Face mill finish

[Edward]

Thank you, re-machining to dovetail on the opposite side to the gibs so that head and column run completely parallel seems like a solution. But it is way beyond my scope, something better left to the experts:)

Next mill will have a head adjustment, that's for sure:)


Edward

[Edward]

Latest news on this subject:)

I came across this video by hossmachine about tramming the head to the column.

I stuck a rod in the spindle and followed his procedure exactly, setting up my indicator like he has done, as I have the same bars. I can't adjust the head like he can, as mine is fixed but I was nevertheless very curious to see how far off my mill head was using this method.

First I jogged to the top of the rod, rotated the spindle by hand and zeroed it to be exactly half way between the maximum plus and minus readings of the runout. Since this was measured at the top of the rod, the runout deflection was quite small.

Then, without touching anything, I simply jogged the Z axis so that the indicator was at the bottom of the rod. I rotated the spindle again and the deflection on either side of zero was exactly the same. I did the same to the Y side of the rod. So I guess this mean I have been worrying about nothing?

Provided this method is good, and I am only going by his video, then I guess I am OK.

Edward

Tramming video by Hoss here:

[magicniner]

So if your spindle is parallel to your Z axis movement and you have your column square to the bed there will be no error when you check the tram?

[Edward]

Well, in theory you are correct.

Tomorrow I will double check the squareness of the column to the table again. It must be pretty close because when I used the facemill, the stepover raised level was gone completely
whereas before I did the column alignment there was a small raised level on the piece, as can be seen in the very first post.

Earlier I read 0.4mm out of square on a 30cm swipe. I will fine tune this and see what happens.

Edward

EDIT video included:

Forgive the crappy video, but it shows how I measured it. First the top of the rod, hardly any runout, less than 0.01mm. on either side of zero.

Then again at the low end of the rod, notice the equal deflection either side of zero, around plus/minus 0.05mm

[magicniner]

before I did the column alignment there was a small raised level on the piece, as can be seen in the very first post.

You keep mentioning column alignment but what were you using to check the angle between the column and table, given that you chose to align that first?

[JAZZCNC]

But do you know the Bar is Perfectly round and straight.? If the bar isn't calibrated test bar and the collet high quality then your wasting your time. However I think for machine this size and quality that's good going to get or should expect.!

[Neale]

Edward - your very first adjustment/measurement didn't do what you thought it did. Putting a dial gauge in a collet and winding the table back and forth only tells you that the table is flat. You would get the same result with the column at 45deg, say! The only useful measurement is the turn-round/tramming test where you keep the table still and turn the spindle. However, this only tells you that the spindle is square to the table. The column could be tilted, and the head off-square to the column by an equal and opposite angle, leaving the spindle square to the table and you would not be able to detect this. The test to detect this is to tram the spindle, probably by shimming the column base as you have done and using the spindle turn-round measurements, then with your test bar in a collet and without turning the spindle, clamp dial gauge to table and then run head up and down column, note any variation, then run spindle up and down in head (drilling movement). If these match, head is square to column. If not, then there's no simple fix but at least you can double-check manufacturing accuracy.