Lacking creative title, (yet preserve continuity) "Wait, one more second......"

[mwmkravchenko]

Like so, brought from Illinois, by way of PA.
Attachment 44369
Worst object to ratchet down, ever.
Attachment 44370

I could see this thing being a handy item in a shop. To bad that i live in an area that is devoid of manufacturing industry. Ottawa is a government town. I have to travel to the greater Toronto area for anything like this. But I will keep my eyes open for one of these.

[Toolmaker51]

It was very clumsy to operate, at first. But once a physical set-up sorted out, some finesse IS possible. All the utility is in tooling it up, like any machine tool.

I wouldn't recommend one as a whim. My favorite press type and most anxious to build is a screw press. The utmost ratio of tonnage and incremental travel. All the others can only be monitored, screw press is full control.
Suppose some kind of CNC control has been applied with linear readers. OK, how is a few thousand $'s of electronics better than a long travel indicator?
The oldest use of screw presses I know of, straightening barrels before and after rifling. The craftsman would peer thru a barrel angled upward, pointed at a thin wire hanging in a window. It imparts a line reflecting off the tubes inside surface revealing every deviation from straight. The barrel is already mounted in a press, so rotating and moving back and forth ironed out everything.

[WmRMeyers]

It was very clumsy to operate, at first. But once a physical set-up sorted out, some finesse IS possible. All the utility is in tooling it up, like any machine tool.

I wouldn't recommend one as a whim. My favorite press type and most anxious to build is a screw press. The utmost ratio of tonnage and incremental travel. All the others can only be monitored, screw press is full control.
Suppose some kind of CNC control has been applied with linear readers. OK, how is a few thousand $'s of electronics better than a long travel indicator?
The oldest use of screw presses I know of, straightening barrels before and after rifling. The craftsman would peer thru a barrel angled upward, pointed at a thin wire hanging in a window. It imparts a line reflecting off the tubes inside surface revealing every deviation from straight. The barrel is already mounted in a press, so rotating and moving back and forth ironed out everything.

I knew they could straighten barrels by looking through them, didn't know they used a wire for a reference line. Amazing where you can learn new (to me) and nifty info! Now if I can just find and shoehorn a screw press into my shop...

Not anytime this week, anyway!

Bill

[mwmkravchenko]

It was very clumsy to operate, at first. But once a physical set-up sorted out, some finesse IS possible. All the utility is in tooling it up, like any machine tool.

I wouldn't recommend one as a whim. My favorite press type and most anxious to build is a screw press. The utmost ratio of tonnage and incremental travel. All the others can only be monitored, screw press is full control.
Suppose some kind of CNC control has been applied with linear readers. OK, how is a few thousand $'s of electronics better than a long travel indicator?
The oldest use of screw presses I know of, straightening barrels before and after rifling. The craftsman would peer thru a barrel angled upward, pointed at a thin wire hanging in a window. It imparts a line reflecting off the tubes inside surface revealing every deviation from straight. The barrel is already mounted in a press, so rotating and moving back and forth ironed out everything.

I keep looking for screw presses and think yo myself that it is possible to make one. I would cast the frame in reinforced high strength concrete and the rest is fairly basic turning and milling. Some welding to. I would have to figure out how to make the screw though. They are some aggressive on the thread. And I think multiple start, but not sure on that front.

Thanks for the heads up. Off and on I have seen those larger presses and wondered the finesse that you can apply with them.

Having watched quite a few videos about a screw press I was sold on the idea rather quickly. It's just that I would probably want a 6 ton, and they are not so easy to pay for. Perhaps a 3 ton would be a good beginning and make a larger one if needed.

Mark

[Toolmaker51]

Knowing greatest power is in a fine pitch thread, but of course they advance slowly, those conditions offer a lot of solutions to both. From manual standpoint, multi start threads generate little power but advance quicker than same apparent pitch (ie 8 TPI 2 start, looks like 16. Variety of press using multi-start threads to advantage are "fly presses", a pair of arms with heavy weight at the ends, threaded with the screw. The ram, about a half turn above project, is forcibly accelerated into the material. They're mainly used cold-forming but an operator, maybe with helper could do hot-work.

Concrete and rebar would probably work if there is sufficient tensile strength (cross section/ area of columns) but potentially 2x size of steel frame. Plate, C-channel and angle iron, more practical. BTW commercial screw presses went up to about 20 tons. That's calculable by thread pitch and applied torque.

