Bought Clausing 6900 series lathe, has 7/8-14 leveling bolts but no isolator feet

[David2011]

That wouldn't really work for the OP's setup. The screws are hollow all the way through. They have a shoulder at the bottom that rests on the metal pad and they slightly protrude through the bottom, but are much smaller diameter than the body of the screw. There's a groove at the bottom of the screw for a retaining ring that keeps the pad secured to the screw. Putting the level screw on the concrete or on a metal pad like you've done would have all the weight on a small circle maybe 1/2" OD with a fraction of an inch all the way around for surface contact.

The illustration above shows that the weight was borne on a narrow shoulder. Aren’t leveling screws that don’t have an integral pad typically tapered or rounded to locate them in pads as I described above? The screws on my lathe have rounded ends. Could the hollow screws be replaced with ordinary screws? The original system for the OP’s lathe is convenient but not a necessity. Once the lathe is set on the pads they’re not going anywhere. His Clausing weighs about the same as my Victor 13x40; 1500-1600 pounds. My Victor sits on four 12mm (under 1/2”) screws.

The Clausing’s screws are 7/8”. If a solid screw is reduced to 5/8” at the contact point the compressive strength is around 33,000 pounds each. Making an assumption here, if the existing screws have 80% of their area removed, they are still good for about 52,000 pounds of compressive strength each. That’s all based on a mid strength steel with a compressive strength of 109,000 psi.

 

[G-ManBart]

The illustration above shows that the weight was borne on a narrow shoulder. Aren’t leveling screws that don’t have an integral pad typically tapered or rounded to locate them in pads as I described above? The screws on my lathe have rounded ends. Could the hollow screws be replaced with ordinary screws? The original system for the OP’s lathe is convenient but not a necessity. Once the lathe is set on the pads they’re not going anywhere. His Clausing weighs about the same as my Victor 13x40; 1500-1600 pounds. My Victor sits on four 12mm (under 1/2”) screws.

The Clausing’s screws are 7/8”. If a solid screw is reduced to 5/8” at the contact point the compressive strength is around 33,000 pounds each. Making an assumption here, if the existing screws have 80% of their area removed, they are still good for about 52,000 pounds of compressive strength each. That’s all based on a mid strength steel with a compressive strength of 109,000 psi.

Yes, as I mentioned above, the screw has a shoulder that sits on the pad. I don't recall the width of the shoulder, but I don't recall it being particularly narrow. I doubt the section of screw that projects below the shoulder is bigger than 1/2" as the retaining rings are pretty small and can be a real pain to get in place since they're recessed below the rubber pad. I'll try to remember to look at my 6913 tonight as I have it raised off the floor (adding a taper attachment from another 6913).

I've seen all sorts of leveling screw configuration so I'm not sure there is much of a standard, but I'm sure the OP could simply swap to a different kind of screw.

My point about not putting the current screws on the concrete or on a steel plate was that the small OD with fairly thin wall would either dig into the concrete or likely damage the end of the screws.

The simplest solution is a metal pad with a hole just big enough for the shoulder on the adjusting screw. I had to make one for the 6913 I sold...just sized the hole and glued a piece of thick rubber (semi-truck mud flap) to the bottom...worked perfectly.

 

[citizendefenseusa]

Thanks for the continued discussion. I found a temporary solution I just tried tonight after looking for anything for potential options that might work without designing mine from the ground up. I found one foot that seems like it will work, I leveled the lathe tonight using it but may need some shims to get more travel. I'm about 0.2 to 0.25 degrees from level in one direction and closer to level in the other. I'm out of travel to get it any closer so I think I'll try it and see how the finishes and tolerances come out compared to before.

 

[verbotenwhisky]

Can't find anything 7/8-14 to fit the leveling bolts for my isolating/leveling my lathe. Clausing sent me a drawing for the bolts, but they are already on the lathe so that's not what I was needing. This lathe is installed on concrete but I can't find any isolator feet that have a compatible thread or any other method of setting it up properly without rigging any home-grown band-aid. Any ideas or direction would be appreciated. Thanks.

