Lathe Leveling Foot Pads

[Mikebr5]

Excellent information. Thank you much Toolmaker!
Precision levels are on my search list.

[Paul Jones]

The current footpads provide all the stability I need but have always wondered about the rare case of an earthquake. The 1994 Northridge earthquake was 60 miles away and I remembered it violently shook for what seem like a long time. I didn't have the current lathe and wondered if it would remained standing with the current footpads.

I actually saw one of the Northridge earthquake aftershocks. My wife and I were playing doubles tennis and I was about to serve the tennis ball when about 400 yards away on the open grass green belt I could see what looked like a green undulating wave coming very fast toward us. Within seconds it hit us on the tennis court and hard to stand up and then gone. Being a geophysicist I thought this was so cool but I was the only one who was thrilled to be able to see an earthquake.

[LMMasterMariner]

Nice job. I was too lazy to make it, so I bought them in China at https://world.taobao.com/item/527980....5VuIoa#detail
Bought 4 leveling foot pads dia 60 mm M12 thread for the lathe and 4 leveling feet pads dia 80 mm M12 thread for milling machine.
Here they are laying on the table in my cabin among some other stuff bought in China.
BTW, They are still in the box home. Not mounted yet.
Cheers
LMMasterMariner

[Toolmaker51]

The current footpads provide all the stability I need but have always wondered about the rare case of a earthquake. The 1994 Northridge earthquake was 60 miles away and I remembered it violently shook for what seem like a long time. I did have the current lathe and wondered if it would remained standing with the current footpads. (abbreviated by TM51)

.
Seeing an earthquake is stunning. In 1964(?) SoCal, Buena Park I saw the undulations start in a large fish tank. We lived in a split-level home with quite a long [as in parallel to the street] footprint. The 2nd floor family room, kitchen and pantry were all on the same plane; then a wave could be seen traverse 70-80 feet distance in rattling glassware, door frames, floor, curtains, hanging light fixtures, pedestal lamps from end opposite the tank. I dropped to floor between a sofa and sturdy coffee table. Probably safe enough, as only thing above was roof, rafters perpendicular to length of house, and a very tall wall connecting the level above but behind me. Makes me remember another mid-80's event at work. 40 something people ran like crazy, only to jam up around the nearest exit door. That building was tilt up concrete. My toolroom was along that edge midway between front and back. I crouched at left-side of Bridgeport to wall on right. A heavy bench was on left too, seemed substantial enough to bear some weight of the flat roof rafters above. Situational awareness I guess, a good tendency to cultivate with San Andreas Fault as a 'neighbor'. Don't recall seeing anything sway other than fluorescent lighting.
Anyway. Where I am contracting in Reno uses a portable 'machine shop' built in 40 foot shipping container. Can't post pictures from my phone until home again but I will. The portable aspect is tangible and reasonable. 1" x 8'" hot rolled plate is bolted to the floor and machines are bolted to them. No consideration of leveling is made; mill, surface grinder, drill press or lathe. The bolting suits transport, not precision machining.
1) Common milling machines forgive precise leveling better than lathes; because the ways are mostly independent of the body casting, even the verticals are well inside the footprint depicted by the 4 pad locations. And coolant drainage is iffy, no matter level or not. Anchoring is a different story because weight on the table can tip a mill, (ie) a 12" rotary table on one end, the X extended far as it will go to swing a big radius...Just saying. In a different shop, during set-up I could elevate the right side after zeroing the table center and moving left. Likely could have flipped it. Instead I swung the head to the right, indicating a tooling ball preset according to position of rotary table. Sometimes, set-ups need a set-up of their own before attending to job at hand.
2) Lathes are a different situation. Bench machines need a sturdy, flat level plane, to run as intended. Can't prove it, but the 5's, 7's and little 9x's people have trouble with, are probably due to fact it was just plunked on a flimsy pressed wood table and plugged it in. They haven't the mass to counteract the dynamic & harmonic force even a small machine can [will] create. Even the heaviest floor machine is just a casting. Never seen one with the anchor pads milled into a single plane, nor is any flooring material a single plane. A lathe might not oil it self correctly, or dump coolant all over if set on a 10 degree angle along the X, but it would still be accurate, if otherwise set correctly.
3) Grinders, saws, etc, different again. It is common to use a bubble level in set ups. Just because the bubble zeroes on material, has nothing to do with the wheel, blade, or ways.
So stability is king. Mating two non-flats requires adjustment, shimming, or bedding compound. Level is the standard reference; in reality that each pad bears it's proportion of weight is what is achieved. Level is almost a convenience, easily verified at a later date. Will it be if unstable?

