Cutting Odd-shaped Holes In Flat Stock

redsquid2

redsquid2

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I can drill up to about a 5/16" hole with my drill press, then the belt starts to slip. I want to make bigger holes, but not necessarily round. I have used a jewelers saw, but it is really time-consuming. Also, it does not have a deep enough throat for some jobs.

There must be a machining tool that is available in maker spaces/hacker spaces that would do this.

Plasma cutter? I saw some flat stock cut by a plasma cutter, and it looked pretty messy.

Thanks,

Andy
 
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what shape holes are you thinking?
Round hole + needle files , a smal hole and a jewelers saw. It can cut sideways if you bend the blade at the top and bottom
 
Hengelo_77 said:
what shape holes are you thinking?
Round hole + needle files , a smal hole and a jewelers saw. It can cut sideways if you bend the blade at the top and bottom
Click to expand...

I am looking for a tool that will cut any shape.

I toured a maker space that had something called a "bridgeport." Would that be capable of doing it?
 
Bridgeport is a brand. It's a mill. If you can manually run a mill or program a cad/cam program, with a capable machine you can make anything. Up to and including odd shaped holes!
 
Kali4nia said:
Bridgeport is a brand. It's a mill. If you can manually run a mill or program a cad/cam program, with a capable machine you can make anything. Up to and including odd shaped holes!
Click to expand...
If you're ambitious you can build a Space Shuttle, Space Station, Lunar Lander, Sky's the limit with proper Milling skills!!!
 
First, I'd get a new belt for your drill press. Often there's a way to tighten the belt tension as well. If it's a little 8" or 10" drill press, you're not going to be hogging steel with it anyway, but most presses should be able to handle a 5/16" drill bit if the bit is sharp. Pilot holes may help as well.

As you get into larger holes, bi-metal hole saws are usually a decent option. A cutting lube and slower speeds will help get through the cut on thicker materials.

Similar to a jeweler's saw, a powered scroll saw CAN work, if the saw is set up well and the material is not too thick. It's a little better on brass or aluminum and other softer metals than on steel though. A bandsaw is the next best option, though you have to have a lead in cut for inside shapes. You might also look into die filers, though these can be limiting.

Aside from that, you have CNC waterjet, laser, plasma, EDM or milling, though these can be cost prohibitive for low quantities.

You can manually mill some pretty complex holes too I guess, but time and setup is a big factor.
 
It depends on the thickness and hardness of the material, and the shape you want to cut, but there are lots of options. A couple that have not been mentioned yet...

Properly adjusted, and used at the right speed, a plasma cutter will leave a decent edge. But like anything else it takes some time and practice to learn to use. A skilled user with an oxy-acetylene torch can produce a high quality cut as well

A lot of metal cutting bandsaws used to have built-on blade welders. You could cut the blade, feed it through a drilled hole in the workpiece, weld the blade back together and mount it back on the saw, and then make your inside cut. And then you had to cut the blade again to get the workpiece out of the saw. A lot of trouble, but the way to cut an odd shaped hole in metal without a lead-in cut.

Don't dismiss a sharp cold chisel and a bench vise. This can make quick work of cut outs in mild steel up to 1/8" or more.

Instead of drilling, you can use a punch to "chain drill", and if the tooling is available you can punch square holes (or other shapes)

There are various hand held and stationary nibblers, some like the Trace A Punch can even follow a template.
 
IMHO odd shaped holes require a more advanced approach than those described above, not to denigrate using a needle file to achieve that hole cheap. Needle files can achieve the desired result albeit with blistered hands a likelihood to say nothing of serious cussing.

You need an EDM or a Waterjet

Electrical discharge machining
From Wikipedia, the free encyclopedia



Electrical discharge machining (EDM), also known as spark machining, spark eroding, burning, die sinking, wire burning or wire erosion, is a manufacturing process whereby a desired shape is obtained by using electrical discharges (sparks).[1] Material is removed from the work piece by a series of rapidly recurring current discharges between two electrodes, separated by a dielectric liquid and subject to an electric voltage. One of the electrodes is called the tool-electrode, or simply the "tool" or "electrode," while the other is called the workpiece-electrode, or "work piece." The process depends upon the tool and work piece not making actual contact.

