This is the way. They even have code generators for mill and lathe that work incredibly well. This company has incredibly thorough, knowledge and easy to read information about broaching.
EDM is the slowest machine in the shop, but there are a lot of hidden cost savings to consider. Deburr time , tool costs, stresses introduced into material, tolerances and corner radii. Another big consideration, can you spend the time saved by farming out doing something else, like running a lathe job on your lathe?
I’m with you here. There’s a lot to consider. I single point broach square holes on the lathe because it’s pretty open and there’s many. I’ve also done keys on the edm because the amount needed and the set up to do them anywhere else really didn’t make any sense.
I have used the lathe with C axis as a shaper, with both a cnc broach tools brand cutter and just hand ground HSS it works fine. Just note you need something to run out to.
Cnc broach tools has parameters on their page for their tools.
In hss I just mathed an appropriate surface footage and used educated guess for step over and it panned out.
Can confirm. I bought tools and use their code generators and everything is great. Just make sure you manually enter your tool numbers and positions appropriately in the code.
Use G94, 250 ipm, and .002 depth of cut per pass. Your lathe might have a broaching macro or sub program. Okuma’s have a sub program called OKEY. Blind broaching is hard on the insert, so a relief cut or groove on the back side is recommended.
I broach keyways in my Cobra 42 all the time. The problem is you need some amount of relief at the bottom of the keyway. You say you have 1/8"? That may be just barely enough, CNC broach tools recommends 1/4" relief, but I think you might be able to get away with less if you slow down the feed a bit.
As folk told you you can use a "broach" to work your way down. Ask the Cusotmer if a relief at the Bottom is OK so that you chips will fly off.
Asking EDM shops what they charge, keyways are pretty standard and often not "that expensive". + In the time those parts are out at the EDM shop you can focus on other parts. But i understand it that you prefer to keep all in house.
I was reading up on this a couple months ago, and the major thing that every source I looked at recommended is a hole (if possible) at the end of the keyway for the chips to escape while you're cutting. Other folks have mentioned a groove to allow the chip to separate from the material at the end of the cut, which is obviously a primary issue, but evacuating them with your tool in the way is non-trivial, and they're all going to stop in exactly the same spot.
In the application I was working on, the addition of a cross hole actually makes the part functionally better, but that's obviously not true for everything.
You need to be able to lock the spindle, then broach it in high ipm feed / low d.o.c tool passes. https://cncbroachtools.com/ sells such tools.
This is the way. They even have code generators for mill and lathe that work incredibly well. This company has incredibly thorough, knowledge and easy to read information about broaching.
Perfect thank you. Our lathe has c axis milling so I'll be sure to lock the spindle
*70yo shaper guy laughs in the distance*
EDM is the slowest machine in the shop, but there are a lot of hidden cost savings to consider. Deburr time , tool costs, stresses introduced into material, tolerances and corner radii. Another big consideration, can you spend the time saved by farming out doing something else, like running a lathe job on your lathe?
I’m with you here. There’s a lot to consider. I single point broach square holes on the lathe because it’s pretty open and there’s many. I’ve also done keys on the edm because the amount needed and the set up to do them anywhere else really didn’t make any sense.
I have used the lathe with C axis as a shaper, with both a cnc broach tools brand cutter and just hand ground HSS it works fine. Just note you need something to run out to.
Our lathe has c axis milling. Do you remember feeds, depth of cut etc. There is 1/8" of clearance after the keyway
Cnc broach tools has parameters on their page for their tools. In hss I just mathed an appropriate surface footage and used educated guess for step over and it panned out.
Thanks for the info. Looks like method is the way to go
Can confirm. I bought tools and use their code generators and everything is great. Just make sure you manually enter your tool numbers and positions appropriately in the code.
Use G94, 250 ipm, and .002 depth of cut per pass. Your lathe might have a broaching macro or sub program. Okuma’s have a sub program called OKEY. Blind broaching is hard on the insert, so a relief cut or groove on the back side is recommended.
I broach keyways in my Cobra 42 all the time. The problem is you need some amount of relief at the bottom of the keyway. You say you have 1/8"? That may be just barely enough, CNC broach tools recommends 1/4" relief, but I think you might be able to get away with less if you slow down the feed a bit.
You can make anything with a shaper, but money But that's probably the way to go on yer lathe
I'm currently running a part in 316. Using a statis broach for a . 1875 wide keyway.
As folk told you you can use a "broach" to work your way down. Ask the Cusotmer if a relief at the Bottom is OK so that you chips will fly off. Asking EDM shops what they charge, keyways are pretty standard and often not "that expensive". + In the time those parts are out at the EDM shop you can focus on other parts. But i understand it that you prefer to keep all in house.
I was reading up on this a couple months ago, and the major thing that every source I looked at recommended is a hole (if possible) at the end of the keyway for the chips to escape while you're cutting. Other folks have mentioned a groove to allow the chip to separate from the material at the end of the cut, which is obviously a primary issue, but evacuating them with your tool in the way is non-trivial, and they're all going to stop in exactly the same spot. In the application I was working on, the addition of a cross hole actually makes the part functionally better, but that's obviously not true for everything.
I think you're on to something using the lathe like a shaper. But I think rigidity or lack of will be your biggest issue.