I have a Jet 1442 with the cast Jet legs. I would like to add some storage below the bed and as long as I am at it, I am going to integrate some ballast.
I have a couple of questions:
What? Bags of sand are probably the easiest, with some kind of block/brick at a close second. Is there any advantage ridged or firmly attached ballast over sand?
Where? Is lower better, or closer to axis of rotation?
How much? I'm guessing that a joint compound bucket load of sand about 100 lbs. Besides "more is better", how much is enough/reasonable?
For general stability and to increase inertia, I would put as much as I could on the bottom outside surface of each leg. Casting lead is easy to do in wooden molds.
Question--why? I've turned a 13" dia x 12" chunk of trunk on my 1442. It weighed in the range of 40 to 45 pounds. I carefully centered it, but it still vibrated enuf that the lathe wanted to walk a bit. I fixed that as below. As the lathe was bouncing around, I couldn't help wondering what the off center load was doing to bearings, tail stock and all the other parts that were being pounded by that off center turning 450 times a minute. My decision was to improve my balance of the blank rather than brute force to overcome the bouncing.
Suggestion one--I solved the walking problem. I had put the lathe on a 2x4 base to get the axis even with my elbows. I took the base and drilled a hole larger than the pads under the foot, and about 1" deep. Screwed the adjustable pad down into the hole. Now, even if I have vibration, the 2 x4 x 24" is still in contact with the concrete, and the lathe stays put.
Suggestion two-- to quote OJ "If I did it" weighting it I mean, I'd build a horizontal box supported by the leg castings, and put some of the sand tubes sold for winter traction (here in the Northland) in the box. I'd rather have the limp sand damping the vibration, rather than a bunch of bricks or blocks jiggling and dancing under my lather. I'd also MUCH rather NOT have a bunch of loose sand leaking out on my floor.
Good luck
Old Guy, Eagerly anticipating shop time after the Christmas lights get hung.
FIRST - get rid of as much imbalance as the final piece will allow. Means cutting with the table on your bandsaw tilted, or on a slant with the chainsaw so you don't have those sections of log on either end that you'll be turning away. Remember, the imbalance is increased proportionally to the distance from axis of rotation. Simple leverage.
SECOND - stay slow as you can go until you're able to guide the bevel on the work. Difference in mass caused by irregularities in the piece produces imbalance on the basis of Mass times the square off velocity. Remember, you already have more imbalance if you left lumps on the outside, where they count for more.
THIRD - and this may not be possible if you stick with the stock legs, though the Old Guy gave you a hint as to how to broaden your footprint, keep the footprint broad and the mount rigid.
All that said, the greater (difference) mass will want to accelerate as it crosses 12:00 on its way to about 8:00, which will try to lift the rear legs. If you bolt the rear legs or otherwise provide them some resistance to lift by weighting them low and behind the axis of rotation (leverage, remember), you should be able to do just fine.
I'm swinging 16 of wet wood on a lighter lathe, but I have legs slanted out front of my cabinet to counter the thrust with their incompressibility, and a cabinet extending out behind unto the wall which holds some of my portable tailed tools down low. Knew that physics class would come in handy someday....
How about this idea? Build a lower shelf in the form of a box, with sides
3-4" deep. Fill it with concrete. If you want to make it even heavier, go to tire shops and beg or buy used lead balance weights, and mix them into the concrete. This would provide plenty of weight, and provide a smooth upper surface that is suitable for tool storage.
Let's not discuss how you would get rid of this heavy block when it comes time to move the lathe or get rid of it.
Most tire shops only sell their lead. Lead is one of the most recycled metals. Tire shops are paid for their lead. The going rate is 10¢ a pound. I suggest leaving the lead weight loose, and not cast, so it is easier to move.
Actually it's not. The jet 1442 has the same legs and I have 2x4's in the same position (there is a pocket in the casting specifically for them). I have a currently have a shelf that overhangs the 2x4 by 1.5" and that is not even a shin-buster.
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