I’ve never had cause to do this before.
Other than a sharp bit, cutting oil, supported work and a light touch. Are there any concerns I should be aware of? My task is drilling through fairly robust recent era castings.
|
I’ve never had cause to do this before.
Other than a sharp bit, cutting oil, supported work and a light touch. Are there any concerns I should be aware of? My task is drilling through fairly robust recent era castings.
Replies sorted oldest to newest
Sounds like you've got it figured out already, especially the bit about a "light touch". 🙂
Whatcha working on?
Mark in Oregon
what Mark said..
Slow to medium speeds only. Light oil a plus….be sure you’re making chips. No chips means you ain’t drilling…….if drilling deep holes, clear chips frequently, and watch for grabbing ……too much speed can actually start a re-melt of the material, and make a mess,…..
Pat
On smaller size holes, I prefer to drill the hole with an undersized drill bit maybe 10% smaller than the desired final hole size. Then redrill with slightly larger bits to get the final desired size. It helps to reduce the bulge (if there is one) on the exit side.
Most of my drills have the rake removed for drilling in brass (essential). I find that in most zinc alloys this helps to avoid grabbing. Modern castings should be easier to drill and tap - use the yellow can fluid.
@PRR Man posted:Other than a sharp bit, cutting oil, supported work and a light touch.
That all seems right.
Are there any concerns I should be aware of? My task is drilling through fairly robust recent era castings.
Take your time and back out & clear the chips and drill; re-oil as needed.
All good advice on methods I use.
Bob, tell me more about removing the rake?
Thanks
one reason Diecast and especially with more lead tend to grab because the material melts a little from the heat heat generated by the drilling and grabs the drill. A lubricant and light touch are really needed especially with smaller size drills that tend to break easily.
Difficult to describe rake here - I will look for a drawing. What you want is 90 degrees between the work and the cutting surface. I just touch a Dremel disc to the drill lip.
Cannot safely drill brass without doing this on #50 and larger drills.
I understand. I've had the bit grab the material on several occasions.
I'll look up rake. Thanks.
Fiber Laser?
@A. Wells posted:Fiber Laser?
Everyone has a couple of those in their toolbox...
Not only don’t I have a fiber laser but I don’t know what it is. Also a center might help to start the hole and to keep the drill from walking
@JohnActon posted:Perhaps @A. will loan us his. j
I saw a very nice 60w Fiber Laser engraving system for $27,500 on eBay this morning and immediately thought of all the nice holes you could make in diecast metal.
@PRR Man posted:I’ve never had cause to do this before.
Other than a sharp bit, cutting oil, supported work and a light touch. Are there any concerns I should be aware of? My task is drilling through fairly robust recent era castings.
Most importantly keep it cool
Start the hole with a prick punch. A drill bit, once it starts wandering, is awful difficult to shift back to the correct location.
If I need precision, I typically start with a pin vice and about a #80 drill. After I get a starter, I use a big bit and some power. As others have stated, I find slow on the RPM is best for diecast.
In addition to the SLOW part I would step up drill bits start small and gradually;;y work up to the finished hole size. This will keep the heat down as it will cool between drilling and put less stress on the casting.
Access to this requires an OGR Forum Supporting Membership