Hitec 605BB servos are not suitable for the H9 1/4 scale Cap!  
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All Forums >> Radios, Batteries, Clubhouse and more >> RC Radios, Transmitters, Receivers, Servos, gyros >> Hitec 605BB servos are not suitable for the H9 1/4 scale Cap!
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Hitec 605BB servos are not suitable for the H9 1/4 scal... - 5/8/2002 3:02:19 AM   
splais


 

Posts: 2753
Joined: 12/12/2001
From: Yuma, AZ, USA
Status: offline 		Well, after reading all I could find on Hitec's site and this forum I opted for Hitec 605 servos on my two H9 Cap's (1/4 scale). I have not posted before this because I thought it was maybe just coincidence or me. But I have now had 3 of 4 wing servos strip. Plane has been set up according to specs and flown well within the flight envelope. The only thing that has changed in the past few weeks is: that as I have gotten more familiar with the plane and engines I have started to do more acrobatics. It is now painfully clear that these servos are not up to stresses of this type flying. This can be my only conclusion. So I urge any of you using them and doing things like snaps, spins, tumbles, etc, to keep an eye on them. I have 5925 digital on the rudder and also have 605's (dual) on the elevator. So far they are all OK.
       Post #: 1

605 BB - 5/8/2002 3:05:27 AM   
wolf152


 

Posts: 43
Joined: 1/12/2002
From: sanford, FL, USA
Status: offline 		Are these MG?

wolf152

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Hitec 605BB servos are not suitable for the H9 1/4 scal... - 5/8/2002 5:10:04 AM   
Ladyflyer



Posts: 1035
Joined: 1/13/2002
From: North Am, PA, USA
Status: offline 		Ganged servos without metal gears ?
If the Hitechs stripped any similar servo would likely strip as well.
I had a pair of JR 531s on the Elevator of a slightly over powered 4 star 60. The first hint of flutter destroyed the gear train on one. They were replaced with 605s and flawless sevice since.

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LF
When they have to say "NO FEAR" it really means NO SENSE.

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Hitec 605BB servos are not suitable for the H9 1/4 scal... - 5/8/2002 5:32:33 AM   
splais


 

Posts: 2753
Joined: 12/12/2001
From: Yuma, AZ, USA
Status: offline 		No they were not metal geared. And mine were flawless also right up until they stripped. I haven't taken them apart, but it feels and sounds like the plastic gears were not up to the task.

(in reply to splais)
       Post #: 4

Hitec 605BB servos are not suitable for the H9 1/4 scal... - 5/8/2002 7:34:27 AM   
Geistware



Posts: 12946
Joined: 4/9/2002
From: Locust Grove, GA, USA
Status: offline 		I have used the HS-605 on the rudder of a CGB Sukhoi. I could hold a knife edge at slow speeds but at high speeds, it could not stand up to the force. THEY NEVER STRIPPED! Are you sure you don't have another problem?

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Hitec 605BB servos are not suitable for the H9 1/4 scal... - 5/8/2002 7:46:58 AM   
splais


 

Posts: 2753
Joined: 12/12/2001
From: Yuma, AZ, USA
Status: offline 		I just checked them. Teeth broke off the smallest gear on all three. I really wish we could figure out what might have happened. I have a bunch of money tied up in 8 of these. It's kind of strange that the only problem has been with the aileron servos, because I would think the elevator gets much more pressure. but the snaps and tumbles I have been doing are on low rate elevator and high rate aileron, so I don't know. My only point here is to watch them, because I generally really like Hitec stuff and their 5925's have been great so far. I plan to replace the 605's on the ailerons with 5625 digitals and see how that goes. Can't afford anything else. And I sure don't want to pour another $20 into the metal gear kits.

< Message edited by Splais -- May 8 2002 2:28PM >

(in reply to splais)
       Post #: 6

Hitec 605BB servos are not suitable for the H9 1/4 scal... - 5/8/2002 4:33:01 PM   
MMallory


 

Posts: 1115
Joined: 12/11/2001
From: South Plainfield, NJ, USA
Status: offline 		Splais,

It sounds like you have a problem other than the servo. If you don't fix the problem, any servo you put there might just move the damage to the control surface. Are your seams sealed? Are your linkages tight? Are you flying too fast for the plane? Are your hinges securely attached? Are the surfaces stiff enough? is your prop balanced? Is your plane over powered? Are your surfaces counter balanced? When you say "Dual", do you mean ganged? If so, are the servos working against each other? I would review and double check all of these things before "testing" other servos.

Mark M.

(in reply to splais)
       Post #: 7

Hitec 605BB servos are not suitable for the H9 1/4 scal... - 5/8/2002 7:42:21 PM   
splais


 

Posts: 2753
Joined: 12/12/2001
From: Yuma, AZ, USA
Status: offline 		Mark, everything you said has been done: the gaps are sealed, the ailerons are mounted well, plane has flown beautifully with no indications of flutter; it is not overpowered with the MVVS 1.60 Gasser, props are balanced, does not appear to be any excess flex in aileron or wings. the "dual" you mention is the fact that I have a 605 servo on each elevator half. The fact that this has happened on the aileron servos on two different planes kind of negates anything relating to a particular setup goof on one of them. Actually I forgot that I have had all four wing servos go bad. the first one stripped a while back on an early flight and I replaced the gears on that one. It to was the little gear that broke a tooth.

There has got to be something I am doing that is putting too much stress on the aileron. But I'm not doing any of the real serious 3D stuff. My most violent manouvers have been snap rolls and lomcaveks (spelling?) in the vertical plane.

