Milling Stainless Steel on a Sherline Mill

[David Morrow]

I've milled no end of aluminum and brass on my Sherline CNC mill but pretty much avoided steel until now. Especially stainless steel. The Sherline is pretty much a flyweight among mills and I always thought that the tougher materials should be avoided.

I needed to make two cam lobes for Jan Ridders designed Atkinson I.C. engine. As most of you know, not all steel, aluminum, or brass etc is created equal. There are many alloys available. I did some googling and found that 416 stainless has the best machinability rating so that's what I used. I found very little reference material on machining steel on the Sherline mill.

In the end, I was most pleased with this experiment. Next time, I'll increase the depth of cut a bit but on such a small job, it didn't kill too much time going so light.

Here's a video of the milling. I started with a piece that I turned on my lathe which kept the mill time to a minimum.

[ame]https://www.youtube.com/watch?v=L_Ho1QlsKok&feature=youtu.be[/ame]

 

[bouch]

Nice work.. I'm assuming you're CNCed your shereline. What were you using for spray lubricant? Just air to remove chips, or was there a fine mist of cutting fluid you can't see in the video?

Always better to take light cuts first. All that'll cost is some time. Crashing an endmill might damage a lot more...

 

[David Morrow]

Just a bit of air to remove the chips which I use on pretty much all of my CNC work. Even that wasn't necessary on this job as they pretty much just fell off to the side because of the nature of the piece I was cutting into. After this cam, I made a slightly larger ignition cam out of 12L14 and oddly, the 416 SS was easier to cut.

I made a flood coolant system that I used for a long time but found that it was too messy and the air worked just as well if not better. Using a light mist or brushing coolant seems to make things worse for me as the chips then tend to stick to the workpiece and create a bigger problem.

 

[gus]

Hi David.

You have given me the inspiration to resurrect the CNC Training done in 1984 and not put into practice. Was taught Fanuc Machine Language.I am behind time. Will look up Sherline CNC Milling. Perhaps invest in a CNC Sherline Mill. Currently all the cams for Webster,Rupnow H&M and Nemett-Lynx Engines were done manually. The cams for the current Howell V-2 will be done manually too.

 

[Metal_slicer]

Thanks for sharing that video. I have a sherline mill also. I love it. Very easy to use. My mill is the 5400 inch model using sherline steppers and controller box. Software is mach3 and visual mill from mecsoft. I was wondering what you are using? I bought harbor freight 7x10 lathe but I wish I got the sherline lathe. Hf lathe has issues with the ways having play.

 

[David Morrow]

Here's my mill, at least the way it looked a few years ago....

http://ldrider.ca/cnc/sherlinebase/sherlinebase.htm

It's a bit of a hybrid having removed the stock base and made my own from 1" plate steel plus a new column. I'm also using Mach3 and Sheetcam although I should update them both.

I have a Myford Super 7 lathe but I recently bought a Sherline lathe for the really tiny stuff and inter-changeability of tooling.

 

[petertha]

I did some googling and found that 416 stainless has the best machinability rating so that's what I used.

Good to hear. That's what I've picked for my valves, but not quite there yet. Here is a comparative table FWIW.

https://www.carbidedepot.com/formulas-machinability.htm