8411 Alternative.
 

Yes I know that the 8611 are coming and I have some on back order. That has just been pushed back at least another 2 weeks. For those that can't wait, has anyone tried any of the JR car servos on a plane. The DZ8550 looks like it should fit the bill more than adequate. Does it have the same slop? I know it is .03 faster than the 8411, case size difference is miniscule, it also has metal gear, but then again this one also has more torque and Best of all its IN STOCK NOW. I ordered one just in case anyway. Worst case is I end up using it on my R.C. Car

Turbulence

Part Number: JRPSZ8550
Product Name: Z8550 ULTRA TORQUE DIGITAL SERVO
Specifications
Torque: 188 oz/in at 6V
Weight: 1.92 oz
Gear: Alloy Metal
Motor: Coreless
Speed: .15 sec/60 degrees at 6V
Size: 0.73" x 1.52" x 1.32"
Ball Bearing: Dual

Part Number: JRPS8411
Product Name: DS8411 ULTRA TORQUE DIGITAL SERVO
Torque: 155 oz/in
Speed: .18 sec/60°
Weight: 2.03 oz
Size: 0.75 x 1.54 x 1.36 in
Ball Bearing: dual wide spaced
Motor: coreless

RE: 8411 Alternative.
 

The 8550 is NOT for aircraft use. The motors in the car servos are very different from the aircraft servos and they draw high current. They can get away with it because they use only 1 or 2 servos.

RE: 8411 Alternative.
 

Is power consumption of these servos published information?

RE: 8411 Alternative.
 

I honestly don't know. I'll ask Horizon and see what I can find out.

RE: 8411 Alternative.
 

SEE that is not posted on the Horizon website. Do we know how much more current? Or should be move on and also ask about the Airtronics 358 and 359? they claim 200 inch Oz. of torque. I know Dr. Le has them on the Yellow F-18 (twin) for elevators, anyone else using those. 358 does not have the metal case the 359 does. Ken how are yours holding up?


Turbulence

RE: 8411 Alternative.
 

Turbulence, consider this:

The RC electric cars typically run on a 6 cell 7.2 volt battery. So far as I know there is not a voltage regulator dropping the voltage of the battery to 6 volts for servo useage, but in regards to what I'm about to say, if someone knows for sure that there is a voltage regulator, please chime in. I say this because:

I called Horizon tech support a couple of months ago wanting to know what the maximum voltage an 8411 could operate at.

I was told 6 volts never more. I said dude, you are full of crap, I want to talk to a supervisor. He asked why and I said that a 6 volt power pack charges to over 8 volts in some circumstances and that I know for a fact that the 8411 operates correctly from 6 volts to at least 7.5 volts and possibly more.

He then put me on hold and came back and said well, it's a five cell pack. Never use more than a 5 cell pack without going through a regulator. I was going to push the issue farther, but he was clearly embarrased and I work him hard on the full of crap comment so I let it go. I really wish there is someone out there who has data showing what safe voltages you can reach with an 8411. Maybe even go to 9 volts for *****g out torque with say a hot charged 6 cell pack?

What I further wanted to know is what's coming out here, current draw. Their website does not publish this information. I'm tired of calling those guys at horizon cause the questions we ask are over most of their heads and I don't know where to go to get real information.

In other words, Doug came back and said "no, it's a car servo not an airplane servo" and he based it on "current draw". this is a typical answer to a quesiton like this, and when questioned further on current draw, Doug says, "well, I don't know".

If the current draw of the two servos is nearly identical, there should be no reason not to swith the servos in either application. In fact, according to Doug's initial response, if you put the 8411's in the car, you'll be able to go longer with less draw. how long? Hmmmm. My guess without any data is 10 to 20 seconds. Measureable, but insiginificant considering.

Don't mean to bust on anybody here, but a lot of opinions go around here with no data to support it. To support Doug'sstatement, I believe you have to have current draw information. Which I would very much like to have!

Sean

Also, I forgot to mention, if there is not a voltage regultor on the RC car's, then I'm guessing that it's ok to run a 6 cell hot charged battery pack as your receiver pack in an airplane. Does this conclusion seem ok?

RE: 8411 Alternative.
 

Turbulence-

Other servos to consider (I'll be using in my Roo):

Hitec HS-5645MG
Speed: 0.18 sec/60 degrees at 6.0v
Torque: 164.2 oz/in at 6v
Length: 1.59" (40.6mm)
Width: 0.77" (19.8mm)
Height: 1.48" (37.8mm)
Weight: 2.11oz (60g)

or

Hitec HS-5945MG
Speed: 0.13 sec/60 degrees at 6.0v
Torque: 180.53 oz/in at 6.0v (11.4 kg/cm)
Length: 1.55" (39.4mm)
Width: 0.78" (20mm)
Height: 1.48" (37.8mm)
Weight: 1.97oz (56g)

RE: 8411 Alternative.
 

Warbird, I strongly discourage the use of 5645 in Jets. There is a very real centering issue I explained in another thread in the jets forum. I can't comment on the 5945 as I've not done testing with it.

