Hi Bob. You can just go to my channel page and click the "Videos" tab. It will list all of them starting with the newest. I think I've got around 150 videos now. Thanks for watching!
How does depth of cut play into the equation? Also, on a manual machine are you just taking the IPM and dividing it by the travel per turn of your lead screws and then roughly turning in your head? Like, 6IPM on a 10TPI screw would give 1 turn per second, a fairly easy thing to do by hand. This gives me an idea that a lead screw RPM readout for X travel power feed would be a neat and useful thing to have.
For the most part, I use this formula as a starting point and then make adjustments depending on the feedback I get from the machine and the look of the part. Depth of cut plays a big part in that. The deeper your cut, the more load it puts on the tool. Depending on the material I'm cutting, I'll choose a depth of cut that I know from experience definitely works. That might be .050" in harder materials and .100" in softer. From there, if the parts looks good and it doesn't sound like a cat being disemboweled, I'll start increasing either the feed rate or depth of cut. If I start having issues, I'll back down again. You're spot on with regards to turning the results of your math into turns of the handle. A Bridgeport advances .200" with each handle turn, so it takes five turns to go 1". If you've got to go 10 IPM that would be 50 turns, so a little less than one turn per second. Hope this helps.
Stuart de Haro thanks for the response. I try to use stefan's tip about cutter economy and cut with full depth where possible, and a gentle feed rate, to make the most use of the cutter side edges and keep the tip and corners alive as long as possible. And for non dimensional items I try to use reground cutters that are no longer marked diameter, and save the dimensionally correct cutters for where its critical.
Hi Marvin. While I'm sure there is one, I don't use it. I just try to balance out the cut radially and axially just by intuition and paying attention to the machine. I change it up a lot as well depending on cutter diameter and material being cut. If I'm taking a finish cut that is relatively light radially, I know I can get away with more engagement axially. If I'm taking a pass with the whole diameter of the endmill, I know I want to back off the depth of cut axially so the endmill doesn't overheat and destroy itself and my self esteem. You have to take the size of the cutter into consideration too. You can cut .100" deep all day with a 1/2" cutter, but that would break an 1/8" cutter pretty easily. If I think about how I usually do it, I probably start around 20% of the cutter diameter for the axial depth if I'm cutting with the whole diameter, and then see how it sounds and how it feels through the machine handle. That said, I routinely cut keyways in steel shafts with the full diameter and 50% depth with no problems. I just pay attention to the machine, the sounds, the chips, etc. and make adjustments accordingly.
1st rate video....thank you very much
Do you have a complete listing of your videos. I didn’t know you had so many.
Bob
Hi Bob. You can just go to my channel page and click the "Videos" tab. It will list all of them starting with the newest. I think I've got around 150 videos now. Thanks for watching!
This one I got right first time :)
Awesome!
How does depth of cut play into the equation?
Also, on a manual machine are you just taking the IPM and dividing it by the travel per turn of your lead screws and then roughly turning in your head? Like, 6IPM on a 10TPI screw would give 1 turn per second, a fairly easy thing to do by hand.
This gives me an idea that a lead screw RPM readout for X travel power feed would be a neat and useful thing to have.
For the most part, I use this formula as a starting point and then make adjustments depending on the feedback I get from the machine and the look of the part. Depth of cut plays a big part in that. The deeper your cut, the more load it puts on the tool. Depending on the material I'm cutting, I'll choose a depth of cut that I know from experience definitely works. That might be .050" in harder materials and .100" in softer. From there, if the parts looks good and it doesn't sound like a cat being disemboweled, I'll start increasing either the feed rate or depth of cut. If I start having issues, I'll back down again.
You're spot on with regards to turning the results of your math into turns of the handle. A Bridgeport advances .200" with each handle turn, so it takes five turns to go 1". If you've got to go 10 IPM that would be 50 turns, so a little less than one turn per second. Hope this helps.
Stuart de Haro thanks for the response. I try to use stefan's tip about cutter economy and cut with full depth where possible, and a gentle feed rate, to make the most use of the cutter side edges and keep the tip and corners alive as long as possible. And for non dimensional items I try to use reground cutters that are no longer marked diameter, and save the dimensionally correct cutters for where its critical.
@@StuartdeHaro Is there a formula for calculating optimal cutter depth?
Hi Marvin. While I'm sure there is one, I don't use it. I just try to balance out the cut radially and axially just by intuition and paying attention to the machine. I change it up a lot as well depending on cutter diameter and material being cut. If I'm taking a finish cut that is relatively light radially, I know I can get away with more engagement axially. If I'm taking a pass with the whole diameter of the endmill, I know I want to back off the depth of cut axially so the endmill doesn't overheat and destroy itself and my self esteem. You have to take the size of the cutter into consideration too. You can cut .100" deep all day with a 1/2" cutter, but that would break an 1/8" cutter pretty easily.
If I think about how I usually do it, I probably start around 20% of the cutter diameter for the axial depth if I'm cutting with the whole diameter, and then see how it sounds and how it feels through the machine handle. That said, I routinely cut keyways in steel shafts with the full diameter and 50% depth with no problems. I just pay attention to the machine, the sounds, the chips, etc. and make adjustments accordingly.