# I'm curious about my mill tram



## Aukai (Oct 16, 2021)

I put a Copmac 513 10ths dial indicator in a collet chuck. Full X travel on a 50" table with 0 to the right +.002. If I split the table 0 the indicator, and go 12" table right I get  +.0005. I return to center, and 0 repeats, then 12" left I get +.001. My noodle is not comprehending, I thought I saved a traming guide from here but cant find it. The Y in, and out is less than .0005.


----------



## mksj (Oct 17, 2021)

That is about as close as you are going to get on a 50" table. Should also be a spec sheet with actual values and tolerance


----------



## Aukai (Oct 17, 2021)

I do have that, I'll look at it tomorrow. All I've done is cranked the head back to the 0, and this is the reading, much easier than the Grizzly actually. My machinist square looks pretty air tight against the spindle on the X, and Z too.


----------



## Eddyde (Oct 17, 2021)

As you crank the table away from the center it will start to drop from the increasing weight on that end thus the spot under the spindle will rise.


----------



## Asm109 (Oct 17, 2021)

To me, tram means the spindle axis is perpendicular to the table top.  You are measuring how parallel the table top is to the ways. You also capture any slop in the ways (there must be some) as the table weight gets overhung at the extremes of travel.


----------



## Winegrower (Oct 17, 2021)

I agree with Asm109.   No matter the head inclination, just holding an indicator and moving the table past it will show 0 change if the table is flat, but won’t measure anything about head alignment.


----------



## MrWhoopee (Oct 17, 2021)

Agree with the others, tram is considered to be perpendicularity of the spindle to the table. What you seem to be checking is the repeatability of the table travel. For the distances you are measuring you really can't expect better than what you are seeing. That's why they made jig borers.

edit: using a precision square against the quill is a good place to start tramming the head, but it needs to be finished by sweeping the table with an indicator.


----------



## markba633csi (Oct 17, 2021)

Remember too that tables can warp from the action of the t-bolts stretching the metal of the slots.
Good reason not to overtighten
Your measurements are actually quite good for a table that long
-M


----------



## Aukai (Oct 17, 2021)

One of the dial indicators on the Edge Pro Tram is broken, I've used it only a couple of times. The bezel separated from the face, and won't 0. My Noga spindle mount has a kinda short sweep, but I'll see what I come up with. Thank you for the replies.


----------



## Aukai (Oct 17, 2021)

So, I trammed the X, then the nod, and X went out. I got it back, and have a 0 sweep 360*,. The Noga only has ~ 5" of sweep, hopefully that does it.


----------



## Winegrower (Oct 17, 2021)

Sounds about as good as possible with what you’re using.   Now repeat by checking the vise bed.


----------



## Aukai (Oct 17, 2021)

I'm not sure if I want to mount the 6" kurt, or the 4" Glacern, and what placement on the table.


----------



## Aukai (Oct 17, 2021)

My friends came over to look at the new mill, one of them is the Community Collage instructor(ret) for the machine shop. He asked what vise I was going to use, and we ended up using the Kurt 6". He saw that I had the swivel base on the side as well, and wanted to install it, so I gave in to peer pressure, and it is on. It can be removed if I don't like it. I also made use of the new set of precision ground stones I got from Lance, awesome technology, and easy to figure out, you can see the high spots. So, the table is trammed, the vise is trammed, and I have 20 handles to drill, but I don't want to get the mill dirty, OMG


----------



## jwmelvin (Oct 17, 2021)

Looks great but I think you should get it dirty.


----------



## Illinoyance (Oct 18, 2021)

Take off the swivel base unless you frequently need to make angled cuts.  I have keys in the bottom of my vise.  That way I don't have to tram the vise each time I mount it.  Usually I just loosen the T-bolts and slide the vise to the end of the table when using the rotary table or indexer.  Shars have keys that are considerably less expensive than Kurt.  My swivel base sits on a shelf.  I do not remember the last time I needed it.


----------



## Aukai (Oct 18, 2021)

Yes I've had it for awhile, and not needed it, so I just followed along. I may leave it just to see if it's there I might use it, we'll see how it goes


----------



## Winegrower (Oct 18, 2021)

I use the swivel base when milling for indexable tool holders.  It makes it easy to mill for triangle inserts, for example.  And occasionally I will rotate 90 to use the X axis power feed on what would otherwise be a lot of Y axis manual cranking.    It’s a nice big compass rose, big divisions, and easy to get to small fractions of a degree, say half or fourths.


----------



## Winegrower (Oct 18, 2021)

To get a good level of accuracy with the swivel table, set the index to zero degrees exactly, and tighten the vise bolts to the swivel.  Then move the whole vise and assembly as a pair while tramming .  Then tighten the swivel bolts to the table.

Try this, loosen the vise to swivel bolts then turn 90 degrees exactly on the swivel scale and run an indicator in the Y direction.   I think you will be surprised at how accurate this is.


----------



## Aukai (Oct 18, 2021)

OK, I'll give that a try also


----------



## rb67mustang (Oct 18, 2021)

Aukai said:


> I'm not sure if I want to mount the 6" kurt, or the 4" Glacern, and what placement on the table.


I wouldn't use a 4" vise on that machine, a 6" kurt vise, or a no name copy is the way to go. The shop I worked at made their own aluminum jaws for them as well as steel jaws 4 inches tall for special jobs. We made vise stops that could be clamped on the back jaw and we made vise stops that bolted to the back of the vise. Here's a link to show you what I mean. https://www.ebay.com/itm/324491077830?_trkparms=amclksrc=ITM&aid=1110006&algo=HOMESPLICE.SIM&ao=1&asc=20200818143230&meid=2f829eca75ac4955a3a989632fe4342c&pid=101224&rk=2&rkt=5&sd=324128905162&itm=324491077830&pmt=1&noa=1&pg=2047675&algv=DefaultOrganicWeb&brand=HHIP&_trksid=p2047675.c101224.m-1


----------



## rb67mustang (Oct 18, 2021)

Here's one of the vise stops I mentioned. It's beat up, but it's quick & easy to make. This one is made from a 3/8" x 7/8" cold rolled bar and it has two 8-32 Allen cap screws to hold it in place on the back jaw. I prefer to make these out of mild steel so if an end mill should contact it, the end mill isn't damaged.


----------



## rb67mustang (Oct 18, 2021)

Aukai said:


> One of the dial indicators on the Edge Pro Tram is broken, I've used it only a couple of times. The bezel separated from the face, and won't 0. My Noga spindle mount has a kinda short sweep, but I'll see what I come up with. Thank you for the replies.


Over my time in machine shop, I bought all kinds of indicator holders and spent lots of money in the process. The way many of us trammed in Bridgeport heads was using a soft steel rod 6 to 8 inches long. On one end, make a 90 bend so you have about an inch and a half to hold it with a collet or a drill chuck. Then use an indicator clamp that fits the rod and holds the indicator. Then sweep the table until the heads trammed. https://www.ebay.com/itm/303018822331?hash=item468d544abb:g:o-YAAOSw11BcL336

It's almost 21 years since I worked as a machinist. So many of my tools were sold because I thought I'd never use them again, and now I have a Bridgeport and need the tools I once had.


----------

