I was given an 1045 mild steel automotive hub that was destined for the scrap bin as it had been machined incorrectly, from which I plan to make my spindle nose clone. I flame cut most of the flange off and then cleaned it up as best as possible. Of course, this results in a less than concentric section that still needs machining.
I used a Tungaloy CCMT 9T304-24 T725X insert for this, as these are described as being for "Low to medium speed turning...effective in roughing, heavy and interrupted cutting where the cutting load varies".
Once the remainder of the flange was turned down to the point that I was cutting continuously I noticed that I wasn't making chips. Given that I was at the top speed for my lathe, I increased the depth of cut from 1mm (.040") to 1.5mm (.060") as the DOC for this chipbreaker is in the .050" to .140" range. However, the increased DOC actually started to slow my spindle. So, I backed the DOC off and decided to increase my feed rate (manually). This also worked but again started to slow the spindle when I fed it fast enough to break the chips.
Is there anything else I can do here or do I just reside myself to the fact that this is the best I can get from these? I guess that I should have tried a DOC of .050" and a faster feed but I didn't think of that at the time.
I switched to an Iscar CCMT 9T304-SM IC907 insert which did a nice job of braking the chips at a 1mm DOC and even down to .5mm (.020), which is the minimum recommended DOC. I'm starting to document insert grade/chipbreaker performance in known materials, so your thoughts and comments are always welcome.
Edited to fix up format issues and missing text (in blue). I did a cut and paste on my phone and must have screwed up!
I used a Tungaloy CCMT 9T304-24 T725X insert for this, as these are described as being for "Low to medium speed turning...effective in roughing, heavy and interrupted cutting where the cutting load varies".
Once the remainder of the flange was turned down to the point that I was cutting continuously I noticed that I wasn't making chips. Given that I was at the top speed for my lathe, I increased the depth of cut from 1mm (.040") to 1.5mm (.060") as the DOC for this chipbreaker is in the .050" to .140" range. However, the increased DOC actually started to slow my spindle. So, I backed the DOC off and decided to increase my feed rate (manually). This also worked but again started to slow the spindle when I fed it fast enough to break the chips.
Is there anything else I can do here or do I just reside myself to the fact that this is the best I can get from these? I guess that I should have tried a DOC of .050" and a faster feed but I didn't think of that at the time.
I switched to an Iscar CCMT 9T304-SM IC907 insert which did a nice job of braking the chips at a 1mm DOC and even down to .5mm (.020), which is the minimum recommended DOC. I'm starting to document insert grade/chipbreaker performance in known materials, so your thoughts and comments are always welcome.
Edited to fix up format issues and missing text (in blue). I did a cut and paste on my phone and must have screwed up!
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