Extending Torxis i00800 range with jrk21v3 using rc control

Hello, I am using a torxis i00800 servo to manipulate the steering on a custom RC ride on I made for my son.
The stock range setting is 90 degrees. I would like to get some more range out of it in order to increase my turn radius.
I have used the config utility previously with one of your linear actuators, but only to set the end points.
I have the config utility installed and working via the USB interface.
I have saved the stock settings, but am unsure where to go from here to extend the range. The end points seem to be maxed out. I assume there is a way to scale it differently, but have no clue how to.

Can you give me the simple way to extend the range of the servo? I am looking to get somewhere around 120 to 180 degrees rotation.
Thank you,

I apologize, I believe I should have posted this in the RC servo controller section. If so, can a mod please move it.
Thank you


I think you posted in the right forum because the jrk is a motor controller.

Someone called us today and told me that the Torxis comes with a note about extending the range to 180 degrees, but does not say how to. I think the best approach would be to ask Invenscience, the manufacturer, what to do to increase the range. If they suggest you change settings on the jrk, but do not have suggested settings available, you can try using the information in the jrk user’s guide to configure the jrk.

Please let me know if you have any additional questions about the jrk, and I am sure other Torxis users would love to hear what you end up doing.

- Ryan

Thanks Ryan, that was me that called actually. I had posted in the morning and was on a bit of a deadline to get this running so I called later in the day.
I called Invenscience, and one of their engineers was very helpful. He got me straightened out.

It is basically opposite of what you would think.
By default the maximum is 4095, and the minimum is 0. You lower the maximum and raise the minimum to extend the range either way. If you go too far either way the pot reaches its maximum and spins back around.
So I ended up with around 600 for a minimum and a maximum of around 2000.

I am very pleased with the result, these servo’s are awesome! My only complaint is I wish there was access to the usb port on the jrk without removing the cover. I ended up notching the cover so I could just leave one end of the cable in, and then sealed it with some gasket maker. I snaked the other end up into the truck so I can make adjustments without turning the truck over or having to take the cover off.

Here is a quick video demonstrating how I used the servo.
Not sure how to embed on this forum, but here is the link

I am glad you got it working; thanks for posting what you learned here. It looks like it is working well for you (at least when not under much load).

- Ryan

It works excellent under load as well. I have maybe a hour of testing on various surfaces including pavement, grass, and even full on woods riding. And the complete truck without a passenger is probably topping 200lbs between all the steel and 3, 12v12ah lead acid batteries. Add my son and thats another 50lbs.

Its a great balance between the two linear actuators available. I tried both the 150lb actuator(too slow), and the 35lb actuator(not strong enough).
If there was a say 75lb linear actuator that would be a perfect middle ground. I had to pay almost double for the torxis, but I am 100% happy with its performance so far. Time will tell if it can hold up to the abuse.

Hello, Jason. I am glad that the Torxis is working well with you. We would love to see more videos of your project!


I am in the process of making a video of its performance. My son rode in it and loves the quick steering now!

The basics are I bought a used Peg Perego Gaucho Super Power for $60. It did not run, but the motors/gearboxes were good. It was extremely sun faded and neglected.

My son only being 2 at the time was unable to drive a vehicle with a steering wheel very well. So I set out to make this RC.
I really wanted to make this extreme, so I built a custom steel chassis out of 3/4" square tube. I used a simple 1 link 4x4 design. I had zero experience with 4x4 suspensions so I was learning on the fly. I had a few people that helped me out tremendously.
I bought two more 24v gearboxes from a newer peg perego ride on for the front wheels. I kept the stock GB’s in the rear.
The shocks were custom built coilovers. I used 30lb 4" stroke gas pistons and machined custom cups to hold springs over them. They worked out really well.

For the drive control I am using a Syren 50a controller. It can handle a constant 50 amp draw with up to 100 amp spikes. I reall dont know what my 4 motors draw, but I am assuming its overkill because I am yet to blow a 40 amp fuse.
For the RC I am using a Traxxas TQ4 setup I believe.

I had done so with a few other ride ons before this so I had a little experience, though I was a totally green to the world of large scale RC. I was learning on the fly, and the steering ended up having a expensive learning curve!

I spent a lot of time and money trying to master the steering. I went from a servocity servo gearbox(worked ok, but the plastic gears proved to be unreliable), to a pololu 150lb 2" stroke linear actuator with feedback controller by a JRK. This worked well, but was just too slow. I even tried a 35lb version but it would barely move the wheels on the ground before stalling out.
I finally broke down and bought the Torxis and that is where I currently am.

BTW anyone looking for a used 150lb actuator and jrk :wink:

Here is a link to the build thread on my modified power wheels site. Its about 5 pages long but documents all my work, and mistakes I made along the way!

forum.modifiedpowerwheels.com/vi … =19&t=4645