Need some help with the best option for completing a boring operation on a high quantity order, repeat as well.
Been programming and machining professionally for a few years, I have bored holes with a 4” standard criterion boring head. All bored holes though were single one-off jobs and weren't the best looking. In other words, I’m not very skilled at this. Always low and slow on speeds and feeds in low carbon steel 1018 and aluminum. Always had better luck with aluminum. All that said, I have never tackled a high quantity job requiring bored holes.
Got a part, CR1018, that needs 1x 1.001-1.000 diameter hole 1" deep, it needs to be round and straight, no interpolating. I know reaming is an option, but I haven't had the best of luck with reaming. I either overshoot the tolerance or I don't get that great of a finish. Guess I’m not that skilled at that as well.
This bore has two intersecting .172 hole drilled through to the center of bore. This has given me issues with the boring bar "skipping" around the hole as it passes the cross holes. Makes for a very odd finish. Goes from a “smooth” finish, to a rougher finish with small step at the holes, back to a smooth finish again once it passes those holes. So, there's that as well.
What I’m looking for is a good recommendation for a boring head, or technique for boring it accurately and smoothly. I was recommended a balanced boring head so I can turn the RPM’s up, I'm good with that but seems to have opened the door to a ton of questions... Such as, do I rough it in with a drill, do I interpolate, use a twin boring head, rough it with a standard boring head, what kind of boring bar, type of tool holder (CAT40), how do I deal with the intersecting holes? Lots of questions that I do not have a lot of experience with and unfortunately most of my learning has been on here, trial and error, and youtube.
Also, I’m not opposed to reaming, seems simple and cheap, but I just haven’t had the best of luck with it. Same questions apply to that as well.
I can make something happen but I want it to be right and not fight this thing the entire time.
If any of you experienced machinists could drop some knowledge this way I’d greatly appreciate it!
CR1018
1.001 to 1.000 bored hole
1 in depth, thru hole
2x .172 intersecting cross holes
currently using 4" criterion boring head (not ideal)