# Lets Revisit this 'Tramming'



## Magnum (Sep 18, 2011)

It's like preventative maintenance on your car. If it's not done it can be costly. I think tramming is probably more important in machines that have a tilt head in making sure they are lined back up properly. For my CNC machine, I honestly have not had time to check the tram in probably a few months. time to check.

In the hobby field, material and time is not too bad. But I know we have sent parts out that have failed inspection, I am sure some were due in part to machine misalignment. For me I just had several parts running for over 5 hours today. I ran my DI across the plate so I new it was flat. If the machine was too far out of tram I just lost a lot of work and time. 

So guess it is time to go tram my machine and make sure it is still in tolerance


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## brucer (Sep 20, 2011)

if your squaring up material you have to make sure the head is trammed or your blocks will not be square... also if your deep hole drilling, the head has to be square with the table or your holes go out of round and out of location on the opposite side... if your milling to get close, or drilling shallow clearance holes i wouldnt bother with it actually..

 when i worked in a machine shop/ job shop and had to run a manual machine i would always check the machine on initial use, generally around .001-.0015... 

pretty much same for mold work, sometimes i would check the machine a couple times throughout the day... kind of depended on what i was doing, or what machine i was running.. mainly we would back drill ejector pin holes about 10inches deep in h-13, although not difficult, if the hole went out of location on the opposite side you were screwed when you drilled and reamed the ejector pin holes to size , because we drilled and reamed from the other side after heat treat..

 the cnc mills i've always ran we checked them periodically, but the main concern was backlash on those... i ran a couple twin spindle carbon cutter mills that we checked backlash and spindle squareness weekly on those. they were different animals compared to regular cnc mills though.  last year me and a maintenance guy checked a 1989 leblond makino mill, i ran this mill when it was new in 1989, the spindle was .002 out of square, pretty good for a machine that old.. we put bearings in it and it was within .0015, called it good.. i know that machine was ran pretty hard throughout its life...


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## Blogwitch (Sep 20, 2011)

I have already stated that I use one of the twin dial tramming aids, and whenever I start a new project, tramming the head and checking the vice jaws are parallel to the table movement are two jobs that I don't shirk on. It is good practice to keep everything aligned.

In the C-o-C (Crap-o-Cad) shown below shows exaggerated effects of being out of tram.

Once you start to ignore the signs, you will start to get ill fitting out of square parts or leaking joints.

A machine is only as good as the person operating it, if you ignore the basics, they will creep up on you and bite your bum when you least expect it.

Don't give it the chance.


John


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## Magnum (Sep 20, 2011)

Might I stir the pot some? ::


If you tilt the head on your mill at 45 DEG. Then run your DI down to the table and zero it, if you go from one end of the table to the other your DI will not move off of zero, but your machines head is still at 45 DEG?

Tramming is taking two points of reference from the "current" position of the head to determine its angle in relation to the bed.... 

See my confusion?





> author=DaveH link=topic=3624.msg26569#msg26569 date=1316522264
> Whyemier,
> 
> 
> ...


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## Magnum (Sep 20, 2011)

> author=DaveH link=topic=3624.msg26634#msg26634 date=1316561273
> 
> It is important to understand the difference between using a dti to tram the head, and using a dti to "level" the workpiece.



DOH! Workpiece... Darn it.. I need to stop speed reading.


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## Magnum (Sep 20, 2011)

> author=DaveH link=topic=3624.msg26641#msg26641 date=1316563200
> Found it http://hobby-machinist.com/index.php?topic=1723.msg10506#msg10506
> Some good info here about tramming.
> ;0
> DaveH



Thanks for going the extra mile... I'll try and read through it.

But you raised a good point. As I have moved my head across my vise at times to check to see if I had some chips under it (paranoid). But now I realize a "sweep" would have been more appropriate.


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## Tony Wells (Sep 20, 2011)

> author=Magnum link=topic=3624.msg26648#msg26648 date=1316564680
> 
> 
> > author=DaveH link=topic=3624.msg26641#msg26641 date=1316563200
> ...



Moving the head (moving the table, really) will tell you if the part, vise, parallel, or whatever, is running true, or parallel with the ways of the axis you are moving. A chip under the vise, etc. will show up as though you were seeing a incline, either up or down. 

Leaving the table stationary and sweeping the surface in question by rotating the DTI in the spindle will tell you if the spindle is perpendicular to that surface, whatever it is. A chip will show up on that test ONLY if the spindle is perpendicular to the table, and the chip has one side of the part elevated.

It's really two different tests.


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## bjmh46 (Sep 21, 2011)

> author=Whyemier link=topic=3624.msg26556#msg26556 date=1316515887
> 
> 
> > author=brucer link=topic=3624.msg26547#msg26547 date=1316495648
> ...



