Need sage advise of truing up Bridgeport style vertical mill.

[MRA]

(My home-made pillar-drill-and-3-axis-table-miller - I did a thread here somewhere - has a head which doesn't adjust for tram. If I want to be more accurate, I take a few more passes with a smaller cutter . That's a joke, but a reminder too that these errors get bigger, the bigger the diameter of your cutter).

 

[rick9345]

Tramming a head is just a procedure,find a way your comfortable with, practice makes it easy and quick..
Like all things practice. If your afraid of it get rid of mill find another profession.
Just my take on things.
New brake rotors are cheap and parallel, if they weren't brakes would be unsafe.granite plates are only true on top a parallel top to bottom, wouldn't want to guess price.

 

[toadboy65]

Thanks to everyone who replied to my question here.
I had not thought about the expense of granite, I am lucky enough to have family connections to a manufacturer/resurfacer, and have several small surface plates flat on all sides.
If I have an epiphany or learn of a quicker, reliable tramming method, I will post it here.

 

[Chiptosser]

Its a matter of practice! practice, practice!
If you are not using a indicator You aint doin it rite.
No way around it.

 

[Rocket Man]

I have no problem tramming the head of my Bridgeport I can do it in 3 minutes. Remove vise, make sure gibs are not loose. I have a surface ground 1" thick metal plate 8" diameter to lay on the mill bed. Slide a file over the bed to make sure there it no nicks or dings or bumps. Wipe bed clean. Locate bed on center. Lock both gib handles. Put dial indicator in chuck then rotate 360°. Its easy to get .0005 on the indicator and a bit harder to get .0002 on the indicator. When tightening bolts it sometimes changes indicator reading. Tighten bolts a tiny bit 1 by 1 and watch the indicator.

 

[Asm109]

You can tram as Rocket man describes without the metal plate. The plate is superior in all ways, but lacking a plate, you can do it directly on the table. I use a Test indicator and only preload it about 0.010 inches onto the table. When you swing across the t slots go sloooooooooow so you don't bugger up the indicator. You are limited in swing to the width of the table, but you can do a credible job of tramming, it just takes longer.