As an alternative but equally (I believe) accurate you could use a waterjet.

Water jet cutter
From Wikipedia, the free encyclopedia


A diagram of a water jet cutter. #1: high-pressure water inlet. #2: jewel (ruby or diamond). #3: abrasive (garnet). #4: mixing tube. #5: guard. #6: cutting water jet. #7: cut material

A water jet cutter, also known as a water jet or waterjet, is an industrial tool capable of cutting a wide variety of materials using a very high-pressure jet of water, or a mixture of water and an abrasive substance. The term abrasive jet refers specifically to the use of a mixture of water and abrasive to cut hard materials such as metal or granite, while the terms pure waterjet and water-only cutting refer to waterjet cutting without the use of added abrasives, often used for softer materials such as wood or rubber.[1]

Waterjet cutting is often used during fabrication of machine parts. It is the preferred method when the materials being cut are sensitive to the high temperatures generated by other methods. Waterjet cutting is used in various industries, including mining and aerospace, for cutting, shaping, and reaming.

Just my 2¢ of course.................. or perhaps my $20,000 (because, as my wife often remarks, I have too much money).

Corey "synthesist" Gimbel
 
Del Raso Knives said:
This might help for one off work. After removing the bulk of your material use a solid carbide burr to clean up.



1980-01-01 00.02.03 by Peter Del Raso, on Flickr



440C Mop integral by Peter Del Raso, on Flickr
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Del Raso Knives Del Raso Knives ,
I know this is an old thread, but as I was trying to do exactly this thing a couple of months ago, this looks very clean, I was hoping you could explain a little more about the technique and the second picture? Looks like a burr in a pretty small drill press? I have been warned that side load can do bad things to drill bearings. Have you had any problems? How fast did you run the burr? Full depth cut or did you work down in stages? Did you go straight from the first picture to the burr or did you do some hand filing first?

thanks

Chris
 
C_Claycomb said:
Del Raso Knives Del Raso Knives ,
I know this is an old thread, but as I was trying to do exactly this thing a couple of months ago, this looks very clean, I was hoping you could explain a little more about the technique and the second picture? Looks like a burr in a pretty small drill press? I have been warned that side load can do bad things to drill bearings. Have you had any problems? How fast did you run the burr? Full depth cut or did you work down in stages? Did you go straight from the first picture to the burr or did you do some hand filing first?

thanks

Chris
Click to expand...


Hi Chris,

re side loading, I know many will disagree but I don't worry about it. I'm 60 and have been doing horrible things to this Taiwanese made drill press since I was 14. It is a bench top model, 5 speed, with a half inch chuck.

I used a hole saw to create the large radius at the butt end, then chain drilled the rest of the perimeter. I then used a hammer and chisel to cut through any webbing. The hack-saw took off any high spots prior to filing. Lastly I used the solid carbide burr (1/4" shank X 3/16" cut) to ensure the cavity walls were flat and square. The blade stock was 3/8" thick and I used the full length of the burr for the clean up. Can't recall what speed I used but I would always recommend starting at the lowest and working up to find which one works best for your application.

The same method employing a template that runs on the shaft of the cutter can be used to cut a very accurate inlay for the cavity. Just ensure the shaft and cutting diameter are the same. Hope this answers most of your questions.

Peter


IMG_0610 by Peter Del Raso, on Flickr


IMG_0611 by Peter Del Raso, on Flickr


IMG_0614 by Peter Del Raso, on Flickr


MOP Integral by Peter Del Raso, on Flickr
 
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Wow!
Amazing looking knife and thank you for that detailed reply. I think maybe the burrs I have tried have not had the right size and tooth pattern for the speed and material I was trying to cut.
Wouldn’t have thought to use a chisel to cut the webbs. I used a section of 14tpi high carbon bandsaw blade in a bow saw and it trashed the blade pretty quick.

thanks

Chris
 
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