Tool Post Boring Bar Holder For H.F. 9" X 20" Lathe (UpDate)

[rossbotics]

After making the 2-way tool post for the Harbor Freight 9” X20” lathe that I previously posted a few days ago I discovered I couldn’t bore a hole without grinding up a special cutting tool which I thought would be a royal pain in the you know what, so I decided to make a boring bar holder for the tool post.

The boring bar holder accepts standard 1/2” shank boring bars (Carbide or HSS) and is made from O-1 steel, the tool holder was hardened,tempered and ground, the tool holder has a 5/16” square tang that fits into either slot of the tool post and is secured in place by the set screws that holds the 5/16” square HSS tool bits.

I want be doing a lot of boring but I know if I didn’t make one I would soon be kicking my butt for not doing so.

Below you will find a couple photos of the machining process and the finished tool, I have also included a detailed drawing.

As always thanks for looking and happy machining

Doug

[DIYer]

Thanks rossbotics! We've added your Boring Bar Holder to our Machining category,
as well as to your builder page: rossbotics's Homemade Tools. Your receipt:

Boring Bar Holder by rossbotics

tags: holder, boring bar

[olderdan]

Nicely done Doug, have you also seen the triangular toolpost on the Stepperhead lathe, I thought that was pretty cool too.

[mfslater]

Why didn't you save yourself a toolholder and make the whole setup more rigid by fitting a steel block directly onto the toolholder post on the compound and drilling the 1/2" hole in that? It would have been closer to the center of the toolholder post and less likely to pivot away from the workpiece when boring. At present, the whole setup will pivot away under pressure during a boring operation resulting in a bellmouthed bore.

The best sort of boring setup here would be a tall steel block on the cross-slide held down by long t-bolts. The lower face must have a lip that drops over the left-hand edge of the crosslide and prevents the setup from pivoting. The 1/2" hole is then bored directly from the headstock and is guaranteed to be on center height.

[rossbotics]

Didn't want to

[crazypj]

I needed to do a small bore and made something very similar. Milled 'tang' onto a steel block (unknown material grade) Just drilled a half inch hole by holding drill in lathe chuck and using saddle to feed material. Dilled and tapped for a few 6mm bolts, 1/2" slid in but did need modifying to get correct centre height (cheap Chinese brazed carbide, needed modifying to be usable )