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Bridgeport Rigid Head/Boss Head Tram

mtparker18

Plastic
Joined
Apr 3, 2013
Location
Pittsburgh
Hello,

I have a boss R2E3 machine, and I've been getting some back cutting with larger diameter cutters. Upon checking the tram, it seems that I'm `.0025" out of trams. Does anyone know how to tram these machines? Does the head need to be shimmed? That's the only thing I can think of, unless I'm missing an adjustment somewhere. Pictures of what I'm talking about are attached.

Thanks in advance. tram.jpghead.jpg
 
Try leveling the machine. I'm not familiar with this particular machine but with large machines the base can twist. Or it could be just worn out. If you move the table, does the tram change with it?
 
You may want to check out this website: Bridgeport ==> Series II

There should be an attachment point for the head and that should have adjustments. Your picture don't show the head. After looking at photos of the Boss R2E3 on the web I don't think Leveling the machine is going to help much although it won't hurt it. I have two Series II Specials here that are obviously not level to anything.
 
the front to back alignment would need to be scraped in where the face of the spindle housing attaches to the "Z" housing. The side to side alignment, however is adjusted by an eccentric nut on the lower right side of the mounting face.
 
You've made a lot of "assumptions".

1. IMHO, your method of tramming sucks. I hate those types of aids and find them to me in error most of the time.
2. Your head might by fine, it's the knee that's off.
3. Did you check the quill for play the last time you had a crash?

This is the best head tramming thread so far. Use a single test indicator and "sweep" the tabele: https://www.practicalmachinist.com/...nge-mills-and-lathes/tramming-bp-head-117024/

JR
 
Hello,

I have a boss R2E3 machine, and I've been getting some back cutting with larger diameter cutters. Upon checking the tram, it seems that I'm `.0025" out of trams. Does anyone know how to tram these machines? Does the head need to be shimmed? That's the only thing I can think of, unless I'm missing an adjustment somewhere. Pictures of what I'm talking about are attached.

Thanks in advance. View attachment 238889View attachment 238890
.
.
double indicator setup normally calibrate you zero indicator 1 over a gage block and rotate spindle so indicator 2 over same spot and zero the 2nd one. usually can get within .0001", final tram measurement just look at only indicator 1 if you worried about a .0001" error
.
if machine has no adjustment then you might need to use shims where it bolts together. thickness gage or feeler gage stock comes
.0010", .0012" (.03mm), .0015, etc
by using .0010 on one side and .0012 on other side thats .0002 difference so you can shim by mixing shims like
2 each .0012 one one side and .0010/.0015 to get .0001 difference
 








 
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