Growing Pains on the Bridgeport

Janderso

Jeff Anderson
H-M Platinum Supporter
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Mar 26, 2018
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I have heard from many sources, you will break end mills, gouge work, cut too thin etc. But you will learn from each experience.
Today I was cleaning up my final cuts then something happened. I should have stopped. I am making a vise block for my old horizontal band saw.
The work slipped in the vise and it was too late, I continued to cut chips even though I knew something was wrong.
Lessons learned, keep the work supported in the vise using parallels or some equivalent support.
The other is, I plan on keeping the work clean and de oil the jaws every time I move it.
I think I can salvage the work.
 
One thing about using parallels in the vise is that you know that your workpiece is seated fully in the vise (by trying to slide the parallels under the work after using a soft hammer to seat the work) If the parallels are easy to move, the work is not fully seated, and not in full correct alignment with the vise and machine axes. Even better when possible is to use hold downs such as made by Starrett and others, they insure the job is down tight; in many cases it takes two sets of parallels, one for the work, and one for the hold downs, which should be a bit higher than the bottom of the work, if the thickness of the work allows it, given the need to cut close up to the hold downs.
 
I just remembered something else I saw on YouTube.
If j had the work 90 degrees to the vise jaws it never would have slipped.
Dang
 
@ Janderso, what do you mean by 90 deg.? Just sideways instead of up and down? Kind of curious. I think I learned this lesson already. A piece with a round side on it will tend to move if you have it situated wrong, but if it's correct, then the tool will not push it because the flat sides are clamped evenly.
 
The first time I make something significantly different than before, I tend to make 3 catastrophic mistakes before I end up with a perfect copy of my intention.
 
To stop work from sliding in the jaws, plan your setup so the cutting forces are across the jaws, not in line with the jaws. While you are at it, plan the setup so the chips are ejected away from you instead of toward you. Also pay attention to whether you will be climb milling or conventional milling. Simple to do, just requires a bit more thought to your setup.
 
Learning how much you can cheat and how to recover when something goes wrong are two essential skills for a good machinist. Make it look like you meant do it that way.
 
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