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Futaba new HPS-A700 Servo 1000+ oz servo

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Futaba new HPS-A700 Servo 1000+ oz servo

Old 11-20-2018, 01:17 PM
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mikes68charger
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Default Futaba new HPS-A700 Servo 1000+ oz servo

Futaba HPS-A700 Servo
https://futabausa.com/shop/servos/servos-airplane/servos-airplane-sbushv/servos-airplane-sbushv-std/futaba-hps-a700-servo-01102295-3/

Is it me or are these specs crazy?

What you think? Anyone try one?

I just Ordered 2 for my 1/2 scale Christian Eagle. This way one servo for each elevator vs 2.
Old 11-20-2018, 02:07 PM
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Auburn02
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Holy crap. Are you going to through-bolt it to a 1/2" square steel mount?
Old 11-20-2018, 03:41 PM
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rhklenke
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That means that with a 1" servo arm, it can pick up somewhere between 54 and 60 lbs. That's quite a bit of weight!

The servo mount, the linkage, and the flying surface horn better be securely mounted to be able to take advantage of that power! Also, at that size, its not going to be able to apply that force for long before it gets very warm!

Bob
Old 11-20-2018, 07:05 PM
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Bob_B
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These servos are getting crazy!
Old 11-20-2018, 11:39 PM
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Dave Wilshere
 
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Worst idea for your elevators. The reason we put two servos on many models is nothing to do with torque, it’s the servo gears and gear play. Your huge elevators will have quite a bit of free play and all that unbalanced weight on a bouncy landing with give the couple of small gears revisiting something to think about. It’s a servo for very few practical uses.
Old 11-21-2018, 12:38 AM
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https://hitecrcd.com/products/servos...-servo/product

Been using these for a while and they at at the top.

Also

100kg-cm torque Ultra Heavy Duty Giant Scale Digital HV Brushless Servo for RC ROBOT industrial equipment TAL9150-Large Servo

They also have 200kg versions

Regards,
Old 11-21-2018, 01:10 AM
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David Gladwin
 
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I don’t post much on these forums these days but here goes:

I have purchased and tested two of these servos and will buy more.

They are are quite brilliant devices, obviously with great power but with exceptionally tight gear trains, designed to handle the torque.

My FC Mig 29. Originally had two JR 8911 servos on each stab. but these were replaced by single 6311 HV, which coped well and currents measured by my Weatronic gear were modest. One servo instead of two halved the chance of failure.

On its its last flight the Mig suffered stab. Flutter due to developed wear in the torque tube holes. The servo gear train remained undamaged. The loads imposed by flutter can be , are enormous ,potentially destructive. so if the gear train can handle those forces then landing loads will be a mere trifle. The gear train on the Futaba device, will , I am confident will be just as capable, or even more so, considering the enormous torque capability and the very tight gear train will be exceptionall good for resisting flutter, and preventing it from starting due to minimal gear slop.

These Futaba servos will be used on the Mig. Stabs.with every confidence., and K Lenke states the obvious , the mounting needs to be very solid.

During extensive testing these servos did not get VERY, warm, just mildly so, although max torque was not held for long. This tends to verify Futaba,s published graph of case temperature and time and their decision not to use a “ finned” all metal case as on eg the JR 8931. Brushless motor.

I did a review of these servos in the last but one RCJI, giving some figures for speeds, currents and torque.
DG.

Last edited by David Gladwin; 11-21-2018 at 06:21 AM.
Old 11-21-2018, 06:40 AM
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mikes68charger
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Did anyone else noticed that the final output gear is stainless steel?

Sounds like it will take the vibration better
Old 11-21-2018, 10:24 AM
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Zeeb
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Originally Posted by mikes68charger View Post
Futaba HPS-A700 Servo
https://futabausa.com/shop/servos/se...vo-01102295-3/

Is it me or are these specs crazy?

What you think? Anyone try one?

I just Ordered 2 for my 1/2 scale Christian Eagle. This way one servo for each elevator vs 2.
Did you see the note about running these on SBus? If you are going to run that and have not seen the note I would suggest reading it because it pertains to a power issue. They want you to add a capacitor into the system.

https://futabausa.com/a700-pdf/
Old 11-21-2018, 11:17 AM
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FenderBean
 
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Originally Posted by Zeeb View Post
Did you see the note about running these on SBus? If you are going to run that and have not seen the note I would suggest reading it because it pertains to a power issue. They want you to add a capacitor into the system.

https://futabausa.com/a700-pdf/
Or use the Emcotec system for sbus, its a very nice design for Sbus and large models
Old 11-21-2018, 05:12 PM
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berthoud
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I just received 7 of these today. Unbelievable gear train.

I spoke with Futaba, if used as/with SBUS use the optional capacitor.

I plan on using with Royal and per Powerbox, capacitor is not needed but can be added to each bank. They recommend splitting the servos up between the two power banks as well.

Time will tell but looks like a good upgrade from BLS series.

Scott
Old 11-22-2018, 03:13 PM
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tassos p
 
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Which optional capacitor? What do you mean?

In fact this servo for the same torque (according to Futaba) consumes around 2-5 times less power, hence it's not getting hot.


I bought also 7 for my new project and seem great in performance and indeed I run them in 2 hours each continuous operation on a Polaron Charger (servo test) without issues.

Tassos


Old 11-22-2018, 03:27 PM
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Zeeb
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Originally Posted by tassos p View Post
Which optional capacitor? What do you mean?

In fact this servo for the same torque (according to Futaba) consumes around 2-5 times less power, hence it's not getting hot.

https://youtu.be/7pgCBavvRJU

I bought also 7 for my new project and seem great in performance and indeed I run them in 2 hours each continuous operation on a Polaron Charger (servo test) without issues.

Tassos


I put a link in my post......
Old 11-22-2018, 04:07 PM
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berthoud
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https://futabausa.com/shop/accessories/futaba-rx-capacitor-u-top-ubr0002/

https://futabausa.com/a700-pdf/

Last edited by berthoud; 11-22-2018 at 04:08 PM. Reason: .

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