Hi everyone,

I'm currently working on a new CNC build and recently decided to upgrade to NEMA 34 stepper motors to handle higher torque demands, especially for the Z-axis and gantry movement. I thought I’d share some of my experiences so far and ask for some advice.

My Setup:
Motors: NEMA 34, 6.0 Nm holding torque, bipolar

Drivers: Leadshine DM860T (set to 5.6A peak current, 1600 steps/rev microstepping)

Power Supply: 60V 10A switching PSU

Controller: Running on a SmoothStepper with Mach4

Why NEMA 34?
I initially used NEMA 23s (around 2.8 Nm), which were fine for light aluminum work, but once I started working with harder materials and longer travel, I noticed some missed steps and vibration. The NEMA 34s have made a huge difference in torque and overall stability. The machine feels much more solid and responsive.

Pros So Far:
Massive torque improvement

Runs fairly cool even under load

Noticeably smoother movement with proper microstepping

Concerns/Questions:
Power draw – Has anyone had issues with brownouts or overheating using similar specs?

Inertia mismatch – I'm wondering how critical it is to match the motor inertia with the load, especially on a heavy gantry. Has anyone experimented with adding dampers or gear reductions?

Noise – These motors are a bit noisier than my NEMA 23s, even with microstepping. Any tips on reducing resonance or mechanical noise?

Would love to hear how others are using NEMA 34s in their projects—especially if you’re working with CNC routers, plasma tables, or similar. Are you running them closed-loop? Any major lessons learned or things you wish you knew earlier?

Looking forward to hearing your thoughts and setups!