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04-25-2012, 11:40 PM #1
Best way to make a bunch of 3/8 x 9/16" Rectangle pieces with a 3/16"d hole in center
I need around 100 pieces of 3/8"x9/16" rectangles out of 1/16" thick steel with a 3/16" diameter hole in the center.
I originally thought I'd just drill the holes one after the next using a jig and then just slice them off with a chop saw. But I'm finding that the holes aren't a problem but the precision of the chop saw and slicing is pretty difficult. Also, I had a hard time getting 3/8" wide 1/16" thick steel bar stock.
Would having them laser cut be the way to do it? Would the cost be reasonable for 100 pieces of something like this?
I'm not a machinist (trying to be) but I'm a wood worker so any ideas are appreciated!
04-25-2012, 11:48 PM #2
i would cut them all first, then clamp them together, and gang drill the hole
04-26-2012, 12:38 AM #3
Dunno what kind of precision you need but for only 100 pieces I would use a bandsaw with a stop gauge.
Drill or punch the hole later.
04-26-2012, 12:43 AM #4
04-26-2012, 01:52 AM #5
I would shear the rectangles and then punch or drill the holes. Perhaps a local sheet metal shop can do the shearing for you.
04-26-2012, 07:03 AM #6
I do a lot of stuff like that. Shears are your friends. A hundred blanks is sub 3 minutes. Then stack them in a simple little jig and drill 10 or so at a time. That way only the top + bottom ones will have burrs!
04-26-2012, 08:43 AM #7
04-26-2012, 09:08 AM #8
Simple job for a sheetmetal house.... punch the holes... then punch out the surounding and your done...toss them in the barrel finishing tub for some rock and rolling and then your really done.
04-26-2012, 09:20 AM #9
I would get quotes from a local laser shops. Add a % that makes it worth it to you for your time, and call it a day(If their for a customer). Depending on tolerences, it might just be easier to let someone with the proper machines make em. I don't have the machines to make those cost effectively, so i personally would either outsource them, or not quote em. Its just not worth the time unless your set up for something like that.
Now if your just making them for yourself, and they don't have to be to a tight tolerence. As mentioned, bandsawing them, and drilling in stacks would make quick work of that.
04-26-2012, 11:26 AM #10
Depends on your tools, and expected tolerances.
I don't have shears or punches, so my approach would certainly consider parting them off a bar in one of my Hardinge second ops with a turret.
Not as fast as shear and punch in one op, but might be competitive with shear & drill. Also, as your flatness or other tolerance requirements increase, the turret lathe begins to increase in attractiveness.
But if saw and drill is close enough, make a show with a stop, and bandsaw on edge (instead of across the thickness) then make a corner fixture for the DP and drill in small stacks as has been mentioned.
04-27-2012, 09:16 PM #11
Dumb question but a practical one and I hate to ask it because it's a subjective question but how would you make a corner fixture? I know what the concept is but how would you do it? Being a wood worker, I'd cut two pieces of wood square, glue and brad nail them together at a right angle, then brad nail and glue that to a piece of MDF as a base and make sure it was big enough I could secure it to my drill press table somehow (clamps or drill and bolt it). A 3/16" drill bit is around 2.5" of flute length but I'd realistically only try to do an inch or so stack of parts due to bit drift.
That's how I'd make a corner fixture for the drill press. That's from a wood worker.
How would a machinist do it?
Lastly, I have a band saw but it is a wood bandsaw. My only metal cutting tool is a radial arm saw with an abrasive metal cut-off blade. I need to invest in a good metal bandsaw but space is an issue. My other problem is that I can't get bar stock in 3/8" width (only 1/2"). Metal is really hard to rip I've found and I don't like the idea of grinding 1/8" off. Is it possible to find 3/8" width bar?
04-27-2012, 10:37 PM #12
You could order it 1" wide, bandsaw it in half, mill it to 3/8" on both parts. Or, as everyone else has suggested, shear it/let somebody else shear it.
04-27-2012, 11:07 PM #13
04-28-2012, 12:15 AM #14
Cut some strips out of your 1/16 sheet
Stack them to save time for the following:
Drill holes in a line, center to center distance to allow for a chop saw cut between the holes. You get something like this
o o o o o o .....
Now slot between each hole. Go far enough that next operation will work
o | o | o | o | o | o .....
Now rip along the side, catching the pieces as they fall off
o | o | o | o | o | o .....
04-29-2012, 12:18 PM #15
You might try Robinson Laser in East Chicago. Their system permits an instantaneous quote from the input of the material spec and a .dxf file of the part. I have used them for various pieces that I am not equipped to cut and found their service both economical and timely. You can access their website at Robinson Laser and follow the instructions for obtaining a quote and an order, if you are so inclined.
Edit: As I think about it, I believe that their lightest material is 14 ga., which is about .080" thicker than 16 ga.
04-29-2012, 04:03 PM #16
Why would you start with bar? Or flat as most people here would call it. On a shear you start with sheet. Ours normally comes in a 8x4' sheet. Most places with a shear will have 1/16 steel kicking about. Slice a length or two off what ever way is widest setting the back gage makes it easy, any shear worth owning has a back gauge. Walk around the back deposit a empty bucket in the appropriate spot. Pick up your two strips walk back to front and set shears back gauge to the other dimension. I normally flip from single cycle to constant at this point. Now push both bits in using the side lay till they hit the stop. Press and keep pedal pressed and just let here eat, pushing the stock to the back gauge every time the clamps let lose. The bucket collects them, you don't want to be picking up 100+ bits its very tedious! Don't stack the flat, keep it side by side for a nice clean cut!
The advantage is unlike flat is the parts will be far more accurate. The tolerances on flat is darn sloppy, like circa 1/16" sloppy at times. Secondly by cutting them out of pickled and oiled sheet there lovely and scale free. The edges will be nice and clean and if the shear blades are good they will be burr free, but the corners will be sharp! A saw cut will be far messier less precise. Normally the bits i do are either in 1 or 2mm though but im sure 1.6mm sheet would cut just as easy :-) Not that you can easily get 1.6 here any more its always 1.5 these days.
04-29-2012, 04:36 PM #17
What tools do you have for metal working?
How nice do you want them to look when you're done?
04-29-2012, 08:07 PM #18
A plate shear and hand punch will do this. $55 for the shear at enco Maybe $100 for a Roper hand punch, but there are pneumatic punches too.
Finish flat with hammer and touch the sharp edges to a sander.
04-29-2012, 08:23 PM #19
05-01-2012, 11:17 PM #20
That'd be the way to do this. Bummer those are squares. Too bad it's not easy to find a rectangle at those kind of prices.