Stupid questions about parallels

Mar 07, 2011 10 Replies

When you set something in your vise with parallels do you slide them out before beginning work, or do you press down firmly enough on your work pieces that they won't move easily as the machine accelerates and decelerates?



I seem to get more accurate work piece positioning if I press down gently while tightening the vise, but at that light downward force the parallels can slide out after I have the work piece clamped in.



Seems if you leave them in they could shift on their own or worse slide out and fall between the table and the column, but if you slide them out eventually you will wear them out of tolerance from the friction of removing them.



Not really an issue for a 2 minute job, but I rarely do a 2 minute job. Heck, I rarely do 2 hour job.


I slide them out only if I am will cut something near them.

i

I have an older Wilton vise that doesn't force the moving jaw downward like a Kurt, so I tap the work down with a soft hammer as I tighten the handle, then make sure the parallels aren't loose.

jsw

Same here. Tap with soft hammer. Leave them in place.

You won't live long enough to wear them out sliding them out like that, neither will the next owner of those parallels....

Jon

A lead and rawhide-faced mallet used to be standard issue.

Stan

Leave them in place normally. You can use a spring loaded parallel keeper if you aren't getting a tight enough fit to prevent them from sliding around.

Making sure that vise and parallels are clean and free from chips, I set them in the vise, set my work on them, snug the jaw a bit and give the work a tap with a lead hammer. Then I tighten more to suit and give a final love tap.

I'll pull parallels out part way if I'm about to put a hole though them. I tend to use two thin parallels rather than one thick one most of the time.

Wes

We used to set everything using a lead hammer. If you were using parallel bars to space anything you set it up; tightened all the screws and then gave it a whack with the lead. Check by trying to wiggle the parallel bar under the work. If it wiggles whack it again. After all, if the work isn't down tight on the parallels then you are building in an error.

Hey Bob,

As others have said, tapping with a soft face hammer as you tighten the vise really helps. Another good aid is just put some paper between the work and the parallels.

Take care.

Brian Lawson, Bothwell, Ontario.

I do have a Kurt vise and I still tap the work down on the parallels with a soft hammer after snugging the vise jaws but before going to full tight.

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