Stepper amps x axis

Can anyone help me understand why we run them so low if they are rated for 2 amps? I keep seeing they will run hot. I’m just wondering if that is like fire risk hot or loss of stepper usage life hot

PLA motor mounts will start to distort if they get too hot (>50C)

2 Likes

I know you already have your answer, but I wanted to add a few things for anyone in the future that finds your topic.

V1 machines run well at the current recommend current settings. When I see topics were someone is seeking to increase their current, they are often doing it to solve some issue that turns out better solved in a different way. Most common is an underlying mechanical issue that forces the motors to work harder. Increasing the current is only hiding the underlying issue. So I recommend getting the machine running well with the V1 recommendations then evaluate whether you want to “hot rod” the machine.

Second, the machine may not be running the motors as “low” as it first appears. The motors are usually rated as maximum current, but the current settings for the stepper drivers are sometimes set as RMS (average) current.

If you really want to experiment with running the steppers hotter, there are a few machines were people put insulating spacers between the PLA and the motors. If I remember correctly, cork was used. I also have seen people print the components out of higher temperature plastic, though typically they sacriface stiffness for higher temp ability.

If you really want to run faster, particularily rapids (no load movements), then increasing the voltage seems to have more impact than increasing the current (just my take from reading the forum). Typically this involves reworking your electronics to use external stepper drivers, so this is not a small or simple change and better done after getting the “stock” machine working well.

2 Likes

I’ll repeat @robertbu’s words about getting your machine running with the stock settings first. If you decide that you want to “hot rod” things after that, you’ll also have to research things like acceleration settings, max feedrates, etc. Increasing one or more of these without knowing how they all fit together can result in a decrease in performance (skipped steps) rather than an increase.

4 Likes

https://www.youtube.com/watch?v=4Z2FBA_cBoE is probably the video you need to watch to understand this.

Spoiler:

Pretty much same torque with all voltage/amp levels.

At 24V all ampage levels drop off at a similar speed, a speed that (other than travel moves) we are very unlikely to hit.