The attached image shows a hole pattern I'm needing help with. The yellow is a 20mm hole, 14mm deep, the red is a 10mm hole 19mm (full depth of the material). In the SB Link, I'm using my spindle to 'drill' these holes. At present, it creates the 10mm hole first, then the 20mm hole. I'd like to reverse that.
The reason being that I'm doing these with a 3/8" bit, and I don't like the idea of routing a hole 19mm deep which is only slightly bigger than the bit size (10mm vs 9.525mm), its asking for trouble with the bit heating up. If the material for the 20mm hole were cleared first, then I'm only needing to go though 5mm of material to create the 10mm hole.
No experience with SB link. On my machine I would use a 10mm brad point to drill through. Use the 3/8 to pocket the 20mm hole. In CN there's a setting to "do drilling operations first", or something like that. Has worked well for me.
Hi Nat,
Have you thought about getting a custom stepped drill bit that has the two diameters required?
This would be a quicker way to drill. Of coarse you will loose one of your tool holders if you still need the dedicated 20mm bit.
Regards
if you are using the link can i assume you may not have a tool changer? If so then you might try turning the "do drills first option" off. you might also slow the feed rate for the z axis down which might reduce the heat generated, if the bit can clear the chips more efficiently. can the diameter of the small hole be made bit larger.
David, I may end up doing as you do. I haven't had much luck drilling system hole cleanly through material, but I have some leeway on the holes as they'll be covered with a 15mm cap, which should hide any blowout.
Neville, I haven't had the courage to chuck a 20mm drillbit in one of my Shoptbot drills, I don't think it's up to the task. Also the 10mm hole is offset somewhat from the center of the 20mm hole.
Ralph, No toolchanger here, but I have a spindle and 2 air drills. My concern with turning off do drills first' is that I'd then be potentially drilling parts after they'd been cut free of the rest of the sheet. I'd be worried about them moving...
I believe that no matter what the setting for "Do Drills First" is, it only affects the order of operations within each part (drill, dado, pocket, etc). OUTLINEs are ALWAYS* performed last. (*The exception to this is if "Do Profiling Last" is checked. This only applies to Profile Modeler operations embedded in a nest.)
Thanks Brad, I'll do some air cuts and see what those do.
Oddly, I noticed this morning that if cutting both holes with the spindle it will cut the 20mm hole first, then the 10mm, move to the next location and drill the 10mm hole then the 20mm. Its alternates the order as it moves from fitting to fitting...
Not sure how you are creating your geometry but if you break the larger circle into 3 or more separate arcs the machine may read it as a pocket. The small hole with be machined first will a drilling operation and the larger hole will be machine after with a pocketing operation.
