Hoffman Mechatronics
Bridgeport Mill J1 Rebuild
5.1 Ram Adapter RIR
The Ram Adapter allows you to tilt the J-Head forward and back through an arc of 90 degrees,
45 degrees up and 45 degrees down. It also provides you with the ability to rotate the J-Head
along the Z axis through an arc of 360 degrees.
5.1.1 Ram Adapter Removal
You will want to start by removing the J-Head from the Ram Adapter. Once you have the J-Head
removed, you can remove the Ram Adaptor by removing the 3 bolts and the pivot pin that secure
the Ram Adapter to the turret as shown in Figure 26 below. Save the pivot pin for last as it’s
easier to hold the Ram Adapter and tap out a single pin.
Ram Adapter
Ram
Figure 26 - Ram Adapter
5.1.2 Ram Adapter Inspection
My Ram Adapter was very difficult to remove, and required liberal use of a lubricating solvent,
and wiggling back and forth before it would come off the ram. Once it was off I could see that
the internal cavities of the Ram Adapter had acquired some rust and hardening of grease.
Cleaning the entire unit in a good solvent, then wire brushing the whole assembly went a long
way to freeing up the movement again. As most people do not move the Ram Adapter very
much, you will probably not see a lot of wear. My unit, though 42 years old and used quite
heavily had a very nice and tight slip fit during reassembly. I did polish the pivot surface with
some 320 grit paper and a sharpening stone to remove some of the surface rust, and to provide a
more slippery surface.
5.1.3 Ram Adaptor Reassembly
To reinstall the Ram Adapter you should lubricate the pivot surface and the pivot shaft well with
high quality grease. You can then slide the Ram Adapter into place and insert the pivot shaft.
Once the shaft is in place, the locking bolts can be inserted one by one to complete the assembly.
BPJ1RBLD_002
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January 31, 201111
