Foundry question on lathe bed casting

I know this is not a machining question, but I figured someone here might know. I have a very limited knowledge of sand casting and I was wondering if someone could explain to me how they mold small South Bend, or other similar small lathe beds (not the modern square style beds). For example, is this a two or three piece flask? Would they use any cores? Where is the parting line? Also, I am curious about any design considerations for the patterns and any requirements most foundries might have to use my patterns. By the way, don't bother telling me that I'm an idiot for thinking about making a lathe (I already know). I'm mostly just curious to learn more about foundry work (maybe I do have some hairbrained plan for the distant future to attempt to make a lathe also). I'm not so much interested in something like the Gingery style lathe, more along the lines of a South Bend 9" or even an Atlas 6" or similar. Any info would be greatly appreciated.

lathe bed casting

Frenchy said:

I know this is not a machining question, but I figured someone here might know. I have a very limited knowledge of sand casting and I was wondering if someone could explain to me how they mold small South Bend, or other similar small lathe beds (not the modern square style beds). For example, is this a two or three piece flask? Would they use any cores? Where is the parting line? Also, I am curious about any design considerations for the patterns and any requirements most foundries might have to use my patterns. By the way, don't bother telling me that I'm an idiot for thinking about making a lathe (I already know). I'm mostly just curious to learn more about foundry work (maybe I do have some hairbrained plan for the distant future to attempt to make a lathe also). I'm not so much interested in something like the Gingery style lathe, more along the lines of a South Bend 9" or even an Atlas 6" or similar. Any info would be greatly appreciated.

Click to expand...

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some of my experiences building bigger than Gingery equipment

1) the flask to hold the sand will be heavy. i had a crane monorail and a 1 ton chain fall to pick up and rotate / move the mold halves. literally moving hundreds of pounds of sand around is hard wok.
2) a crucible holding 100 lbs of molten metal throws a lot of heat. I had again a locking tongs for grabbing crucible and hoisting up out of furnace with a electric winch and slide along a monorail. I had to balance the hundred pound crucible so i could push down on handle end to tilt to pour. metal when it pours has a sudden weight shift and it is difficult to control splash.
3) i had leather apron, jacket, face shield / hard hat and the leather would start smoking from the heat in less than 10 seconds
4) if any mold has excess moisture molten metal explodes like a fireworks explosion. being in the center is not fun
5) cast iron if ferro silica level is off can be hard to machine. i often saw sparks milling with carbide tooling.
..... this is just the short list. basically it is vastly cheaper to buy a lathe than make one. when you look at all the engineering work and small details in a modern lathe they will take years if not decades to match the quality.

What you are asking for takes years to learn. First thing you have to think about is how to get the pattern out of the sand. That helps to define the parting line. The foundry tries to not use a third (cheek) flask. For terminology purposes, the flasks are bottom (drag), center (cheek) and top (cope). Unless the casting is very simple, cores are quite common. They are anchored in the sand with core prints, extensions of the core that fit into pockets in sand. Where there is a core print, there is a hole in the casting. If the places where core prints are needed are not available, the use of chaplets can be used support and locate the core. A chaplet is small spacer, kind of like a nail with a very large head on each end of the shank. Think of the columns used in houses to support the beams in the basement. The pattern can be either one piece or several pieces. If several pieces, the parts can be located one to another with pins so that one part of the pattern is used to make the drag part of the casting, then the upper parts are added to pattern still in the sand and the next portion of the mold is made. A simple pattern could be just two pieces.

Now we have to think about the gating system and the use of vents and risers. Just dumping some molten metal into the mold cavity most likely will not work. The cavity needs to be normally filled uniformly. If there are thin and heavy sections of the casting, the flow into each section can be controlled by the size and location of the runners and ingates. Terminology: sprue, the opening to the outside world where the metal is poured from the ladle; sprue bottom, a basin at the bottom of the sprue used to smooth out the flow of metal and to distribute the metal to runners or gates; ingates are the channels that feed directly to the cavity and are connected to the runners. There may be chokes placed in the ingates to control the flow.

Once the metal is in the cavity, it solidifies with the heavy sections feeding the small sections. If left uncontrolled, this will lead to shrinks and possible holes or pipes in the metal. To control this, heavy sections of metal can be added to the mold called risers. These are essentially a boss that is used to supply molten metal to the casting. The shrinkage and pipping occurs in the risers instead of the casting. After cleaning, these are cut off.

