Losi lst servo Upgrade

[Shafferboy207]

I am having a hard time finding new replacement steering servos that will fit. Are there new servos that’ll fit without modifications to the truck? Or is that just the name of the game now, “mod it till it works”
Any help is greatly appreciated

 

[Greywolf74]

I am having a hard time finding new replacement steering servos that will fit. Are there new servos that’ll fit without modifications to the truck? Or is that just the name of the game now, “mod it till it works”
Any help is greatly appreciated

Not sure what the issue is that you're running into. Any standard 8th/10th scale servo will fit in the LSTs

 

[Shafferboy207]

Not sure what the issue is that you're running into. Any standard 8th/10th scale servo will fit in the LSTs

I’ve tried two different servos and both of them are too tall and hitting the steering arm, and they stick out the top too tall and hit the radio box.

 

[WickedFog]

Pics would help. Also, model numbers of the servos that don't fit. But Greywolf is an LST aficionado, so...

 

[Greywolf74]

pics and what servos are you using?

 

[Shafferboy207]

At work right now I will get photos after work but the servos I tried
Power star pc-2500
Yahboom yb-p25m

 

[tntpoof]

you get sizes of old servo.then go to google and search a torque amount in that size servo sizes are also listed at servo city
https://www.servocity.com/

 

[Greywolf74]

Those are pretty standard size servos. They should fit. Ill check back this evening for pics.

 

[WickedFog]

Check your servo dimensions against these. Is the distance from the mounting flanges taller on yours (12.8 dim)?

 

[Shafferboy207]

 

[Greywolf74]

Ok, Its been so long since I've messed with the original JR Z590s I forgot how small that actually were. The Yahboom servo you have is 40 x 20 x 40.5mm which is a pretty standard size these days but not so much back when these rigs were made. The Z590's are 39.4 x 18.5 x 37.1mm. I know Savox (The brand I usually use these days) has some standard size servos that should work. The Savox SC1268SG-BE - Black Edition, for example, is 40.3 x 20.2 x 37.2mm. Judging from what I'm seeing in these pictures here, one of those should fit as the Yahboom is approx the same length and width and is just too tall. That being said Savox servos are not cheap so if you're looking for an Amazon cheapie type servo you'll probably have to find something in a low profile type servo unless you can find something in a standard size thats approx 37-38mm tall. You may be able to fit something taller by using longer screws and spacers to lift the receiver box up a couple of mm as long as the height from the tabs to the output shaft (illustrated below) allows for bellcrank clearance.

 

[WickedFog]

Couldn't the spacers under the servos just be shaved down a millimeter or so? Looking at the pics, seems that would be the easiest option.

 

[Shafferboy207]

Ok, Its been so long since I've messed with the original JR Z590s I forgot how small that actually were. The Yahboom servo you have is 40 x 20 x 40.5mm which is a pretty standard size these days but not so much back when these rigs were made. The Z590's are 39.4 x 18.5 x 37.1mm. I know Savox (The brand I usually use these days) has some standard size servos that should work. The Savox SC1268SG-BE - Black Edition, for example, is 40.3 x 20.2 x 37.2mm. Judging from what I'm seeing in these pictures here, one of those should fit as the Yahboom is approx the same length and width and is just too tall. That being said Savox servos are not cheap so if you're looking for an Amazon cheapie type servo you'll probably have to find something in a low profile type servo unless you can find something in a standard size thats approx 37-38mm tall. You may be able to fit something taller by using longer screws and spacers to lift the receiver box up a couple of mm as long as the height from the tabs to the output shaft (illustrated below) allows for bellcrank clearance.

View attachment 159541

This is very helpful thank you. I really didn’t want to do the expensive route just because I’m doing two trucks with four wheel steer The cheaper Amazon route is more appealing but harder to find what I’m looking for.

Couldn't the spacers under the servos just be shaved down a millimeter or so? Looking at the pics, seems that would be the easiest option.

I thought about that too but it just sticks the bottom of the servo out the top side farther. Then I would have to Space the receiver box up higher. I just didn’t want to have to do little mods just to get the servos to work.

 

[Greywolf74]

This is very helpful thank you. I really didn’t want to do the expensive route just because I’m doing two trucks with four wheel steer The cheaper Amazon route is more appealing but harder to find what I’m looking for.

I thought about that too but it just sticks the bottom of the servo out the top side farther. Then I would have to Space the receiver box up higher. I just didn’t want to have to do little mods just to get the servos to work.

Yeah, I looked around on Amazon a bit and didnt see anything right off that would work but I only looked at a couple of brands I could think of right off the top of my head. If you find a cheaper alternative that fits post it up here in case others are looking for a budget option that will fit.

 

[tudordewolf]

This is very helpful thank you. I really didn’t want to do the expensive route just because I’m doing two trucks with four wheel steer The cheaper Amazon route is more appealing but harder to find what I’m looking for.

I thought about that too but it just sticks the bottom of the servo out the top side farther. Then I would have to Space the receiver box up higher. I just didn’t want to have to do little mods just to get the servos to work.

If you find a cheaper alternative that fits post it up here in case others are looking for a budget option that will fit.

JX Servo PDI-4409MG's have a low profile like that, and are under $20 a pop. I've used them in several builds, they've got great centering and very crisp response.

 

[Greywolf74]

Yeah, i looked through the JX low pro servos but theyre all only 125oz/in (9kg). Granted theres 2 of them but personally Id want more torque. It would work though if your on a tight budget