RE: 8411 Alternative.
 

Mark, I would also discourage you from using the 5645 in the Roo. I had a lot of problems with the 5645 and have been on the phone with Hitec about it. When the "rubber met the road" the Hitec manager questioned why we weren't using the 5945? He gave me the impression that he personally would not use the 5645 on any high dollar performance aircraft. I never did get an answer to why my 5645s were faulty. The 5945s use coreless motors the 5646s do not.

RE: 8411 Alternative.
 

Electric RC cars use regulators if they run the radio from the power pack. The regulator is built into the speed controller, and is referred to as a BEC (Battery Eliminator Circuit or some such).

RE: 8411 Alternative.
 

Ok, a regulator is built into the speed controller. My next question, is if you know that for sure, can you tell me what voltage they are typically regulating to? Is it 4.8 or 5.2 or 6.0? And where would one go to read that. It may not be as important in a car application however, clearly you'll get more torque out of a servo at those different voltages which to an end user would definately help in servo selection.

Were you just told that the speed controller had a regulator, or was it published somewhere? If published, can you show me where?

RE: 8411 Alternative.
 

The problem is simply one of current draw causing the voltage seen at the receiver to drop below a safe margin. We saw this years ago with the JR Super Servos where you could not run more than 3 in an airplane using a 4.8v battery. As the current went up, voltage went down and the use of 4 or more could cause the receiver to see an unsafe voltage under load.

The 8550 is designed as a car servo where current draw isn't an issue and users want high speed and power. Most r/c cars have only 1 or MAYBE 2 servos installed. This servo also only has a 7" lead on it fitting in better with the car requirements.

As I said, I will try to find out the electrical specs on the servos from Horizon.

RE: 8411 Alternative.
 

My Nitro R.C. Car only runs on 4 double AA batteries, so it's not 7.2 maybe you’re thinking of an electric R.C. car, which I also have an E-Maxx that runs on 7.2.

Sorry the Hate might be nice but it's not even a consideration for me. I have and still use them on other planes but not my jets. Heck I had two quarter scale Hitecs on my kids power wheel corvette to drive him around when he could not reach the pedals. (two quarter scale, one on each side of the steering wheel rod with each one having it's own 5 cell battery pack, one standard servo for the Forward and Back switch and one standard servo for the Accelerator pedal).

Now don't get your panties in a knot and start some flame war crap about it. It is personal choice, I have my personal experience with them and will not use them on jets period. For the Jets, I only use JR, Futaba and but now thinking about the Airtronics as well.

I stand corrected Dr. Le uses them for the elevator of the Fiber Classics MIG 29 not on the F-18

Turbulence

RE: 8411 Alternative.
 

ESC,s for cars deliver a maximum of between 5 and 6 Volts
See: http://www.teamnovak.com/products/ESC_Specs/index.htm

RE: 8411 Alternative.
 

Thanks VIPER!!

That's good information..............

RE: 8411 Alternative.
 

Go to the Tower Hobbies website and search for speed controllers.

Some of the car controllers specify the receiver voltage and current. It's also known as B.E.C. voltage.

Some were 5.0 V and others were 6.0 V. I found one that specified the current as well (3.0 A).

Some of the lower power aircraft speed controllers also have BECs. Typically these BECs are rated at 5.0 v at 1 or 2 A. Since aircraft go way beyond the six or seven cells found in cars the dissipation in the regulator can become quite high, so separate receiver packs are common once you get over ten cells or so. Aircraft BECs are typically rated for two or three mini or micro servos and up to eight or ten cells.

RC cars with spring type battery holders expect you to use alkaline cells. The cell voltage is 1.5 V, so a four cell battery will give you 6.0 V. Car servos are typically specified at 6.0 V, with expectation that user will use four Alkaline cells, or five NiCd cells.

RE: 8411 Alternative.
 

DITTO

RE: 8411 Alternative.
 

I was leery about trying Hitecs in my jets but after seeing them work in some nice planes I decided to give them a try. I have the 5945's on the elevons in my Rookie and so far they have been flawless. I've always used the small Hitecs for retract, brake, and speed brake valves...I've never had one fail. I have had some of the Hitec 6XX series servos not center properly and I won't use them on anything I fly. However, the 5945's have been really good. I know that Tam uses them on just about everything----I've never heard Tam complain of a 5945 failure.

Just my experiences...Kevin

RE: 8411 Alternative.
 

Kevin, no disrespect to you, but I'll never give hitec another dollar of my money based on what I've read here and my own experiances with their 5646 which in my opinion is garbage. The 5945 sells for 89.95 at servocity.com the JR 8411 sells for 104.95 at chiefaircraft.com. Fifteen Bucks difference to go top of the line!! Maybe the 5945 is a good servo, but I'll spend the extra $30.00 for a pair just to keep my money out of Hitec's hands. Again, MAYBE the 5945 is a good servo. We KNOW FOR CERTAIN that the 8411 is not a gamble. It will be there everytime you need it according to those that fly them.

