Boosting existing stepper motor circuit...

Thread Starter


Joined Jun 8, 2022
Hi ...I've got an application where I'm using a system that is designed to motorize a microscope, controlling 3 axis - X & Y Stage drive, and a verticle Z axis drive. When applied to a regular microscope, this works great. In my project, I'm trying to salvage a really nice microscope that, unfortunately, has had a reduction gear break...rendering focusing impossible (Microscope is no longer made/supported & gear is too costly to try and recreate).

I was able to get the Z axis mechanics under compression spring balance, where it now is resting at mid-travel, and can turn the focus knob with my hand...but when I try to hook up the motor, it is not powerful enough to drive the stage up/down very far before free-wheeling/slipping. I need a way to boost the signals coming from the controller board such that I can drive a stronger motor.

The driver board did have switches to set motor current, and I have them set to max, which is 1A. I'd like to still be able to use this controller (as it is a really nice package, combining extra functions I need) wondering if there might be a way to double the current (like from a stand-alone circuit) - similar to a voltage changer...or similar...keeping the stepping control, but developing stronger current. Would like to hear your thoughts!


Joined Jul 10, 2017
It would be much simpler to add a reduction gear to the motor output to get more torque than to modify the electronics to overdrive (and probably damage) the stepper motor.


Joined Jul 10, 2017
The stepper motor will only draw the current it was designed to take. Setting the switches on the driver to maximum will not change the current the motor is drawing. Find a more powerful stepper motor with the same configuration as the existing one that will work with the existing supply voltage and is rated for 1A.


Joined Sep 30, 2009
(Microscope is no longer made/supported & gear is too costly to try and recreate).
Have you looked or do you know about Boston Gear? They have been around forever and have a very large selection of gears and most aren't all that expensive. Maybe you should look at what they have available . Many times I find their part number and then use it in a Ebay search to get a better price. Back when I was still working we couldn't make most gears for what they sold them for.