Extending the feet on a lathe would work if a 'bond' was made between prescribed feet to added material. Like Mikebr5 I'd hate that impediment on the floor.
Seems I'll edit into this post when ideas pop up.
One will be a foot bolted to the original holes, 3x or 4x thickness of existing cast area. It is long enough to move pads outboard of footprint including wrench clearance to casting. The underside is cut away for the pads to function with out jacking up lathe higher and higher.
Drawing is jpeg, click it for increased size.

[Frank S]

I agree with Toolmaker 51 in post #10
While in Kuwait there was this one company that we had sold several lathes to through our machinery sales division this company seemed to move their machines around more often than in indecisive housewife would rearrange the living room furniture. The biggest problem was they had this one extremely long light duty older lathe, the bed was less than 1 ft wide but 24 ft long and only about 9 inches deep it only had about a 10 inch swing over the carriage, I think it was originally intended to be fixed to a concrete pedestal not the 8 fabricated legs that it rested on. The only way I found to move it with any safety was to fabricate a long ridged spreader beam then lift it with 6 adjustable slings once in place we would shoot it in with a laser level to get it to a reasonably roughed in level then spend a full day fine tuning the levelness of the thing with 3 1 and 1 3 ft long machinery levels . Our levels and other installation equipment were 3rd party calibrated in a lab regularly as clock work every 6 months whether they had been used or not
Paul Jones the base of your lathe in the picture looks like a Victor I used to own a 16x40 gap bed Victor it was an excellent machine I made a few rifle barrels and hundreds possibly a 1000 hydraulic cylinders on it

[Paul Jones]

Toolmaker 51 and Frank S,

Thank you for the advice. Both of you are far more experienced than I in the best way to set up machine tools. My lathe is a circa 1987 Taiwanese equivalent of the Victor and very well built with hand scraped surfaces. I like the suggested design of the extended leveling pads.

My lathe is located in my garage that has a slightly sloping floor. The lathe is located parallel with the floor slope. I use a 0.0005"/10" precision level (it took me almost two hours to first precisely adjust and self-validate this level on a surface plate - it is an extremely sensitive level and takes a while to settle in).

In my experience, the lathe ways have to be as close to leveled front to back (cross slide direction) and with the same reading at the headstock and tailstock in order to remove any minor twist in the lathe ways if you truly want to work within very tight tolerances. During the leveling process you have to take test cuts to verify the diameters over several inches from the headstock. The vertical leveling along the long axis direction of the bed is important because it makes doing cross bed leveling so much easier to set up. There are plenty of YouTube videos on doing this lathe leveling work. Don't assume the headstock is out of alignment until the lathe is very closely leveled and not an error due to lathe way twisting. From my experience, leveling the lathe ways makes the final and most critical cut along the lathe's long axis very predictable and consistently allows a constant cut diameter along the lathe long axis. The extra effort doing leveling for the lathe eliminates scraping parts and makes the final cut far more predictable and a less stressful operation when you have to hit your mark.

Paul Jones

[ragsflh]

awesome.going to make some

[backyard_cnc]

Nice job on the feet and I originally did something similar on my own 12x36 lathe however I found the lathe was far too tippy on such a narrow footprint as offered by this cabinet and ended up adding outriggers to increase the footprint and make it dramatically more stable.

[Paul Jones]

backyard_cnc,

Your photo of the lathe leveling feet improvement is what I had in mind when I will be making the next set of leveling feet improvement. I think I will make it easier to construct by just coming straight out perpendicular to the cabinet sides and placed only 3" away from the front and back of the cabinets. I am sure your design was to optimize the support in all directions.

Depending upon the electric motor mount and lathe supporting feet designs, there can be many differeernt bad harmonics generated and can effect the lathe fine finishes ( see http://www.homemadetools.net/forum/l...ovements-17293 ). I found using Cylindrical Vibration Isolators for mounting the electric motor made a very big difference in the lathe final machine surface finish (see http://www.homemadetools.net/forum/1...chniques-19914 ). We have find a good way to support lathe on the floor and isolate the electric motor mount in order to reduce vibration harmonics. Even the fine adjustment of the change gears behind behind the headstock of a gear-head lathe with quick change gears can affect the final machined surface finishes.

Regards,

Paul Jones

[backyard_cnc]

Truth be told I bought a cabinet with these stabilizing legs attached and it was a simple matter to drill 4 new mounting holes and bolt them up to the lathe. I often use handcrank to do short threads up to a shoulder and if you got carried away it was easy to rock the top heavy lathe on the small footprint. On these outriggers it is rock steady. Had I made them from scratch I would have just done straight 2"" tubing. The increase in height was also a bonus!

Gerald