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need good HT servo

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Old 09-12-2012, 12:06 PM
  #1
nitrosportsandrunner
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Default need good HT servo

I need a good high torque servo for my 1/8 (soon to be 1/5) MOA crawler.

I posted here cause the crawler section doesnt get alot of traffic.

I currently have a MG996R servo. It struggles at times, and if the tires are against a rock then forget it.

that servo has 10kg torque (around 200 oz i think)

I figure I need 300-400 oz.

Now, does anyone know of a $25 or under servo that can put out that kinda power? I know there are servos with that kinda torque if I was willing to spend alot of money....but im not willing...lol

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Old 09-12-2012, 12:28 PM
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celica49
 
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Default RE: need good HT servo

For something very strong, and relatively cheap, I would suggest this

http://www.servocity.com/html/hs-5995tg_servo.html

Youll end up choking it down a lot with your EPA from the stock 180 degree rotation, but its wickedly strong, and at that price cant be beat. I have one in each of my 8th scale buggies.
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Old 09-12-2012, 12:30 PM
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Default RE: need good HT servo

You are going to spend more than 25 bucks on just the BEC you will need to run a 400oz-in servo. What you ask is completely impossible.

If I were you nitrosports, I'd try to find a way to make a large scale servo fit. The HS805BB for example, but you're still gonna need a BEC for a servo that strong in a crawler.
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Old 09-12-2012, 10:22 PM
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Default RE: need good HT servo

Is the $25 limit arbitrary or all you can afford?
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Old 09-19-2012, 11:42 AM
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nitrosportsandrunner
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Default RE: need good HT servo


Quote:
ORIGINAL: TheKennyKiller

Is the $25 limit arbitrary or all you can afford?
as is often the case, most of my builds are limited by funds.
at the moment, I have mulitple credit cards which are way behind, winter coming and fuel I need to buy...ect.

If money were not an issue, i could build some really sweet stuff. I buy some good metal working tools as well...lol.


If I use a standard "AA" battery pack to power the Rx (or a 2s lipo rx pack) and pull the red wire off of the ESC's plug...then that should insure that my current servo gets max voltage all the time, right?
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Old 09-19-2012, 11:45 AM
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Default RE: need good HT servo


Quote:
ORIGINAL: Foxy

You are going to spend more than 25 bucks on just the BEC you will need to run a 400oz-in servo. What you ask is completely impossible.

If I were you nitrosports, I'd try to find a way to make a large scale servo fit. The HS805BB for example, but you're still gonna need a BEC for a servo that strong in a crawler.
that would be sweet.
but a decent 1/5 servo is well over $50, correct?

If I run a 2s lipo pack to power the rx, and remove the red wire on the esc plug, then that should keep the servo's power at max no matter what the esc does.
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Old 09-19-2012, 02:29 PM
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Default RE: need good HT servo

4 aa batteries, even 1.5v alkalines, will not be able to deliver the current required to turn a servo of that kind of strength in a crawler. If it were a regular car i'd say try it, but butting up against rocks, no way. Also with a direct connection without a bec you run the risk of burning the servo on burst draw. The lipo will power it fine but increase further the risk of overvoltage and overdraw.

You can get an 805bb on ebay for 30 bucks sometimes, i think it would be your most economical option if you can be bothered to make it fit.
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Old 09-19-2012, 04:23 PM
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Default RE: need good HT servo


Quote:
ORIGINAL: Foxy

4 aa batteries, even 1.5v alkalines, will not be able to deliver the current required to turn a servo of that kind of strength in a crawler. If it were a regular car i'd say try it, but butting up against rocks, no way. Also with a direct connection without a bec you run the risk of burning the servo on burst draw. The lipo will power it fine but increase further the risk of overvoltage and overdraw.

You can get an 805bb on ebay for 30 bucks sometimes, i think it would be your most economical option if you can be bothered to make it fit.
ill keep that one in mind. found it on ebay for $33 shipped, and ships from usa.

If I can make a 1/8 crawler into a 1/5, I atta be able to make a servo mount for that servo.

I just finished the new chassis (for the most part)
I just have to make a battery mount, and body mounts. And possible a front bumper to protect the body.
Here is a pic of the early mock up
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Old 09-19-2012, 04:26 PM
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Default RE: need good HT servo

http://www.hobbypartz.com/33p-solarservo-d772.html

I have one of these, and while the rating on the site is somewhat inflated, it still outputs ~300oz-in at 7.4V.
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Old 09-19-2012, 04:30 PM
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Default RE: need good HT servo


Quote:
ORIGINAL: HPI_Savage_RC

http://www.hobbypartz.com/33p-solarservo-d772.html

I have one of these, and while the rating on the site is somewhat inflated, it still outputs ~300oz-in at 7.4V.
I have one in my Exo and it is a decent servo just on the slow side. I think it really puts out more like 250oz at 6v, but for $18 it's a good deal I guess.
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Old 09-19-2012, 04:47 PM
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nitrosportsandrunner
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Default RE: need good HT servo

Ok, now i need a quick lesson in figures...lol

the figure on my mg996r servo is 10kg (stall torque)

how does that relate to oz? I thought my servo was around 200oz but maybe its more?
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Old 09-19-2012, 11:22 PM
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Default RE: need good HT servo

Simply go to google and type carefully...

'convert 200 ounce inches to kilogram centimeters'

It'll give you the answer right away, but you ned to write it out exactly how google wants you to, usually with the long descriptions of the units (inches instead of 'in' for example). Works for almost any conversion you can imagine. 200oz-in is 15kg-cm.

Also, stall torque is usually less than holding torque.
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Old 09-20-2012, 03:06 AM
  #13
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Default RE: need good HT servo


Quote:
ORIGINAL: Foxy

Simply go to google and type carefully...

'convert 200 ounce inches to kilogram centimeters'

It'll give you the answer right away, but you ned to write it out exactly how google wants you to, usually with the long descriptions of the units (inches instead of 'in' for example). Works for almost any conversion you can imagine. 200oz-in is 15kg-cm.

Also, stall torque is usually less than holding torque.
yeh, i posted the Q cause a google search gave me a few different answers...lol.

but one i found said to multiply the KG by 13.8. That would make my servos around 138...and as you say foxy a 15kg servo would be 200ish.

So the 300+oz servo mentioned above is probly worth a shot. I could have sworn at some point I found that the MG996r was 200oz. Its certainly much better than any RTR servo (not that thats a huge feat)

Ill pick up the one mentioned above when I can. Thanx guys.
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Old 09-20-2012, 03:19 AM
  #14
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Default RE: need good HT servo

Yeh I'm not talking about a google search. Google actually has a converter, you don't need to follow any links. Just type the conversion you want, and it gives you the answer directly, no need to guess which site is accurate or to try to remember how many to multiply by. But as I said you do need to type accurately exactly what you are asking.

Here, check it out...

https://www.google.co.uk/search?q=co...DOOj0QWMmoDgDg
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