Slitting Metal Sheets on a Lathe

DoN. Nichols prodded the keyboard

Good advice ! If you have'nt a copy of "Machinery's Handbook" get one. It's very worthwhile.

Re: Gauge Plate. This is special in so much as the steel is intended to be able to easily be hardened after machining. It mills quite well and is very useful for all manner of tooling.

Put Beverly to work with it. Jig up a guide and go to town.

Gauge Plate is so-called because it is ground to specific gauge dimensions -- generally quite close ones.

It's usually the equivalent of US tool steel grade 01: basic oil-hardening tool steel. But it can be other alloy grades. It's the grinding to specific dimensions that makes it "gauge plate."

Most US suppliers would be more likely to recognize "ground flat stock, 01." It's expensive these days.

Ed Huntress prodded the keyboard

Yes it is expensive compared to, say five years ago. I just looked at

for, and was supplied by

• vat. More than double in price.

the cheapest but have it on sale from time to time. I'm used to the round silver steel being in 13" lengths but the ground flat stock always seemed to be in 18" lengths for inch sizes and 500mm for metric sizes. It may depend on the supplier. For the application of punching out blanks from a sheet it would seem easy to do a rectangular punch and die for the OPs job and I've done non rectangular shapes in the past where I've milled to the profile by eye and then hand stoned to get the punch and die to fit and then all went well. I do have a fly press, (screw press US?) to run these tools in though.

Thanks. I'll do that. | Darren Harris Staten Island, New York.

Thanks.

I still would need to determine the best way to get it to shape. I assume I would mill it to rough dimensions with the proper end mill, but grinding those rows into the points I mentioned would be more of a mystery.

I'd then have to figure out a way to use my milling table as an index jig to work with a press punch.

Darren Harris Staten Island, New York

I'm not sure if I can cut .0156" wide strips off of Phosphor-Bronze stock with a shear.

They did however just open up a new Harbor Freight here on Staten Island. Located it on the block in between the two blocks that have a Lowes and Home Depot. :)

Darren Harris Staten Island, New York.

In an earlier post you said that the stock was up to .042" thick. And you want to shear this into strips .0156 wide? Do you really mean .156" wide? If the latter then I think I know a way to cut your strips on the lathe. The explanation is kinda long because I can't show you a picture so let me know if wide strips will work. Eric

I have a Central Machinery 30" 3-in-1 and an 8" Enco bench shear. Both are OK for a hobbyist but fussier than I would put up with for any sort of production, especially when used near their capacity. The original owner of the 30" gave up on it. Both distort narrow strips, the 30" slightly and the 8" considerably.

-jsw

Oh, sorry. I could have sworn it said 0.156, which should be easily doable. 42 thou thick and fifteen thou wide? WTF,O?

This is a Good Thing(tm). You Gnu Yawkahs need good tools.

Yeah, the deeper we get, the more it sounds like he's actually looking for a microtome.

My mistake. As I said in my first post the strips have to be no more than .156" wide.(Not .0156). But yes, I did say the thickest will be .042"

Thanks.

Darren Harris Staten Island, New York.

Greetings Darren, So I guess you need lots of these strips and this tooling suggestion is for doing lots of strips. You will need a plate, steel would be best but aluminum or brass would work, just not last as long. I seem to recall that the strips are 4 inches long. So you would need to start with shim stock that was 4 inches wide and some convenient length, say 4 to six inches. The shim stock should be stacked so that it is about .25 thick, maybe even up to .375 thick. The pieces must be stacked carefully because you are going to cut through the whole stack at once. This is for two reasons, for production and to minimize burrs. It would be best if the stock is cleaned of oil at one end so that all the pieces in the stack can be glued together. This gluing just needs to be at the end of the stack farthest from the cutter. The glue should be something that easily dissolves in some sort of solvent. Super glue would work and acetone will dissolve it. The reason for the gluing is so that when the stack is moved into the cutting zone all the pieces will move together. When I have done stuff like this I apply the glue and then clamp or weigh down so that the glue is spread very thin, maybe .001" or .002" thick. Now that you have your stack of glued up pieces you need to put them in the cutting fixture. Which I had better explain how to make. There are three basic pieces and several screws. The first piece is the base plate. It needs to be of some substantial thickness, at least .500". Even better would be .75". You will need to come up with some way to affix it to the cross slide on your lathe. Since I don't know what your lathe looks like I can't say exactly how you will do this.Maybe you can drill and counterbore some holes and then run screws through the plate into the top of the cross slide. Or maybe, if the compound needs to be removed to make room for the plate, you can use the nuts that hold the compound to the cross slide. The plate should be about 5.00" x 6.00" to support the stock and for a couple tapped holes for a clamp. Machine the plate so that the sides are square to each other. Now for the other two pieces. The first is just a rectangular piece made from steel. It should measure 5.0 by .500 by .25 thick. Drill two 1/4 inch holes centered on the bar and 4.300 apart. After the bar is all machined it should be gently curved through the .25 thick direction. This can be done easily in a vise. Lay the bar in the vise with the bar spaced away from the fixed jaw using any convenient spacers. A couple pieces of keystock for example. Now use a third spacer that touches the bar in the middle and close the vise on the assembly. You will need to bend the bar a little at a time until you get about .04 inches of bend. This bar will be one of the clamps. The gentle curve is so that when tightened onto the shim stock it will contact the center of the stock first and then flatten as the screws are tightened so that the bar will tend to clamp all along the shim stock, not just at the ends. The third part is the other clamp. It should be milled from steel. It should be 4.00" long, .875 high, and .400" thick. A step needs to be milled in the .400 thickness direction that is .150 deep by .750 wide and runs the complete length of the part. So in cross section the part will be L shaped. Now drill 3 holes .375 diameter through the .250" thickness. The two holes closest to the ends should be .375 from the ends and the third hole should be centered. Then drill two more holes .290 (letter L drill) diameter each centered between the center .375 hole and an outer .375 hole. All 5 holes should be drilled .230 from the bottom of the bar. Now drill and tap 5 each 1/4-20 holes in the end of the base plate that will match the holes you drilled in the clamp bar. The screws going into these holes are socket head cap screws. Next, for three 1/4-20 screws, put them in the lathe in a 4 jaw chuck and adjust for .040 TIR runout. Turn until they clean up. All three screw heads should be the same diameter, about .335. Screw the three eccentric head screws into the base plate until they bottom out and then back off until all three screw heads are in the high position. Assemble the clamp bar to the base plate with two 1/4-20 screws that go through the two .290 holes. Use a flat washer between the screw head and the bar. Use Loctite on the screws and adjust so that the clamp bar moves with slight pressure. Now you should be able to slide your stack of shim stock under the clamp bars and use the eccentric screws to clamp the stock that will be cut off and the other clamp bar to hold the stock yet to be cut. You should use a saw blade that is about as small in diameter that will work. This is because you will be climb cutting with the saw blade. You want to climb cut because this will direct the cutting force down into the cross slide and pushing the shim stock against the base plate. The drawback is that the cutting forces will want to draw the saw into the work and pull the work out of the clamping fixture. Using a smaller daimeter saw blade will lessen the tendency of the saw to pull the work form the fixture. When cutting you will want to adjust the gib screws so that there is a little drag when turning the feed handle. This is to prevent the cross slide from being pulled into the saw blade. Run the saw as fast as you can for the material being cut, use the proper cutting fluid, and use a fairly slow feed. Using this cutting technique will lessen the burrs. The first cut made with the setup will also be cutting into the base plate so if it is steel make sure your saw RPM is slow enough so that it is not damaged. The first cut should be deeper than all the rest of the cuts so that the saw blade won't be touching the steel when running at high speed. The same thickness saw blade should always be used. If a wider slot is cut into the base plate this will leave room for burrs to form. You could cut a slot in the base plate that is deeper than the gullets between the saw teeth by about 30%. Then the slot can help guide the saw blade. Make sure the carriage is locked in place when using this fixture. Whew! I sure hoped this helped. A picture in this case surely would have been worth a thousand word. Cheers, Eric