Whyemier,

I can't see inside your head to figure what you mean by referenced to the spindle. Forget the workpiece, what has to be done to insure flatness, is to set parallel, the plane of rotation of the spindle (bearings), and the plane of motion of the table.

Regards
Bob


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## November X-ray (Sep 21, 2011)

> author=Whyemier link=topic=3624.msg26651#msg26651 date=1316567709
> Goodnite we'll continue in the morrow.I gotta get up about 4:00am



Um, Doesn't Everyone???


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## bjmh46 (Sep 22, 2011)

> author=Whyemier link=topic=3624.msg26686#msg26686 date=1316634882
> Can't forget the workpiece. It will run parallel to the spindle and cutter if set up this way. Unless the table runs kitty wampus in the x axis.




You can clock the workpiece till the cows come home--get it perfect. If your table is out of tram, i.e. the plane of xy motion is not parallel to the plane of rotation of the spindle bearings, you will not machine flat and square. Clocking the workpiece while moving the table, or tramming the workpiece while rotating the spindle, it doesn't matter. You are still using the xy motion of the table to do the machining (with the exception of plunging with the quill motion) and if the conditions I stated are not met, you will not get flat and square.

Regards

Bob


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## bjmh46 (Sep 22, 2011)

Whyemier,

No offense taken! I stick with what I've stated so far. If you use the spindle rotation to sweep the workpiece, (tram) it (the workpiece) can be made perfectly parallel to the plane of rotation, and for all practical purposes perpendicular to the spindle axis. Then if you proceed to drill a hole and bore it with the quill motion, plunge a cutter, tap the hole, then all is well. As soon as you use the xy motion of the table to do your machining, you've introduced an error, if the spindle is not trammed to the table (xy motion). The degree of the error may be insignificant for the work you are doing , if so, all's well! I shoot for .001 max total error in a 9 inch diameter sweep. Sometimes I do a little better, but I don't accept worse. At the .001" error level, you can still detect heel drag in one direction if using a fly cutter. It's all a matter of what you are willing to accept for the class of work you do. After 40+ years of doing this, I've decided the best course of action is to make my machines as close as I can, and check often.

BTW, Pete's advice about "Machine Tool Reconditioning" is good advice. I bought mine back in the early 80's, and it's served me well. It will teach you that there are many sources of errors in machine tools, many of which are not intuitively obvious.

Regards
Bob


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## brucer (Sep 23, 2011)

> author=Tony Wells link=topic=3624.msg26650#msg26650 date=1316567391
> 
> 
> > author=Magnum link=topic=3624.msg26648#msg26648 date=1316564680
> ...




this is why i actually call it squaring the spindle... i've actually never called it tramming until i came here, because thats the term people were using here..

Whyemier, are you a good wood worker? have you ever heard of the term "Plum" this is basically what your doing, your adjusting the spindle centerline "Plum" to the Work Table.... at that point your mill table and spindle are square and perpendicular with each other, then you put your vise on the table, your back jaw (hard jaw) on vise should also be square and perpendicular with the spindle.. then when you locate a block of material in the vise, if it is saw cut, it doesnt matter if its square or not, when you cut it, the cut surface will be parallel with the world, then when you flip the surface you just cut and place it against the hard jaw, clamp your vise, if the block is firmly seated against the hard jaw, when you cut it ,the side to the hard jaw and the side you just cut will be square to each other....


now if your spindle was out of square/tram to the mill table when you started, the block you just cut would not be square..

hope this helps some....


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## Tony Wells (Sep 23, 2011)

Brucer, I'm with you. Tramming??? What is that? Taking the little tram ride from the parking lot at Six Flag to the gate? I never heard the word used in connection with machine shop work until reading some forums. I had to look it up, and sure enough, way down the list, it does have to do with machine alignment. We always just called it "sweeping" whether it was a vice, or the spindle on a Bridgeport or something along those lines.


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## bjmh46 (Sep 23, 2011)

Kind of like a regional thing. Tramming is common parlance in machine shops around here. Some expressions vary by company, such as "duck-board" vs. "chicken ladder".  (The nailed up lattice of pine boards that ease the pain of standing in front of a machine all day)

Bob


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## Chazz (Jan 9, 2012)

bjmh46 said:


> Kind of like a regional thing. Tramming is common parlance in machine shops around here. Some expressions vary by company, such as "duck-board" vs. "chicken ladder". (The nailed up lattice of pine boards that ease the pain of standing in front of a machine all day)
> 
> Bob



That's 'Old School'  they're called 'anti-fatigue matting' now.  

Our 9,000Lbs Miltronics Mill only gets trammed after the head has been moved off axis, the little 250Lb mill gets trammed about once a month.

Cheers,
Chazz


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## Shopdawg (Nov 3, 2014)

We had the outer race of a 6" tapered roller bearing that we would lay on the table. It had a perfectly ground surface for the DTI. You could sweep a full 360 degrees and not worry about jumping T-slots.

Kevin B.
(Shopdawg)


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