My only conclusion is that these plastic gears are not up to the loads in this size planes aerobatics.

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       Post #: 8

Hitec 605BB servos are not suitable for the H9 1/4 scal... - 5/8/2002 8:16:51 PM   
MMallory


 

Posts: 1115
Joined: 12/11/2001
From: South Plainfield, NJ, USA
Status: offline 		Splais,

Sometimes the most stress put on a plane is in getting it to the field. Futaba told me that a bumpy runway was enough to strip the gears on their 9101 servos (and I don't mean ruts). Most 1/4 scale aerobatic planes I see are flown much faster than they should be flown. If this were my plane, I would counter balance the surfaces, go with a metal gear servo and use throttle management. Just remember if you are having a flutter problem, and the new servos are stroger than the surface, the surface can fail. Read some of the ARF posts about hinges coming out with wood attached (flutter).

Keep in mind, I am only guessing. It is hard to troubleshoot without knowing/seeing the plane and knowing the pilot.

Good luck. I hope this helps.


Mark M.

(in reply to splais)
       Post #: 9

605 servos - 5/8/2002 8:25:36 PM   
dirtybird


 

Posts: 3096
Joined: 1/25/2002
From: Mesa, AZ, USA
Status: online 		If you are breaking the first gear, going to metal gears won't help as the first two gears are plastic even in metal gear servo's. Going to digital servo's should help as the tighter control loop helps control flutter. The 605's I have had had very poor resolution.

(in reply to splais)
       Post #: 10

Hitec 605BB servos are not suitable for the H9 1/4 scal... - 5/8/2002 8:48:12 PM   
splais


 

Posts: 2753
Joined: 12/12/2001
From: Yuma, AZ, USA
Status: offline 		Mark, we do fly off a grass soccer field. Something to look into.

Dirty, Inoticed in a picture of the metal gear replacement kit it looked like some of the gears are plastic. Your right, if the gear that is breaking is still plastic, no help. I have an email at Hitec on this issue. Waiting to see what they think.

(in reply to splais)
       Post #: 11

Hitec 605BB servos are not suitable for the H9 1/4 scal... - 5/9/2002 1:30:30 AM   
hilleyja


 

Posts: 2186
Joined: 1/7/2002
From: Salem, WV, USA
Status: offline 		Splais,

I'm very interested in your response here because I am starting to put my 1/4-scale H9 Cap together now and am going all out in quality and expecting max performance from the product. Unlike you, I am going with a high power 2-stroke powerplant (Moki 180). I expect that before I even think about getting into 3D I'll be doing a lot of high-G basic acrobatics, including highspeed runway passes.

I've already made the decision to spend the extra $15.00 for the Hitec digitals. I'm going with dual 5625s on the airlons, dual 5625s on the elevator, and a 5645 on the pull-pull rudder. I'll replace the CA hinges with 1/4-scale nylons and pin them on the inside and outside of the surface. Clear monocote will then be used to seal the hinge line on the airlons, elevator and rudder. I plan other strengthening steps during my assembly.

I do have a question. You stated on more than one occasion that you have 4 servos in the wing. Why? Are you using 2 servos for each airlon and if so maybe Mark has a point -- they may be fighting each other? That plane should do fine with good torque servos on the airlons and the 605s come out close to 90ozs with a 5-cell (6volt) source. One of the complaints I have heard about Hitec 600 series servos are their lack of centering preciseness, upwards of 4 degrees. This could mean that one servo is dragging the other servo along its course and when the two are snapped during highspeed maneuvers you may be torquing them beyond the nylon gears capability.

I did have another 1/4-scale H9 Cap and had 605s all around. I had one servo strip its gears but that was due to the plane nose diving into a tree line -- no problems during normal flight.

BTW, I have a friend using those same servos on a 1/3-scale H9 Cap 232. He has flown a few times and appears to have no problems. He is using 4 servos in the wing and I will be bring this post to his attention.


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Jim Hilley
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RCCA# 758
Twist 150 Brotherhood #14

(in reply to splais)
       Post #: 12

1/3 Cap N 605BB - 5/9/2002 2:11:21 AM   
Whymee


 

Posts: 171
Joined: 1/8/2002
From: Grafton, WV, USA
Status: offline 		I am the guy Hilley refered to when he said "BTW, I have a friend using those same servos on a 1/3-scale H9 Cap 232".

I have 605BB all around on my Cap 1/3. As of yet I haven't had any problems. (knock on wood) I will attest to the POOR centering of the 605BB. Actually, for a hi preformance servo, they are a pretty crappy servo. (My opinion only) Especially when ganging them on a single surface.

Going to replace them with digitals as soon as I can come up with some extra cash.

Keep in mind that I have only had about 32 oz. of fuel thru my Cap, and have flown it 'round the patch only. No high stress manuvers.

Hope you get your problem figured out, before you loose an expensive plane. The above posts have given some good advice. I cannot think of anything additional to add.

Blue Skies

Stan
Whymee

(in reply to splais)
       Post #: 13

Hitec 605BB servos are not suitable for the H9 1/4 scal... - 5/9/2002 2:59:16 AM   
splais


 

Posts: 2753
Joined: 12/12/2001
From: Yuma, AZ, USA
Status: offline 		When I was talking about 4 aileron servos, that is on two different planes. I only have one servo per aileron. I just read a post in the ARF forum of a guy loosing his sukoi because a 605 aileron servo stripped.

(in reply to splais)
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