Need to cut perfect hole in thin guage brass

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Anyone have an inexpensive idea for doing so?I have a very old and very large brass lens I want to make what is called a Waterhouse Stop for it. I need to cut varying sizes of holes which need to be quite neat in 22 guage or thinner.Suggestions?Thanks in advance.Regards,RobGreat Basin WeldingInstagramBlue weldersRed weldersMy luscious Table DIY TIG Torch cooler
Reply:what size holes?tackleexperts.comwww.necessityjigs.comhttps://www.facebook.com/groups/mach...dingequipment/
Reply:If you are not doing production work an easy way is to sandwich it between two thin pieces of aluminum and drill through. LarryMiller XMT 304 CC/CVSyncrowave 180 SDLincoln PowerMig 255XTTermalDynamics 52Lincoln 305GComlpete machine shop to back it up
Reply:Ah, I knew I would leave something out.Probably from between 1/2 and 2 1/2 inches. I think I could manage the smaller ones with a sharp drill and sandwich the thin stock between thicker sacrificial stock. But to go beyond 5/8ths is the issue.Regards,RobGreat Basin WeldingInstagramBlue weldersRed weldersMy luscious Table DIY TIG Torch cooler
Reply:look up adjustable circle hole cutter
Reply:How many different sizes are needed? Do you have a lathe? I have made sheet metal type punches for jobs like this, but not dozens of different sizes, each to be used once only. If you can clamp tightly as suggested above, fine toothed hole saws in a mill or tight drill press might work, as might even a flycutter w/ single point (very sharp) toolbit. Similar to the adjustable circle hole cutter  just above. This might even work using synthetics like compressed board (not large-grained particleboard) or thin, high quality plywood for the top layer. I have access to scrap material like this from a cabinet shop.Careful work with a nibbler, perhaps using a round guide and again sandwiching the material between thin sheets of aluminum, can also work; touching up of the edge with a sanding drum can remove imperfections, if needed.
Reply:Thanks for the ideas.I have a fly cutter. Have not tried it yet. The edge needs to be all perfect as one gets refraction from a poor edge. I would surely love to have a lathe, I think that would do it for me.What about a laser cut? Where would I go looking for a shop that would have something like that?I probably need 3 or 4 of these guys, different sizes.Regards,RobGreat Basin WeldingInstagramBlue weldersRed weldersMy luscious Table DIY TIG Torch cooler
Reply:If you can afford it laser would probably be your best option, I would be worried that any kind of cutter would have a tendency to tear something that soft and thin.Any shop that offers a laser cutting service would be able to do that for you, just look around in your area.Have we all gone mad?
Reply:Originally Posted by Robert HallThanks for the ideas.I have a fly cutter. Have not tried it yet. The edge needs to be all perfect as one gets refraction from a poor edge. I would surely love to have a lathe, I think that would do it for me.What about a laser cut? Where would I go looking for a shop that would have something like that?I probably need 3 or 4 of these guys, different sizes.
Reply:I was hoping to do it a little more cheaply than going to Grimes, but there is no one better. I have them shutter all my stray lenses.I will look around for a laser close by, but I think Ed has the right idea.Regards,RobGreat Basin WeldingInstagramBlue weldersRed weldersMy luscious Table DIY TIG Torch cooler
Reply:My first choice would be using a lathe, largely because I have one. I've used double sided tape and epoxy to hold the rough stock to a waster plate on a face plate or mandrel. Second would be a boring head on a mill using a similar set up. You could probably mount it on a DP also.  A lathe is a bit better in that your angle of attack is much more versatile.
Reply:Thanks for the idea(s). I've been looking at a mini lathe. any recommendations?Regards,RobGreat Basin WeldingInstagramBlue weldersRed weldersMy luscious Table DIY TIG Torch cooler
Reply:How about a step drill?
Reply:Edges way too messy, but that may be more on my part than the tool. Regards,RobGreat Basin WeldingInstagramBlue weldersRed weldersMy luscious Table DIY TIG Torch cooler
Reply:Anyway, I've not seen step drills over 1.5"Hole saws can work, if the brass is sandwiched in something.  You'd need a whole set.
Reply:Do not try to use a drill that large!!!Brass is very soft and the bit will just grab that metal and take it for a ride.  And you- along as far as you are willing to go.The best way to cut a circle /hole in brass is this tool.Lay the sheet on a piece of wood and use a very slow speed 100-200 rpm.Photo coming:Around $30.00Works perfect and I have used one many times.Google with "cutting circles in soft sheets"Last edited by Donald Branscom; 01-12-2011 at 06:10 PM.AWS certified welding inspectorAWS certified welder
Reply:I have one and will try it this weekend when I have some light to work in the shop. Thank you for the speed recommendation. That helps.Regards,RobGreat Basin WeldingInstagramBlue weldersRed weldersMy luscious Table DIY TIG Torch cooler
Reply:Maybe greenlee knockout punch sizes  would be close to some of the hole sizes needed.Fast and easy.clean,round hole.Do you have an electrician friend that you could borrow from?Miller a/c-d/c Thunderbolt XLMillermatic 180 Purox O/ASmith Littletorch O/AHobart Champion Elite
Reply:If you go the route of looking for a shop that does laser cutting, check around for one that does water jet as well.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:Might be easier to find someone with a water jet CNC than a laser, better cut too IMO, not much heat involved so very little distortion possibilities..-at the job-Miller Dynasty 200DXMiller Syncrowave 350MillerMatic 250Millermatic 350Miller Bobcat 250Lincoln AC225Miller Spectrum 625 Plasma-at home-Everlast PP256Longevity WeldAll 256PI'slow is smooth, smooth is fast'
Reply:Originally Posted by jpump5Maybe greenlee knockout punch sizes  would be close to some of the hole sizes needed.Fast and easy.clean,round hole.
