How do you ensure the milling head is parallel with the table?

Looking for many and quick replies at 11.30 pm ???

You,ll be lucky ! Are you on night work,by any chance?

Another few hours will make little difference,and we,ll all be awake then [well,most of us anyway ]

Go to bed and sleep on it,you,ll feel better in the morning.

As someone said,a simple clock on an arm should do the trick,it,s not rocket science.

Interesting answers but due to my poor explanation "sorry" only XD351 understood what I was actually asking, thank you.

So not interested in the nod as you say of the head "up and down" I use one of the single dual indicator devices for that and ensure the head is perpendicular to the table on both axis.

I was trying to ensure that the head rotation is indeed aligned with the table at 90 degrees, yes you can clamp a bar to the table, but how do you know that the bar is running parallel to the table in the first place.

I guess that that does not matter as log as the spindle and hence head is trammed parallel

Thank you all.

Gary

Google never sleeps

Martin's nailed it! It should be added that in most cases, you'll probably not need to move the ram or head for any job.

If you are working on something that's big enough that you want to use the entire table area without re-setting the work on the table, it's best to assume that moving the head means that you need to find your references again, so have a datum point that you can reach with the available table, knee and quill movements in some position that you can reference from before and after moving the ram. It doesn't matter whether it's some feature of the work that isn't going to get milled off, or some landmark on the table (T-bolt with a centre punch mark on its top or even a known and annoying 'oopsie' put on the table by a previous owner).

Then, before starting work and after moving the ram, set your dials/scales from this landmark and you've now got consistent measurements over the entire range of the machine. If the scope of the job is sufficiently enormous, you can even have a couple of reference datums that you can work out the relative positions of from one setting, then use them to extend the working envelope. At this point you're into making 4" traction engines on Myford lathe territory...

Initially, I thought that you were looking to ensure that the spindle (Z axis) was perpendicular to the table. Then, I began to think that you were looking to set the head so that it was at right angles, in the horizontal plane, to the table.

If this is you objective, may I suggest?

1) Set a clock on the spindle and ensure that the fixed jaw of the vice is in line with the plane of the travel of the table X axis (left - right) by winding the table to and fro, and gently tapping the vice until the clock reading is constant.

2) Then swing the head around the column until the clock reading, against the fixed jaw of the vice is maximum.

The head should always at right angle to the table, in the horizontal plane, but the above will maximise the clearance table to column.

Hope that this helps

Howard (Typos corrected)

Edited By Howard Lewis on 03/11/2017 11:01:58

Which is why many users, once they've got it right, drill taper pin holes to enable them to realign again quickly when they've moved it.

Martin (and Mark) are correct, but having set the Ram rotation correctly, clamp it and check again.

I would not rely on any reference mark, other than as a general guidance that you are near. I have a 48" table and use it all, at times, so a reset is properly done after each time.

Same applies to a machine vice, even if it has a tenon or pegs locating in the T slots. Once moved or rotated, reset properly.

Edited By KWIL on 03/11/2017 11:26:35

Hi Gary I have sent you a message PM.

David

I have never worried that the ram on my BP was perpendicular to the X axis. I suppose if I had to check it I would use a precision square on the table. One leg would be set against keys in the T slot. With an indicator mounted in the spindle and riding against the other leg of the square I would move the ram in and out. If here were any deviation in the indicator reading it would be necessary to loosen the turret bolts and rotate the turret. Repeat until you get the accuracy you want.

When I was working on a part that exceeded my Y axis movement I bored a reference hole at known X and Y. I moved the ram in or out as needed then indicated on my reference hole and set the X and Y coordinates into the DRO. If a reference hole is not permitted in the part you can clamp or glue a sacrificial piece onto the part and drill the reference hole in that.