Vents are opening from the casting to outside to allow gases to escape. The sand is porous but may not be able to handle all the gases.

That's about as short a primer as I can come up with.

Tom

If you visit the "lathe Archive" and go to the "Hendey" subsite, there are photos of the Hendey plant. These include some shots taken in the pattern shop & foundry.

The lathe bed pattern for a typical lathe bed would have been a "loose piece" pattern, having three (3) major sections:
-base flange (if used)
-bed body with core-prints (more about that in a few lines)
-ways

A stack of molding flasks would be used so that there were three sections (drag, middle "cheek", and cope on top).
The main body of the bed would be molded in the cheek or middle flask section, with parting lines where the loose pieces of the pattern for the bedways and base flange joined the main body of the bed.

Core prints were used to establish locations of the dry sand cores for the "girths" of cross members and openings that spanned inside the two vertical sides of the bed casting.

Dry sand cores were used to mold the girths (which were often like an inverted "U" channel section) or to mold the "lattice webbing" (used on South Bend's heavy 10" lathe beds).

Dry sand cores might also be used on the side of the bed to create a relief for the feed shaft and lead screw, and to include the raised lettering and any mounting pads for the quick change gearbox and rear bearing block for the feed shaft & lead screw,

Dry sand cores enabled intricate castings with otherwise "unmoldable" geometry to be made. Core prints are usually some sort of boss or projection that sticks out from the body of a pattern. The core print is a means of locating and fixing a dry sand core in the mold cavity.

Molding a lathe bed was a fairly tricky business as, once the main pattern parts were withdrawn from the sand, the cores had to be set. The core locations had to be checked in the mold, as cores, despite a core print, could cock. Properly venting a mold with dry sand cores was also a bit trickier than a regular sand mold. Then, there was the matter of providing proper gates and runners and risers to prevent shrinkage problems. A lathe bed is a long casting with deep, relatively thin side-walls and heavy sections at the top and bottom, as well as the girths or webbing on the inside. Arranging the gates and runners so the molten iron filled the mold uniformly without one section getting ahead of the other, and arranging for risers to prevent shrinkage defects also took some doing.

The other part of the equation is the molding sand and the "facing". Regular green molding sand uses silica sand and clay. Silica sand melts and vitrifies (forms glass) at some temperature below the temperature of molten iron. If molten iron is poured into a sand mold, the heat of the molten iron will vitrify the sand closest the iron and create a glassy scale and all sorts of defects in the casting (inclusions of this glass and porosities), along with a very hard shell on the casting. This problem was recognized at least a couple of hundred years ago. The problem was solved with what is known as a "facing" on the sand mold. This is often nothing more than powdered soft coal, known in foundry work as "plumbago". This is dusted onto the mold and cores before the mold is closed for pouring. When the mold is poured, the molten iron comes into contact with the plumbago. Being made from soft (bituminous) coal, the plumbago dust promptly forms coal gas. This coal gas forms an insulating space between the molten iron and the molding sand. The coal gas dissipates thru the venting in the sand mold. But, this coal gas "barrier" remains just long enough for the iron to "skin" or "freeze" on its surface. This lowers the temperature below the melting point of the sand.

Pouring iron and semi steel castings is a trickier business than molding lower melting point metals such as aluminum or bronze.

The other requirements for a pattern are to have sufficient allowance for shrinkage of the iron. Patternmakers used what was known as a "shrink rule" which had the shrinkage allowance built into the graduations. Different shrinkage rates for different metals. Iron, as I learned as a kid in Brooklyn Tech HS in the 60's, shrinks 1/8" per foot.

When a pattern is made, aside from the allowance for shrinkage, there has to be some consideration or sense for how the molten iron will cool and what stresses will be developed. Every corner on the pattern has to be rounded on external corners, and every "internal" corner has to have a generous fillet.

Then, we have to think about draft, or the relief angles on the pattern so it can be withdrawn from the sand. There are general rules for draft on patterns, but for something with cores and complex geometry, extra draft is usually put on the patterns.

Finish allowance is yet another issue. Normal finish allowance for machining is 1/8". Finish allowance has to be included on any surface that is going to be finished by machining and may be a bit more on some surfaces where there may be intersecting surfaces and perhaps some deeper cuts meeting shallower cuts.

