Deep boring

[bpimm]

This may be a bit off topic because of the material, I need to bore a tapered then strait hole 10.5" deep in Black Walnut. I have already turned the OD and bored a 2.5" hole to depth with a Forstner bit. I have a 5/8" boring bar but it's only 7" long. working with wood would it be strong enough to make an extension to get it out to the 10.5"? I am building a steady rest using skateboard wheels to keep the surface damage to a minimum. The hole tapers from 2.5" to 4.25" in the first 4.5" then stays at 4.25" for the remainder of the hole and it has to be done through the 2.5" hole.

Any ideas are welcome.

The project is a Black Walnut artillery projectile Urn for my Uncle who passed away last week, he was retired Army and My dad and I thought this would be fitting for him, also the black walnut blank I'm using came from a tree we had to take down in My Great Grandmothers back yard where my Uncle grew up playing in the tree. The fuse is Maple for contrast and came from a tree in My Dad's yard.

The flange on the back is unfinished, just a place to grab with the 4 jaw chuck.

Thanks
Brian

 

[eac67gt]

This looks like one member Gary Max would be a good source for.

Ed

 

[Syaminab]

This may be a bit off topic because of the material, I need to bore a tapered then strait hole 10.5" deep in Black Walnut. I have already turned the OD and bored a 2.5" hole to depth with a Forstner bit. I have a 5/8" boring bar but it's only 7" long. working with wood would it be strong enough to make an extension to get it out to the 10.5"? I am building a steady rest using skateboard wheels to keep the surface damage to a minimum. The hole tapers from 2.5" to 4.25" in the first 4.5" then stays at 4.25" for the remainder of the hole and it has to be done through the 2.5" hole.

Any ideas are welcome.

The project is a Black Walnut artillery projectile Urn for my Uncle who passed away last week, he was retired Army and My dad and I thought this would be fitting for him, also the black walnut blank I'm using came from a tree we had to take down in My Great Grandmothers back yard where my Uncle grew up playing in the tree. The fuse is Maple for contrast and came from a tree in My Dad's yard.
View attachment 48858
The flange on the back is unfinished, just a place to grab with the 4 jaw chuck.

Thanks
Brian

That is very Kind of you... My advise would be that if you are taking the time to do a steady rest, you might want to make a boring bar, with a 2" cold roll and weld a bit at the end. I make them all the time and they work fine on metals, I think it will work fine on wood. Specially if you point it downwards a little.

 

[bpimm]

Thanks Syaminab for the idea, I modified it a little, I used 1" drill rod, it's a small lathe, and made it mount in the tool holder and accept a standard .375" tool in the end. Hope it works, I need to build the steady rest before I can test it.

 

[Syaminab]

Thanks Syaminab for the idea, I modified it a little, I used 1" drill rod, it's a small lathe, and made it mount in the tool holder and accept a standard .375" tool in the end. Hope it works, I need to build the steady rest before I can test it.

View attachment 49296

That is a beautiful boring bar, worth of keeping for later jobs. If you can add an adjustable counter wheel you can make it antivibratory. Congratulations!

 

[bpimm]

That is a beautiful boring bar, worth of keeping for later jobs. If you can add an adjustable counter wheel you can make it antivibratory. Congratulations!

Thanks, I thought if I'm going to build something I should build it good enough to keep. Can you explain "adjustable counter wheel"? I'm not familiar with that term. I'm not a machinist that may be why.

 

[Syaminab]

Thanks, I thought if I'm going to build something I should build it good enough to keep. Can you explain "adjustable counter wheel"? I'm not familiar with that term. I'm not a machinist that may be why.

Well, by adding an adjustable wheel that will roll on the opposite side , a bit behind the bit and adjust it on the inside imagine a steady rest for the inside, rolling over the surface just machined, will dampen the cut and you get better finish.
regards

 

[bpimm]

Well, by adding an adjustable wheel that will roll on the opposite side , a bit behind the bit and adjust it on the inside imagine a steady rest for the inside, rolling over the surface just machined, will dampen the cut and you get better finish.
regards

Got it, Thanks. That wouldn't be hard to do.

 

[llarson]

I've had good result making a bar out of heavy wall tubing, welding the tool holder part on the end, generally with a fairly long register fit instead of butt welding, and filling the remainder of the tube with lead. Preheating the tube before melting the lead into it helps prevent voids in the pour.

 

[bpimm]

Would the lead filled tubing be less prone to vibration than the drill rod? I would think it would be denser so the resonance frequency should be lower and the lead should be better at damping the vibration than the solid steel would. Is my thinking on this right?

Brian