In previous incarnations of this thread, 0.156" has been the usually-mentioned width, reflecting the 0.156" on center spacing of

is his former rec.woodworking thread about making 30-wide sets of grooves on 0.156" centers to hold sets of springy contacts.

is his former rec.crafts.metalworking thread about making a gangsaw for cutting strips of 0.032 phosphor-bronze sheet to widths of about

is his former rec.woodworking thread about the subject, and there's a picture and description near the middle of the page (in the post dated February 12, 2009, 12:18 am) with the following explanation: "I will need phosphor-bronze strips in the same width because I will be soldering them to the traces on fingerboards like that shown. The other end of these phosphor-bronze strips will run over a wood or nylon housing similar to the black JAMMA housing pictured, but it will not be hollow. Instead it will just have a slit that the fingerboard will fit into. So I'm effectively separating the proximity of the traces on both side of the fingerboard and wrapping them around the housing that holds the fingerboard. The (wood/nylon) housing's thickness will be 3/8" of an inch and the phosphor-bronze strips will wrap around it just short of meeting at the other side."

Returning to the present, it would be easier to give useful advice if Harris were to explain the big picture, and say what he is trying to do (which I think might be trying to make something than can connect different game boards into a single console assembly, without damaging the game boards when changing them in and out; or it might be something about making a way to select one of several boards inside a console; etc) instead of asking how to cut off strips that are 0.156" wide from a phosphor-bronze sheet. If I correctly understand the application, maybe one of the next several methods could be adapted to solve the actual problem:

1. Buy some 28x2 pin, 0.156" spacing, edge connectors like at (or whatever size of connector is appropriate) and with a slitting saw cut it from the back into two long pieces, each with 28 springy contacts still attached and hanging out ready to use, analogous to a leaf battery connector. (Leaf battery connectors are available at several pitches, eg 3.9 mm is close to the 3.96 mm of 0.156", but they usually have not more than 4 to 6 leaves.)

1. Make a 5"x0.5" printed circuit board to hold 28 pogo pins on

1. Use a jeweler's wire-rolling press (see pictures of examples at ) to roll phosphor- bronze wire to desired thickness/width. Starting with half-hard wire, eg #14 AWG / #12 SWG / 2mm, roll it down to 0.031" thick, when it will be 0.156" wide if I calculated right. By trial and error with a few feet of wire, one may be able to find a rolling sequence that work-hardens it to desired hardness. Without a wire-rolling press, experiment with the wire using an anvil and small hammer. A few rolls of alloy C510 phosphor bronze round or square wire of several sizes would run to total and provide a few hundred feet to experiment with.

2. Contact some of the small-quantity phosphor-bronze wire sellers that show up when you google, and see what they'd charge to supply hard flat wire that's 0.03 to 0.04" thick in the desired width. Small-quantity sellers include mentioned above and has (or had) bronze half-round wire. Also see but they are in India and I don't know if they sell small amounts. sells small-diameter (possibly too small) alloy 510 phosphor bronze wire in small quantities and sells spring brass likewise, and does custom drawing for > 0. has phosphor bronze wire in gauges 10, 12, 14, 16, 18, 20, 22, 24, 26,