Then, we get to the age-old debate. Patternmakers and molders, at least years ago, insulted each other and each craft claimed the other did not know what the ---- it took to make a good casting. The molders accused the patternmakers of making patterns which were next to impossible to mold or get a good casting with, and the patternmakers accused the molders of being prima donnas and being unable to mold anything remotely complex. Add to this the foundry's requirements. The foundry will have certain sizes and types of molding flasks, certain types of sand they use, and their own ideas and preferences for what a pattern needs to have.

Finally, we get to the alloy of iron or semi-steel the foundry will pour. Years ago, lathe beds were poured with iron melted in a cupola furnace, using a coke fire. The iron poured was often nothing more than busted up scrap- worn our machinery castings, busted up engine blocks, old cast iron pipe fittings and radiators. This was a basic gray cast iron. Sometimes, fresh blast furnace pig iron ingots were added to the melt. This produced a fairly fine grained casting, but it did not have much tensile strength and when machined, was fairly soft. This meant a lathe bed would wear more quickly. The machine tool builders started ordering "semi steel castings". These were castings having a certain percentage of scrap steel in the melt. This added strength and increased wear resistance. It let them cast lighter lathe beds. Then, the higher strength nodular and ductile irons came into being. These are much more predictable, more machineable and have much higher strength and a better grain structure. It's all a question of what the foundry you contract with to pour the lathe bed is melting for their castings. Some cast irons are a bitch to machine. Some are more dimensionally stable than others.

After casting comes snagging (grinding off the extra iron in the form of gates, runners, risers, sprues), followed by shot blasting and chipping of any mold flash. Then, the casting is inspected for any defects like blow holes, shrinkage defects, sand inclusions. On certain less critical castings, these could be lived with or repaired (Ni Rod welding). On a lathe bed, a homogenous casting free from defects is the only thing acceptable. With today's ultrasonic testing, it makes it possible to check a casting for internal flaws like shrinkage cracks that are not visible, or gas bubbles that might be opened up during machining. Years ago, castings got the visual inspection, and oftentimes, the defects were uncovered during machining. By then, it was too late, and a lot of shop time got wasted when the casting was scrapped.

Then, there is the matter of "seasoning" the castings. The old machine tool builders would take a run of castings for lathe beds, headstocks, carriages, tailstock bodies, etc and leave them outside in the weather. The castings stood out in the weather for a couple of years or more before they were machined. This was said to "season" the casting. The belief was the exposure to many freeze-thaw cycles and temperature swings, sun, dark, wind, snow, and all else in the way of weather would let the castings work out any internal stresses. Sometimes, the castings were stress relieved in a furnace, and then parked out in the yard for awhile. It was only after some form of stress relieving and/or seasoning that the castings were dragged into the shops and machining begun.

Some shops would rough machine a casting, then set it aside or do an in process stress relieving. After that, it was usually shot blasted and finish machined. machining a long casting like a lathe bed opened up a lot of "locked in stresses" in the casting, so it was predictable that the casting would "move" and what was a flat or true surface immediately after rough machining might not be there after a short time.

Making a good lathe bed (and the other cast parts) might take a few years if it were done the old way. Machine tool builders and automobile engine builders used to order the runs of castings a couple of years out from the time they would be machined and finished. Auto makers and machine tool builders would speak of "seasoned" castings. If you took delivery of, say, a 1935 model year car, despite the advertising as to the innovations in the 1935 model year engine, the block and head were probably cast in 1933 or 1934. The oldtimers had quite a belief about "waiting for the molecules to stop moving" in precision machine work.

Some really great accounts of the process here.

I think this is one of those projects (casting your own lathe bed) that is fun and informative to think about, but not really practical to do for real. My family ran a foundry and largish machine shop and I was exposed to this at a very early age. Health and Safety now would have kittens about children being in an old fashioned foundry, but I was well supervised and in no great danger. The description that Joe gives is absolutely right for that type of environment where a lot of one-offs or short runs of the same casting were made. It gets more exciting for really large castings for big machines, and we use used to make a quite a few of these. In that case the mold was built up in a hole dug in the floor (quite literally). Building up a mold like that could take days and the pour was a big event. You need to have enough metal at the right temperature and pour at a fairly critical rate. If you end up short of metal you have many tons of scrap and start again.

