Question about tramming a bridgeport

[Asm109]

On the first cut, one parallel against the fixed jaw is good enough. Really you are machining the top surface to be square with the back vertical wall.
Then flip the part over with same face against the fixed jaw. Machine top.
Now you have two parallel faces and one square face.

 

[verbotenwhisky]

Sorry. It was added in and wasn’tproof read. It was supposed to read I trammed the head and was able to reach out about 5 inches from center when tramming to the table so about 10” of distance. Then I added in that I trammed the vise, what I meant was I trammed the vise along the x axis to the head. I just put that in the wrong part of my post.

Do you have any tips to tram off the vise? Should I tram off of a clamped parallel?

I had a Bridgeport that was driving me nuts with the same and it turned out to be wear in the table ways it slide farther to either side it issue would get worseit was in the X, the Y was Okay because the table had plenty of support in the Y. If you put some weight say your vice or rotary table on one end of the table, then run the table out that direction and run the process of traming it as you did previously, You may see your taper issue.

 

[verbotenwhisky]

I keep cutting a taper in the y axis. I haven’t had much time to investigate but it’s consistent. I need to double check tram. I’m using a 1/2 endmill on aluminum. I trammed it the. Tightend down then rechecked. Something could of slipped. The vise operates nice and looks like it hasn’t been damaged but it’s very old. It looks likea Bridgeport vise without the bridgeport name. I’ll give it all another once over see where I’m coming up.

This is all trying to square stock. It’s tapping the stock down against a parallel and using a copper wire on the moving jaw. I keep the first faced side against the stationary jaw the face the “top and bottom” sides still using the copper wire. Does this sound like the right process?

Oh wow, in the Y axis... when you tramed the head after you tightened the nod up did you check it again to see if the process of tightening it pulled it out some?

 

[verbotenwhisky]

Okay looks like you had it covered, sorry I should have realized the thread was advanced and read all the replies first....

 

[tq60]

Some steps to check.

Place DI in spindle set to measure the spindle to table.

Open the vice fully.

Clean surface of the vice with Scotch bright to insure just the vise.

Lock the spindle and sweep across the vice to make sure it is FLAT and parallel to table.

Assuming you trammed to table before.

Get a mic and double check parallels to verify straight and equal.

Locate a chunk of flat material and check it first to see if it is parallel top and bottom.

Place this in vise, on parallels, check with DI to confirm how it sits, make a sketch and document the 4 corners.

Also check the top of the fixed and moving jaws at both ends defore and after tightening and after cutting but before loosening.

Tighten vise and recheck.

Did you tap the part down to seat it?

Check again and document the 4 corners.

With light cuts, do the whole top, just enough to get the surface skimmed.

Measure and document again.

Everything should have measured same until you placed the test part.

All 4 corners of the test part should now be equal.

If at any point they were not, investigate why not.

If material in vise was not equal before cutting, but the relative position changed when tightened the vice is moving.

This is a troubleshooting process.

Sent from my SM-G781V using Tapatalk

 

[MyLilMule]

I recommend this technique.

 

[D.sebens]

I recommend this technique.

That’s the one I am following.

 

[Firstram]

One thing I like to do when squaring stock is take a 0.2" deep side cut on #5 just after #4. This gives you a square surface to sit on the parallel to machine the 2 ends.

 

[Gaffer]

Made good progress! I got 7 of the eight measurements(measuring all faces of the cube on each end) to .003” difference and the other to .004”. I think my issue is I need to figure out how hard to tap the part right and when. I think it’s bouncing up a bit when tapping it in.

I have two questions, one should I tighten it fully before tapping the part down? Two, when squaring stock should I use two parallels or one if the bottom face isn’t machined yet? I assume use two but it’s possible it won’t touch both if out of square?

I’ll keep fiddling with it. It seems to be operator error.

 

[D.sebens]

My vise is indicated in (at least well enough). My question is when and how hard to tap the stock down to seat it on parallels or the vice bottom. I was tapping it before fully tightening and I think it was bouncing back up