Tips for cutting steel??

[Smooth90]

I have a Fireball V90 with a Bosch colt router on it. So far I've read about people cutting aluminum on it with "good results" but I haven't seen a nice video about it. Right now I've got some free time so I decided to see if I could make some videos of cutting aluminum and mild steel.

I decided to order the mini misting system from littlemachineshop to cool the bit.

LittleMachineShop.com - Spra-Kool Midget Mist Coolant Spray Unit & Coolant

I also ordered some 1/8in bits from precisebits so that I can cut steel and aluminum. My end mills right now are for soft media, they should work for steel but would probably dull out really quick.

My machine is in a fully enclosed box so any oil mist should stay contained and if need be I can seal it further and add some sort of filter system. The koolmist 77 coolant claims to be safe to people and the environment. I had read some websites that said inhaling oil mist can lead to a plethora of health problems so I wanted to get something that was non harmful.


Now on to the questions


1. How deep should I make my passes with my bits. Should I make more shallow passes at a higher feedrate or make deeper passes at a slower feedrate?

2. Should I set my router to operate at a lower rpm 15,000 or set it to a higher speed like 35,000.

3. Do I always need to use cutting oil for aluminum?? I've seen people do it online just wondering if the oil makes the bit last longer or something like that.

4. What would be a decent feedrate for the machine, I know I'm not going with 30ipm but would the router be able to chew through steel at say 4 - 6ipm?

[InventIt]

I'd be surprised if you'll be able to cut steel with the colt. Or for that matter, any wood router based machine. You need torque (read: lower rpm and more power) and LOTS of rigidity to cut steel. At 15000 rpm and low feed rates you'll put so much heat into a end mill it will destroy it very quickly, even with coolant. Aluminum is a different story, you should be able to cut aluminum. Keep the spindle rpm low and feed rates as high as your machine will allow. Take shallow depth of cuts until you feel confident how your machine will react.

[Smooth90]

I'm not trying to take deep passes.


I saw a video online of a gantry style machine cutting a steel plate

[nomedia="http://www.youtube.com/watch?v=FAXWolzuh8I"]YouTube - K2 CNC Router - cutting steel[/nomedia]

If I use a lower feedrate 20ipm and .008in passes then I doubt the router would generate that much heat it is after all taking off less than a hundredth of an inch. I'm not talking about cutting anything thicker than a 1/4in plate so I can deal with 30 passes it would only take an hour.

The bits I bought said in the description they could be used to cut mild steel with an operating rpm of 20k to 100k rpm.

Though I think I might move away from steel because the only reason I wanted to use it was so that I could weld it easily. I found something called alumaloy online that I can use to braze together aluminum so I think I'm going to move to all aluminum. I figured I will just use that until I can justify buying an aluminum welding setup.

I still want to try cutting steel just to see if it can be done. The worst thing that can happen is the bit could wear out but if it works then as far as I know it would be a first for the fireball.

[oldvan]

With enough time, a little bitty river carved out the Grand Canyon.

This guy cut a 12" circle from 0.021" steel in only a bit over 40 minutes.
[nomedia="http://www.youtube.com/watch?v=dlQGiRrejuA"]YouTube - Routing Steel on K2 CNC Machine #1[/nomedia]