Lathe bench advice

Hi,

I just completed the attached bench. I built it out of concrete block, tied in to the concrete floor with drilled and epoxied rebar. Then all the cells were filled with concrete. The bench top is 3/4” steel plate, approximately 612 pounds.

My plan is to drill the top and the concrete filled blocks and tie them together with expansion bolts / redheads.

My question is should I put some rubber / conveyor belt in between the blocks and the steel top plate to act like a dampener, or grout the top of the blocks and set the plate down, or use some structural epoxy to fill the deviations so I have 100% contact between the plate and the blocks.

Any advice would be greatly appreciated.

The holes you see are going to be filled with cabinets to hold the tooling. Also is a picture of the 10k that will be going on top.

Thanks

Nick

Wouldn't it have been simpler to just buy a Sturdier Lathe to start with ?

Larry S
Fort Wayne, IN

I would go the epoxy route, don't think you'll have any problems, but if harmonics become and issue and need damping then add rubber around lathe feet. Try to keep the top flat without nuts and bolts sticking up, maybe anchor a piece of angle to the block and bolt top on from underneath.

What's wrong with the bench it is already on?

If you do do this, you'll have to insure that the 3/4" plate is level in both directions, and I mean level level, like 0.0005" in 12" level - or, a handful of metal shims.

I never thought about using a lathe bench as a bomb shelter...

The only thing missing is a 3' X 6' X 1' granite surface plate to provide real stability to your setup, along with superb vibration dampening to boot!

jmm03 said:

I never thought about using a lathe bench as a bomb shelter...

Click to expand...

Well, to each his own; no offense intended.

I personally would have kept it on the original metal bench. The only problem I see is that if you need to machine
something longer than the lathe bed, you will have to punch a hole in the wall. At least the bench is moveable.

PMc

I can see the benefit of the 3/4" plate for leveling if it was his intention to drill and tap the plate for holes and use leveling studs. It does seem a little overkill for a 10K though...

Give me a call I will make you a deal on a Starret inspection plate pure rock 36x72x12 1 ton should make a good top.oh its sissy pink...Phil

Hey if it's worth killing, its worth over killing.....

I think I would put the lathe back on its factory stand and make that plate into a welding table with 2x2 square tube legs.

My eyes aren’t what they used to be but the current stand looks like a painted wooden desk. I am guessing it might be lacking some in the structurally sound department these days. There is rumored to be a war department document outlining construction of a poured concrete lathe bench. The bench was supposed to provide a significant improvement to the performance of smaller bench lathes. I would love to find a copy of it someday.

If I were building this bench I would be spending time shimming the steel plate to get it as flat as possible. Using small shims in 5-6 spots, I don’t think you can get away with three pointing it. Paying particular attention to getting any twist out of it. I’d then lift it enough clean the underside of the plate and apply the structural epoxy to the brick and set it back down. Hopefully it would push the epoxy out and come to rest back on the shims bonding everything together.

Bolt the feet directly to the plate making sure there is enough room to remove the tailstock easily. Loosen the bed alignment set screws on the tailstock feet before bolting it down. You should be able to remove any residual twist in the bed with the alignment screws and a precision level or trial and error cutting a test bar.

Hope it works out well for you.

Ben

badharley99 said:

...should I put some rubber / conveyor belt in between the blocks and the steel top plate to act like a dampener, or grout the top of the blocks and set the plate down, or use some structural epoxy to fill the deviations so I have 100% contact between the plate and the blocks...

Click to expand...

I would level it and bed it down solidly.

jmm03 said:

I can see the benefit of the 3/4" plate for leveling if it was his intention to drill and tap the plate for holes and use leveling studs. It does seem a little overkill for a 10K though...

Click to expand...

This is what I'd do with it, at this point.
Instead of shimming the lathe feet to remove twist, I'd grout 4 large diameter, fine thread rods into the top of the blocks (1 front and back of each of the feet), screw on leveling nuts, drill out the plate and set on top. Let the plate set entirely on the 4 bolts, floating above the base.

I suspect that 3/4" plate won't deflect much under it's own weight in between, but even if it does it won't affect the area under the feet sitting solidly on the nuts/bolts.

I would NOT use expanding bolts in them blocks for fear of them busting apart, try epoxy set bolts instead.

Looks like a great lathe base
It should act like your using a heavier lathe.
Let us know how it works.

Hal

I always pictured that War Dept poured concrete base for small lathes as a massive solid block that would just eat up the vibrations. It'd have cast-in threaded hold-down studs, and the lathe would be leveled, and any twist shimmed out -- that might be the finicky part. SBs floating tail end, like on my 9A, came much later (and only neutralizes stress, it doesn't necessarily take out inherent twist, or for that matter, do anything to help rigidity) .

Come to think of it, an SB9 sitting on a big pile of sandbags would probably be more vibration-free than any bench.

Good luck w/ your project -- I guess it isn't going anywhere in a hurry