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Mar 31, 2019, 05:44 PM
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5087MH servo max Voltage question


Hi all,

Been running the awesome Hitec 85MG servos for years. Now I want to upgrade.

5087MH is digital and HV and same size.
Interested in running couple of them on a small 2S or Castle UBEC 2.0

Servo Specs show 6.0V and 7.4V performance data

***A full 2S Lipoly will be near 8.4V , and little less under load.

Receiver spec sheet shows it can take 9V or 9.6V max

Questions:

1) Can I run the 5087mH servo direct on a full 2S lipoly , or do I have to install the Castle UBEC?

2) What is the Max voltage allowed if a full 2S lipoly voltage is not Ok?

3) what size 2S is good to feed couple servos, receiver and guardian 2D/3D stablization for several flights?
(Have to carve foam to make the pack fit, so size matters).


Thank you in advance.

Gryphon
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Apr 01, 2019, 11:36 AM
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1. 8.4v is no problem, we only provide spec at 7.4v as that is nominal pack voltage. All of our 7.4v servos are like this.

2. See above.

3. That is not exactly a straightforward answer. Depends on what the current figures are for the intended servos being used, the loads you intend to put on them, the current figures of the Guardian, and how long each of your 'several flights' will span.
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Apr 01, 2019, 04:19 PM
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Thank you for your reply Xpress,,

Over the weekend been considering staying with a UBEC but still upgrading to those Hitec HV servos.
My new Castle UBEC 2.0 will handle various input cell counts for future setups.

Running the receiver at higher than normal voltages should help some in event of brownout???
Maybe more buffer if voltage sage some.

****So, what voltage do you recommend for nice life from 5087MH servos?
7.4V may give me a lot more life than 8.4V

I assume lowest input voltage may increase life a bit more.
85MG worked great for me at 6.0-6.1V. (Was not too worried to go down to 4.8V for even more longevity)

Application is 150 MPH F27 Evolution. Mostly level passes and just a few yanks/banks.
Planning on buying a hitec servo programmer too and setting end points for added protection.

———

Thoughts on DPC-11 programmer?
Will use PC/laptop.
Rather not spend bunch more, but if you want to make a case for a different programmer, would like to hear it.

———-

Finished with my 8 track player (13-14 yesr old DX7)
Getting a new Telemetry radio/receiver. DSM-X
Can you comment on any settings which effect servo response time or resolution?
Should I adjust the receiver voltage to help the servo given some of these settings?


Thank you for spending some of your valuable time on this.
Gryphon
Apr 01, 2019, 05:45 PM
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Quote:
Originally Posted by GryphonRCU
Running the receiver at higher than normal voltages should help some in event of brownout???
That's the theory at least.

Quote:
****So, what voltage do you recommend for nice life from 5087MH servos?
7.4V may give me a lot more life than 8.4V

I assume lowest input voltage may increase life a bit more.
85MG worked great for me at 6.0-6.1V. (Was not too worried to go down to 4.8V for even more longevity)
Higher voltage has not proven to reduce lifespan in our servos, even in the millions of cycle count.

Quote:
Application is 150 MPH F27 Evolution. Mostly level passes and just a few yanks/banks.
Planning on buying a hitec servo programmer too and setting end points for added protection.
I would use a CC BEC set to 8.4v, rather than a separate pack for the servos. EPA's can be set in your Tx, there's no point in using the programmer in this application.

Quote:
Can you comment on any settings which effect servo response time or resolution?
Should I adjust the receiver voltage to help the servo given some of these settings?
Rx passes voltage straight through to servos, see above voltage info. Honestly, I would plug the servos in and use them as they come. No need to make this complicated on any level.
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Apr 01, 2019, 06:04 PM
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Xpress,
Thanks for the reply.

EPA adj is to protect from Eagle Tree Guardian 2D/3D stablization over driving the servos.
Guardian does have some setting to prevent that (using PC software), but I was having some issue with EPA adj. of E.T. Software adversely effecting other things, so put that back to Default.

覧覧覧覧

Really would like to buy a Hitec programmer.
Eyeing the DPC-11 unless you get me to spend more for a better one.

***Forgot to say; One main point for getting a programmer is to set center position.
Really never liked using Subtrim and kept that to a minimum by trying various heavy duty Dubro servo arms to see which ones needed less subtrim.

覧覧覧覧

Servo being digital, figured 11ms might be option, but not very familiar with the Pro/Con.


