Here is how I mounted my igaging DRO on my J Head:
There are two half inch NPT drain holes in the back of the table. One had a spigot the other a plastic plug. I removed both.
I used two half x three eights NPT bushings and two three eights plugs (galvanized). I tightened the plugs into the bushings then cut them off flush with the bushing face using a hacksaw.
I then chucked the bushings in the lathe and faced them off. Then, while still in the lathe, I drilled and quarter twenty tapped both.
These two fittings were then wrenched into the drain holes in the back of the table and the igaging DRO rail was attached using quarter-twenty button head screws. One end of the rail has a hole but it was necessary to drill into the other end. When drilling you will short out the grid so, after drilling, take a new single edge razor blade and cut the grid. This will fix the short.
Next I milled a piece of 2"x .5" flat scrap to fit between the saddle and the sending unit leaving enough room for three .5"diameter neobium wafer magnets. I then attached the milled piece to the saddle using Devcon two ton epoxy.
After the epoxy cured I attached the sending unit to the milled piece using the three magnets (two or even one of these powerful magnets would probably do just fine).
That's it. All done without drilling or tapping any holes in the machine and not altering it in any way.
There are two half inch NPT drain holes in the back of the table. One had a spigot the other a plastic plug. I removed both.
I used two half x three eights NPT bushings and two three eights plugs (galvanized). I tightened the plugs into the bushings then cut them off flush with the bushing face using a hacksaw.
I then chucked the bushings in the lathe and faced them off. Then, while still in the lathe, I drilled and quarter twenty tapped both.
These two fittings were then wrenched into the drain holes in the back of the table and the igaging DRO rail was attached using quarter-twenty button head screws. One end of the rail has a hole but it was necessary to drill into the other end. When drilling you will short out the grid so, after drilling, take a new single edge razor blade and cut the grid. This will fix the short.
Next I milled a piece of 2"x .5" flat scrap to fit between the saddle and the sending unit leaving enough room for three .5"diameter neobium wafer magnets. I then attached the milled piece to the saddle using Devcon two ton epoxy.
After the epoxy cured I attached the sending unit to the milled piece using the three magnets (two or even one of these powerful magnets would probably do just fine).
That's it. All done without drilling or tapping any holes in the machine and not altering it in any way.