Lets Revisit this 'Tramming'

[Magnum]

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

 

[brucer]

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...

 

[Blogwitch]

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

 

[Magnum]

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,

author=Whyemier link=topic=3624.msg26556#msg26556 date=1316515887
Correct me if I'm wrong; If I DI the material both longitudinally and laterally on the table, using the spindle as my point of reference. Wouldn't that ensure I would be square? Seems to me if I am square to the spindle and thus to my cutting tool, I would be square.

Yep, you would. Every time you use the mill you want to do that. You will also have to shim the work piece every time you use the mill, becomes a bit of a pita. What about when you use the vice - you don't want to shim that all the time or the workpiece in it.

Plus sometimes it is nice to know you machine, it will help with the machining.

;0
DaveH

 

[Magnum]

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.

 

[Magnum]

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.

 

[Tony Wells]

author=Magnum link=topic=3624.msg26648#msg26648 date=1316564680

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.

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.

 

[bjmh46]

author=Whyemier link=topic=3624.msg26556#msg26556 date=1316515887

author=brucer link=topic=3624.msg26547#msg26547 date=1316495648
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..

Correct me if I'm wrong; If I DI the material both longitudinally and laterally on the table, using the spindle as my point of reference. Wouldn't that ensure I would be square? Seems to me if I am square to the spindle and thus to my cutting tool, I would be square.

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

 

[November X-ray]

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???

 

[bjmh46]

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