how much weight can i put on 4 bolts?

[Lee Alkureishi]

Hi,

I'm in the process of building a bowl lathe, and am working on the feet. I'd like to build in a leveling system, and was wondering what size of bolts to use.

The projected weight for the lathe will be around 500lbs with ballast. The 4 legs are splayed at 25 degrees each, and at each foot will be welded a short section of angle iron with a hole through it. On the underside will be welded a nut, through which a 3" bolt will thread. The head of the bolt will be on the ground (maybe in a hockey puck), so the weight will be mostly axial on the bolt.

I was thinking of using 1/2" nuts and bolts for this - can anyone advise if they'll handle this kind of weight/stress?

Thanks!

Lee

[George Carlson]

The bolts will be under compression, so you shouldn't have any problems. I've built stands similar to this in the past. I used carriage bolts setting in thick washers on the floor. The carriage bolts have a round head, which allows them to set in the hollow of the washer without concern for angle. They also have a square that allows you to turn the bolt with a wrench. Welding a nut below the angle is good. Use another nut to lock the assembly above the angle. If you don't do this, the bolt will rattle and wobble in the nut. The addition of the jam nut will prevent this and lock everything secure. Frankly, if it were my bowl lathe, I would anchor it to the floor with anchor bolts.

[Lee Alkureishi]

George, thanks for the reply. I like the idea of the carriage bolts. How did you secure the carriage bolt to the washer?

I'd love to bolt it down, but my shop is also a working 2 car garage, so it's not an option at the moment!

[George Carlson]

I just set the head of the bolt into the washer, let gravity do the rest. The washer's job is to distribute the weight and keep the bolthead from digging into the concrete. I built a stand similar to this for a small metal lathe. I put one pair of fixed casters in the middle of the stand such that I could screw the bolts up, and the stand would ride on the casters. Then in sort of a teeter-totter way I could roll the lathe around on the center casters. If you do this you will need a couple of inches of travel on the bolts, so it would be a good idea to use larger bolts to reduce wobble.

[Lee Alkureishi]

I really like that idea - been pondering how to move this beastie!

Thanks again,

Lee

[Dan Hintz]

I used carriage bolts setting in thick washers on the floor. The carriage bolts have a round head, which allows them to set in the hollow of the washer without concern for angle. They also have a square that allows you to turn the bolt with a wrench.

That's what I did for my metal lathe... a carriage bolt in each corner, and a wrench to level.