Mr.E.G.

Fellas,

I just purchased a Harbor Freight milling machine (http://www.harborfreight.com/two-spe...ine-44991.html). I intend to use it primarily (maybe even exclusively) to machine aluminum to make firearm accessories and maybe a car part or two. I will not be making anything with complex surfaces or engaging in complex geometry. Most everything I make will be polygonal, no circles or tubes or anything.

In light of that information, what bits and accessories do I need?

I gather that a I need a couple of sizes of "side cutting" bits (sorry, I'm not up to speed on the lingo yet), some bits that can cut straight down (like a drill bit... can I just use drill bits for that?), some blocks or positioning apparatus that I can use to hold parts in place or at different angles, and maybe some sort of clamps to hold the parts to work surface. I can foresee needing these things, but I don't know enough about them to know which version of these things that I will need.

Most of the items I will be milling will be brick-sized or smaller. With that in mind, what can you guys recommend? I appreciate any suggestions you may have. Also, I've ordered a book on milling as to not sound like a moron forever.

Ryanthegreat1

You are going to need some r8 collets to hold end mills. The drill chuck was not designed for side loads and will come off the Jacobs taper if you load it that way. Plus the run out and stick out of the drill chuck will not be ideal.

For aluminum and a manual mill stay with high speed steel end mills. They are sharper and cheaper than carbide. And the extra hardness of carbide is not needed in aluminum. HSS will also flex a little where carbide will just shatter.

They do make end mills with specific geometries for aluminum. For a hobby shop the added expense may not be necessary. But there is a huge difference in quality when looking at cheap chinese end mills and nice german, american or japanese end mills.

Also check out Little Machine shop for tons of mini mill accessories.
littlemachineshop.com

Mr.E.G.

Thank you. I understood some of that. LOL.

Researching...

Mr.E.G.

Ah crud. I wish I had seen the Little Machine Shop site before I bought the Harbor Freight unit. It looks like they sell one that is comparable in price. It'd get my vote just because it isn't from HF.

Mr.E.G.

Does this seem to be missing anything major: https://littlemachineshop.com/produc...ProductID=3491

Ryanthegreat1

That kit has 2MT collets from the link you posted you need R8 collets. Just be sure to order what fits your spindle.

Decent little kit they have there to get you started.

Mr.E.G.

I really appreciate the feedback. I'm sorry to be a pain, but I'm struggling to learn the subject matter. So, I understand that 2MT collets are different than R8 collets. When you say that I need R8 collets rather than 2MT, is that conclusion based on the way my machine works or based on what I'm wanting to do with it?

Ryanthegreat1

Based on the link you posted to the Harbor Freight mill. The 44991 says it uses an R8 collet. Should also say in the manual what spindle your machine has.

Have to buy collets and anything else you want to put in the spindle in the same size or taper as your machine. There are many different taper sizes out there.
http://en.wikipedia.org/wiki/Machine_taper

Mr.E.G.

Thank you so much. I read that Wiki article and I didn't understand any of it. LOL

Mr.E.G.

I suppose this is the kit I need for my machine:

Tooling Package, R8 Mini Mill 3489 - LittleMachineShop.com

kingofbattle909

iTrader: (6)

I miss thee ol' mill.

spoolinlude

You bought it to finish 80% lowers - just admit it.

aluthman

Haha, this is exactly what I thought too!

Mr.E.G.

Haha. No, actually. You can buy ARs so inexpensively that I don't see the value in it. Plus, I give exactly zero ***** about being on the government's radar.

But you're not too far off. I bought the machine to make a carbine conversion for one of my Springfield XDs. Plus, I have a Bushmaster Carbon 15 that has a non milspec barrel nut and D-ring assembly that won't accept most hand guard conversions, so I'll probably make one from scratch for that, just for the heck of it. I also would like to make some accessories for my Colt M4 as well. Again, though, the main thing I wish to accomplish is to make a carbine conversion for my pistols.

Mr.E.G.

