This youtube is entitled "Craftsman are making the flour milling machine roller". It is an amazing study in how the Pakistani machinists, foundrymen, and forge shop blacksmiths work to produce flour mill rollers. The youtube begins with a neighborhood foundry. This foundry uses torpedo shaped melting furnaces, fired on waste engine oil. The torpedo furnaces turn slowly when firing. They are charged with scrap cast iron, much of which looks like products of other local foundries- stuff like curved spoke pulleys, smashed finned motor stators, busted pump housings, and any other cast iron scrap. The foundry uses centrifugal casting machines, driven by one-lung diesel engines. A flat belt spins the mold, and it is shifted and held in location by a bar driven into the ground to keep the mold spinning.
The hollow cast iron roller bodies arrive at the machine shop. This shop can only be described as the Pakistani equivalent of the shop where the "Bull of the Woods" worked. Old lathes are adapted to part off the ends of the cast roller bodies. A strap clamp around the rough casting trips a 'peck feed' mechanism to work the cross feed and run in a parting tool.
The shaft ends of the rollers are made in another local forge shop. Again, waste oil fired furnaces are used to heat the steel, which appears to be scrap from the ship breakers. The hammer smiths are quite good and have swage dies made up for this particular job.
The machinists bore the roller bodies using a shop-made line boring setup on another old lathe. Interestingly, the line boring bar is supported on a tapered roller bearing, the roller/cone being on an arbor in the tailstock, the female race or outer cone being in the end of the boring bar. The machinist uses a home-made telescoping gauge to get the inner diameters of the bored ends of the roller body. His telescoping gauge is two studbolts with rounded ends, a tapped bushing and a couple of hex nuts. He gets the bore diameters locked in on his home made telescoping gauge handily.
The shaft ends for the rollers are turned on another lathe, and the home made telescoping gauge and outside micrometer are used to turn the shaft ends for a shrink fit. The roller body is heated with open propane burners, with what look like oil drum lids used as heat/flame shields to keep the heat in the roller bodies. The machinist figured his shrink fit correctly as the shaft ends slide in, and soon are locked solid.
After the roller and shaft journals are turned to final diameters, a shop-made motorized milling head is mounted on a lathe topslide and used to mill a keyway in one shaft end. It looks like the Pakistanis use water dripping on the milling cutter as coolant. No guard or shroud on the milling head motor's cooling fan, and wiring looking like it could give someone a nasty shock, and water dripping for coolant. The milling head appears none too rigid in its setup, or the camera was shaking, but it does hog in a large keyway.
The really interesting finale comes with the machining of the grooves in the surface of the milling rollers. This shop has several specialized machine tools for this operation. These appear to be a light duty openside planer crossed with a rifling machine. As the roller is moved along the ways of the planer, it rotates a few degrees. This causes the toolbit to cut a groove on a very long spiral, almost a diagonal line. The machine tool for this job appears to have been specially built, and automatically indexes the roller for the next groove. No name was visible on these machine tools. The amount of 'spiral' appears to be adjustable, as is the indexing. When the rollers are finished, there are numerous fine 'rifled' grooves around the outside surface.
This shop has a mix of geared head engine lathes and cone drive lathes. Some of the cone drive lathe headstocks were modified to use roller chain drive for very low speed/heavy work like parting off the roller body casting ends. The carbide lathe tools look to be shop made with chunks of carbide brazed to steel bodies. In one sequence, a shop made carbide-tipped parting tool is used as a shim in a toolpost to hold another tool. As this particular lathe operation was being filmed, a chunk of the carbide tip on the parting tool/shim breaks off, but does not affect the operation and no one seems to notice. The shop has some overhead powered hoists, and rigging is done mainly with chains. It is a somewhat dark older shop, and while not having lineshafts, is a forest of older lathes and older machine tools. Instead of the Bull of the Woods walking the shop floor, there are a variety of older men, some who seem to be keeping a watchful eye on the work, some who do lend a hand to the younger machinists. The machinists use a surface gauge and pointer of sorts to center work in the lathe 4 jaw chucks, no dial indicators seen in use. However, they do use micrometers for the critical fits. They do not seem to own a combination center drill or 60 degree countersink. Rather, they simply poke a drilled hole in the end of the work and run the tailstock center into it. The shop is not what we'd consider a safe place to work, with many unguarded or open gears and unguarded belts and pulleys and similar. No one seems to wear safety glasses and many of the men work in sandals or light shoes. Despite this, whether in the foundry, the forge shop, or the machine shop, no one is wandering around with any bandages, eye patches or obvious missing parts. The men wear loose clothing typical of Pakistan, yet no one seems to have gotten wound up in the open gearing, nor does anyone get burned by molten iron, sparks or hot scale. The men in this youtube all seem happy to be working, and invariably, there are also men in these youtubes who are taking pictures or video on their phones aside from whomever is taking the actual youtube. While conditions there are not the safest and overall living conditions are a subject not for discussion here, it is heartening to see how local industry works. Scrap iron and old crankcase oil and scrap steel from the ship breakers and old machine tools and ingenuity and grit on the part of the Pakistanis all come together to meet the needs in their country.
In another youtube, a local shop is building what might be called 'wheat separators' or "threshing machines". These are PTO driven small threshing machines. The local shop builds them using plate brakes, shears, oxyacetylene cutting torches and stick welding. The Pakistanis have moved up from the locally built 'buzz box' welders to inverter power supplies. Seeing this, I was surprised they had not started using MIG welding as the building of the threshers required a lot of long seam welds on light sheet steel and light angle. They use stick welding, and despite having the inverter welding machines, do all their tack welding and some stitch welds without a shield. Aim the electrode for where they want to strike an arc, close their eyes and turn their head aside and burn rod for a second or two. When they do use a welding shield, it is a beatup piece of fiberboard with a welding filter lens, held in one hand. No one seems to wear gloves when welding or using a cutting torch, nor does anyone wear cutting goggles or similar. Feet in sandals, working cross legged while welding or burning with a torch seems the norm. Again, no one seems to be showing obvious past injuries, but I cringe when I see how these guys work. Anyone who has ever 'caught a flash' around welding knows what that feels like (sand under your eyelids later in the evening after you are done working). Anyone who has ever had a piece of weld slag pop into their eye and had to have the slag removed at the ER also knows how that feels. Been there a few too many times with both these injuries, so marvel at the Pakistanis and how they subject themselves to those conditions and keep on working. They produce equipment to meet their needs- threshers to harvest grain and mill rollers to mill it into flour to feed the population, using recycled machine tools and recycled materials and fueled on waste crankcase oil.
This youtube is unique in that it traces the making of the flour mill roller from the casting and forging to the complete machining.