Later I was an apprentice in an automotive company. I worked in their engine foundry for a while. There is a massive contrast between high volume foundry work and small batches. Everything about the process needs to be controlled and virtually everything is automated to some degree. Just the molding sand re-circulation, analysis, treatment and mulling is a science in itself with laboratories to back this up. Of course if you have high volume casting, you need high volume core making and this is another big area in its own right. Machine tool volumes have never approached this level, but some of the bigger machine tool makers did invest in some of the same ideas.

billmac

I was fortunate to get a really fine education at Brooklyn Technical HS, 1964-68. My education included some basic wood patternmaking, and some foundry classes as well as 4 years of mechanical drawing & machine design, machine shop, strength of materials and lots more. In our foundry classes, we started off with simple flat-back patterns, then progressed to cope-down molding jobs, and jobs with green sand cores and dry sand cores. I opted for a mechanical course of study, so had some more advanced foundry classes. We did have an arc furnace which we did not use, a pre-war Acme-Junkers induction furnace, used once while I was there, and a Whiting cupola which could melt 2 tons of iron an hour (also used once to teach us about pouring iron). We mostly poured aluminum and bronze castings.

I found out about a working iron foundry in the Greenpoint section of Brooklyn, in about 1967 or so. I called, told them I was a student at Brooklyn Technical HS, and was invited to come spend a day there. No "this is hazardous" or "sign this release". Just: "You're a Brooklyn Tech student, make yourself at home and be careful". No hardhat, no safety glasses. That foundry had a cupola and had a yard full of scrap. A gang of Eastern European immigrants with sledges was busting up the scrap to charge into the cupola. The melter was a recent German immigrant. The molders were going like crazy, all hand ramming assorted patterns for laundry, printing and process machinery parts. It was a real education and I enjoyed spending the day there. At the day's end, the owner of the foundry ( a man named Halloran, who said his people had been in that foundry since the 1850's), asked me my impressions and took the time to talk with me at some length. Halloran and his foundry (Metropolitan Iron) are long gone, as are cupolas.

Another funny story came out of this. We had this oldtimer as a teacher in wood pattern shop. He minced no words, and had come up the hard way as an apprentice boy in the pattern shops. He told us stories of being sent out to get beer pails filled for all the men in the shop. When he heard I had spent the day at Metropolitan Iron, he asked me in depth about how the molds were faced to pour iron, and lots of questions about the patterns. He then told the class a funny story. It seemed when this teacher was an apprentice boy, he worked in a shop which was a machine shop and pattern shop. They sent their patterns out to be poured in a local iron foundry. The castings came back, and the shop he was an apprentice in would machine them. The shop seemed to be having a run of really bad castings. They'd get into the machining, get some machine shop time sunk into the casting only to discover the thing was punky with gas bubbles in the iron. The foreman of the shop told our teacher, who was then an apprentice boy, to go to the foundry and spend a day there. He was given carfare and told to be at the foundry when the day's work began.

Our teacher said he showed up, and was told in no uncertain and very unflattering terms, what the foundry thought about the machine and pattern works, and anyone who worked there. He kept an eagle eye on everything that went on in the foundry. He said the apprentice kids came thru with the beer pails, giving a gallon beer pail to each molder. The molders put the beer pails on their benches and drank off them as the day progressed. The molds were to be faced with plumbago, and the foundry had a ball mill to pulverize the soft coal to make it up.

By afternoon, the ball mill was running, making up the facing dust for the molds, and the cupola was in full blast. The molds were faced and closed, pouring weights on them, and readied for the afternoon pour. The furnace was tapped, and the ladles were soon moving thru the foundry, some on a bridge crane, some being carried by two men and tipped by a third. The molds were poured.

This wrapped up the afternoon and the day shift clocked out. The foreman or super asked our teacher if he'd seen anything that might make for blowholes in the castings. The teacher/apprentice patternmaker said he'd seen the molders "pissing in the sand and pissing in the soft coal pile by the ball mill". He said all that beer had to come out somewhere, and he said that probably accounted for the blowholes. Of course, he was told he was crazy, that molders had been pissing in the sand and coal piles forever to get rid of their beer, and what would an apprentice patternmaker kid know... The apprentice (who went on to be our teacher years later) held out, and the foreman finally agreed to stay into the second shift with him. The second shift came on and started knocking molding flasks open. The foreman grabbed a casting out of the sand, took it out to the yard and had one of the guys there bust it up with a sledge. Sure enough, there were blowholes. Another casting got busted up and it had blowholes. Now, the foreman was thinking there was something to it. The next day, he got hold of some facing that the molders had'nt pissed on, rammed up a mold, and faced it himself. He had it poured that afternoon, and by evening, had found he had a sound casting. He called the foreman of the machine and pattern works, and they made good on the castings but not the machining time, according to our teacher.

