Let me preface this by stating I'm a woodworker, using a basic drill press, with limited knowledge of machining steel.
I'm needing to drill several hundred .17" holes in .5" 1045 steel shaft. The holes need to be pretty accurate, as they're to align a mortise on a gear for a key to prevent rotation. I'm using a jig made I built with a drill bushing. Photos of the jig are attached.
I did a few samples to make sure this was possible for me, and they went fine, but when I started to drill the batch I encountered a problem. It seems like I must have hardened an area or something like that.I's like to understand what went wrong, and how to be sure to avoid it.
The problem seems related to drill speed, and perhaps the stock I received for some of the shafts was harder than the samples I drilled previously. Within the first few seconds I encountered resistance, and then I forced the feed, and it became clear something was wrong. The bit was misshapened from the incident.This was at about 3000 rpm's. Was that too fast?
I was able to resharpen the drills (by hand and eye, certainly not good as new) and drill a few holes at lower rotation (about 500 RPM) speed on other shafts, but I want to avoid whatever happened to ruin the new drills.
What rotation speed should I use for this? I used WD-40 as lubricant --would proper lube make a difference? I used cobalt drills , 135 degrees, from Mcmaster --would different drills help? Any advice here would be appreciated!
I'm needing to drill several hundred .17" holes in .5" 1045 steel shaft. The holes need to be pretty accurate, as they're to align a mortise on a gear for a key to prevent rotation. I'm using a jig made I built with a drill bushing. Photos of the jig are attached.
I did a few samples to make sure this was possible for me, and they went fine, but when I started to drill the batch I encountered a problem. It seems like I must have hardened an area or something like that.I's like to understand what went wrong, and how to be sure to avoid it.
The problem seems related to drill speed, and perhaps the stock I received for some of the shafts was harder than the samples I drilled previously. Within the first few seconds I encountered resistance, and then I forced the feed, and it became clear something was wrong. The bit was misshapened from the incident.This was at about 3000 rpm's. Was that too fast?
I was able to resharpen the drills (by hand and eye, certainly not good as new) and drill a few holes at lower rotation (about 500 RPM) speed on other shafts, but I want to avoid whatever happened to ruin the new drills.
What rotation speed should I use for this? I used WD-40 as lubricant --would proper lube make a difference? I used cobalt drills , 135 degrees, from Mcmaster --would different drills help? Any advice here would be appreciated!