Milling Machine Head Tramming

[platypus20]

A couple of customers of mine, showed me a easy and quick way to tram the head of the milling machine. One of them is an aerospace contractor and the other is a sub-contractor to the first one as well as a job shop. They mount a brake rotor on the mill table and then using a simple indicator bracket sweep the surface of the rotor, which gives them a smooth surface to work with. They said if you have any doubts, rotate the rotor 90 degrees and rerun the test. I made the bracket out of 1/2" shafting, drilled and tapped it to hold the indicator. I then removed the vise and mounted the rotor and bolted it down. I installed the indicator and trammed the mill head. Rotated the rotor then reran the tests. Remounted the vise and trammed it in.


1 - the simple bracket
2 - the indicator
3 - back view of the indicator mounting
4 - front view


jack

[platypus20]

5 - tramming using the brake rotor
6 - closer view
7 - sweeping t the back
8 - tramming the vise


jack

[Cavalry]

Great cheap way of tramming.

I use the swivel off my vise. Precision ground and I already have it
http://www.shopfloortalk.com/forums/...ghlight=swivel

[the spyder]

Excellent- I even have a brand new rotor that I have no idea where it came from.

[rmack898]

Some company sells a gizmo called EZ-Tram or something like that and all it is, is a brake rotor with the center cut out and 4 legs on it so it will fit over your vise. I think they get about $180 for it.
You can buy a new brake rotor for $25 and if I am taking enough care to tram the table before a job I'm gong to tram the vise too.

Good idea Jack

[A_Pmech]

I don't know about a brake rotor, but large bearing races work well. What's the TIR on the brake rotor?

Hang out around the local mine repair shop and take your pick. Most are HEAVILY trashed, but ever now and then you find a perfect one with a little brinelling and metal transfer on the inner race.

Poifect!

I like your indicator setup. Just don't do something dumb like I would when I'm hurrying and hit the "go" button. Yes... It's been reported on PM before...

[platypus20]

Originally Posted by A_Pmech

What's the TIR on the brake rotor?

Unknown, but thats why the tell you to rotate the rotor 90 degrees, if its off the readings will change. If its good enough for an aerospace contractor, its good enough for me.

Jack

[A_Pmech]

Originally Posted by platypus20

Unknown, but thats why the tell you to rotate the rotor 90 degrees, if its off the readings will change. If its good enough for an aerospace contractor, its good enough for me.

Jack

Turn 90 degrees... Good point!

[Charlie C]

Some one one time told me to use a bearing race as A_Pmech mentioned. So I went looking for one and found one about 6/8 inches, don't remember now here in the house.

[Setup boy]

That's cool and thanks for sharing Jack. I would absolutely use that method if I was mounting work directly to the table but if I am using the vise I feel safer tramming the ways of the vise because my work typically sits on parallels that sit on the ways of the vise.

No matter how careful I am about cleaning the mating surfaces it is still possible that somehow something may have gotten between the vise base and the table when mounting thusly throwing the vise out of parallel with the table. If I tram to the vise that takes that out of consideration.

Now if my vise opens up wide enough to allow the rotor to lay on the vise ways then that is what I will do.