Plunge or mill?

I have a couple of jobs i make in small batches, they all have features that must have the ability to accept a square part - the way this is done with a round cutter is by dog-boning or T-boning the corners, this gives a result like the picture here...

Attachment 20825

The materials are either 3mm or 5mm thick and the tool is 2mm chosen as the smallest sensible size for the job.

So, being a small tool, it only takes small cuts and to make the corners takes around 5 passes on the 3mm plate, this takes a fair bit of cycle time.

Is it better to plunge-cut the corners with the tool first and then run the straight edges at a larger DOC probably 2 passes??

Will a 2mm tool plunge through 5mm aluminium ?

Some of the features are far bigger and take even longer naturally.

Could you not use a larger tool to hog out the bulk and then use a helical op to cut a hole in each corner with the 2mm cutter down to the required depth?

Sent from my HUAWEI VNS-L31 using Tapatalk

the way I do it personally is to mill the pocket square first and then peck drill the corners with the cutter afterwards so there is not so much force on the cutter

Quote:

---

Originally Posted by njhussey

Could you not use a larger tool to hog out the bulk and then use a helical op to cut a hole in each corner with the 2mm cutter down to the required depth?

Sent from my HUAWEI VNS-L31 using Tapatalk

---

Most of these holes are only 5mm x 6mm so the 2mm is pretty well suited, the larger ones are hogged with a 5mm tool as they are 15mm x 8mm

Quote:

---

Originally Posted by johngoodrich

the way I do it personally is to mill the pocket square first and then peck drill the corners with the cutter afterwards so there is not so much force on the cutter

---

OK, thats the opposite way i was thinking but sounds just as effective, i guess plunging the corners after the hole is opened does leave less strain on the tool.

Well, i've re-cammed the first job and will test it tomorrow.

In simulation its much faster, have also discovered how to quickly create the hole locations in Vectric, probably quicker than adding the dog-bones :)

When peck-drilling however, it seems a little unclear. The tool path options show peck depth and retract height so it looks like a full retract every peck? Is there no chip-breaking or partial-retract option?

This works really well, faster and I'm not even certain peck drilling is needed for a 5mm deep hole, just a straight plunge would be even faster.

Have to be careful if roughing corners with a 5mm tool as in my case, after the corners hole is drilled it leaves a little lip where the edge of the 5mm tool radius reached, the 2mm finish tool takes a bit of a bite here but seems ok with it.