Our teacher went on to become a fine patternmaker, and at some point, decided to teach it. He told us his opinion of foundry molders, including some who were our foundry teachers. Our teacher would probably be fired for some of the stuff he did and said. In one instance, a student showed up wearing sneakers in pattern shop class. We had a dress code, and we had shop safety rules. No sneakers allowed on either of these sets of rules. If you wore sneakers you put them on for gym and took them off and put on regular shoes to go to classes. This student had sneakers on, and the pattern shop teacher told him to go sit in a toolroom cage. He gave the student an oil stone and a bunch of dull paring chisels and plane irons and told him to stone the cutting edges and not come out of the cage as it was unsafe for him to be in the shop. Our double shop period ended, and our teacher went to the toolroom cage to tell this student it was time to leave. The student made a snide remark to the teacher: "I'll leave when I'm good and ready". The look on our teacher's face was something I will never forget. He slammed the toolroom cage door shut and padlocked it. He hollered into the cage at the student: "Now you will leave when I am ready to let you out, and that won't be until your old man comes up here, even if it takes into tomorrow. If this was back in the Kaiser's Navy, I'd have you shot for insubodination. Now shut up and stay there till hell freezes over."

We all thought this was just the coolest thing. Nothing like a tough oldtimer from the shops to teach young boys. We filed out of the pattern shop and went to our next class, World History. It was nothing compared to pattern shop, and the teacher was a soft spoken and meek man compared to the shop teachers. The world history teacher took attendance, had the absentee roster, and realized this student was AWOL, MIA or cutting class. He asked the rest of us where that student was. We told the teacher that the pattern shop teacher had him locked in a tool cage and was not letting him out anytime soon. I think the pattern shop teacher DID let the student out, but it was a trip to the principal's office and suspension until his old man came up. Different times, and misbehavior and smart mouths were dealt with in a meaningful way.

We got disciplined for horseplay in our first term of foundry by having to polish shovels and strike off bars and wheel barrows with steel wool and kersoene, no gloves, no concern about anything and the whole class got a zero for that day's grade. We were being treated as young men in the workplace, not as coddled kids. We soon learned that we were working with real machinery and pouring molten metal, and we also learned we could kid around with our shop teachers, but had to toe the mark.

That whole technical high school has effectively been de-nutted to where there is nothing remotely like the education we got in the 1960's. It's a pity, and the "kinder gentler" approach and reliance on computers has sure ruined a generation or two since I came up.

One of the great old time books is Principles Of Iron Founding, 1917, by Richard Moldenke. Richard claimed to have personally poured 250,000 tons of castings. When he was done with that, he got himself educated to the doctoral level and was secretary of the AFS for 14 years.

Joe -

Your story about the East European immigrants breaking up scrap rang a few bells for me. One job given to apprentices in the engine foundry was to break up cylinder block castings with a sledge hammer to get sample pieces from around the bores. All the bores had to have a few samples and they had to be broken out as cleanly as possible, not distorted. These would then go to the metallurgists to be polished up for examination under a microscope. Now this is quite hard work, and a sledge hammer gets pretty heavy if you use it all day long. It was one of those jobs that was more character building than skill forming.

Once you had done enough of that you were given softer jobs, such as testing the moisture content of the molding sand. The traditional way to do this is get a handful and squeeze it to test the consistency. This is fine for a low volume foundry work with skilled molders, but not for high volume production of very complex thin walled engine blocks. The method we used was to climb up the side of the muller and dive in with a small bucket as the muller rotated. This was dicey at the time and I am sure no longer allowed. The moisture content was found by putting a sample of sand in a steel bottle with a small amount of carbide, closing the bottle then shaking it until the reaction was complete. A pressure gauge would show the acetylene pressure and this in turn told you the moisture content. I'm sure you will have come across something similar.