6 to 7 tons wouldn't require welding. Enough Grade 5 or 8.8 threaded fasteners, properly placed in minimally sized clearance holes, using bolts, washers & nuts. It's how all kinds of 20 ton hydraulic presses are built, assembled often by purchaser.

I'd never bother with a casting. There are manufacturers of good quality un-plated allthread rods, you would prefer rolled over cut threads, definitely. The threaded barrel, is about the only thing needing some machinery to produce, bet a frame with three purchased nuts would be acceptable. A handwheel is normal, bet a salvage yard would turn up a cast tractor steering wheel. Might be one hanging on a barn, if one doesn't mind a little rock salt.......

A small wire winch for the table, some round barstock cross pins, symmetrical uprights right and left with the holes. There is more sawing and drilling than anything.

Of all features presses should have, I consider two (three) paramount; a] the head slides right and left in the top most frame and clamps into position. b] Uprights are open to allow long material. c] Bed is parallel in both planes, when owner builds tooling (furniture) that fits and slides in relation with top frame.
Few commercial units have those, most supply a couple notched flat plates to accommodate axles with bearings and that's it. Oooh big deal.
There should (could) be punch holders, forming dies, Vee blocks at a minimum. 6 or 7 tons will punch 1/8" and 3/16, after-all.
https://www.americanmachinetools.com...punch_hole.htm
https://news.daytonrogers.com/how-to...e-free-formula

Writing this conjured a hybrid press, hydraulic with a screw ram. Not like the ordinary combination of a coarse ACME thread that just advances quicker than the air or hydraulic cylinder. Connecting them, that close-up hasn't focused yet. Don't know connecting is important, just secure alignment.

[mwmkravchenko]

Knowing greatest power is in a fine pitch thread, but of course they advance slowly, those conditions offer a lot of solutions to both. From manual standpoint, multi start threads generate little power but advance quicker than same apparent pitch (ie 8 TPI 2 start, looks like 16. Variety of press using multi-start threads to advantage are "fly presses", a pair of arms with heavy weight at the ends, threaded with the screw. The ram, about a half turn above project, is forcibly accelerated into the material. They're mainly used cold-forming but an operator, maybe with helper could do hot-work.

Concrete and rebar would probably work if there is sufficient tensile strength (cross section/ area of columns) but potentially 2x size of steel frame. Plate, C-channel and angle iron, more practical. BTW commercial screw presses went up to about 20 tons. That's calculable by thread pitch and applied torque.

6 to 7 tons wouldn't require welding. Enough Grade 5 or 8.8 threaded fasteners, properly placed in minimally sized clearance holes, using bolts, washers & nuts. It's how all kinds of 20 ton hydraulic presses are built, assembled often by purchaser.

I'd never bother with a casting. There are manufacturers of good quality un-plated allthread rods, you would prefer rolled over cut threads, definitely. The threaded barrel, is about the only thing needing some machinery to produce, bet a frame with three purchased nuts would be acceptable. A handwheel is normal, bet a salvage yard would turn up a cast tractor steering wheel. Might be one hanging on a barn, if one doesn't mind a little rock salt.......

A small wire winch for the table, some round barstock cross pins, symmetrical uprights right and left with the holes. There is more sawing and drilling than anything.

Of all features presses should have, I consider two (three) paramount; a] the head slides right and left in the top most frame and clamps into position. b] Uprights are open to allow long material. c] Bed is parallel in both planes, when owner builds tooling (furniture) that fits and slides in relation with top frame.
Few commercial units have those, most supply a couple notched flat plates to accommodate axles with bearings and that's it. Oooh big deal.
There should (could) be punch holders, forming dies, Vee blocks at a minimum. 6 or 7 tons will punch 1/8" and 3/16, after-all.
https://www.americanmachinetools.com...punch_hole.htm
https://news.daytonrogers.com/how-to...e-free-formula

Writing this conjured a hybrid press, hydraulic with a screw ram. Not like the ordinary combination of a coarse ACME thread that just advances quicker than the air or hydraulic cylinder. Connecting them, that close-up hasn't focused yet. Don't know connecting is important, just secure alignment.

I'm going to have to do some thinking. Generally a dangerous thing

Mark