able to hold up to abuse as other brands I use. I use Hitec 615MG (3pole Super Torque) excclusively for steering servos in my RC monster trucks. Even with a servo saver, that application sees the kind of abuse that airplanes only dream about in their worst nightmares. An 8ft jump landing hard on the front wheel - WHAM!!!!! After 2 yrs of this kind of punishment, the 615MG are holding up just fine.

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Si vis pacem, para bellum.

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       Post #: 11

You guys had me scared on HS-605BB - 9/25/2002 8:29:51 PM   
MikeMayberry



Posts: 2864
Joined: 1/15/2002
From: Poway, CA, USA
Status: offline 		TheEdge- 5245's http://www.hitecrcd.com/Servos/hs5245.htm

(in reply to ilikeplanes)
       Post #: 12

You guys had me scared on HS-605BB - 9/25/2002 11:48:51 PM   
ilikeplanes


 

Posts: 1058
Joined: 3/30/2002
From: portland, OR,
Status: offline 		Hey Mike, why don't we have worm drive servos. That would prevent the control surfaces from back-driving the servo. Blow-back induced flutter would be eliminated. It would also greatly reduce the number of gear tooth meshes and should improve virtually every aspect of servo performance except package size and torque/amp.

(in reply to ilikeplanes)
       Post #: 13

You guys had me scared on HS-605BB - 9/26/2002 1:19:37 AM   
SMALLFLY-



Posts: 2150
Joined: 12/9/2001
From: Evansville, IN, USA
Status: offline 		Have you tried the 625 and 645 servos, there a bit more expensive but I am flying the 625's and love them powerful and precise with good centering with at least 50 flights on my edge. I just ordered 6- 625's and 645's for my GP PW
92 and 133 oz for under 40 bucks at 6 volts, heck of a deal comparatively.

(in reply to ilikeplanes)
       Post #: 14