Bill:

Interesting method of testing moisture content in molding sand. I remember our foundry teacher simply picking up a handful and squeezing gently, then showing us the impression of the lines and folds in his hand. He had us do it a few times, and we were on our own. We had some castings that had some wicked "dents" in them from students whose sand was too wet, and we had some castings that had an avalanche of sand in them from sand too dry, and we had some with blowholes from insufficient venting. We got the hang of it pretty quickly. Our HS foundry shop was one short city block long x 2 stories high, with the top being the roof of the building (a 9 or 10 story building as it were). This was to allow the cupola to poke up thru the roof. We had a hand operated bridge crane, and the floor was actually about 24" or maybe a bit deeper of molding sand. We had a muller, and we used it to mix the sand and break up clumps after pours. We also had a power riddler we used which we hung off the hook of the bridge crane. It was a great thing to teach young students.

About that same point in time, my Mom was studying for a master's degree in Library Science at Pratt Institute. Mom was already a grade school teacher, and decided to go get a master's degree. She would go to Pratt on weekends to study and do assignments in their college library. One Sunday, Mom took me with her to the old library at Pratt. It was an interesting place with glass brick mezzanine floors to let light perk through. Mom took me up in this cramped rat maze of shelves to a section of old technical books. I found this one book called "Tales From the Gangway". It was a collection of anecdotes and satire with the practical side of a lot of foundry work as basis, written by a fellow named Dwyer. Dwyer had come up from the foundry floor. I started reading the book and then Mom had to leave, so I never got back to it until a couple of months ago. Found a great copy, used, on Amazon, for 10 bucks. It was owned by Campbell Foundry Company, and then a private individual in that part of New Jersey. I finally, after a mere 45 years or so, got around to being able to take a leisurely read of "Tales From the Gangway". Dwyer recounts all sorts of different and challenging molding jobs interwoven with wit, humor and satire of the 'teens or 'twenties. Dwyer writes quite a lot about methods of molding large gears, using loam molding, and methods where a pulley or flywheel pattern might be "cheated" to cast a wheel or pulley of slightly different overall dimensions. I've enjoyed the read, to say the least.

Your story of the carbide test for moisture in the molding sand reminds me of a test we did on concrete. It was a test for "air entrainment" when concrete was delivered to jobsites. Air entrainment within 3 to 5% is needed to help concrete better resist damage from freeze-thaw cycling. Any more than that, and the concrete is weakened structurally. The old style air entrainment tester was a "pot" which was filled with concrete from the batch plant truck in a prescribed manner. The concrete was "rodded" with a rod of prescribed diameter, and then the pot was struck off so the concrete was flush with the top. It was then whacked with a rubber mallet a few times, and the cover was dogged on. The cover was gasketed and sealed. A small petcock and funnel were tapped into the cover, and the clearance space over the concrete within the cover was filled with water via this petcock & funnel. The petcock was then shut, and a built in hand pump, sort of like a beer tap hand pump, was pumped a set number of strokes. You then read the pressure gauge, and this correlated to the amount of air entrainment. It was a kind of laborious test, and you had to do it before the concrete started being placed into the forms. Another more basic test was the "slump test". This was a test young engineers did on concrete as it was received on the jobsites. You took a truncated sheet metal cone and placed it on a square of plywood which was set level on the ground. You then told the mixer driver what slump was wanted. Slump is a recognized unit of concrete measurement, and correlates to the developed compressive strength of a particular mix. Low slump = stiff mix, less water and greater strength but harder to place in forms and work. Bigger slump = wetter concrete, easier to place, but more prone to curing cracks and lower strength. You told the mix truck drivers you wanted about 2 1/2" or 2" slump and they would yell the mix was too stiff to make it down the chute of the truck. The interchanges with the mixer truck drivers were colorful and ribald. You asked the mix truck driver to add some water to get the slump where you needed it, and to give it a few turns for a sample, and he gave the mixer on the truck a few turns, then sent some concrete down the chute. At this point, you took a wheelbarrow of concrete off the truck, and with a "peanut scoop", put about 1/3 up in the slump cone. You then rodded it with a steel rod, rounded end, 12 shots, rod held plumb. Another 1/3 up, rodded it, and then overtop the cone and rod the last third of concrete. You then struck the concrete off flush with the top of the cone, lifted the cone carefully, and set it alongside the pile of concrete. You then put a straightedge off the top of the cone so it spanned over the pile of concrete and measured down to the top of the pile of concrete. This was the slump. About then, at least three men on the jobsite were saying things like: "Lookit the kid injineer.... he went to college to learn to f--k around like a kid making sand castles at the beach..." You smarted some when that remark was made. About then, the mixer driver was hollering about you being a college engineer, not knowing jack s--t about the real world, and asking if the concrete was within spec, hollering the stuff would set in his truck while you were f--g around making sand castles. You told the mixer driver you wanted a stiff slump, stiffer than his ---- ever was on his honeymoon night, and you were going to send any concrete that was loose as cows--t right the hell off the job. You then said whether the concrete met spec for slump. If it needed more water, you had to do it all again. If it was OK, he put more turns on the mixer, then started it into the concrete bucket (off the crane) or down the chutes. As the pour progressed, you played another round, and that was to get some "cylinders" or cylinder molds filled for "lab breaks" (compressive strength tests). As a young engineer, I did this whole thing a LOT. I learned to throw back the insults and wisecracks as fast as they came at me. I also learned to reject concrete and tell the contractors and batch plant drivers to get it off my jobsite. When you reject 400 cubic yards of concrete and live to tell about it, you have "made your bones".

