Photos by Multiple Sources
To fortify or not fortify my lathe: that is the question I often ponder. At one point or another most woodturners will push their lathe a bit, causing the lathe to shimmy and shake. When this happens, it not only raises safety concerns, but it also indicates that the lathe is under a good deal of stress that could potentially accelerate wear. There are varying opinions on how to best remedy this:
Many turners will add mass, such as bags of sand, to the lathe to provide some additional resistance to vibration. Most modern wood lathes provide some accommodation for this, like a location in the frame where a shelf can be placed to position some incremental ballast.
Bolt It to the Floor
Some turners take a more extreme approach and actually bolt their lathe down to the shop floor, delivering maximum stabilization if done properly.
No Fortification? Slow Down or Turn Something Else
Some woodturners believe their lathe is structurally designed to handle a specific load, and that any enhancement that allows the machine to spin additional mass is likely to place stress on the lathe that will accelerate its wear.
I believe there is no simple one-size-fits-all answer to the question of whether or not to fortify. All lathes are designed differently and can handle different loads. This inherently means there is no universal law about how much additional weight can be added, even as a percentage of overall lathe weight.
As a general rule, I operate my lathe without any additional weight. But on a couple occasions, when I was turning something that was at the upper limits of the lathe’s capacity, I added some weight. It definitely helped to stabilize the machine, particularly during the roughing stages.
Weight added to the bottom shelf helped a little. When I moved it up and set it on the bed itself, it helped a lot more. So I understand the benefits, but when I do this it makes me wonder about the additional strain that it would place on the lathe itself.
Experts Weigh In
Should the lathe’s shake and shimmy act as a governor, telling me I’m beyond the lathe’s capabilities? Or is it telling me to take action and stabilize the machine? That led me on a discovery quest to get perspectives from some serious wood turners, as well as lathe manufacturers.
Professional bowl turner Mark Stinson is known for turning massive 20” bowls (Ambrosia maple shown above) and avoids adding weight to his lathe.
“I think I have a different view on this topic than many,” he says. “While I agree that adding weight can help, I’m not convinced it’s a good idea. A lathe’s organic weight is based upon its construction. Thinner stock, possibly smaller spindle and bearings. So, if you force a lathe to remain more stable than it wants to be for the task, I believe, you risk stressing the integrity of the machine. This is only a theory of mine. But if you take a lathe that weighs 800# and a lathe the weighs 400#, adding 400# to the lighter lathe doesn’t make it as robust and durable as a lathe that weighs that total mass organically. You can bolt the thing to the core of the earth, but you may still be stressing the welds, spindle, bearings, bed, etc., and it will not eliminate the vibration that can occur between the bed and the sliding headstock, or the bed and the banjo.”
Avid wood turner John Lucas built a box for his Powermatic lathe that holds 250 pounds of pea gravel (pictured at the top of the article).
“I have always added ballast to my lathes,” he says. “I put the weight as low as I can. This setup works pretty well but then I don’t turn a lot of big stuff. I turn a fair amount of smaller out of balance or off-center pieces and it helps quite a bit. I have every confidence that I’m operating within the lathe’s natural limitations, and that the added ballast simply stabilizes the tool and provides me with a better turning experience.”
For turners who might consider taking things a step further and bolting their lathe down to the floor, Canadian turner Lewis Golden shared his experience. His 20” swing General Lathe is bolted into 6” of mesh-enforced concrete using ½” x 5” galvanized wedge anchors (pictured above).
“I have roughed in pieces on the outboard that’s were larger than 20 inches in diameter,” Golden says. “The machine was built at the factory to be fastened down and I believe that there is no more solid fashion, (excluding modifying the machine), to limit movement than anchoring it using the factory drilled base. This has never presented any problems whatsoever and it has not been unbolted since I bought it new 21 years ago.”
I also spoke with a couple individuals who design lathes to get their perspective. Benjamin Helshoj, designer of the Revo Lathe series for Laguna Tools, says it’s a complicated, multi-variable question.
“We do not provide any specific guidelines to our lathe customers,” he says. “I believe that it is ok to add some weight to slightly extend the capabilities of a lathe, but there is a point at which it will mask problems and potentially cause damage to the machine. In that vein, I believe that bolting a lathe to a floor is potentially a bad idea, depending on the design of the machine, as it can muffle the lathe when it is trying to tell you something important. It would be like disabling a smoke detector that is sounding an alarm so that you can get back to sleep.”
Brent English, founder of Robust Tools LLC, weighed in as well.
“I think adding weight or bolting a lathe to the floor will certainly make the lathe more stable, and may improve the experience at the lathe for the turner,” English says. ”It’s important not to impart a twist on the lathe bed as that will negatively affect alignment. But I think if you’re adding weight and/or bolting the lathe to the floor to mitigate a weak or light weight lathe you may be setting yourself up for a false sense of security. If the lathe is shaking, that’s nature’s way of telling you to slow down and/or get things more balanced. The wood will fail before the lathe will, and failed wood flying off the lathe is not to be trifled with.”
Based on my own experience, and after getting input from several knowledgeable sources, I feel comfortable adding some weight to my lathes. I will occasionally add a couple sandbags, particularly when turning on a midi or midsized machine, but I rarely feel the need to do this on my 24” lathe.
Given some of the massive chunks of wood that I turn, weighing over 100 pounds in some cases, I wouldn’t feel comfortable bolting a lathe to the shop floor without first having a conversation with the manufacturer about the potential risks. If you are operating within the limitations and design of the lathe, then bolting it down might be an option, but with the “smoke alarm disabled” you are left to your own instincts as to what the lathe can handle.