Gryphon
Apr 02, 2019, 11:46 AM
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11ms is fine. For this application, a programmer will not prove to be more beneficial to servo use. Personally I prefer a field programmer so my suggestion is the HFP-30.
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Apr 02, 2019, 04:55 PM
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Thank you for the replies.

Without specifics, looks like I will have to go with DPC-11


If you can think of any accesories, or adapters I should get with it, please let me know.
Otherwise, I think I知 set.


Your replies have been very helpful.

Have fun,
Gryphon
May 01, 2019, 05:13 AM
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Little more help please.

What about D85MG ?
How does that compare to 5087MH ?
How do I pick between them.
Seems D85MG may handle up to 8.4V
Does it get stronger/faster/wearout quicker at double its min voltage?
Just $1 difference.

Like to run in the 8V-8.4V likely from Castle UBEC 2.0
Not interested in fitting a 2S anymore. But prefer to run 8V+ to my receiver.

Will they take the same servo arms or different splines compared to 85MG.

Can DPC-11 connect to D85MG as well?

Thank you,
Gryphon
Last edited by GryphonRCU; May 01, 2019 at 05:18 AM.
May 01, 2019, 10:41 AM
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Quote:
Originally Posted by GryphonRCU
What about D85MG ?
How does that compare to 5087MH ?
It's not HV like the 5087, if you want to run HV go 5087 or preferably the new D89MW.

Quote:
Seems D85MG may handle up to 8.4V
No, ~7v max.

Quote:
Does it get stronger/faster/wearout quicker at double its min voltage?
Yes, yes, no. All servos increase in torque and speed as voltage increases.

Quote:
Will they take the same servo arms or different splines compared to 85MG.
Should be the same spline.

Quote:
Can DPC-11 connect to D85MG as well?
DPC-11 is designed to work with all of our programmable digital servos.
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May 10, 2019, 09:35 PM
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I want to thank you for all the help you provided.

My buddy and I did end up ordering both of the updated servos.
He got the D85MG
I got the D89MW

Got a chance to connect the DPC-11 and managed to get my new servo to move around using a 2S which was at storage charge.
Software install went super smooth. Did not deal with any driver issues or messages on screen.

Awesome, some new toys to thinker with over the rest of this month.

————-

I do want to note that before the parts came in, my research suggested that the splines were indeed updated/changed.
On these size “D” series it seems like the splines were changed from 24 splines to Futaba standard of 25 splines.
So also ordered some Dubro heavy duty long servo arms.
Dubro Black (Futaba) servo arms on my D89MW instead of Dubro white (Hitec) which was on last plane running Hitec 85MG.

Have not placed the Dubro servo arms on the new D series servos yet, but they should fit according to HitecRCD help.
Dubro’s tech was going to call HitecRCD and to note that on their servo arm page.


Gryphon
May 11, 2019, 05:12 AM
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Update:

The Black Dubro servo arms ( part # 670 for Futaba) fit perfectly onto the splines of my Hitec D89MW.
The Dubro servo arm slide down the servo's spline with ease, and seem to have no slop.

https://www.dubro.com/products/super...nt=27880391239

***Only thing is the Stock servo Arm's "Lock washer" does not fit down the semi deep hole of those Dubro Servo arms.
I'll either barely drill out the center on these VERY Beefy servo arms so the stock lock washer can get down, or will just go to the hardware store and see if I can buy lock washer with a little less outer diameter.

Eitherway, I AM HAPPY !!!!!!!


Gryphon
May 13, 2019, 11:51 AM
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The D85MG has a 24T spline, we did that mainly because the main purchaser of that servo wanted 24T splines. The D89MW is all new, so we made it 25T to align with the rest of our new servo lineup.

You don't need the lock washer, just set it aside in your spare servo parts bins.
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May 13, 2019, 02:16 PM
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So D series are all 25 splines Except D85MG having 24 splines.
My buddy usually runs stock servo arms and I have plenty of after markets Arms if he wants any.

I値l use some blue thread lock on the servo screw (medium strength).

覧覧覧-

A lot of muscle in IL.


Thank you.
G.
May 20, 2019, 05:41 AM
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If you're using the stock plastic horns, or any form of plastic horn, do not use threadlocker as it breaks down the plastic and will cause it to fracture. The plastic itself already acts as a good vibration insulator on it's own.
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May 20, 2019, 09:02 AM
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I知 using these, and will finish the install this week.

https://www.dubro.com/products/super...nt=27880391239

Local hobby store suggested letting the loctite dry a bit on the threads of the screw before inserting in and tightening.
That痴 what I知 going with in the next day or two.

G.


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