With many years of experience under my belt when it comes to woodworking and panel processing using Pod & Rail Machining centers (mostly Biesse Rovers) I am stumped by a new requirement for a new product segment: I would need to process Aluminum Tubing. Mostly drilling into the face of the tubes with diameters between 1/8" to probably 1/2" or even 3/4". Is someone doing this already and can give me some pointers where to start?
The profiles are usually rectangular tubes from 3/4" x 3/4" all the way to 3"x2". Some might be round pipes as well. I am especially concerned about the small diameter holes of 1/8" I would need to drill for riveting. Would I need to run cutting fluids to saveguard the tooling? This seems to be pretty messy for someone who is used to produce wood dust. Or is there tooling out that can withstand reliably continuous drilling into tubes with fairly thin wall thickness ~1/16".
From contributor Ma
You can drill certain grades of aluminum without mist or flood coolant within the parameters you stated ( thin wall !). You will not want to do this with your boring block because of the fixed rpm nature and it could be cumbersome when "pecking" and the limitations on shank size.
You will want a carbide drill designed for drilling non-ferrous (Kennametal, gerung,etc.), most have their own proprietary coatings. You will also want a drill with a 130~135 degree split point design for accurate centering. Aluminum drills typically have larger flute gullets and they are polished to overcome the "sticktoittoness" inherent to the material.
You will have to mount the drill in a collet sized for the shank and run in the electrospindle - small diameters (up to 5/16") should be fine, much larger and you will want to interpolate the holes with a nice aluminum router bit. A 3/4" drill in a router electrospindle is not a good idea. The thrust is much greater on drills once you go over 3/8"~1/2"
It is ideal to run mist or flood coolant, but in your conditions (thin wall) you should be able to get the feed and speed correct to drill through with light pecking. Your tooling manufacturer can assist with that but keep in mind you will be working in a different "power band" than what your normally used to.
You will also need to fixture the part to the machine a little better than just relying on the pods. Mushroom clamps at a minimum - maybe a vase type fixture depending on the condition of the material.
If you have a cam program you will want to select very light pecking (.02~.05 in .5~1.2 mm) if no cam you can create a peck cycle within the control using a sub program and or incremental Z moves and a jump statement.
All of the above is applicable to 6000 or 2000 grade aluminums, 5000 grade would require different strategy.
Hope this helps.
Mark T.
From contributor Vo
Hello Mark
Thank you for sharing your wisdom. Yes, I intend to create vise style jigs for proper positioning and holding of the tubes. Using the spindle with a much better control is good advise as well. I hope I can get by without misting/cooling.
Thanks again
Volkhard
From contributor La
We machine parts that are too big for the machine shop down the street. He provides the tooling, feeds & speeds. Peck drilling is usually used. There are some alloys that machine easily and some that stick like glue. Have to resort to mist for the sticky ones.
