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Tramming my Mill

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ddickey

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#1
Does anyone see a problem with tramming like this. I like to use the vise as that is where my work is held. The parallels are 4-way Anton .0003" accurate on height, width and straightness. thumbnail_IMG_20180708_195533303.jpg
 

4ssss

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#2
I have always used the table for tramming.
 

Eddyde

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#3
I would crank the vise all the way open so the 123 blocks are farther apart, less chance of magnifying any error. Or perhaps you could tram directly off the bed of the vise.
 

westerner

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#4
Car/equipment mechanic/redneck that I am- I use a NEW automotive brake rotor, big and spendy as I feel necessary. Current one is 86 Chevy 3/4 ton four wheel drive. I would have to go measure to be sure, but more or less 12" in diameter. Big circle, no worries about ripping my indicator needle off in a rude fashion. Don't ask, ok:eek 2:?
Ya, sure, they are made in China. And, the indicator will dance a little running over the machining marks left on the rotor. Still, I feel it is the best, easiest way to get a good job done. The real tramming tool looks just like a brake rotor, except it is sitting on three legs and a scary price tag. If brake rotors were not flat, then the brake pedal would pulsate, customers would not be happy, and sales would drop. You can check for that anyway, by spinning the rotor 90 or 180 degrees and checking again.
In addition, you get to see the same distance from the spindle in the x and the y. Helpful to quantify a "nod" issue.
 

Technical Ted

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#5
If I understand your question correctly, I would only tram a vise in if I was sure I would not be moving the knee up and down. Tramming the head to a piece in the vice would in fact align the spindle with the piece, but if that piece were not perfectly in the same plane as the table top (perpendicular to the knee's vertical axis) then moving the knee up or down would throw things off since the spindle travel would not be perpendicular with the knee's vertical travel. The spindle would be at a slight angle to the knee's vertical travel.

Ted
 

ddickey

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#6
If I understand your question correctly, I would only tram a vise in if I was sure I would not be moving the knee up and down. Tramming the head to a piece in the vice would in fact align the spindle with the piece, but if that piece were not perfectly in the same plane as the table top (perpendicular to the knee's vertical axis) then moving the knee up or down would throw things off since the spindle travel would not be perpendicular with the knee's vertical travel. The spindle would be at a slight angle to the knee's vertical travel.

Ted
That was tramming the node or the Y axis in the pic.
 

Technical Ted

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#7
That was tramming the node or the Y axis in the pic.
In thinking about this more, if that alignment bar you are tramming isn't perfectly parallel with the table top (and therefore the Y and X axis travels) if you were to face a work piece with multiple passes, the facing tool would leave steps because the spindle is not trammed to the table's travel. The farther off the alignment bar is from being parallel to the table top, the worse the steps.

It looks like you have a beautiful vise there and a very nice table/machine, but all it takes is one little chip or burr to throw things off. YMMV, but I would not trust it unless I was doing a job that was not very critical.

Just my two cents,
Ted
 

BaronJ

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#8
Hi Guys,

If you are going to tram the head, you really need to use the table surface, particularly if your mill is adjustable for nod as well as angle. Have you actually checked to see if the bed is truly flat and doesn't have any twist in it ? Once you have then you can tram the head in both planes and be reasonably sure it is square to the table.

After mounting the vise you should check that for squareness and flatness. As has been said a bit of swarf or a burr can throw the vise and any work piece out. Cleanliness is a must for accurate work.

Regards:
BaronJ.
 

P. Waller

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#10
Hi Guys,

If you are going to tram the head, you really need to use the table surface, particularly if your mill is adjustable for nod as well as angle. Have you actually checked to see if the bed is truly flat and doesn't have any twist in it ? Once you have then you can tram the head in both planes and be reasonably sure it is square to the table.
Indicate the work holding device, in this case a vice, do not assume that a $1200.00 Kurt vice will hold the .0001" parallelism that people are looking for, doing so on a hobby mill is a tall order.
 
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