Boring bar holder for lathe

[JimM]

I've got some 12mm round shank boring bars that I want to use in my lathe but I currently don't have a suitable holder for the tooplost.

To knock together a makeshift holder would I be better to

1. Simply just drill out a 12mm hole through some square stock and then cross drill and tap for a couple of grub screws to hold the bar in place

2. Drill out the 12mm hole as before, but then slit cut along the length of the bore. Drill and tap a couple of holes to the side of the through bore so that the screws would clamp the holder on to the boring bar

Thanks

Jim

 

[kvom]

Here's what I did:

 

[JimM]

Thanks Kvom

That's eaxctly what I meant with option 1 - it's the slightly easier of the 2 and if it works that's good enough for me

Cheers

Jim

 

[kvom]

You will want to drill a small depression where the set screws touch to keep the bar secure in the holder.

 

[shred]

Some QCTP holders have a groove milled along the bottom of the slot. Those are intended to hold round-shank tooling like boring bars. Otherwise, I've done the drill-n-setscrew and it's been ok as well.

 

[David Morrow]

You will want to drill a small depression where the set screws touch to keep the bar secure in the holder.

I have a holder with a groove as noted above. I never drilled a depression or ground a flat on the bar and never had a problem. Most of my end mills are held in the holder with just a single, small set screw and never been a problem either... except when the user didn't tighten it properly. Initially I was very surprised that they would stay put but they've done just fine so far.