Cutting multiple round rodswith cold cut chop saw

Cllewellyn22 · Mar 26, 2019

I have hundreds of 3/16" non hardened steel round rods to cut. I just got a dewalt cold cutting metal saw and have run into problems cutting my material. I have tried an 80 carbide tooth blade and a 120 tooth blade. Both blades have the same outcome. When I try to cut the rods 6-8 at a time the blade catches the rods and bends them and hacks up my rods. Does anyone have any tips on how I can fix this issue. Is this a clamping issue? I also tried cutting 6 round rods flat on the deck with a piece of wood on top to prevent the kick back from happening but it still happened. If I tape the rods together will this make a difference if so what is the best way to hold this in the clamp so I don't get hit with shrapnal. I have cut one at a time and it cuts the rod but it seems like it wants to kick back on me. your help is appreciated

paulz · Mar 26, 2019

Try clamping a fist full of them together (on both sides of the cut) with some good screw type hose clamps?

no704 · Mar 26, 2019

Also try backing up the clamp jaws with some flat stock to extend the clamps closer to the blade.

memphisjed · Mar 26, 2019

Never bundle cut.
ever.
ever.
never.

The cold cut chop saws have very little feed back on small stock, you are feeding at uneven speeds- guessing at very beginning of cut of end of cut your arm is flinching feed to fast. One smooth motion is hard; stops unexpected movement.
do the math, and you find speed is not increased (feed rate reductions, sfm reductions, the crazy trying to properly clamp...) Oh, already cut fifty parts before the bundle is even ready to start cutting. 3/16 in abrasive saw is 2-4 seconds tops, band saw just shy of a second. bundle cutting, being round two (side by side, not vertical) is only way to prevent spin, 10 - 12 seconds a cut abrasive, 4 seconds in bandsaw.
hundreds of parts only sounds scarey, some toe tapping music on the radio and no fear of changing how you stand and stage material will have the first 25 suck, the next 300 will be gravy once you find how to stand/move material. Then you need a coffee, the next 100 will be done before you even finish that cup. Thousands takes longer because brain fizzles.
Listen for any time the saw is not cutting, that time is what you need to reduce to zero. Not cutting is when blade is not making chips.

Thompsonguitars · Mar 26, 2019

Make a horizontal V block to go against the back jaw of your vise
Bundle and tape your rods tightly with fiber tape . Have the tape
where the cut will be 2" on either side, 2 layers of tape .Have the end of the V block right up to the blade for max, support . Clamp bundle in V block in vise and feed slowly . Bundle the rods so they are organized straight not crossed .We use a metal band saw with 10tpi. 100 rods in a bundle
no trouble at all.
I can see the cold saw being more problems . You might have a better time using an abrassive cutoff disc.
Ted

partsproduction · Mar 26, 2019

Normal for me is to weld all the ends together at the back end. Then if you can make a set of special jaws that hold the bundle like a hex shape, with two sets of jaws, two on each side that scissor past each other pulling the bundle down as the pressure is applied.
Otherwise what happens is that some of the parts will pop out at the center and suddenly the remaining bundle is floppy. There must be no way for the center rods to roll in the cut, thus the welding.
In the end your remnant is a wad of ends welded together, but it's far faster than single cuts.

partsproduction · Mar 26, 2019

Here's a setup for bundle cutting. It's a given that the machine has hydraulic down feed control, and here we see the bundle formed into a hex shape so every layer is controlled, there is also a "Downward" vise that keeps parts from popping vertically out, as I said. The pipes or tube are strapped, if done tightly enough and the OD's are close to the same diameters that might stop rollers.
A round bar that rolled eats up blades. Also, coolant can be really messy bundle cutting.
It's a special cutting job that makes me put up with all the hassle's of bundling, uneven length parts, coolant all over the place, and poor blade life.
But when you have thousands of cuts to make it may be worth the learning curve.

YouTube

TKassoc · Mar 26, 2019

Wrong tool, just buy a Whitney or old Pexto rod shear. You will destroy enough cold saw blades to easily afford one outright in no time.

memphisjed · Mar 27, 2019

TKassoc said:
Wrong tool, just buy a Whitney or old Pexto rod shear. You will destroy enough cold saw blades to easily afford one outright in no time.

a bantam mechanical iron worker would be in the mix as first choice too. I had a gig forging 1/8 square stock widgets. set a hard stop and foot down on pedal you would have just enough time to feed in 12 sticks, not bundled - flat across blade.

still, sawing like op ask... never bundle cut. You can nap on hydmechs video of saw (granted horizontal, but jeesh), a sales video!

lionelt · Mar 27, 2019

How many teeth are in the cut on the bar?

3/16” I would of thought 200 plus teeth on blade?

Are the bars dropping in between pitch of blade?

What diameter blade?

https://scotchman.com/uploads/Scotchman Cold Saw Blade Basics.pdf

plastikdreams · Mar 27, 2019

Abrasive disc, problem solved.

Milland · Mar 27, 2019

I'm with the "shear it" crowd, but being lazy, I'd get a 1/4HP or greater gearmotor with a 25 to 50 rpm output shaft, make a cam or eccentric link for it, then drive two D2 hardened blades, one with a 3/16 through hole, the other a scissor blade.

Set up a plate with everything mounted to it, along with an adjustable stop, and just feed the rod in as cut blanks pop out. Better still, set it so the rod is vertical, use a PVC tube as a guide, and let gravity feed the rod in as the scissors chunk the rods out.

You can set up a number of rods, put a conical lead into the "holed" shear blade. You might get lucky and have the rods self start and feed for a magazine effect. Have to balance cone size and angle against having other rods wedge the feeding one.

Cllewellyn22 · Mar 27, 2019

Thanks for your response. Can you recommend an automatic machine that will do this for under $1000?

Cllewellyn22 · Mar 27, 2019

I need a clean bur free end will an iron worker do this? Can you recommend a machine that will do this for under $1000?

Milland · Mar 27, 2019

Cllewellyn22 said:
I need a clean bur free end will an iron worker do this? Can you recommend a machine that will do this for under $1000?

I'm not sure any of the processes we've discussed will give you a true burr-free edge. I wonder if it would be possible to hack together a craptastic wire EDM dedicated to just to parting these rods?

More likely you'll need to two-step this, first a cut, then end cleaning on a lathe.

What's the application? I'm thinking you'd be better off just contracting with a company that does bar cutting and prep as their business.

Ries · Mar 28, 2019

I hate bundle cutting, be it bandsaw, cold saw, or even abrasive.
And none give a burr free edge. When I really need burr free, I use a real cold saw, the kind with coolant and a 45 rpm blade, and then I debur on the disc sander.

shearing is great, but it leaves more than a burr- it leaves an upset or notched end.

The pros do this with a machine that takes a spool of wire (3/16" round is considered wire) unspools it, straightens it, and cuts it to size, but they dont cost less than a thousand dollars.

5/16" Lewis No. 2 CV Wire Straighten & Cut-off
Equipment Detail
9999-140 Lewis 2CV Wire Straighten & Cut-Off with 5-Die Rotary Arbor & Additional Rolls << Gold International Machinery | The One Stop Shop for all of your Machinery, Equipment, Tool & Die Needs

plastikdreams · Mar 28, 2019

Abrasive chop saw and a belt sander...you can cut as big a bundle as you want

guest · Mar 28, 2019

If they're short enough and I need a lot of them, I like to set up the barfeeder and part them off. I can break the edges at the same time, and go do something else while the lathe is dropping them into the bucket.

If you have to saw bundles, welding up one end and clamping it well like partsproduction mentioned.

Cutting multiple round rodswith cold cut chop saw

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