johnm
07-11-2007, 06:59 PM
Folks -
My Father in Law make McGyver look like a rube. We just got a small job for turning some columns that were just a tad long for our SB lathe. We'd planned on extending the bed to be able to do 8' long turnings, so this seemed like the right time.
I gave my FIL some measured drawings and good pictures and he welded up and assembled an extension bed (I helped a little - I got him coffee...) Then, he fabbed up a jackshaft setup and separate drive motor to reduce the lathe turning speed - a serious issue for us as the existing low speed of 600 RPM would be scary with large diameter turnings
Bottom line is that the new speed reduction setup drops the rotation speed to about 120 RPM and we have the capacity to do 98" long turnings.
I have attached several photos here - some of you wanted greater detail from my earlier post. I took the lathe drive spur, removed the center spur, and aligned the laser to shoot through the center of the spur hole to align with the tip of the live center on the tailstock at the other end of the lathe. This gave me, I think, a pretty good method to align the bed extension to the existing lathe bed. The blurry photo shows a long shot of the laser shooting through the drive head to the other end of the bed and the tail stock. I still need to do a bit of adjustment in having everything aligned with the SB spindle, but for this job I think we’re good.
The speed reduction is a small 1550 RPM motor running through a jackshaft, then driving a pulley attached to the lathe spindle.
I didn't disconnect the main lathe drive motor - I can still use it for sanding, but I unplug it in low speed operation. It only ends up turning about 80 RPM so I didn't think this would cause any trouble.
Now if I can just come up with stepper and the trim to do index work...
If any of you want a more detailed description or pics, etc. drop me a note.
John
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300
301
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303
My Father in Law make McGyver look like a rube. We just got a small job for turning some columns that were just a tad long for our SB lathe. We'd planned on extending the bed to be able to do 8' long turnings, so this seemed like the right time.
I gave my FIL some measured drawings and good pictures and he welded up and assembled an extension bed (I helped a little - I got him coffee...) Then, he fabbed up a jackshaft setup and separate drive motor to reduce the lathe turning speed - a serious issue for us as the existing low speed of 600 RPM would be scary with large diameter turnings
Bottom line is that the new speed reduction setup drops the rotation speed to about 120 RPM and we have the capacity to do 98" long turnings.
I have attached several photos here - some of you wanted greater detail from my earlier post. I took the lathe drive spur, removed the center spur, and aligned the laser to shoot through the center of the spur hole to align with the tip of the live center on the tailstock at the other end of the lathe. This gave me, I think, a pretty good method to align the bed extension to the existing lathe bed. The blurry photo shows a long shot of the laser shooting through the drive head to the other end of the bed and the tail stock. I still need to do a bit of adjustment in having everything aligned with the SB spindle, but for this job I think we’re good.
The speed reduction is a small 1550 RPM motor running through a jackshaft, then driving a pulley attached to the lathe spindle.
I didn't disconnect the main lathe drive motor - I can still use it for sanding, but I unplug it in low speed operation. It only ends up turning about 80 RPM so I didn't think this would cause any trouble.
Now if I can just come up with stepper and the trim to do index work...
If any of you want a more detailed description or pics, etc. drop me a note.
John
299
300
301
302
303