Advise for Milling Steel with the X3

[fort]

I just got the Grizzly X3. I'm pretty new to milling in general was trying to cut a piece of steel.

When either climb milling or conventional milling with a 1/2 inch 2 flute HSS cutter at about 800 rpm, I am getting vibration that I don't like. The electronics cover on the column vibrates and just makes a lot of noise. I'm not sure of my feed rate, but if I go slower or faster it doesn't seem to make much difference. The axis all feel tight and I don't notice backlash but that may still be the issue. I just don't know. The chips are coming off hot and blue, and after checking my tool it feels duller. I don't have any coolant, mostly because I'm concerned that it will have an odor that will stink up my house, and I worry about the effectivness of a enclosure when I am handmilling.

I'm looking for setup advise or what I should be looking for / expecting when milling on steel.

Thanks

[quicksilver02]

Your spindle speed is too fast. Try something closer to 400 rpm using a cutter that big on plain carbon steel.

You should pick up a copy of Machinery's Handbook to use as a reference for speeds and feeds (among other things).

-Nate

[S_J_H]

fort, Try a 4 flute for steel. It will cut a lot smoother. 2 flute end mills are normally used on softer metals like aluminum.
Steve

[Trapper14]

Sounds like you have it running a bit fast; ideally you want your chips to be a straw color, or a little lighter. If they are blue, you are running too fast and burning up your tools...

[fort]

I tried using a 4 flute mill running much slower. It did cut much better. Chips were coming off much cooler. Thanks for the help. I still notice some noise coming from what I assumed to be the drive gears. I assumed it was from loading and unloading the gears as the cutter engages. Is there anyway to avoid that? I assume it would run much quieter if I added a drivebelt to replace the gears. Have any of you tried that? How much difference does that make? Is it very hard to do?

[project5k]

just my thoughts, how deep are you cutting?

and on the coolant, i'm using koolmist77 mixed at double the suggested mix rate, (if the instructions said 4oz for a gallon of water i put 8) and i cant detect any odor in my cnc room, its a 8x10 room in my shop, not air tight, but i would smell anything foul... so far i'm ver impressed with it, cuts well, cleans up easy, and i dont have any rust on my machine. ofcourse i'm only working in alum right now...but there is some steel in my future...

[Trapper14]

One more thing, climb milling and acme screws don't get along well... I would recommend going with conventional. CNC's do well climb milling because of the ballscrews, but manual machine usually "jump" and that can scrap a part in no time. Good luck!

Sean

[ZipSnipe]

I agree with Trapper, conventional milling and a rpm betwen 550 to 650 is fine, 4 flute(carbide preferred) for steel. Coolant unless you plan to make serious money with your mill, you can use wd40 for coolant or just buy a gallon of some coolant and a squirt bottle. One of the biggest problems I see on this site is newcomers(including myself) taking to big of a cut, like these little mills can hang with the Bridgeports. Good luck and enjoy.....