How can I get a rotary encoder resolution that is not one of the standard resolutions?
US Digital has developed a device that allows you to generate a wide variety of custom resolutions from a standard fixed resolution encoder. We call it the EDIVIDE. When placed in-line with the encoder cable, it can divide the encoder resolution by any integer number by setting the DIP switches.
US Digital routinely makes custom disks for very reasonable costs. There is no minimum order for specials, and lead time is typically around one week. We can laser-cut virtually any ID, OD and hole patterns in the .007" Mylar material. Simply talk with us. We will take care of the details to make your job easier.
If your desired resolution is within 3% of one of our standard resolutions, only a custom disk is required; no mechanical changes are necessary. All of our assemblies will work.
If your desired resolution is greater than 3% away of our standard resolutions, we can stretch or shrink the disk and the optical radius to obtain virtually any resolution. We will select one of our standard encoder modules to read that special disk and give you the mounting specifications. You would need to drill and tap two holes in your mounting surface and use two #4-40 screws to mount the module. We will specify the mounting hole locations since our standard packages will not fit the special disk diameter. You can provide a dust cover if desired.
What are the minimum and maximum resolutions available with US Digital encoder modules?
Resolution is measured in cycles per revolution. Each cycle can provide 1, 2 or 4 counts depending on how many signal edges the quadrature encoder counts. For example, 1000 CPR can provide 1000, 2000 or 4000 counts or pulses per revolution.
For 1" diameter disks, we can provide 32 CPR to 1250 CPR using the EM1 module.
For 2" diameter disks, we can provide 64 CPR to 2500 CPR using the EM1 module.
For linear strips we can provide 120 CPI to 500 CPI using the EM1 module.