toggle quoted messageShow quoted text
Steven, I'll first recommend that the concrete not be placed in direct contact with raw unfinished steel due to moisture issues and rust. Secondly, I'd still embed sch60 rebar 2" in from all edges and on 8" centers in both directions to keep the concrete cracks from opening up over time and there for sacrificing any ridigity. Next I'd use a mix that had 3/4" limestone aggregate and at least 6.5 bags cement to the cyd. In other words...those bags of premixed concrete at your local big box store wont work. The whole concrete bench concept here is cost and time prohibitive for even a concrete guy. It'd make more sense just to utilize cast iron legs and bolt them to a sound concrete floor or make a heavy hardwood bench as prescribed by South Bend Lathe. Roger
On Mon, Dec 30, 2019 at 12:34 PM, Steven Schlegel
Dale, yes, please report success or failure of your stand.
Roger, you make some key points. Don't rely on the concrete to support the weight. My purpose for using concrete was to deaden the lathe, so making a steel frame table with a concrete insert for the table top and maybe some frame pieces passing under the mounting
positions on the lathe for added strength sounds doable. The question then is how heavy would the concrete slab need to be to deaden the lathe bed. I think the concrete would be in compression and transferring the weight to the steel members.
From: SouthBendLathe@groups.io <SouthBendLathe@groups.io> on behalf of Dale Scroggins <scrof@...>
Sent: Sunday, December 29, 2019 1:02:05 PM
To: SouthBendLathe@groups.io <SouthBendLathe@groups.io>
Subject: Re: [SouthBendLathe] Southbend 9" lathe table in CONCRETE?
I bought 9" C model, 42" bed, about 20 years ago, but am just now putting it into full service. I retired a few years back, and no longer have free access to machine tools. I was an engineer, working for an aerospace company. If you use CATIA, you likely
know the company name. Weight matters in the industry.
I believe a 2" slab, 36" long (just long enough to support the feet) and 10" to 12" wide should provide all the stiffness the lathe needs. One 80lb bag of mix, remesh, polymer admixture, maybe glass fibers. Total weight about 100lb. The rest of the bench
top will be wood; 3/4 plywood substrate, topped by ripped 2x4s on edge to match slab height. Bench frame is an existing steel weldment. On wheels. Will report if it works. And may report if it doesn't.