Turning to capacity on SS

[scollins]

I will be turning a 16" x 30" pedestal on my SS. It will be constructed from (10) 3" thick staves. It will be ~1/2" from round to start out (used a cool geometry trick from http://en.wikipedia.org/wiki/Decagon to match the stave material to my pattern), if I don't bevel the miters after glue up. It should be fairly, well balanced. No clue as to the weight of the mahogany.

Has anyone turned anything this big on their SS? I don't think that it will be out of balance enough to make the SS dance, but I am thinking about sand bagging the legs to be sure that I don't have to worry about the mass of the turning and a "dancing" SS. I will probably use a face plate to mount the blank.

Any advice before flipping the switch will be appreciated.

5-16-11
I appreciate the suggestions, but what I am really looking for is has anyone here turned anything that big on a SS?

I can borrow a Nova or probably even a monster Oneway, but it would be better to do it at my leisure on my machine and I am curious if the SS will do it. I used the decagon trick to size my material to be sure that I had the thickness that I needed for the beads and coves that the turning will require so thinner material is not an option. I am competent enough in my skills that I believe that the blank will run smoothly and as true as possible or I would not even consider putting it on the lathe. I'll look up the mahogany weight later today and try to calculate the weight. Turning it in sections is an option as part of the base is too big for the lathe and will have to be shaped with the band saw and router.

Pics will be a definite for this project. I set up a jig yesterday to use the insert on my table saw as the pivot to run the 78" top thru my bandsaw. I still have to make clamps to glue up the top blank.

5-25-11
Talked to SS and was assured that it should not be a problem. Just scored a speed reducer, supposedly new, in the original packaging so that just turned on the green light for sure. Mahogany is around 3.25 lbs/BF so the weight will be less than 40 lbs. Hopefully, I can get the wood today and do the initial milling so it can aclimate to my shop.

10-28-11
Photos are posted further down in the thread. I should have asked for advice on adding the photos so I apologize that they are out of order. Number 12, 13, 14 and 10 show the progress thru the project.

[algale]

I've got no advice but would ask that you post a few pics of your progress.

[henecle]

The largest standard Shopsmith faceplate is 6", given the size and weight of the object I wouldn't think that would be big enough. Maybe some type of custom jig or an adaptation of the 12" sanding disk with mounting holes drilled. There are more experienced turners in the community who may have suggestions. Safety equipment goes with out saying...

[pennview]

That's a big, heavy chunk of wood and too large for even the slowest speed on your Shopsmith. With everything right on the Shopsmith, that's 700 RPM, but it's likely higher. The slowest speed on mine, measured with a tach, was about 900 RPM. If you calculate the rim speed of the column, I think it will make you nervous. I'd not want to flip the switch.

It would be a bit of extra work, but likely much safer, if you constructed a type of tool holder so that you could use a router and straight bit for truing up the column. Attach a faceplate to one end of the column and bore a recess in the other end to accept a live center. Then make a fixture attached to the Shopsmith carriage to hold a router. Slide the carriage and router back and forth while turning the column by hand -- never turn on the Shopsmith. Then attach a belt sander to the fixture to clean up the column.

[justplaingoofy]

That's got me thinkin...
If I were gonna try something that huge, I'd see if I could find a 9" or so v-belt pully and fasten it to the end of my project, shimming it to get the pulley to run as true as needed. Then I'd take the 1/4HP 1725rpm motor off my old delta drill press with the 4-step pulley on it, and rig it up on a board and drive the work with that off the back side of the SS.

[greitz]

Hopefully you have a Shopsmith Speed Reducer? If I remember correctly, that would reduce the speed down to ca. 100 rpm, which would be much safer.

I'd mount the piece, align the toolrest close to it and mark all the high spots, then use a handheld belt sander (or a rasp or plane) to remove the high spots. Repeat until the piece is within ca. 1/8" of being completely round. THEN turn on the power (with the speed reducer).

Yeah, a lot of manual labor, but better than a hospital visit.

If you increase the number of staves, they can be thinner (and less total weight), and the piece will start out rounder as well.

Gary

[terrydowning]

What Gary and others have said.

Slow is not slow enough for an item that large. A larger faceplate would also be advisable.

Last but not least. STAND OFF TO THE SIDE WHEN POWERING UP AND BE READY TO POWER DOWN IMMEDIATELY! Don't stand in front of it until you are sure that it will not fly off at you.

I had a 6 X 4 inch long green oak blank start my SS walking and bouncing at the lowest speed. Shortly after the dance started it was thrown from the faceplate as my attaching screws were not long enough to counter the force. It missed me by that much ||.

[scollins]

With the speed reducer, one can turn a 15X24" cylinder w/o modifications or trickery. I actually mounted a 15x27" approx. 65# cylinder with trickery.

[rdewinter]

Be careful of the slightest catch with something that big. Two days ago I had a 2"x2"x9" hardwood blank chucked into the jaws of my Barracuda2 lathe chuck and the end supported in a OneWay live center. The lather speed was set at slow on the speed dial of my SS.

During rounding operation, I must have gone a little deep and it caught. The catch ripped the blank out of the chuck jaws and threw it directly at me. Thankfully, I had on my face shield and I took a direct hit in the face shield. I never saw it coming it happened so fast. Thankfully, I was not hurt, but certainly shook up.

Obviously, it was my fault for not apparently securing the blank in the chuck correctly. The moral of this story is.........Always wear a face shield.

[scollins]

I actually ended up turning the blank on a 20" Laguna. Satisfaction is not having it fit on a 20" lathe either. It would have fit on the SS provided that I routed a groove on the tail stock end to allow for the carriage clearance. I had to use a Jawhorse to hold a board on end as a tool rest until I removed 3/8" and could slide the banjo under the blank.

While it sounds crazy and potentially unsafe, it was not at all because I took the time to insure that the blank was well balanced before mounting and turned at 50-100 rpms to start. The speed never exceeded 200 rpm because of the circumstances of the turning location. The only unknown when mounting was whether one of the staves might have a different density and throw the balance off, but that did not happen and the blank was more balanced than I could have possibly hoped for.

Final tweaks and sanding were on my SS and it ran perfectly. No vibration when I placed my hand on the motor.