used oil/frame drilling? (1 Viewer)

[Live to Ski]

What do the mud gods think?

instead of drill lubricant while drilling holes in 100 series frame (mounting aftermarket rear bumper), is there a downside to using used crankcase oil (from same cruiser)?

 

[Grayscale]

Machining oil is not the same as motor oil. Just get rid of it, or use it to preserve wood and metal from oxidation in the landscape. Chemically speaking it is wasted, and it usually has stuff from the crankcase that is not pleasant to be around. Use fresh oil inside the shop, it is cheap and so little is ever really needed.

The best machining coolants are water jets that you see on CNC mills and lathes. Steel benefits from a coolant and lubricant. However, it isn't like we are processing aluminum or copper here - steel doesn't stick so well to the drill's cutting edge. Personally, if I need machining lubricant, in the shop at home, it is for using taps and dies. If I'm drilling or sawing wood, steel, etc then I use a bar of beeswax, or paraffin wax on the blade or drill. It keeps tiny bits of wood sap from sticking to metal. Paraffin can also be rubbed into metal, like a crayon, and heated with propane to provide resistance from oxidation as long as the wax doesn't melt. Paraffin is what your typical candle is made of.

My suggestion is getting a cheap set of 'jobber' drills. They will be the best quality drills that are not sold individually, at a physical location nearby. Mine have three flats on the shank (needed, because regular drill chucks are not good means of holding anything). They are split-point, titanium nitrite coated (not important), high-speed-steel (not "high carbon steel"). Buy only the most expensive drill set there, trust me! Start with a center-punch dent, then about 1/8"diameter for your first hole, then work up in diameter. I'd follow it with a 1/4" drill, then, a 3/8" drill. That will get you plenty of bite each time, reducing the amount of pressure necessary to get thru the steel. Basically, the drill will take a deeper chip per pass, if it doesn't have to take such a long chip - drill radius. Use a non-jobber set (odd/precise sizes (numbered drills) that might be purchased individually) for final passes, precision work. If your drill chuck slips, use a file to remove the burr from the drill shank. Keep drill rpm down for drilling steel (particularly large-diameter cutters as they move faster per rpm, and the torque high with a good drill motor. Speed/heat, not lubricant use, is the number one way to ruin a drill on steel - just keep it spinning without taking much material by just rubbing, that will ruin it. It is nice to have at least two or more drills around so you don't have to switch out cutters all the time.

I'm not a god, even with a little g, trust me.

 

[Live to Ski]

Wow, great response and explanation.

Worked 20+ years as an engineer, many in a model shop. Never knew this info. Guess I did' read the "machinist's handbook" enough. Total respect for the machiist.

 

[Grayscale]

I also have a DrillDoctor sharpener that keeps me from running around town when I eventually find tool failure.

 

[Live to Ski]

I'm drilling the holes today.

I'll use "3 in 1" oil as its not production (holes x4). Used drill bgits will be treated as disposibles as this is a rare event in my world.

 

[Mauser]

Used oil works better than nothing for drilling holes, but stinks. I use beeswax.

 

[Grayscale]

Also, plan your final pass/cut. In other words, if your final hole size is just over the size of the one that you basically made the hole with, you might have too much of a cork-screw-effect, and it makes the final hole pass a bit more out of your control. I've broken drills this way. The better way is to plan for a wider final chip, and making a bigger step-up, on radius, in the overall sequence. It also helps you maintain your rpms much lower, saving your cutters/tools.

Also, a cordless drill with a step-drill-cutter (used typically for sheet metal) is run at low rpm, and it also makes for an excellent deburring tool/countersink tool to finish your hole with.

Always countersink before you run a tap thru a hole, and the minimum number of threads for machine screw engagement is three.

 

[Live to Ski]

10-4

Struggling on this. You'd think I would know better.