How to program this part on my t-2?

Hello Philabuster and Company.

I've got a part I'm having trouble with.

It's got a flat bottomed feature inside this big id dish, and I have had trouble making this from solid.

The trouble is getting the bottom of the hole drilled and then cut with a boring bar to a flat bottom. How is this normally done? I'm using a 1.5" insert drill to get a clearance hole, but I cannot get all the way to the bottom or it'll gouge the part. I follow it with a .75 ccgt boring bar which chatters or breaks (!) or otherwise indicates that I'm on the wrong track.

Ideas??

Here's the print.



Thanks guys!

Grant

My method would be to break up ID profile onto into several processes instead of trying to do it in one continuous process.

Rough with 1.5" drill.

Rough profile with CNMG432 (or other) down to 1.5" hole, but do not try to go deeper right now.

Change to boring bar with more clearance (many choices available with this large of a part) and use CPY IN process with SPT-X at 0 and CPT-Z where the CMNG432 left off. This process will be using rough tool but no finish tool.

Stock removal for CPY process X value needs to be equal or larger than your PNo0 line for X finish allowance, Stock removal Z=distance from where CPT-Z starts and bottom of part (.100"?). Set DOC to take about .020" or so depending on the tool. This will profile out the stock the insert drill cannot remove.

Finish the profile (CPT-X=0, CPT-Z=0) on next process with no roughing tool.

Here is a tool that will finish a .500" spherical radius and I use it to cut the feature exactly as described above. Your part has MUCH more room so you have more choices, but the idea is the same.

Thanks Philabuster!

I've got to check the turret (likely needs alignment), fix the dent in the door(!!), and get a suitable boring bar and I'll try again.

Your method seems much safer than my method....

I've never used the copy process, so I am not quite sure what to expect there, but I'll be looking at the graphic preview a bunch, and then moving on to cutting a bunch of air before I get to any metal though.

I'm printing all these threads by the way, so I can reference them again and again while standing at the machine!!

Thank you again,

Grant