Use a caliper to measure the carbon brush. If you don't have a caliper, use a ruler
- Step 1:
Remove the carbon brushes from the device (and possibly from the carbon brush holder)
- Step 2:
The actual carbon brush is the black block or rod. It has three dimensions: "Width" (the shortest dimension), "Depth" (the middle dimension), and "Length" (the longest dimension, but this dimension is often worn out). Enter the 'width' here
- Step 3:
Enter the 'depth' of the carbon brush here. So the second-shortest dimension
- Step 4:
Finally, measure the 'length' of the carbon brush and enter it here. It is likely to be worn, but you can probably estimate the length by measuring or estimating the space in the holder. Carbon brushes are usually about 2 to 3mm shorter than the length of the holder.
Note: No problem if the carbon brush is a bit too long: you can adjust this with a file or with sandpaper