Spindle performance, feed rates, and tool coatings

[prestigious-iceberg77]

I tested my DIY CNC router on steel machining, and the results were pretty exciting. I worked with mild and hot-rolled steel using a 2.2kW water-cooled spindle from Amazon paired with a Huanyang VFD. I used a ¼" carbide end mill for tooling, running at 8500 RPM, 12 IPM, and a 3mm depth of cut.

Surprisingly, the process went well, but I'm curious how long this setup will hold up with regular steel cutting. Has anyone pushed a similar spindle this far and how did it perform over time?

I also noticed how different the cutting feedback felt compared to softer materials. Are there better techniques or settings for CNC routers cutting steel and would specific spindle speeds, feed rates, or tool coatings improve efficiency? I would appreciate hearing insights from those experienced in CNC router steel machining.

 

[ClosingTime]

Ooh that's an interesting test you got there. Isn't steel tough on CNC routers? Is your spindle designed for heavy duty cuts? Well I'm sure long term there's gonna be normal wear and tear on the bearings or overheating buuuut if you do lower depth cuts, high-qual coated end mills (maybe TiAIN?) + flood cooling can help you with that? I think if you reduce RPM or something it can also help with chip evacuation? Try other toolpaths if you wanna reduce the stress on the tools.

 

[prestigious-iceberg77]

Ooh that's an interesting test you got there. Isn't steel tough on CNC routers? Is your spindle designed for heavy duty cuts? Well I'm sure long term there's gonna be normal wear and tear on the bearings or overheating buuuut if you do lower depth cuts, high-qual coated end mills (maybe TiAIN?) + flood cooling can help you with that? I think if you reduce RPM or something it can also help with chip evacuation? Try other toolpaths if you wanna reduce the stress on the tools.

Great points! Steel can definitely push the limits of a CNC router. TiAIN-coated end mills and flood cooling are solid suggestions. Have you noticed any challenges with chip clearance at your current RPM or tried experimenting with shallower depths of cut or adaptive toolpaths to ease the strain on the spindle?

 

[Jon S]

Those 2.2kw water-cooled spindles are not designed to run at 8500 RPM or whatever the lower end says on yours for very long periods. It will wear out much faster, it's something to be aware of.

 

[prestigious-iceberg77]

Those 2.2kw water-cooled spindles are not designed to run at 8500 RPM or whatever the lower end says on yours for very long periods. It will wear out much faster, it's something to be aware of.

@Jon S You are absolutely right about being careful with spindle wear, I actually took a bit of a beating from my buddy for pushing mine too hard on a project. He really drove home the point that tough materials like steel will truly put these units through their paces over time.

 

[Jon S]

having burned through one myself, mostly through not having been supplied with any manual or instructions when I bought my machine and because I didn't check... I made a video on the subject, which also garnered a few comments from those who've done this a very long time, which I hadn't picked up during my own research. Sometimes taming the 'lets get it done' is a challenge.

 

[prestigious-iceberg77]

having burned through one myself, mostly through not having been supplied with any manual or instructions when I bought my machine and because I didn't check... I made a video on the subject, which also garnered a few comments from those who've done this a very long time, which I hadn't picked up during my own research. Sometimes taming the 'lets get it done' is a challenge.

That urge to just make it work can be a real bear to manage sometimes. What was the most surprising bit of wisdom you received from the old hands who commented on your video?

 

[Jon S]

That urge to just make it work can be a real bear to manage sometimes. What was the most surprising bit of wisdom you received from the old hands who commented on your video?

The surprising comments came from the ignorants who didn't like the advice!
The best bit of wisdom, the same applies to laser, don't run them at full speed. 90% at most, that wasn't in the manual either, I'm happy to take that advise.

 

[Jams Tung]

Your setup is decent for occasional steel cutting, but for longevity, consider lower RPM (6000-8000), higher feed rates (15-20 IPM), and TiAlN-coated tools; regular steel machining may wear the spindle bearings faster, so monitor for vibration or heat.

 

[prestigious-iceberg77]

Thanks to you both for that input. The 90% rule is an excellent pc of wisdom and aligns with the lower RPM range you suggested. How do you balance lower spindle speed with a higher feed rate on steel without causing tool chatter or stalling?