A lot of field testing and inspection is still a sort of "art" that requires a knowledge of the work and actual conditions as much as anything. As a young engineer on a jobsite or in any workplace short of maybe a total office environment, you are "tried on for size". How you respond determines how your career will go. If you learn to roll with the insults and banter, and realize this is not what your mother raised you to be a part of or what the professors told you would happen, you move ahead. You learn that beneath the insults and banter, the men will teach you if you admit what you do not know and ask them to show you. Any shop or jobsite or powerplant is probably like that. To my way of thinking, throwing a green kid out on the shop floor or out on the jobsite with the crafts is the best thing. You paid your dues busting samples out of engine blocks, and probably heard all about how you handled the sledge and more. paying ones dues on the shop floor or jobsite is the admission to "finishing school". It is where a young person really learns whatever profession they have chosen to go into. Now we live in a world of political correctness and all sorts of procedures and policies about what we can say, what we can talk about, and much else. The workplace is a bit the worse for it, I think.

I love this site! Thanks for all of the responses. Joe, you're info was especially helpful. I know that making my own lathe is not a practical thing to do, or cheap by any means. My intention is not to save money and avoid having to buy a lathe (I already have 3). This is just one of those things that I'd like to do one day just for the sake of doing it. Also I am interested in foundry work but I don't intend to ever get into casting iron or attempt anything this complicated myself. I only have enough time and brains to be any good at one trade (or at least halfway decent as a machinist).

I guess what I'm wondering is what I would need to get a quote from a foundry for the work. Since I don't know much about foundry work, would it be better to make a very basic drawing and let them have some room to make things easier and more logical for them? Or is it the sort of thing that they need exact detailed drawings because they're not able to take their time to design a couple sets of castings? Also, does anyone know the cost of having patterns made? I know its expensive but I was hoping to get an hourly rate and a guestimate on the time it would take to make the patterns for a simple lathe (like Atlas 6" simple). Or if foundries will still use patterns that some yahoo (like me) would send them and what sort of requirements they may have for those (mounted/ not mounted, etc.)

Once again, thanks for all of the responses.

Tim

I make occasional patterns and have them cast in commercial foundries.

The short answer is that very few foundries are going to give any meaningful quote based only on drawings. It is not worth wasting their time, unless you are a big corporation in the planning stages of keeping one of their lines open for 6 months of the year with product. They will generally quote if you have the patterns, or can clearly communicate the patterns (photos) and sizes

How much a foundry will charge to pour iron for you will very strongly depend on the quality and complexity of your patterns and core boxes. You can probably still get grey iron poured a few places for around $2/lb in small batchs with a minimum order around $500 - 1,000. But it could cost you $12/lb or more, if your patterns and core equipment do not make it easy for them to make moulds; or if the castings are "complex" in terms of required gating, runners and "rigging" that the foundry puts on to make the iron flow correctly. If you go to the trouble to have a lathe bed caste, perhaps you would want to specify something harder than class 30 or merely "grey" iron, unless you have a way to harden the ways separately? Higher classes of iron take higher heats, and don't flow as well so cost more to pour.

