Kevin is adjusting his Bridgeport mill (milling machine) to help him make some braces for a fountain he is building. The braces will go under the dishes to hold up their weight.
To make the braces, he cut out 12 pieces of steel about the same size. He cut and shaped one of them to get the metal the way he wanted it, then cut out the others to match it. He cleaned them up by getting the dross off them and hitting them with a grinder. Then he stacked the pieces of steel and clamped them down.
Now it’s time to clean them up on the mill, trimming them to the right size and shape. He put his pattern piece – the one he originally cut to size – on the top so he can follow its line.
Kevin had gotten most of the milling done, but one edge was stuck over the side of the table, so he still needs to clean it up. He unclamped the pieces, got out his vacuum and cleaned up the metal chips, and put it all back together. Now he’s just going to trim off the ragged edge so they’re all pretty much the same size.
He turns on the mill. Then Kevin checks to make sure that the end mill isn’t touching the metal. He explains that he is using a roughing end mill, which is for doing quick work or a first pass. There are also finish end mills, which have a finer tooth on them to do a smoother, cleaner job.
The roughing end mill is fine for this job, though, because he will still need to do some adjusting and clean up on each brace. He’ll weld them in place then smooth them off a bit with an angle grinder, so there’s no need to use the finish end mill on this job.
Kevin puts on his safety glasses, then checks his settings, and begins cutting away the metal with the end mill. He makes one quick pass to get rid of the worst roughness. Then he’ll come in and get a little closer and make the cut a little cleaner.
It took him about 45 minutes to clean up all three sides to get them all the same. Now he can take the braces over to the vise and clean each of them up a bit, getting rid of any rough spots so he can weld them in place.
Kevin says he’s had a lot of fun learning to use the mill and watch the metalflying everywhere, which is why it’s important to wear safety glasses while using it.
He’s ready to unclamp the pieces and go back to work, but you might want to wait one more moment to see Kevin just walk off the job ….