[jon003]

I've got a mill, and I've purchased a DRO. I've got no problem with fabricating the components that will hold the DRO to the mill, but I'm kind of unusure of the best way to drill and tap the actual cast iron base of the mill in order to attach my fixtures to hold the DRO.

Do you just use a hand drill and work very slowly and carefully?

Any tips you can give me on how to accomplish this well?

Thanks,

[Teyber12]

what mill do you have?

I had to drill some holes into the the bottum of my x3 table for home switches-

i just drilled a 1/8" hole, then a 5/16" or something hole in, (on my tabletop lowes drill press) then just tapped it. if you have a drill press, a x2 or similar, and some patience i imagine you can do the same.
p.s. i don't tap a lot so i did a lot of practice taps in plastic.

hope this helps

[jon003]

It is a G0619, which I thinks is considered a super X3 style.

Did you drill your holes with a hand drill?

[escott76]

I've got a mill, and I've purchased a DRO. I've got no problem with fabricating the components that will hold the DRO to the mill, but I'm kind of unusure of the best way to drill and tap the actual cast iron base of the mill in order to attach my fixtures to hold the DRO.

Do you just use a hand drill and work very slowly and carefully?

Any tips you can give me on how to accomplish this well?

Thanks,

Hand drill, work slowly and carefully. You can of course make guide blocks which will make things easier, if you want to get crazy fancy you can even press in drill guide bushings.
It should go without saying, but don't use the drill to tap. Again guide blocks can be a big help, but unless you used them to drill you won't be sure that the hole is straight to the face anyway. Go real slow, use good quality (read, not taps you buy at home depot or lowes) and tapping fluid. Back off and clear chips after every half turn or so. It will take longer, but you really don't want to have to try and remove a broken tap from your mill base.

[jalessi]

1. Use a automatic center punch to mark the position of the holes.

http://littlemachineshop.com/product...3553&category=

2. Drill holes using a tapping block with whatever drill you have available ( electric, battery operated cordless or drill press).

3. Using a tapping block tap the holes.

http://littlemachineshop.com/product...ProductID=2571

You can make a cheap tapping block on a drill press.

Jeff...

[jalessi]

escott76's directions are very good.

[jon003]

I think I'll make a tapping block and a guide for the drill bit, and use a hand drill to drill, followed by a hand tap.