Need help with milling setup, please!

[evo803]

I am new to this forum as well as new to metalworking and just bought a Grizzly G0704 mill . I want to square up some 3/8 plate cut-offs ( roughly 3"l x 4"w x 3/8") that I got from the local steel supplier he called them drops and did not know want kind of steel it is. My question is how should I position the work ? Should I use a vise and true the edge with the end of the cutter or lay flat and use the side of the cutter ? I am using a cheap 1/2" 4-flute hss end mill from Grizzly and manually feeding the numbers I am using are 90SFM ,.002 load per tooth, 650 rpm and feeding at 5 fpm taking a .030 deep cut. Is this a good place to start ? Thanks in advance I am looking forward to hear everyones thoughts.

[UUU]

I wouldn't have it sticking up out of a vice without a thicker piece either side. It will vibrate too much on its own. Better to clamp it to an angle plate.

Or clamp down onto the table overhanging the edge and mill off that way. Or onto a piece of MDF that you can cut into.

Clamp HARD. Really clamp it - you'll be amazed how metal you though you had fixed down can move.

Even though they're called end mills, they're designed to take a rebate that's deeper than it is wide, so don't be afraid to cut on the side.

If you're blanks have been flame cut, beware of nasty hard edges. Sawn or sheared will be better.

[M250cnc]

This is easily done using a vice.

The fixed jaw of the vice is made parallel with the table using a DTI

Then using parallels to bring the plate to the top of the vice you clamp it in the vice using the best two edges with the very best against the fixed jaw.

The fixed jaw is the reference edge that you will get true edges.

Set the cutter so that you are as close to the shank of the endmill as possible & take cuts that your mill is happy with. IE cut as high up the cutter as possible.

When you have one good edge turn the plate 180 degrees still using the first edge against the fixed jaw then mill the opposite edge.

You now have two milled edges which you can measure to see how parallel they are.

Repeat this process on the other two sides always using same newly milled face against the fixed jaw.

You should have a perfect square but you may need to return to the first two edges, when you are happy that the sides are parallel then you can size the plates.

Quicker to do than to say.

Phil

[pete from TN]

Install your vise on the mills table, using whatever dial indicator you have make sure it is square with the travel of the X axis, securely clamp the part in the vise with the edge sticking out the side of the vise a little bit and then using conventional milling as opposed to climb milling, run the cutter down the side of the vise using the Y axis. Conventional milling is where the cutters teeth are rotating against the direction of feed. Climb milling would be obviously the opposite where the cutter might seem like it is rolling along the part like a tire on a car moving the part past it like the road goes by in the car. Easiest way to describe it I guess. If you do not have good backlash DO NOT attempt to climb mill steel as you will find the friction of the cutter will drive the table itself making a mess of your part and possibly hurting you as well... Climb milling CAN be done on a manual machine with one axis of motion locked down to not be able to move and the table locks on the moving axis snugged down carefully allowing you to more carefully control the moving of the handwheels. This is all for more experienced machinists tho and if you are new as it sounds stick with conventional milling until you start to get a feel for the forces of the machine and the force of the cutter you are using. Also be careful if the part is grossly out of square before you machine it that you might try to gind or saw it to be at least close to square or you will not be able to hold it securely in the vise. Good luck, be careful and peace

Pete