Roland Desktop Mills: Preventing Spindle Overcurrent Error

A spindle overcurrent error is a safety feature built into the Roland Desktop Mills. This feature shuts off milling operations when the stress on the spindle becomes too high, protecting the spindle from damage. The key to preventing spindle overcurrent errors is to reduce the load on the spindle during operation. There are many things that can cause extra stress on the spindle, so here I will go through some of the more common ones.

Things to consider before beginning:

Can your machine cut the desired material? Make sure that the material you plan on cutting is compatible with your machine. Trying to cut a material harder than what is recommended for the machine will put a higher than tolerable load on the spindle. For example, attempting to cut aluminum on an MDX 50.

Does your cutting tool need to be replaced? Even when taking every other precaution, a dull tool will still impose significant stress on the spindle.

Will your part require long reach tools? Be sure to have long reach tools available in case the short reach tools can’t achieve the final cut depth. SRP player will tell you the necessary tool lengths, but the machine itself will try to run the operation regardless of tool length. A too short tool will inevitably crash the spindle into the workpiece.

Cutting Aluminum on the MDX 540? Overcurrent errors occur more frequently when using the rotary axis. This is likely due to added vibrations during the cutting process causing rubbing and extra load on the spindle.

In SRP Player:

Did you select the correct material? Choosing a soft material like milling foam when you’re meaning to cut a hard plastic like Delrin will likely cause a spindle overcurrent error. Selecting different materials changes milling parameters like spindle and feed speeds.

Did you adjust margins after changing the tool size in the toolpath tab? If you get the message below after changing the tool size, you need to change your margins:

To adjust these margins, go to the modeling form tab and click the “Automatically” button in the margin settings.

Also seen in the image above is the “Make sloped” button. This will slope the margins away from the final depth of cut which reduces rub during lower tool paths. I recommend using this feature as well when you are trying to prevent spindle overcurrent error. 5-10 degrees is a good range.

After taking all these steps, if you are still running into spindle overcurrent error, it may just be time to replace your spindle motor as they do wear out over time. Check with your local Roland dealer for help diagnosing any further issues.

Cody Doiron
Application Engineer
Computer Aided Technology, LLC