If your Mach3 Motor Tuning menu has suddenly disappeared, the cause is almost always the same — and the fix is simple.
✅ Why it happens
Mach3 relies on a small component called ntgraph.ocx to draw the acceleration and speed graphs used in Motor Tuning. When Mach3 is first installed, this OCX file is registered with Windows so Mach3 can find it.
If you rename or move your Mach3 installation folder, Windows can no longer locate the OCX file, and the Motor Tuning window fails to load — so the menu vanishes.
✅ How to fix it
You just need to re‑register the OCX file.
- Open Command Prompt as Administrator
- Run the following command:
regsvr32 C:\Mach3\ntgraph.ocx(Assumes Mach3 is installed in C:\Mach3— adjust the path if yours is different.)You should see a confirmation message. After that, restart Mach3 and the Motor Tuning menu will return.
Background (for those curious)
What is an OCX file?
An OCX (OLE Control Extension) file contains reusable code that applications can call to perform specific functions — in this case, drawing graphs. OCX technology originated with early Visual Basic (VBX), and although now largely replaced by DLLs, Mach3 still uses it because Mach3 was written in an older version of Visual Basic.
What is OLE?
OLE stands for Object Linking and Embedding. It was Microsoft’s system for embedding objects (like spreadsheets or controls) inside other applications such as Word or Excel.
Why Mach3 depends on it
Mach3’s developer used ntgraph.ocx to provide the graphing functions in the Motor Tuning screen. If the OCX isn’t registered, Mach3 can’t load the graphing component — so the Motor Tuning feature fails.
Re-registering the file restores normal operation.