filling my banjo!

[Lee Alkureishi]

Hi all,

In in the process of making a wood bowl lathe, and am currently working on the banjo. it's constructed of 2 pieces of 5/16" thick 3" iron pipe, welded at 90 degrees. The horizontal section is welded to 2pieces of angle iron, which will ride on the ways, and measures 19" long.

The vertical section is 12" tall, and at the top will be welded my tool holder, which is a 6" long section of 1.5" stainless steel rod with a 1" bore. I'd like to set the tool holder 3" inside the larger pipe section, but can't see any good way to secure it there.

I'm thinking the best way will be to tack weld it in place, weld the top section that i can access, then pour concrete into the vertical pipe section. That way, the concrete will secure it further, and also provide mass/vibration dampening for the banjo.

Can anyone advise if there's a problem with this approach, or a better way to do it?

Thanks in advance,

Lee

[Dennis Ford]

An alternative:
Weld a circular disk to the bottom of the 1.5" tube and a donut shaped disk 3" up from the bottom. The OD of these disks should be a snug fit into the 3" pipe. Slide the bottom disk into the 3" pipe until the donut is flush and weld the donut to the top of 3" pipe.

If you go with the concrete; use a high strength mix.

[Lee Alkureishi]

Dennis, that's a fantastic idea - I never would have thought of that.

I'd like to use that idea. I'm wondering, though, if I still need to find a way to dampen vibration in the pipe? The banjo + tool holder will stand 15" tall, and the lathe will have a 34" swing. I've read that vibration can be a problem in some of the bigger homemade banjos.

If I need to use concrete, no problem. I'm just wondering if there's a more elegant solution...

Thanks again