how much torque?

[toka100]

how much torque is really needed for a honcho. after one of my super high torque servos seemed to get weak i came up with a test. not really scientific but just simple enough to test strenght. since my scale only measures to 35oz i was limited with what i could actually use for weight. so i just used stuff i had sitting around.

3 cans of mountian dew. 13.8 oz each
1 liter large mouth mt dew 33.8
my 4 wheels off of my honcho. fronts 17.5 oz each rears 13.8 each
lastly a new 5lb bag of sugar for my coffee.
everything was put into a grocery bag for a total weight of about 217 oz.(13lbs) then dead lifted from the floor with the servo.

so the first servo was the one i was worried about. digital servo rated at 388 at 6v 428 at 7.2v. my ccbec is set at 7.2. the servo lifted it but struggled. would not hold at center with the weight hanging on the arm.

the second servo was a analog 221oz at 6v. ccbec still at 7.2. no issues lifting it or holding it at center. struggled a little but not as bad as the high torque.

the third one was my home built winch servo. gear set out of one servo motor out of another servo with a cc sidewinder v1 controlling it. this one i know has no issues lifting my entire truck off the ground. lifting my grocery bag of weight had no affect on the servo.

after doing this test i started thinking about just how much torque is needed. i know my truck is heavy so i need more. for a scaler under 10lbs i think 200-300 would be fine. i know with the steering linkage and drag the power of the servo is lost but not that much.

sorry for a long post but what are your thoughts on this?

[Perkolator]

many will agree that more torque is always better, especially for crawlers and when you start upping tire size or adding weight to your rig. it's gonna be even more important on a crawler that is going slow in rocks and the tires have lots of resistance, which is sorta like a dead lift for the servo, like you tested, vs a go-fast RC that doesn't see much resistance at all in the steering since you're usually on flat ground and have speed to help turn.

i wish i had some funds right now for a high torque servo...my HT 5645 is pretty weak for my 8.5lb rig, yet was a HUGE improvement over the stock Axial AS-2 servo when it was all stock - i can only imagine what a real servo would do...might be able to lift the rig when it's flopped on its side and help me get right side up easier

[C*H*U*D]

Originally Posted by toka100

3 cans of mountian dew. 13.8 oz each
1 liter large mouth mt dew 33.8

...what are your thoughts on this?

My first thought is you like Mountain Dew

I guess I'm not sure how you are doing your tests. You mention that one of your tests involves using the arm, but then you mention a servo winch. Are you testing for steering strength, or pulling strength of a winch?

[toka100]

Originally Posted by C*H*U*D

My first thought is you like Mountain Dew

I guess I'm not sure how you are doing your tests. You mention that one of your tests involves using the arm, but then you mention a servo winch. Are you testing for steering strength, or pulling strength of a winch?

yah slightly....lol i was just looking for the heaviest things i could still weight on my scale....lol

both. mounting the servo on a block of wood with the arm hanging over. just testing the holding strength and the lift or push for the steering. the winch was just to see how strong it was.

[AsILayDying]

IMO steering torque is one of those things that seems to be "the more the better" "better to have and not need it en need it and not have it. ". Overkill on a high torque servo is a good idea, buy once instead of a couple times figuring out which one works. 200-300 on a stock rig seems fine for 1.9 tires but 500oz/in is BETTER! Lol

[Gvus]

I put a futaba S9157 in what's left of my honcho, 425oz/in has been more than enough torque to move the rig or whatever the tire is up against.

[Jus]

I've got a Hitec 7955tg on my Honcho now and think it's about perfect for a 1.9" truck. IMHO any more servo $$$ wise or torque values would be wasted and better off on a 2.2 rig such as a Wraith or big scaler.

[indiana mudcat]

I find my 7954 disappoints me at times, even at 8.4v, running 1.9 TTC events. Maybe I'm just used to my comp rigs 7980, but I don't think there is too much. Always buy the strongest your willing to drop the cash on.