Buck Converter Recommendations


I’m putting my OrangeCube on my lawn mower and I wanted to purchase correct buck converters to lower the voltage for all my devices.

I’ve got the following hardware which needs to run on 5V

  1. CubeOrange and a X8R receiver attached to it. (X8R will pull max 100mA, I’m not sure about CubeOrange, but if it worked with my computer’s USB, it shouldn’t need more than 1A)
  2. RFD900x Telemetry Radios (can use up to 1A when Transmitting)
  3. ArudSimple GPS (SImpleRTK2B and SimpleRTK2Blite and Xbee radios) - max 250mA
  4. 5V Relay switch to cut off seat switch (I’m not sure how many amps it needs)

Overall, I don’t think I need more than 3amps at 5V for all this, but maybe having 5 is better

Option 1: https://www.amazon.com/Converter-Reduced-Voltage-Regulator-Interface/dp/B08VHZJ3C8/ref=sr_1_3?keywords=buck%2Bconverter%2B12v%2Bto%2B5v&qid=1652225954&sprefix=buck%2Bconve%2Caps%2C119&sr=8-3&th=1

Option 2: Amazon.com

Most buck converters I see on Amazon can output 5V at 3amps. There are other that can output 5 amps. Do you have any thoughts on the ones I’ve linked above or if you have any better recommendation?

I then also have 2 HiTec D845WP Servos that I plan on running at 7.5 volts (I’ve read online that their stall current is 10A, No Load Current Operating Draw is 1.6A, current draw at Idle is 30mA, but I couldn’t find how many amps they used when functioning normally.

One of them outputs 3 amps at 7.5V and the other one outputs 5 amps
Option 1. Amazon.com
Option 2 Amazon.com

Option 2’s output voltage can be adjusted. I’ve never bought these before and I was wondering if anyone here can provide some recommendations.

Thank You

@Yuri_Rage @ktrussell

I like these Mauch power modules for the 5V components. They make a nice voltage/current sensing module as well that is plug and play.

I used a cheap 8V buck converter for my D845s, but I’ve since upgraded to 12V servos from AGFRC and no longer use any buck converters for servo power.

Thank you so much. Can you please tell me which AGFRC you’re using. I just bought the HiTec ones, so I should be abe to return them.


Did the HiTec ones malfunction or you just wanted even better performance?

Also any idea how many amps the HiTec ones used?

Thanks for the quick reply

Pretty sure I used a 10A buck converter without issue.

I had reason to redo my linkage and decided to eliminate some electrical inefficiencies at the same time. The D845s do occasionally fail. Kenny and I both had at least one of them quit.

I experienced an AGFRC failure as well, but I think I traced that to a high D gain during alpha testing of the new position controller causing oscillation.

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Thanks. I’m done with all my testing and I feel I’m ready to attach things to the mower now. I’ve got the GPS Yaw. The RFD900 telemetry had range on all corners of my property, so that was great. Can’t wait to get it working on the mower.
Many thanks to your and Kenny’s videos

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All the buck converters I see on amazon bring down the voltage from 12V to 7.5 volts but most only output 3A and I found one that does 6A. Would 6A be enough for both HiTec servos? Do you have any link for a buck converter that can output 10A? or just use two of the 6A ones?

Outputs 3A

Outputs 6A



I don’t think 6A will do it. I used this one, but I definitely didn’t pay the current $100+ price for it.

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Thank you.

You used just one to connect both HiTec servos?

Yes. 15A is plenty for both servos in my experience.

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Thank you. And one last thing, the connectors you had used to connect servo and the mower, Do they have any generic names for them? I think one of them was a rod whose length can be changed

Turnbuckles and/or Heim joints.

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Hi Yuri,

On your youtube video (Solved! ArduRover Mower Steering Linkage Upgrade - YouTube), I see that there is black plate connected to the top of your full servo arm. Is that something you created or an accessory that can be bought. I couldn’t find one online. Because connecting the heim joint without that looks a bit difficult. If you bought it online, can you please point me to it?



That’s a piece of 1/8” mild steel, fabricated to connect the servo horn to the larger diameter Heim joint.

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is that something that can be bought or you made that yourself?

Fabricated. I made it. Just like all of the brackets and linkages. There are no kits of which I’m aware.

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