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coalstove
08-20-2007, 07:55 AM
Alright can't afford a Laser or water jet. Has anybody cut 16-18gauge HP stainless on a table, I have been cutting it by hand and have had pretty decent results, the plastic coating gives me a little trouble sometimes, but know I need to make more geometric shapes. Can submerging it in water do a better job, speeds and feeds? Will be making prototypes from steel. Using a new Hypetherm 1250 (both torches), and looking at the ez- router table. will build my own water tank. Any suggestions would be appreciated. Hope to give a little more to this forum in the future, instead of taking, you guys and gals have been a wealth of info, thanks to all.

Chip

steele
08-20-2007, 10:20 AM
How big are your parts? I've been successful doing this by sandwiching the stainless between thick steel plates, maybe a 1/4" thick. Since the parts I was making had holes in them I pre-drilled the holes clamped the top & workpiece down & went to town. This is suitable for short run production; a lot of work for one piece; & not competitive for long run unless it gets tapped holes or other work requiring a mill. Vacuum can work for big parts but not small ones. I don't think submersion makes a great deal of sense; flushing is more important than cooling.

coalstove
08-20-2007, 10:28 AM
They can be up to 90" x 48" for deck plates and as small as 5x5, most of my holes are cutout for lights that get grommets anyway, but I have parts that are used as filler plates that need clean edges

bekx
08-20-2007, 03:38 PM
How big are your parts? I've been successful doing this by sandwiching the stainless between thick steel plates, maybe a 1/4" thick. Since the parts I was making had holes in them I pre-drilled the holes clamped the top & workpiece down & went to town. This is suitable for short run production; a lot of work for one piece; & not competitive for long run unless it gets tapped holes or other work requiring a mill. Vacuum can work for big parts but not small ones. I don't think submersion makes a great deal of sense; flushing is more important than cooling.

if u do this u get rust in less then 2 weeks.

Mike@Torchmate
08-20-2007, 04:54 PM
Thermal Dynamics seems to be having some extremely good cut quality with the water mist torch on their Autocut series. The cut edge almost looks polished. It's not cheap but it is an alternative

dz1sfb
08-20-2007, 08:04 PM
Stainless steel, if you can't laser, or water jet it, then plasma cut it. Finish the edge by grinding. Any method will require some edge finishing, depending on your requirements. SS is my least favorite material.

Ken :)

dz1sfb
08-20-2007, 08:05 PM
Stainless steel, if you can't laser, machine, or water jet it, then plasma cut it. Finish the edge by grinding. Any method will require some edge finishing, depending on your requirements. SS is my least favorite material.

Ken

probinson
08-21-2007, 11:40 AM
Industrial plasma cutting is done submerged and is supposed to yield an excellent finish but I have not tried it myself so I'll have to base my advice on what works for me.

I suggest you build your CNC to take both a plasma torch to cut out the parts and a die grinder with what's known as a "diamond pin" for polishing the edge. Now not all diamond cutting tools are created equal. You want 100% concentration resin bond NOT ELECTROPLATED.

If you plan to build a CNC track torch here is some information on the one I built to help you along.

My table is 8 foot by 12 foot (I call mine the BAP [BigAssPlotter]). I use 3/23 diameter 7 x 7 Strand Steel Aircraft Cable to drive the X and Y axis in a standard pen-plotter configuration with 15Lbs of pretension on the cable. The positioning is as accurate as standard lead screws, many times faster, and zero backlash. (Try pricing a 12 foot ball-screw!!) The accuracy is good enough to cut gears that can go into service right off the plotter.

Cable drive also gives you accurate control of the cutting force by simply adjusting the power to the motors which is a distinct advantage over lead-screws in a multi-purpose machine. You adjust how hard you want to push the tool instead of how fast the tool should go.

The cable drive is amazingly powerful. The Z control transistors burnt out in the middle of a job and I finished the job by literally standing on the carriage and pressed the manual up and down switches on the router head when the appropriate LED came on.

Oh, you want a 1" minimum bend radius (use 2" diameter pulleys) or the cable will wear out. I used sliding glass door rollers because I needed 26 of them and they were very cheep but, with only a 1" diameter, I have to replace the cable every 1,000 hours or so.

I primarily use a router with a 1/8 carbide endmill to cut polycarbonate and aluminum. I cut Polycarbonate dry up to and inch thick. To cut aluminum I lay down a sheet of brown wrapping paper first and paint it with motor oil. The oiled paper keeps the aluminum from sticking to the bit. Spray coolants didn't work at all. I have accidentally cut through a 1/4" thick steel hold-down clamp with an 1/8 endmill but wouldn't recommend cutting steel plate with a router on purpose.

I made my table out of wood (2x12 frame with 3/4 plywood top) with steel rails on the X-axis for the Y-axis track to ride on. The axis are made square by adjusting the cables so all you need is one straight edge to get a prefect alignment. I used the router to trim the table top level and then use styrofoam sheets as my backing material.

When I use the plasma cutting head, I lay down a sheet of aluminum to protect the table, then some wood slats to space up the steel sheet. I run a 1/2" router in the pattern will be cutting to clear a path in the wood for the plasma cut and spray water on all the cut edges of the wood so they won't catch fire. I clean up the edges by hand but I don't cut a lot of stainless.

probinso @hsc
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