Mini lathe bench and cabinet
With the prices of mini lathes plunging from approximately $600 down to $299, such lathes are finding their way into more and more workshops.
They are just plain fun to use and the only thing you need is a spot to secure it. They are well made, quiet and light. But because they are so light, you sacrifice some vibration dampening which is so prized in the larger lathe. Therefore, you must be sure of the bench on which you bolt it. A bench can either contribute to the vibration in a lathe or help absorb it. Vibration is the #1 enemy of any machine, woodworking or otherwise. We all look for ways to minimize it and we would kiss a toad if any of it could be eliminated.
Well, pucker up because we can eliminate some of it. Specifically, we can reduce the vibration transferred from your lathe down to the floor via your bench and back again. Both increasing the mass of your lathe and creating a barrier impervious to vibration will accomplish this. Increasing the mass of a lathe is easy. Simply bolt it to something heavy. However, this needs to be something that will soak up vibration as it is produced. A box filled with sand, will both increase mass and have a dampening effect. Sand is made up of small particles that rub together to use up the energy of vibration, it makes an ideal medium.
How much sand do you need? The more the better, but sand is heavy and you don’t want to overload your bench or floor.
As an example, a box measuring 57″ long x 10″ deep x 4″ high will hold approximately 61.5kg of sand. This, plus the box material, will substantially increase the weight of the lathe. Use clean dry sand (run your sand through a window screen and dry it in the oven).
This box will increase the mass of your lathe but does not eliminate vibration transferred to the bench. If you mount the lathe on this sand box and sit the sand box on a bench, the bench will vibrate when the lathe is running. The best substance to eliminate vibration is a soft, pliable material. The softer the better, and naturally, air would be a perfect choice for this purpose. Air is an extremely efficient insulator. You can’t feel a palm sander vibrate until you touch it. Even holding your hand 1mm away, the vibration is undetectable.
So how do you suspend your sand box and lathe on a cushion of air? You will need a chamber made of a soft, pliable material. An inner tube with its tough thin rubber membrane is really the only option, and they need not be very big. Consider a wheelbarrow wheel holding a load of concrete.
The dimensions of the sand box given in this article will hold three tubes approximately 10” in diameter, without air. These are trapped in chambers in the bottom of the sand box. Inflate them so there will be approximately ½” of space between the bottom edge of the box and the bench top.
Valve stem extenders are added so the tubes may be inflated or deflated from under the bench. Narrow rubber strips on the front, sides and back hold the sand box and lathe in the desired spot. Without them you could tip the whole unit onto the floor.
Once secured in this fashion. The lathe will rock back and forth on the inner tubes as you push your chisel into the wood you’re turning. Therefore, stops are added to the back and front to limit this swaying. The contact point on the stops is ribbed rubber made from car floor mats glued to cork. Because the ribs flex and there is not a lot of pressure at this point they transmit no vibration to the bench.
This set-up will let the lathe sit on its cushion of air for those delicate cuts and be limited from swaying too much during heavier operations. It is possible for the lathe to bounce if a really out of balance piece is turned. Should this be a concern for you, simply jamb wedges at each corner between the bench top and bottom edge of the sand box, effectively pinning it in place.
Construct the bench that the sand box, and lathe, sit on so that the final height is comfortable for you. The bottom 4″ of the bench is also filled with sand for ballast.
The drawers are used for bolt, screw, and hardware storage. All this adds to the mass of the whole unit. Now if you hold your hand on the lathe as it’s running you feel the vibration, which you can trace all the way down to the sand box. If you hold your hand on the bench top, you feel nothing. Mission accomplished.
To further decrease vibration, the motor could be mounted on the bench, using a longer belt and perhaps a jackshaft. Of course this depends on the construction of your lathe.
All of this takes time and effort but it is well worth it if you are doing delicate items. With this simple bench, your mini lathe will feel and perform like a much larger unit.