Hitec's press here sucks. And my friend lost a huge investment when one of their 600 series failed. That's not cool.

RE: 8411 Alternative.
 

Sean,

These two Hitecs I paid $70 each new. Hey...What works---works!!! Yes, Hitec has had some bad press, especially for their 56XX and 6XX series of servos. Both are similar except one is digital and the other isn't. (3 pole motor instead of coreless)

As for me I've been a JR man for a loooooong time and it really took a lot of convincing to try the 5945's. These really are good servos!!! I won't buy another 8411 OR it's new 8611 cousin until I see for myself that the sorry gear lash (gear play) is gone.

Sean, if you do a search you will see that JR had a LOT of teething problems (failures) with the 8411. When I started using these servos it took a LOT of convincing for me to try an 8411!!! A buddy of mine lost a HotSpot when an 8411 failed on an elevon. Just use what works for you...I know of several guys flying the Hitec 5945's in 40% scale planes----3Ding the crap out of them. These guys run their servos to extremes with as much moolah in their equipment as we have in ours. They swear by the 5945's. Also, all of these guys are using the Hitec programer to EFFORTLESSLY set up their planes...Ganging servos, setting end points, reversing servos, etc., etc.

I'm not trying to have a servo war---I'm impressed with the 5945 and its' versatility when used with the programer. My 8411's have served me well. (With some slop in the gears) So far, the hundreds of grueling 40% 3D flights my friends have and the ones that I have with my Rookie with the 5945's have been great. Again, just relaying my experiences...;)

Kevin

RE: 8411 Alternative.
 

Good Point, no war here. The price you quote on the 5945 is about $5.00 over what I paid for the 5645. Not only was I unhappy with performance, I got gouged in price as well...............[:@]

RE: 8411 Alternative.
 

Sean,

You didn't get gouged---I try to get the most out of my modeling $$$ so I look for deals here on RCU. Unless I need something right away, I lurk in the Marketplace here on RCU and snatch up some of the good deals.[8D] Before I had children I pretty much bought what I wanted to...Now, I have to make every $ count.

I hate that you had problems with the 5600 series of servos. I've heard a lot of bad things about them in the Radio forum.

Again, it took a LOT of convincing for me to try the 5945's!!! I did a lot of investigating...So far I'm happy.

Kevin

RE: 8411 Alternative.
 

Actually.. according to the service dept, the 8411 has been one of the most trouble free servos in the JR line. Just because a few people make noise does not mean there is a LOT of problems. People confused the 8411 with the 8417 all the time and the 8417 is the servo that had the recall for a bad run of motors from factory.

I've been using 8411's since before they came out to the general public and have NEVER, repeat NEVER had a failure. I'm not saying they don't fail. EVERY electronic component can fail, even right out of the box. But to label this servo as problematic? That's stretching things a bit.

-Doug

RE: 8411 Alternative.
 

Doug,

I'm right there with you on the 8411's I have probably 30 of them and have never had a problem with them.

DR

RE: 8411 Alternative.
 

Doug,

I didn't say that the 8411's were problematic..I have witnesses one failure in a jet. Now that the "Problematic" door has been opened---Be truthfull and tell us how many guys from all facets of our hobby have complained about the gear slop in the 8411??? Even Danny Snyder has acknowleged that the 8411 has QUOTE "Wear issues" and "Gear Slop" Anyone here can do a search and find what I have found. Yeah, it's nice to have JR put new gears in my servos for free but what do I do about flying my plane during the down time? Most guys know how to set up their planes using max ATV and utilizing the best mechanical linkage advantage. The gear slop and wear issues are still there.

Now, lets talk about the heli guys----The 8411 was very problematic for these fellows!!! Not only was the gear train excessively sloppy for a heli application but they were blowing servo motors too. Hence, JR created a "new" servo. Let's not forget that the 8411 won't work properly using a six volt pack...Let's also not overlook the countless people that cannot get two matched servos to work in harmony together without a Matchbox. (Which has its' own problems)

I understand that any servo can fail. The initial question in this thread was about servo alternatives. I offered mine and was brow beaten down by those that don't like other brands for what ever reason.

Let's look at my servo experiences comparing the 8411 to the 5945---
I've seen one failure of an 8411....None with the 5945.-----
There are obvious wear and slop issues with the 8411...None with the 5945.---
You have to use an on-board centering device with the 8411 when matching servos together (Matchbox)....You can set up your servos on the ground with the 5945 (One less component to fail)
Using a Hitec programer you can reverse the 5945's at will....With the 8411 you MUST buy a reversed servo if you need one for your application.
You can't use an 8411 with six volts.....You can with a 5945
8411's have a sticker on them stating "For Airplane Use" only.....The 5945's don't have the wear and slop issues preventing it from being used in other applications.
Looking at these facts I've come to the conclusion that the 5945 is a viable alternative to the 8411. The Hitec programer makes the 5945 even more user friendly. Maybe some of you don't agree with me...That's OK too!!![8D]

As I've said before, I had to take a looooong look to try the Hitec 5945 and I like them so far.
Kevin