I need some help

I am planning to make a new cabinet to put my old Delta lathe on & am thinking of building a torsion box base for it & filling the box with sand for ballast weight.

Does anyone know how to figure out much sand it would take to to weigh 400 lbs. & how deep that box would have to be if it was 17" x 48"?

I'll put this on heavy duty locking casters that will be mounted on 2x4" steel tubing that will stick out 6" to the front & back for the base for stability.

These measurements match closely what I have now accept there is no place for drawers now & I will have the motor underneath instead of on the left end like it is now.

As you see the set up I have now it is very very stable & weighs about 420 LBS. This is what I hope to have when finished but on wheels with drawers & the motor inside the case under the lathe so I can use the outboard turning capability of this lathe.

The first picture shows the whole lathe. The second picture shows one ot the feet the lathe sets on as well as my free standing tool rest.



Sometime in the future I hope to add a 3 phase motor & VFD.

Any thoughts an this are welcome too.

Bart,

Sand is *about* 80 lbs per cubic foot. That sounds a little high to me, but likely doesn't factor in moisture, and variances of particle size, which might make a substantial difference.

Thanks,

Bill
(Who still remembers stuff from his days as a gardener...

Hi Bart,

Here are my suggestions and they are worth every bit you are paying for them. First, I wouldn't do a torsion box. I would use glued up 2x4s for the top and make a box for the bottom that's the size to hold 2-4 bags of cheap cement. I would make that as the bottom surface and attach the casters to this base there by keeping your center of gravity low. I don't tink that you need to do 400 lbs. For your lathe, that's probably overkill. A couple of hundred (say, 4 bags of cement) should do fine. If you need more weight than that you have your lathe seriously overloaded.

I'm with Chris on material. I found 'Redi-crete' to be heavier by volume than anything else readily available at the BORG. I got 90# in my DP base at approx. 20" x 22" x 4" internal dimensions less two 3/4" x 4" internal dividers shown here.

The concrete sand we use at work weighs 2800 lbs per cubic yard. That's a little over 100 lbs per cubic foot. But it would vary by moisture content and specific gravity of the material in your area. But I'd use sand for weight rather than concrete if it were me. The purpose of the weight is to dampen vibration and a big hunk of concrete will vibrate right along with the stand. A box of sand wouldn't vibrate with the stand.

And if you live in a humid climate like FL the concrete will eventually "kick off" and become hard. So if you wanted to tear down your bench to move it you might have a problem.

I got mine at the local lumber yard at 80 lbs. per bag already bagged up. I put 4 on the Nova stand and two on the Rikon stand.

Thanks everyone. You've given me plenty to think about.