There is one place in the USA that might work to your ideas with basic split (loose) patterns and modify them to work at a "reasonable" rate, and that is Cattail foundry. Then again, they might refuse your work, too. You have to go there in person, or communicate by USA postal service.

There are a number of patternmakers on this site, if you are serious. Rough guesstimate, if you provide detail drawings of a workable idea, a couple hundred hours of professional time at professional rates. Heck, just start with 50 hours for a flat bed in a simple loose pattern and work up from there.

You are probably farther ahead to go with a length of durabar and start carving.

PS, you need to read the rules (FEQ's) and stop mentioning "Atlas" lathes. They are not actually considered machine tools by the site owner and will get the thread locked.

smt

stephen thomas said:

PS, you need to read the rules (FEQ's) and stop mentioning "Atlas" lathes. They are not actually considered machine tools by the site owner and will get the thread locked.

smt

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Ha! I thought that was a joke about the Atlas lathes until I read the rules! Forget I ever mentioned Atlas and lets think South Bend style lathes instead.

Tim

My family was also in the foundry business, in Philadelphia, although from the time they bought into this--1952--all the casting was subbed out and the cupula dismantled and they bought rough castings of their items and snagged them and machined them there as well as doing steel work of various kinds. I mention this only to say that Joe M's answer to the original question of how a lathe bed was cast in a manufacturing setting strikes me as concise and accurate, and I enjoyed reading it.

Just for fun here's a photograph (about 1915, I think and I think I've showed this before) showing one of the buildings with a lot of flasks stored outside on the sidewalk:



That building still exists and I own a ninth of it.

I have a lathe bed pattern for a Potter lathe, it is kind of like a hardinge. I live in Tucson and have all the equipment to cast one if you are interested let me know I have been wanting to do this as well.

a couple hundred hours of professional time at professional rates

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145 hours about on this small but intense and delicate split pattern

But then as my late brother Vic would say, "I am slow, but then I am expensive"!

http://www.practicalmachinist.com/v...castings-look-good-255315/?highlight=castings

Those are some pretty slick spindles. Very nice work sir. I'd ask how much for a pair to put on my '25 T but I can't imagine they'd do me much good out here in Arizona!

northernsinger said:

My family was also in the foundry business, in Philadelphia,

That building still exists and I own a ninth of it.

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I lived in the burbs of Philly fora long time so I looked....

Have you seen that building lately?... google shows the walls covered with some green plant of sort...

Is it a condo conversion or will it be?

kpotter said:

I have a lathe bed pattern for a Potter lathe, it is kind of like a hardinge. I live in Tucson and have all the equipment to cast one if you are interested let me know I have been wanting to do this as well.

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Now this sounds like an interesting project to me. Are you related to the Potter lathe folks or is the name just a coincidence? I saw your post on getting a new building and I'd love to check it out sometime. An old brick building from the 30's sounds like a great place for a shop.

Tim

Oh my what a fantastic thread. I'm going to buy a copy of Dwyers' book today. My friend who is a factory machinist turned artist has been doing cast iron leg conversions into furniture recently, which is unsatisfactory as there aren't a lot of old machines on the west coast, the legs are never the right height for furniture anyway, and if you try to cut and re weld cast iron you enter a world of pain. This leads to a long delayed plan to explore doing the same pieces in cast aluminum which we haven't explored because he doesn't do administration and I'm extremely busy. But I take to heed the notion that you can't get a proper quote without a pattern. On that note, if one were to machine a pattern on a CNC Router, what would be a good material? Would MDF work? Or good plywood? Or should it be a solid wood glue up? I'm thinking in particular of a set of legs which are art deco-flat and of a suitable size for a coffee table.

My vote for thread of the year.

Thanks,
RC

Frenchy said:

An old brick building from the 30's sounds like a great place for a shop.

Tim

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Good ...not great, and only if you dont EVER need parking for so much as a bicicle... car? even a minni car? FORGIT IT... the parking cost will kill you....
Then there's the Philly TAXES that will tax you up and out the wazooooo....
Then the location... right there in what they call Center City... or close enuf to it to make it cost a HUGE bag a cash for EVERYTHING....
Most everyone that could leave did...30 to 40 yrs ago...
You gona pay wages?... city tax last I knew was 4.3125% on top of the State 2.2% Not Biz friendly at all