How do I buffer/Amp stepper current?

I have an Arduino board that works my laser and it has lots of other "stuff" on the board, but what doesn't do is add any additional current for the steppers.

I want to increase the umph my steppers have a touch buy either giving them more current, or upping the voltage a bit... neither of which this board supports...

IS THERE a board I can put between my Arduino board and the steppers to "Buffer" the output?...

I did a search on 2-phase amplifiers and found that was -NOT- the right search term...

Any products or search terms appreciated.

A suitable stepper driver is used to control the stepper current, and you should be using a separate power supply for any motors, steppers, servos, etc. Please post the details of your setup, especially the steppers, and a wiring diagram.

You should find this tutorial helpful:

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The fact that your Arduino still works says a lot for it. You should never connect a motor directly the Arduino, always use a motor shield/module/driver board. With this approach there is no real limit to the size of the motor you use, even in the hundreds of horsepower range.

When you sort this out post an annotated schematic showing how you propose to build it, we will happy check it for you possibly saving a few Arduinos. This should help:
Gil's Crispy Critter Rules, they apply to processor hardware:
Rule #1. A Power Supply the Arduino is NOT!
Rule #2. Never Connect Anything Inductive to an Arduino!
Rule #3 Don't connecting or disconnecting wires with power on.
LaryD's Corollarys
Coro #1 when first starting out, add a 220R resistor in series with both Input and Output pins.
Coro #2 buy a DMM (Digital Multi-meter) to measure voltages, currents and resistance.
Violating these rules tends to make crispy critters out of Arduinos.

The laser control board has a lot of other "stuff" on it to buffer and control lots of things, so there is some buffering in there, and there may even be a multi-stepper driver... but even those are limited to 800ma typically.
I want to take the outputs of the board, 4-wire servo drivers, and take them into a "buffer board" and then feed that into some slightly beefier servos. May not much beefier, but better than the seriously cheep chimesium steppers used that shake, skip, wobble and are otherwise junk.

Now the question is why not re-do the board... It's an encrypted OEM board (K40 laser) that actually works pretty well. The software I use was reverse engineered to work with the board. I could replace the board, but that means new software and a MAJOR upgrade process. By just "amplifying" the existing servo output, I can do 1 channel at a time with no effect/impact on anything, other than the servo will be a bit "tighter" in its behavior.

You started talking about steppers, now you are talking about servos...

If its steppers, no you cannot "buffer" the outputs of a stepper driver as they are switch-mode current-sensing power converters.

Sorry, they are steppers. I know how to "buffer" servos...

i was hoping there was a way to use one or more H-bridges to buffer the 800ma output from the control board that it feeds to the wimpy servos. The servos might behave better if they were given more current. Even after a "hard run" they are not even above ambient temperature, so they can likely do "more."

Are you already running the mystery control board at it's maximum voltage?

The K40 Laser control board uses some weird voltages, 5v, 12v and ungodly high... ( the high voltage may be just a trigger) all of which are running their respective supplies right at their limits. (45w laser tube on 35w supply for example)

When I wanted to add some fans, led light strips and an Arduino and stepper driver to run a separate small stepper I added a separate 5v supply.

Trying to separate out the stepper IO lines would be tough due to lots of Hot Glue encapsulate. Thats why I want to do it external to the board if at all possible. i may just have to buy better steppers rather than trying to boost the existing ones.

Try one and see. Most likely problem is the controller. As of now, we do not even know how many phases your stepper motors use.

Good idea. Given the microscopic amount of information you have supplied, forum members can't offer useful advice, so you are on your own.

They are very lightweight 4-wire nema17's The one I used for an additional axis controlled by its own board is considerably beefier.

Thanks to all.

I was HOPING there was an easy solution where I could unplug the cable from the stepper, plug it into a thing, and then run a cable from that thing to the stepper.

Looks like it is going to be a bit harder than that...

You keep saying servos!!

Please provide datasheet or product page for the stepper motors you have, currently they are unknowns to us:

The weight doesn't provide much information about the electrical specifications, but its worth noting small steppers have very little torque at speed.

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Mark im trying to figure out the something. Did u get and where?

Bob call me

Please do not post your phone number on the forum. Use a direct message.

How. ? Sorry!

Bob email me

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