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Steering Servo: How much torque is enough?

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Steering Servo: How much torque is enough?

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Old 09-10-2019, 03:41 PM
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Default Steering Servo: How much torque is enough?

Hey fellas!
So I saw this video the other day where a guy has this jig set up with a scale and an amp meter and he tests several servos to see if they meet the advertised specs. One of the servos he tested pulled 559.5 oz-in at 5.7 volts but it drew 7.28 amps! It got me thinking though how much is too much, 559 seems like way overkill. And most ESCs only have a 2amp or so BEC built in. So I guess what I was thinking is how much torque do you really need for the various applications? Maybe some of you with more knowledge and experience than me could chime in with your opinions. For example how much torque for a 4wd short course truck or a touring car or a rock crawler. I think it would be nice just to get the information out on a thread so down the road if someone tries doing a Google search (like I did before posting this thread) they will be able to have a good reference. Cause servos are expensive. Thanks guys.
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Old 09-10-2019, 03:48 PM
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Here's the video of anybody wanted to watch it. It's pretty interesting

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Old 09-10-2019, 06:35 PM
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In order from most to least torque
rock crawling = the more the better at least 250 oz/in, speed doesn't matter than much as long as its below 0.20 sec
1/8 buggy/truggy = eh try to stay above 220 oz/in on steering, 150 on throttle, speed try to keep it under 0.15 sec
1/10 short course 4wd = 200+, under 0.15
1/10 buggy 4wd and sc 2wd and 1/10 stadium and 1/8 and 1/10 nitro onroad= 150+, under 0.10
1/10 buggy 2wd = 100+, under 0.10
1/10 tc onroad = 100+, fast as possible ex: 0.055

I probably left some categories out, just approx and personal judgement, in general for racing, the faster the better.
The servos that I think are good options
1258tg for any 1/10 offroad class $70 166 ozin, 0.08 sec
1257tg if you want a faster servo for 2wd buggy basically different gearing of the 1258
Team powers dcs/sgs for andy 1/10 class offroad or onroad. This is my favorite servo with 220 ish oz in of torque, its shorty so it saves space and fits in onroad and its 0.055 sec speed is op. Its a little price at somewhere around $120ish
In general savox is a safe bet on a budget, team powers is great, protek and mks not much experience but heard good things, traxxas is bad, any plastic gear is bad unless your on a really tight budget.
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Old 09-10-2019, 07:14 PM
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As for speed you really want as fast as possible. I like anything with a speed of .08 and under. For torque I believe tekno is the only company that give a required torque spec for their cars. Tekno says on the eb410 and et410 requires a servo with at least 200oz of torque. And on their 1/8 scale buggies and trucks they say requires a servo with at least 300oz of torque.

i personally run the futaba cb700 in most of my cars. You can’t beat the specs. It’s brushless with a .07 for speed and 681oz of torque and I run it in SR mode. They are about $150 shipped online. A good cheep option would be the futaba s9372sv. Not brushless but has 341oz of torque and a .06 for speed and it’s about $115 online.
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Old 09-11-2019, 07:10 AM
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Originally Posted by rcbuggy88 View Post
In order from most to least torque
rock crawling = the more the better at least 250 oz/in, speed doesn't matter than much as long as its below 0.20 sec
1/8 buggy/truggy = eh try to stay above 220 oz/in on steering, 150 on throttle, speed try to keep it under 0.15 sec
1/10 short course 4wd = 200+, under 0.15
1/10 buggy 4wd and sc 2wd and 1/10 stadium and 1/8 and 1/10 nitro onroad= 150+, under 0.10
1/10 buggy 2wd = 100+, under 0.10
1/10 tc onroad = 100+, fast as possible ex: 0.055

I probably left some categories out, just approx and personal judgement, in general for racing, the faster the better.
The servos that I think are good options
1258tg for any 1/10 offroad class $70 166 ozin, 0.08 sec
1257tg if you want a faster servo for 2wd buggy basically different gearing of the 1258
Team powers dcs/sgs for andy 1/10 class offroad or onroad. This is my favorite servo with 220 ish oz in of torque, its shorty so it saves space and fits in onroad and its 0.055 sec speed is op. Its a little price at somewhere around $120ish
In general savox is a safe bet on a budget, team powers is great, protek and mks not much experience but heard good things, traxxas is bad, any plastic gear is bad unless your on a really tight budget.
Perfect this is exactly what I was looking for. Thanks man. Also I second the comment on Traxxas servos. They don't center for crap and always seem weaker in one direction.
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Old 09-11-2019, 02:11 PM
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Servo torque can be a highly embellished spec in the industry and some choose to use dynamic torque ratings which appears higher than true stall torque itís something to consider before making a purchase
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Old 09-12-2019, 02:14 AM
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Originally Posted by brian mills View Post
Servo torque can be a highly embellished spec in the industry and some choose to use dynamic torque ratings which appears higher than true stall torque itís something to consider before making a purchase
Does dynamic torque make that much of a difference when it comes to servos? I can't imagine it would effect the rating all that much but I'm probably wrong. You would know more about it than me.
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Old 09-12-2019, 05:48 AM
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Originally Posted by kutless View Post
Does dynamic torque make that much of a difference when it comes to servos? I can't imagine it would effect the rating all that much but I'm probably wrong. You would know more about it than me.
Yes it gives the servo a much higher perception of torque and some marketers choose to use this spec for increasing their sales while static/stall torque is a more useful number for servo comparison
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Old 09-12-2019, 06:40 AM
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I had been doing some searching as well for my mbx7r and finally went with brand/company of Send-It RC servos. Their platinum 458 claims 458/oz torque and .08 speed at 7.4v. Can handle 8.4 I believe as well. Just got them yesterday and the quality seems pretty good. And for the price. It was hard to pass up. I grabbed one for steering and throttle

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Old 09-12-2019, 07:15 AM
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Those are made by AGG and the same as the A80BHSW in case anyone is interested.
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Old 09-12-2019, 09:20 AM
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Originally Posted by frewster View Post
Those are made by AGG and the same as the A80BHSW in case anyone is interested.
youíre in reference to the send it servos I posted? Was curious about them
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Old 09-12-2019, 10:09 AM
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Originally Posted by KeyMB View Post


youíre in reference to the send it servos I posted? Was curious about them
Yep. One thing to note is Send It claims to have a 120 day warranty while AGF is 1 year.
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Old 09-12-2019, 12:42 PM
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If you need 458 oz of torque for your throttle I would suggest trying a drop or two of oil on the throttle assembly
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Old 09-12-2019, 06:16 PM
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For crawling its nice to have the extra torque. But for any racing, something is definitely up. Maybe spilled entire ca bottle onto the steering rack?
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Old 09-14-2019, 07:54 AM
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Originally Posted by lowspark View Post
If you need 458 oz of torque for your throttle I would suggest trying a drop or two of oil on the throttle assembly
lol. I donít need it obviously as thatís a ton of torque, but for the price, and having a the same spare as my steering/throttle, figured why not.
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