I should probably clarify for the sake of anyone reading this who is not familiar with gun lingo. In regard to the AR15 rifle, the only part of the gun that the government cares about (for the most part) is the lower receiver. This is the part that houses the functional guts of the gun, and it is the part that has a serial number. So, when you buy a gun from a retail store, the FBI does a background check on you to make sure you are not a hardened criminal, etc., and you show up on their radar as a gun owner who now owns the gun with serial number xyz123whatever.

There are some gun owners that are concerned about buying a gun in such a way that the government knows that they own a gun. The fear is that if the government decides to turn into a dictatorship, they now know who is armed and equipped to resist them. As such, these gun owners wish to buy guns for which there is no background check and / or record that you now own said firearm.

This has lead to a hobby industry of "make your own gun" kits, of which the staple product is what is called an 80% lower. It is a lower receiver of an AR15 (the part that would ordinarily have a serial number) yet since it is only 80% complete, it is not technically a gun; it's just a chunk of metal, meaning that anyone can purchase it and there is no background check. Someone who purchases an 80% lower will provide the remaining 20% of machine work which enables them to have a fully functioning AR15 lower which they can now attach all the other "non-gun" parts to, resulting in a gun that no one knows exists.

When I say that I'd rather buy an AR15 in a store because I don't care if I'm on the government's radar, I'm not saying, "I don't care if the government likes what I'm doing or not because I'm such a bad ***." Rather, I'm saying, "It doesn't bother me if they do a background check on me," ergo, I don't see the novelty of making my own AR15 from a hobby kit.

While I think that there is considerable historical precedent for governments confiscating weapons owned by citizens in an attempt to control them, I think that it is incredibly unlikely to happen in America, and if it were to occur, that would reflect such an absurd departure from how America operates such that the government wanting to take my guns would be the least of my problems. Again, not that it can't happen. It has happened in world history. But I think of it like the way I think of certain stock market investments. If you invest broadly in the market, as long as the market does reasonably well, your money is growing. "But what if the market completely bottoms out?" Well, then my retirement account is the least of my problems.

"But, Mr.E.G.," you might say. "What about all the Democrats and liberals and Martians and crab people that want to take away our guns and aren't afraid to admit it?" Well, what about all the religious wackos that want us all to worship the same way they do? What about all the people who think whatever the hell it is they think? Just because someone wants something to happen, that doesn't mean that they'll ever get the support for it, so why worry about it? Vote against them? Sure. Try to educate them such that they can learn to share your worldview? You betcha. But gun confiscation is such an impractical possibility that fear of it is irrational in the present climate or in any foreseeable future climate. Consequently, no, I don't need an 80% lower any more than most of their typical customers need a tinfoil hat. ;-)

Mr.E.G.

I ended up buying this one.

moore_716

iTrader: (2)

A friend of mine bought that same mill and he was able to make some very nice and accurate parts. If you are wanting to drill and machine with the same tooling yu will need to buy center cutting end mills. On aluminum make sure you use lots of coolant. If not the heat will build up and the aluminum will get soft and stick to the end of the end mills. I agree hss is all you need for the tooling its much cheaper and fine for aluminum. Lots of different things can be used for your coolant. At work we even put crisco on with a paint brush. It works fine but it does make a mess. For your finish or clean up passes wd-40 works great to leave a nice finish. General rule of thumb for machining and nice finishes is to increase the speed and slow down the feed. Machining takes patience. If you are going to want to remove material quickly buying a roughing end mill. They allow you to remove more material without dulling the tool.
then you can switch out to a regular end mill for your final clean up passes.
Another thing you are going to have to decide is the number of flutes your end mills will have. In genereal is use 2 or 3 flute end mills. More flutes will leave a better finish but the price goes up and they are tricky with aluminum. Meaning they gum up very quickly from the soft materials. Make sure you listen to the machine and get the feel of it as its cutting. If it starts to feel like its dragging or starts to squeal, stop. The tool is either dulled, packed up with aluminum or both. If and when your end mill gets caked with aluminum let it cool and take a small screw driver and pop the aluminum out. Any other questions feel free to ask away.