Does anyone know something about drilling into aluminum? DIY tonearm fail!!

You clearly have not thought about using a lawn mower on zombies where ISO 9001 quality standards will greatly matter.

I refer you to the training film Dead Alive by Peter Jackson, made in the days when he was still making documentaries. (Go to YouTube and search for "Dead Alive Lawn Mower Scene". The best clip is probably LxubSFRs8NU . I'm certain a direct link violates all manner of rules.)

I will personally build my zombie-consuming lawn mower to significantly higher standards. I may even make it riding, because I anticipate a number of zombies and who wants to be pushing a mower all day long. I mean, it's good exercise and all, but that seems too much like work and not enough like post-apocalyptic fun time.

Check out the mowers in the movie "Moving" with Richard Pryor lol. Randy Quaid is the neighbor from hell, and his twin brother, also played by Randy takes it up a notch or two lol.


The neighbor
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The twin brother
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The drill bit pictured in the first post appears to not be symmetrical on the cutting end. I have never seen a bit like that. Is it defective? Is that drill bit the problem here?



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@Doctorhugo
 
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Try
Boelube Paste. About $15 from amazon. Developed by Boeing aircraft for use on aluminum (and other materials). Used it for many years cutting, drilling and tapping. Nothing I found worked better.

Easy cleanup too. It was the only "cutting fluid" allowed on the shop floor at my last job where bonded composite structures lived as it didn't contain silicones or oils that would soak into composites and make them permanently un-bondable.

At my current job they drill everything dry and go through a ton of bits... I can hear them squealing from inside my office sometimes. :confused:
 
The drill bit pictured in the first post appears to not be symmetrical on the cutting end. I have never seen a bit like that. Is it defective? Is that drill bit the problem here?

Agreed. Looks like one flute is 60 degrees and the other is flat. I’d likely try a new bit or regrind it yourself. As many have mentioned Alu with a sharp bit generally cuts like butter. I have a small drill press that will do 1/2” if you work up in size. My mill would also rip chips like swords on Alu too. I do use WD-40 on Alu as a hobby machinest amd find it works fine. I just don’t like the smoke.
 
That's what I was getting at with the comment about the grind being off. If one flute is catching way more material than the other it's near impossible to make a clean hole.
 
I posted long ago stating it;s the wrong bit. Angle of the pic posted can be deceiving w/o end view.
I worked many years in machine shops and drilled or mill bored more holes than Marine Drill Sargent ordering push ups at boot camp.
 
Try Boelube Paste. About $15 from amazon. Developed by Boeing aircraft for use on aluminum (and other materials). Used it for many years cutting, drilling and tapping. Nothing I found worked better.

Out of curiosity I search for information about the Boelube. Very little information exists. But it appears to be long-chain alcohol, cited as cetyl alcohol. (Not all alcohols are liquid, only the short-chain ones.) Which makes perfect sense.

Cetyl alcohol is a very common and well-tolerated emulsifier routinely added to soaps, detergents, and hair products. It was first formulated using whale oil, hence the "cetyl" part of the name from "cetacean", "cetus" being Latin for "whale", but is today made from saturated fats like palm oil, which appears on ingredients as "palmityl alcohol", or from petroleum. It's formed by reacting a fatty oil with a strong base. Soap is made by reacting oils and fats with a strong base like sodium or potassium hydroxide. Back in the day soap was fat combined with wood ash, which is mostly sodium hydroxide, aka lye.

I don't know what else the cutting product contains, as the SDS contains no useful information. But I can hazard a guess.

Cetyl alcohol is insoluble in water but slightly soluble in alcohol. I doubt it is dissolved in an organic solvent or alcohol since that would require an SDS listing. So cetyl alcohol plus a small amount of vegetable oil would form a thick and slippery paste which wouldn't require disclosure of ingredients on an SDS.

Hand lotion may be formulated using cetyl alcohol plus an oil. So that's likely similar to this product.
 