 

[ltlvt]

Considering I put my lathe on casters I took out the Bolt/nut leveling bolts shown in the picture the OP posted. This allowed me to use stem casters, but I had to make bushings to replace the Clausing Bolts. I can adjust the level of the lathe using the nuts on the bottom of the casters. Its not that big of deal to re-level it if I move it. Many have already said every Naval Ship has its own onboard machine shop. So how do you level a lathe that is constantly moving thru the ocean? Which brings up the question that has already been asked thousands of times. Do Lathes need to be level? Which came first the Chicken or Precision Level?

 

[David2011]

Considering I put my lathe on casters I took out the Bolt/nut leveling bolts shown in the picture the OP posted. This allowed me to use stem casters, but I had to make bushings to replace the Clausing Bolts. I can adjust the level of the lathe using the nuts on the bottom of the casters. Its not that big of deal to re-level it if I move it. Many have already said every Naval Ship has its own onboard machine shop. So how do you level a lathe that is constantly moving thru the ocean? Which brings up the question that has already been asked thousands of times. Do Lathes need to be level? Which came first the Chicken or Precision Level?

Lathes do not have to be level to the world although there are some infrequent setup advantages to having one level. They DO need to be twist free and that is what's really meant by leveling a lathe. It needs to be aligned within itself to a single plane. The ship I'm on frequently has lathes both parallel and perpendicular to the centerline. Even so, it's unlikely they would ever be level to the world.

 

[ltlvt]

Lathes do not have to be level to the world although there are some infrequent setup advantages to having one level. They DO need to be twist free and that is what's really meant by leveling a lathe. It needs to be aligned within itself to a single plane. The ship I'm on frequently has lathes both parallel and perpendicular to the centerline. Even so, it's unlikely they would ever be level to the world.

yep

 

[citizendefenseusa]

Considering I put my lathe on casters I took out the Bolt/nut leveling bolts shown in the picture the OP posted. This allowed me to use stem casters, but I had to make bushings to replace the Clausing Bolts. I can adjust the level of the lathe using the nuts on the bottom of the casters. Its not that big of deal to re-level it if I move it. Many have already said every Naval Ship has its own onboard machine shop. So how do you level a lathe that is constantly moving thru the ocean? Which brings up the question that has already been asked thousands of times. Do Lathes need to be level? Which came first the Chicken or Precision Level?

Yes, I was originally talking about the leveling in the twisting of the bed, not so much the level with respect to the length. I'm okay with the current leveling, the original post was mainly to find a solution for acting as the feet for the 7/8-14" threaded bolts which neck down to 5/16" for the rubber isolator pad they don't sell anymore/can't find. So far the ones I found from McMaster appear to be working well so far, I'll see if they hold up to the weight over time since they were a nice, cheap off the shelf solution that allowed me to get the twist out of the bed.

 

[citizendefenseusa]

Lathes do not have to be level to the world although there are some infrequent setup advantages to having one level. They DO need to be twist free and that is what's really meant by leveling a lathe. It needs to be aligned within itself to a single plane. The ship I'm on frequently has lathes both parallel and perpendicular to the centerline. Even so, it's unlikely they would ever be level to the world.

Yes, the twist is what I was trying to get out, although I had a tool height level that I also wanted to use for setting the tool height as well as getting the twist out of the bed. I'm good with the 0.2 or 0.25" out of level for the length of the lathe, but couldn't make any of these adjustments without the feet to add to the end of the 7/8-14 adjusting feet with the necked down 9/16" boss on the end. Mine is sitting on concrete and besides the small edge digging into the concrete flooring, it would not have had enough height to allow any removal of the twist.

 

[David2011]

Super! When you started discussing degrees off of level I just wanted to make sure you knew that level to the world didn't have to be the goal. Dead level is probably easier than estimating portions of a bubble off, though.

Since ships were mentioned, I found out a couple of days ago that we may have a functional machine shop on the USS Texas again before too long. How cool would that be? Can you imagine machining on this?