This has been a little bit of a slow project, but I want to document it before I forget half of what I've done.
I'm attempting to create a set of slip rolls that will roll 1.6mm stainless. The requirement is needed for another stalled project of mine. I need to roll and weld a truncated stainless cone. I require accuracy and decent fit up to aid my shoddy TIG welding. The thicker than necessary gauge thickness is also specified to help make the welding easier too. I already own a set of homemade slip rolls. They use inch and half by quarter inch wall tube with 12 mm spigots into 20mm thick side frames. They are not quite man enough to do the job. They do the job fine on 1.2mm mild steel though. Manufactured rolls seem to be designed to roll ever wider sheets of 1mm or 1.2mm mild steel. My plan is to build a bespoke, compact and stiffer set for stainless, which is a totally different and unco-operative material to put shape into.
This is the previous set I made. They are 600mm wide. The adjusting bolts are m10. The ends of the rollers are 12mm. They give a reasonable account of themselves when rolling stainless so I have some confidence that I'm not a million miles away from getting it done. The minimum width I need to roll is about 14 inches or 356mm. A wider set gives more flexibility, but if I go too wide I risk introducing more flex and deflection that I'm trying to avoid. I have other limits to consider as well. I need to get the material in a lathe.
Pictured below is two-inch solid En8 bright bar. I bought imperial as it was 10% cheaper than 50mm plus I get 0.8mm more on the diameter. Finally settled on 510mm bar lengths with 25mm ends. The pictured cut may be longer, but the cut got revised down once I'd tried a silly idea or two. The 510mm length was decided on as it is pretty much the maximum I can fit in my bigger lathe and still be able to machine the ends. I suppose they can always get trimmed down further if I've been greedy and they have too much flex over the length.
All the lathe is getting used. I'm not sure that the far end of the lathe bed has seen work before. The carriage is against the far end/stop in the boring bar picture. I can sort of justify a bigger lathe to myself now.
The lathe was running 335rpm. Didn't dare try the top speed. Running with a heavy long bar was a bit disconcerting at first but it's amazing how soon you get inured to it. Six ends to drill and bore so plenty of lathe time. Became quite accomplished at tweaking the steady screws by hand to eliminate vibration mid cut. It's an old lathe and things have a tendency to work a little loose at times.
Piece of 25mm bright bar used as go/no-go gauge. I bored some of the ends out to finished size, but in the end it was simpler to bore undersize and use a reamer to save me overshooting. 25mm is a big improvement over 12mm used on the previous roll set.
The bores will get chamfered as there will be some brazing or welding going on to keep the 25mm bar stuck in place.
Continued....
I'm attempting to create a set of slip rolls that will roll 1.6mm stainless. The requirement is needed for another stalled project of mine. I need to roll and weld a truncated stainless cone. I require accuracy and decent fit up to aid my shoddy TIG welding. The thicker than necessary gauge thickness is also specified to help make the welding easier too. I already own a set of homemade slip rolls. They use inch and half by quarter inch wall tube with 12 mm spigots into 20mm thick side frames. They are not quite man enough to do the job. They do the job fine on 1.2mm mild steel though. Manufactured rolls seem to be designed to roll ever wider sheets of 1mm or 1.2mm mild steel. My plan is to build a bespoke, compact and stiffer set for stainless, which is a totally different and unco-operative material to put shape into.
This is the previous set I made. They are 600mm wide. The adjusting bolts are m10. The ends of the rollers are 12mm. They give a reasonable account of themselves when rolling stainless so I have some confidence that I'm not a million miles away from getting it done. The minimum width I need to roll is about 14 inches or 356mm. A wider set gives more flexibility, but if I go too wide I risk introducing more flex and deflection that I'm trying to avoid. I have other limits to consider as well. I need to get the material in a lathe.
Pictured below is two-inch solid En8 bright bar. I bought imperial as it was 10% cheaper than 50mm plus I get 0.8mm more on the diameter. Finally settled on 510mm bar lengths with 25mm ends. The pictured cut may be longer, but the cut got revised down once I'd tried a silly idea or two. The 510mm length was decided on as it is pretty much the maximum I can fit in my bigger lathe and still be able to machine the ends. I suppose they can always get trimmed down further if I've been greedy and they have too much flex over the length.
All the lathe is getting used. I'm not sure that the far end of the lathe bed has seen work before. The carriage is against the far end/stop in the boring bar picture. I can sort of justify a bigger lathe to myself now.
The lathe was running 335rpm. Didn't dare try the top speed. Running with a heavy long bar was a bit disconcerting at first but it's amazing how soon you get inured to it. Six ends to drill and bore so plenty of lathe time. Became quite accomplished at tweaking the steady screws by hand to eliminate vibration mid cut. It's an old lathe and things have a tendency to work a little loose at times.
Piece of 25mm bright bar used as go/no-go gauge. I bored some of the ends out to finished size, but in the end it was simpler to bore undersize and use a reamer to save me overshooting. 25mm is a big improvement over 12mm used on the previous roll set.
The bores will get chamfered as there will be some brazing or welding going on to keep the 25mm bar stuck in place.
Continued....
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