Reply:Yes, lots of distortion. I have a set of those. The water jet is a great idea. I think it will be easier to find.I will try the fly cutter this weekend and if that fails me, I will go looking for a water jet. And of course if that is more than it's worth, I will call Grimes. Regards,RobGreat Basin WeldingInstagramBlue weldersRed weldersMy luscious Table DIY TIG Torch cooler
Reply:If you have trouble finding a place let me know.  We use a local guy that is very reasonable and I wouldn't think shipping would be too much to/from Beaumont, TX.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:Beaumont?I have a very good friend down there in Beaumont! Do you know Dr. Keith Carter? He's at the University there. Great artist with the camera.Regards,RobGreat Basin WeldingInstagramBlue weldersRed weldersMy luscious Table DIY TIG Torch cooler
Reply:Nope, I'm afraid I don't.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!for punching holes in brass, stainless and nylon shim stock and such. i have an assortment of rifle/pistol casings for punching holes .25 .32 .357 .45, .50 cal..  the material your using might be a little thick for this though...tackleexperts.comwww.necessityjigs.comhttps://www.facebook.com/groups/mach...dingequipment/
Reply:Originally Posted by Donald BranscomDo not try to use a drill that large!!!Brass is very soft and the bit will just grab that metal and take it for a ride.  And you- along as far as you are willing to go.The best way to cut a circle /hole in brass is this tool.Lay the sheet on a piece of wood and use a very slow speed 100-200 rpm.
Reply:An optically 'sharp' edge on thin sheets of brass?I'd say a VERY sharp single-point cutter at very low speed, with the brass sandwiched in between some sacrificial sheets.Or put the brass between the sacrificial sheets and mill or route it (template rout to final size/shape with just a 'skim' cut).That or a very precise laser cut (let the shop know what you are doing and what kind of edge you are trying to get, so that they can tweak the parameters to get the sharp edge on the cut and not just 'hog' it out).Punching will distort the edge and not give you that crisp 90-deg shoulder on the cut.  The best laid schemes ... Gang oft agley ...
Reply:For optical purposes, you don't actually want a 90 degree edge.  Ideally, you want a knife edge, so it would have to be countersunk.I've made pinholes for cameras by denting a dimple into a piece of brass with a tiny ball bearing, and sanding through the dent.In that way, a punched hole with its dragged edges may be better.  Just place on a flat surface with sandpaper in between, and smooth out the burr.Of course, a pinhole is much more sensitive to diffraction than a stop aperture.A drilled or flycut hole will provide a 90 degree edge, although if you use a thin enough sheet of brass, it won't matter much, IF you grind the cutter in a conventional way.  You could also grind the cutter to give a countersunk edge I suppose.A laser or waterjet will actually provide an edge with a slight angle, but again, with shim stock, I highly doubt you will be able to tell the difference.
Reply:Exactly. I am using thin material so that I may not need to worry about the "knife edge".  And yes, pinhole is much more affected by the shape and edge of the hole. It is fortunate for me that this is a Verito lens, a soft focus lens. In fact so soft that wide open at F/4 one can focus the 8x10 camera it sits on but the resulting negative is too soft to tell from what the image was made.I do have a friend with a mill an hour north. I suppose a beer or two would get these cuts made. Moonrise: thanks for the tips on the laser. It always renders better results when both parties know what the finished product should look like.Regards,RobGreat Basin WeldingInstagramBlue weldersRed weldersMy luscious Table DIY TIG Torch cooler
Reply:Originally Posted by duaneb55If you go the route of looking for a shop that does laser cutting, check around for one that does water jet as well.
Reply:One other thing that does work.Just draw or scribe the circle and cut it out with some big snips.Works well on thin brass.These kind of snips work better than aircraft type snips.Do not know why I did not think about it before.Was just trapped in machine making mode thinking.If you use aircraft type snips remember the plastic colored covering on the handlesare RED,GREEN, and BLACK.  or left,right and straight cutting.Last edited by Donald Branscom; 01-13-2011 at 03:56 PM.AWS certified welding inspectorAWS certified welder
Reply:All my straight cutters have yellow handles.BUT, unless the hole you're cutting is huge, you'll be making a mess of thin sheet with snips.
Reply:My snips always leave a slighty 'serrated' edge to the metal.  Or a slightly folded over edge.  YMMV.Yeah, knife edge with no burrs or other irregularities.  Again, with thin sheet metal and a relatively 'large' opening and especially with a "soft focus lens" I don't think you really have to worry about edge diffraction effects.  Maybe it would just add to the 'ambience' or Bokeh.    The best laid schemes ... Gang oft agley ...
Reply:I think he might be pulling our collective legs. But hey, it's all fine art, right?If I was any kind of an artist, that's exactly what I would do. Use snips.Regards,RobGreat Basin WeldingInstagramBlue weldersRed weldersMy luscious Table DIY TIG Torch cooler
Reply:A wire EDM would be perfect except for the cost. It can even do the bevel. Laser doesn't give a very smooth finish like water jet. You can attach the brass to a piece of hardwood or aluminum with carpet tape. I would use a wood lathe with a piece of oak on the faceplate and cut the circle by hand to a scribed mark. That would even allow me to cut the bevel.Lincoln SA200, HH135, Lencospot, HF80 Inverter, Rockwell 11x35 lathe, HF drill mill, Kama 554 tractor w/ FEL & BH, Belarus 250AS, lot's of Chinese tools