Tramming a Bridgeport

[Ho55]

Does anyone have any tips on tramming a bridgeport 2J2 head?
On my first pass it was taking me an hour. Partly due to not having the best dial gauge, and the adaptor ( i used a mag block on the under face of the spindle)
I kept overshooting, took ages to work out which way to go.
X or Y first?

 

[Brad93]

Does anyone have any tips on tramming a bridgeport 2J2 head?
On my first pass it was taking me an hour. Partly due to not having the best dial gauge, and the adaptor ( i used a mag block on the under face of the spindle)
I kept overshooting, took ages to work out which way to go.
X or Y first?

Bring quill down flat to table first to get you close.

 

[tigdlo]

How close are you getting and how for from the spindle are you measuring?

 

[Ho55]

Well i've got it pretty good now, but i was looking for tips to make it easier next time. Right now i dont want to move the head again
Spindle was about 200mm above bed.

 

[Ho55]

Bring quill down flat to table first to get you close.

Ahh good tip!

 

[tigdlo]

Well i've got it pretty good now, but i was looking for tips to make it easier next time. Right now i dont want to move the head again
Spindle was about 200mm above bed.

I was interested in the size of the arc you are sweeping when measuring and how far out it was to see if your expectations were reasonable, a few microns over a 300mm radius from the spindle could be perfectly reasonable, others with bridgeports could give you an idea of what to expect.

 

[dieselsamurai]

i use a brake disk to tram mine , accurate enough for what i do

 

[minimutly]

I'm a sheet of glass person.

 

[addjunkie]

You can buy tramming tools…I use a brake disc too! Have in the past used a ships porthole glass as a flat surface.

 

[dieselsamurai]

I was going to get one of these but the brake disc gives more distance from the center of the spindle and a lot cheaper !

 

[oldbikedavey]

Used a huge outer race from a Caterpillar tractor to indicate my Bridgeport in for parallelism.
Haven't dared to check it again....

 

[dieselsamurai]

A huge outer bearing ring would be ideal , just need to find one !

 

[Barking Mat]

Took me ages the first time, and the second.

Then I got my mate who's a lathe / mill man, and he explained it very simply.

'Split the difference' comes to mind.

 

[Smouser]

i use a brake disk to tram mine , accurate enough for what i do

View attachment 494362

I have a big bearing I use.

The table has got too many dings in it to do without.

 

[Brad93]

There was a nice scrap 12" bearing sat on the desk at the local bearing suppliers yesterday