2009-03-07 Boring Bar Fabrication

Opening image of the finished item, a home made boring bar from W1 3/8" diameter drill rod, proceeding through facing, center drilling, rough/finish turning, produced on a Grizzly G8688 mini-lathe.

After finishing filing, heat treating and a quick 'n dirty honing, a piece of aluminum scrap becomes a precision-bored piece of scrap!

Happy! Happy! Happy!

Bore! Bore! Bore!

Category:

Science & Technology

Tags:

• mini-lathe
• bore
• boring
• drill
• rod
• center
• drilling
• facing
• turning

[UpcomingJedi]

Have you used it to cut threads? How do you know what is the spindle speed, is the speed control labeled somehow?

[jlg4880]

@UpcomingJedi

It's not the correct form/profile to cut screw threads. Cutting threads, internal or external, is something I've yet to attempt.

The lathe uses a DC motor with a digital speed control, rather than belts/pulleys so spindle speed isn't that critical an issue.

The larger, heavier & more rigid machines that use belts & pulleys for spindle speed have appeal, but there's simply no way to accommodate one in my apartment.

[fall22123]

Why did you make your own when you can buy them so cheap? Just curious. 

[jlg4880]

@fall22123

Simply because the commercially-made ones I had were too big to fit t he starter hole.

[MuellerNick]

At 3:37: Next time, tighten your QCTP. :-)

[jlg4880]

@MuellerNick

Yeah...That tool post kept working its way loose.

[jlg4880]

@Guds777

You're absolutely right. I didn't have the QCTP locked down properly--had a tendency to work loose until it broke in--and the machine's on a particle board (sawdust & glue) table. I'm worried that drilling holes in it will make the table disintegrate even faster...

[Guds777]

your machine is shaking to much, i think you need to level it and fasten it to the table.

[jlg4880]

@jameasun

Only because I didn't have a live center at the time I was making the boring bar. Kept forgetting to order one for the lathe. I've finally remembered to order one, which should arrive within a few days.

[jameasun]

So just out of curiosity, why did you choose to use a dead center instead of a live one?