Hi All,

Getting back into Technic after a 25 year break.  Much has changed and many sets have been released since then.    I'm wondering if there is a true proportional servo option available now that is "Lego compatible"?  I have dabbled in RC and have gear for that, but I'd like something that works with Lego style motors and connection/mounting methods  So far, all Lego-style things I've seen are non-proportional servos, or references to old PF gear.

My goal is to build a buggy around a power and steering set similar to the MK 4.0 electronics but I know that it is not a true proportional set.  I would love to get alternative suggestions.

Thanks.

PU L motor is accurate to a degree and are the best for such in my opinion.

Welp, there are 2 ”safe” ways to go:

1. PU motors paired with a BuWizz 3.0 or a PU (Technic) hub 

2. Geekservo paired with a custom control unit, as this is basically a small RC servo with a JST connector packed in a Lego Technic case

The 3rd option is to look for a proportional PF replica, but you can never be too sure about them :/

Edited September 10, 2024Sep 10 by Lixander

Hi, all available PU Motors (except the Train Motor) can be used as servos.

4 hours ago, Lok24 said:

Hi, all available PU Motors (except the Train Motor) can be used as servos.

And the M motor, right? I didn't think it could be

8 minutes ago, 2GodBDGlory said:

And the M motor, right? I didn't think it could be

This is not produced any more, since a long time.

But yes: it is "simple",like train motor.

Thanks for the feedback, much appreciated.  I'll look into using PU motors, although I know nothing about that system at the moment.  I will also have a look at this solution and see if it is a viable option.  I have a couple extra Arduino boards laying around and I'm curious to see if I can make some of these PF clone motors work reasonably well.

 

If you are considering an Arduino solution, you can use an UNO with this Shield for DC motors:

https://fr.aliexpress.com/item/33052386718.html?spm=a2g0o.order_list.order_list_main.82.79285e5b8D92md&gatewayAdapt=glo2fra 

or you can use a Nano with this Shield for GeekServo or any RC servo :

https://fr.aliexpress.com/item/33063354279.html?spm=a2g0o.store_pc_home.promoteRecommendProducts_11403406.33063354279&gatewayAdapt=glo2fra

Edited September 12, 2024Sep 12 by oracid

Thanks @oracid, that's very helpful.  I'll start with an Uno, I think.  I also have an old L298N 2-motor H bridge that I was going to try using first, but I did see this Adafruit mosfet motor shield that looks pretty slick.  Need to check how much current the Lego motors draw to make sure the shield can handle it, but I suspect it's fine. 

11 hours ago, lagerratrobe said:

Need to check how much current the Lego motors draw to make sure the shield can handle it, but I suspect it's fine. 

I have already tryed 4 XL motors vehicle with the DC motors shield (link above) and RC remote control. And I had no problem.

On 9/10/2024 at 7:15 AM, lagerratrobe said:

My goal is to build a buggy around a power and steering set similar to the MK 4.0 electronics but I know that it is not a true proportional set.  I would love to get alternative suggestions.

If you don't mind controlling an RC car with your smartphone, than BuWizz 3.0 + PU L motor is the most straightforward way for doing that.

You can also use a gamepad, but in this setup it is paired with the smartphone, which then transmits your inputs to the LEGO hub, so there will be some latency (didn't measure it, suppose it is no more than some additional 10-20 milliseconds).

Another option is BrickController2 app, it works the same way, but supports not only BuWizz, but also LEGO original hubs. However, LEGO Technic Hub with 4 ports is very heavy and bulky, while Lego Powered-Up hub with 2 ports is smaller, but if you connect one motor for steering then your buggy is going to be very slow with just one remaining PU L motor.