I am excited to use my Fireball drill fixture to turn my antique cast iron printers table into a fixture table, but I quickly ran into a problem.
This is my first experience with an annular cutter and mag drill, so the problem is probably user error. After the first row of holes, my Euroboor HMLU3/4 carbide annual cutter had broken 3 of the 6 carbide tips.
I am using a two-speed S
lugger mag drill on low speed, CRC True Tap HD cutting fluid.
I would appreciate advice on what went wrong.
I just send pics and e-mail to the Euroboor distributor. I am hoping they are helpful.
What I believe is happening is that the cast iron cuts into small chips. With the addition of cutting oil, the small chips get gummy and can’t evacuate the jig. So eventually they bind up the cutter. Generally cast iron is cut dry without oil. I’d try cutting dry with a continuous air blast to remove the chips. Cast iron has graphite in it, so it acts like a natural lubricant.
Thank you Jason, that makes sense. The cuttings are more like crumbles than curls. I’ll order more bits and hopefully be sending you pics of the finished product.
I agree with the air blast.
Are you using a power feed or manual?
You may be breaking teeth when the cutter breaks through the bottom with an aggressive manual feed. If your mag drill has a fine feed control or power feed that would be ideal. Otherwise, be sure to back off on the feed as you get near the end of the cut.
Thank you for your input. Once I started drilling according to Jason’s instructions, plus I switched to high speed per the annular cutter manufacturer’s recommendation, things are progressing well. I’m about halfway through the project; the carbide tips are intact but getting dull. I am using constant air blast, but my drill slide doesn’t have enough range to allow full clearance from the surface to blow out the chips. I think for the second half, with a new cutter I’ll add a steel plate under the drill to give me enough height to blow out chips once or twice during each cutting. Any thoughts on adding a plate between the surface and the magnet? My mag drill is a manual feed.
I am pleased to report that I got the job done. The Fireball fixture drill guide works perfectly and I found drilling cast iron to be a breeze once I learned how. A little WD40 and a constant air blast was the key, but it makes a mess!
I love my new DIY fixture table! Thank you Jason for creating such awesome tools.
My tool recommendation that I discovered during this project is a 12 ga shotgun barrel hone to clean and polish your 3/4" holes.
