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One Servo Instead Of Two???

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Old 04-09-2016, 03:43 PM
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BlueBorderRC
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I have a lst xxl 2e. It has two servos on it. Does anybody know if its possible to run one servo instead of two and how would that work?
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Old 04-09-2016, 05:11 PM
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Originally Posted by BlueBorderRC View Post
I have a lst xxl 2e. It has two servos on it. Does anybody know if its possible to run one servo instead of two and how would that work?
Yea,infact I encourage to get rid of it ,an get a better quality steering servo.

My sister had the muggy an I got her to get rid of them ,an those big bulky tires.It made the muggy more faster & maneuverable ,quicker & limber.
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Old 04-10-2016, 01:53 AM
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I like to see how one can remove one of the steering servos and have better performance. As designed, I don't see how one could omit one servo without changing the whole steering setup.

I personally think the twin steering servos make it more durable and controllable than if it had only one. I've gone so far as to replace the stock servos with stronger ones, but I wouldn't try converting to just one servo. I think the cost of the single 300+ in./oz. would be more cost prohibitive than replacing with a pair of 150 in./oz. servos.

To the OP - what is the problem with your steering that you'd consider this? Just curious..
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Old 04-10-2016, 09:57 AM
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cbaker65
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Originally Posted by 1QwkSport2.5r View Post
I like to see how one can remove one of the steering servos and have better performance. As designed, I don't see how one could omit one servo without changing the whole steering setup.

I personally think the twin steering servos make it more durable and controllable than if it had only one. I've gone so far as to replace the stock servos with stronger ones, but I wouldn't try converting to just one servo. I think the cost of the single 300+ in./oz. would be more cost prohibitive than replacing with a pair of 150 in./oz. servos.

To the OP - what is the problem with your steering that you'd consider this? Just curious..
Yea ,your probably right ,after all ,it is an Mt with big monster truck tires!....My bad!

However ,it can be done!
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Old 04-10-2016, 02:52 PM
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Originally Posted by cbaker65 View Post
Yea ,your probably right ,after all ,it is an Mt with big monster truck tires!....My bad!

However ,it can be done!


I'd like to see how. Please enlighten me.
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Old 04-10-2016, 03:46 PM
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Originally Posted by 1QwkSport2.5r View Post
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I'd like to see how. Please enlighten me.
Ive modded rc's before & made my own parts ,however ,I don't have that model so no ,I cant show you!
If I did have one ,it definitely be changed!...
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Old 04-10-2016, 04:23 PM
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Originally Posted by cbaker65 View Post
Ive modded rc's before & made my own parts ,however ,I don't have that model so no ,I cant show you!
If I did have one ,it definitely be changed!...
I have too, but I would never change an LST series truck to a single steering servo. I think there are other mods that could be done to make them perform better and weigh less.

I just dont see how or why someone would convert one to single servo steering. I think it to be poor advice to do such a thing anyway. To each their own I guess.
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Old 04-10-2016, 08:43 PM
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Converting a LST to a single servo has been done by quite a few people and it has been successful as well. The problem with going to a single servo is there really aren't any servo savers out there strong enough, they all flex too easily. Having 2 servo savers to split the load means less servo saver flex and more positive and responsive steering. Switching to MGT servo savers is a popular mod if you think the stock LST servo savers aren't stiff enough. MGT savers are available for all different servo splines.

But back to the single servo mod. Without a strong enough servo saver those going single servo have (and have to) use high quality, really strong servos with no servo saver. A user by the name of Bondonutz (LST forums, RCTech, etc) basically pioneered this mod using a Hitec Robot servo with steel gears that's related to the other Hitec 333oz @ 6v models. He has broken multiple aluminum servo horns and not the servo. I've personally broken multiple really strong 1/8 style plastic servo horns before switching to an aluminum servo horn and my Hitec servo is still going strong over 4 years later. Bondo and I are by no means alone in this, others running Hitec titanium geared 79xx and 78xx servos have all had the same results.

I personally like overkill servo torque and as close to zero steering slop as I can get. This setup and risking a $110 (at the time) servo because I have no servo saver is worth it to me. I feel the servo is strong enough that it's worth the risk for the reward of no steering slop and instant response. That being said it is a risk and I advise anyone considering to acknowledge that risk and plan accordingly. Also I don't want to hear how crazy I am. I don't drive like I'm trying to destroy the truck but I've more than put it through its paces and the servo still lives 4yrs on.

There are other options to tighten up and enhance the steering. MGT servo savers help a lot. For the electric crowd simply increasing the voltage to the servos works wonders. The XXL2e esc and most others puts out around 5.5v, an external BEC set to 6.6v (which is safe for @6v rated servos designed to run on 5cell NiMh Rx packs) will give a huge boost in speed and torque for less than the cost of new servos or an esc with an adjustable BEC. I personally added an external bec to my nephews LST with stock well used JR590's (90oz each) and they barely moved the tires while they were on the ground before the external bec. It looked like the servos were about to take their last breath by how slowly the tires turned. With the external bec set to only 6.3v the tires moved much quicker and could turn lock to lock when without the external bec they couldn't reach lock. It took the truck from having to plan turns in advance and being a chore to drive, to actually being enjoyable to drive. An external bec will enhance any servo by providing greater and more stable voltage under load so I highly recommend it as an upgrade first before considering changing servos, if you're electric powered of course.

As for how a single servo is done. Like this
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Old 04-11-2016, 03:04 AM
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Thanks for posting that. I see there is nothing connected to the other side which is what my concern was about this "mod". I could see this mod being possibly necessary in a racing environment, but since nobody races LST trucks anymore (competitive racing, not racing your buddy on a Friday night) so I don't really see the need to do it. Dumping the servo savers would omit a lot of the slop, as will other things. I learned something new, sorta, but I will keep my tandem servos. I'm running a pair of 166oz/in servos in mine.
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Old 04-11-2016, 06:15 AM
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As far as not having anything connected to the other side, it's really not a concern. If you hold the tire on the side not connected to the servo yes it will lag behind the side connected to the servo every so slightly. The reason is because the drag link connecting the bellcranks flexes slightly and whatever slop there is between the bellcranks and the drag link. I had this and another LST setup with dual servos with similar overall torque and speed specs and I still feel this single setup has less slop, flex and is more responsive than a dual setup with stock LST servo savers. Never upgraded the dual servo truck to MGT savers before I sold it but both had new bellcranks and rod ends to eliminate slop from wear.

Whether its it's necessary or not is open for debate. I don't think it's necessary, I did it as an experiment on a truck that needed servos anyway and I'm very happy with it and like the feel better but that's me. Ideally the truck would have a bellcrank setup more like a 1/8 buggy with built in servo saver but that's not the case unfortunately. I was also concerned with the servo surviving despite others who came before me breaking aluminum servo horns and the servo being fine. That's why I initially went with heavy duty plastic horns to provide a sacrificial part but got tired of replacing them and went aluminum. Btw my Hitec is 333oz on 6v but with the external bec cranked to 7.4v it's 416oz.
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Old 07-10-2018, 03:08 AM
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Muggy single servo mod
Necroing an old thread because I'm bored. I went with a single servo setup in my Muggy. It was an extremely popular mod at the time and greatly improved the steering (along with a tire change). I used a JR Racing z9000t, which was a pricey high torque servo back in the day. No servo saver.
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Old 07-10-2018, 08:03 AM
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Muggy and revo are arguably better with one strong servo, due to how the lst is setup dual works best/easiest. My opinion.
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