Drilled a lot of aluminum in my time as a machinist, no special bits were used. Now when turning on a lathe and making my own cutting tools the angle of the chip breaker was typically steeper, and as already mentioned higher speeds usually work best.

Also as already mentioned this should be done in stages. From the looks of the chatter you're getting I hope you weren't using a carbide tipped masonry bit. For cutting aluminum a nice sharp bit should go through like butter.
I've not tried it, but someone told me that milk works well when drilling and tapping copper.

Then there's "The Alloy From Hell", aluminum bronze.
 
So hand lotion would be a good drill lube? :D

It would smell better than most of the other ones. Until it started smoking, then all bets are off.
 
I've not tried it, but someone told me that milk works well when drilling and tapping copper.

I would not use that because milk, while primarily water, contains proteins, like whey and casein, which are very, very sticky and which will burn. The amount of fat is very small unless one is talking cream. Clarified butter is saturated fat from which the milk proteins have been removed to reduce the browning or burning when heating.

I believe the use of dairy milk to be a misunderstanding of the slang term for the cutting fluids added to water which, being a cloudy white, are sometimes referred to as "milk" by machinists.
 
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So hand lotion would be a good drill lube? :D It would smell better than most of the other ones. Until it started smoking, then all bets are off.

You're not off the mark on that.

Hand lotion is generally a combination of water, oil (lightweight oils like mineral oil, heavier weight ones like petrolatum, and maybe some saturated fats, like coconut oil and shea butter, in the better formulations), emulsifiers (to better blend the oil and water), and thickeners (typically long-chain alcohols). I use the kind which doesn't have perfume in it.

I'd just buy some cetyl, stearyl, or cetearyl alcohol and add it to a high-smoke point oil. Done. Less expensive and one may better control the composition. It's not like one is making rocket fuel, blood substitute, and anti-zombie serum where the proportions of ingredients are critical.

Any petroleum oil is going to stink when burned. Particularly a semi-solid or waxy petroleum combined with something like deodorized kerosene.
 
If one is mounting using washers, sure, the imprecision of a hole saw may be covered. But I don't think that solves the problem at hand.

Hole saws are used for drilling holes for conduit, cables, lock cylinders, door latches, etc. where the precision, quality, and repeatability of the hole are generally unimportant. In consequence, not all hole saws are created equal and not all wood or metal cuts in an identical fashion. Many of those saws are inexpensive and have stamped teeth which are poorly hardened. The quality control is generally low as it is a disposable product.

A concentric hole saw is particularly low quality and cannot make a precise cut, it wanders and will do blowout on exit unless you are very, very careful. It can bind and grab the piece, too. The only virtue is large size holes for installing locks. The fixed-sized ones are often inaccurate in the larger sizes.

Then there's the wobble factor; that can vary something around +/- 0.125 (1/8) on the final hole size. Been there, done that. Fine if precision is often not a requirement. The hole, furthermore, can only go as deep as the cavity, which doesn't matter for this application, but may matter for thicker material such as a door. The hole saw is very prone to tearout, so speed must slow waaaaaaaay down when getting close to going through the piece. In order to keep the blade from deforming during drilling it must be thicker, which means the kerf is bigger so it bites more into the material and consequently requires more torque.

One "trick" can help in reducing chatter and making a cleaner hole in sheet metal using a hole saw.
Once the pilot bit has drilled through the metal, remove the pilot bit and reverse it so the pilot is now smooth.
That way the grooves in the bit aren't cutting into the pilot hole, increasing its diameter.
 
Done that, but with a piece of round rod. Same idea though. The other thing I find people do with hole saws is run them way too fast and just burn them up.
 
1000 rpm assumes a machine has the horsepower and rigidity to back it up. It also needs a bigger pilot hole, maybe 3/4". Wd40 is fine for cutting fluid for aluminum. Run it as slow as it will go, those big bits I run under 200 rpm. You should get two spiral shaped chips when it finally bites.
 
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