How important is levelness of the table for lathes?

[Pcmaker]

I live in Las Vegas, so I'm not so worried about humidity

 

[Pcmaker]

Thinking of scrapping everything and just rebuild from the ground up and use 2" square tubing

 

[tjb]

Thinking of scrapping everything and just rebuild from the ground up and use 2" square tubing

In my opinion, that's a good idea. In my shop, I've made all the tables, workbenches, shelves and rolling stands out of square tubing with tops ranging from 1/8" to 1" thick. No doubt, it's more expensive, but I NEVER worry about sturdiness for anything in the shop. And, it's good practice for project design and welding.

Regards,
Terry

 

[bill70j]

Thinking of scrapping everything and just rebuild from the ground up and use 2" square tubing

Pcmaker:

Agree the ideal is a strong, heavy metal bench. But it would be a shame to see your quality work go down the drain. I think you have a stout frame and, being wood, you can easily add more drawers and/or cabinets.

If you choose to stay with your wood frame I see several options to ensure you have a top that is strong, rigid, flat, and stable.

1) Build a metal sub-frame for the top as has been suggested
2) Build a torsion box using 2x4's sandwiched between 2 sheets of plywood
3) Buy a bunch of 2x4's, joint them, cut them to random lengths, laminate them, then plane the whole thing flat, or have a shop do it for you
4) Buy a solid core door, typically made from particleboard, or a well engineered hollow core door
5) Buy a pre-made quality bench top laminated from hardwood

Any of these options will work, but in any case, if you go with a wood top, it should be fitted with 1/4" steel plates for use as mounting plates, and the top should be secured to the frame with mechanical fasteners.

I have a version of #3 for my 10X42 lathe. I have successfully leveled it with a precision level, and it stays level

HTH, Bill

 

[sru_tx]

I recently bought a PM1228 and needed to build a stand. The lathe was going to be set up on the second floor of my garage which made the "foundation" somewhat susceptible to shifts over time and temperature. I looked at @davidpbest torsion beam design and based my design on it. I used two heavy 7"x2" C-channels welded together to form a 7x4 tube. As per david's design, I put an angle on either end of the beam with threaded adjusters on each end of the angles to act as levelers and bolts to lock it in place. I built a simple frame out of 2" square tubing 0.125" wall and put casters with built-in leveling pads so I can move the machine when/if needed but then lock it in place and level the frame. What I found was that after I leveled the frame on the uneven floor there wasn't much need to level the torsion beam. While testing a sample piece in the lathe with a DTI and looking at the twist, I found that the beam was so stiff that the twist adjusters had not effect on the beam itself. I did find that by varying the torque on the 4 mounting bolts the lathe frame would twist which meant that the beam wasn't truly flat. After a bit of shimming and torquing, the machine was solid and no twist and the lathe turned true.

Bottom line is that the torsion beam is so stiff that I doubt the 2" frame is having any effect which means that the shifting of the garage should have no effect either. I'd consider just putting together a metal torsion beam and mount it on your wooden frame.

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