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[secretweaponevan]

The time has finally come for me to succumb and buy a mill.

For space/budget reasons, I will be getting a mini-mill.

Any machinists out there that can help me by answering a couple of questions? I appreciate it.

I am looking into getting one of the ones listed here.

Which one would you recommend and why?
R8 or MT#3? Or doesn't it matter?
Belt drive or gears?
What books would you recommend to a complete novice machinist?
Are there any starter tooling sets that you would recommend?
And anything else that you feel might be important.

Thank you for your time.
secretweaponevan

[Deus Machina]

Originally Posted by secretweaponevan

The time has finally come for me to succumb and buy a mill.

For space/budget reasons, I will be getting a mini-mill.

Any machinists out there that can help me by answering a couple of questions? I appreciate it.

I am looking into getting one of the ones listed here.

Which one would you recommend and why?

They all work the same, really. Mine is a Harbor Freight, but the Micro-Mark comes with the 'Tru-Inch system', which just means that instead of metric or 16 turns-per-inch, it's an even 20.

R8 or MT#3? Or doesn't it matter?

MT3 will also go with the matching Minilathes. And that's a good plus. But MT3 Stateside (at least that I've found) are a lot more expensive.
R8 is really easy to find tooling for, and the collets can go for only a few bucks. It's the Bridgeport standard.
In short, if you don't have a Minilathe, or have one and just keep a 4-jaw chuck on it like I do, go for the R8 for ease.

Belt drive or gears?

As far as I'm aware, they're all gears. A belt drive is nice--and LMS offers a conversion--because I've broken a few gears using large tools. Flycutters and minimills do not play well together.

What books would you recommend to a complete novice machinist?

The Machinist's Handbook if you can find a cheap one, and/or the Pocket Ref available at many dealers. Nothing specifically for beginning machinists, but great references. I've used the internet, mostly, and the sites linked off LMS are excellent.

Are there any starter tooling sets that you would recommend?

At the very least, a set of high-speed steel end mills (try these before TiN coated; the coated ones tend chip when they really start chattering) in 3/8" or 1/2" shank, and the collet (or end mill holder; I prefer collets) to match. A good vice. Do not use a drill-press vice. Go out and bust $50 or more on one. Probably more, but this is really a point where price=quality.

I bought as I went alone. But relatively early, you should have:
End mills (sets come with 12 pieces and up, from 1/8"-1/2" and further). Ball-end as needed.
Collets/end mills holders. Collets are cheaper, and easy to find in sets. I suggest 1/4" to 3/4" in increments of 1/8" to start. 1/8"-1/4" to 1" or higher is better, but you'll rarely use anything over 3/4" or 7/8" in a mini.
Vice. Expensive=good. At least 3" capacity, more is better. No need for fancy angle-tilts or anything yet.
A good set of drill bits.
Calipers. Digital or dial. Steel, not plastic. Even my steel ones are wearing by now. You should have these before you even consider your first cut. A 6" digital steel one will be the best-spent $15 in the whole deal.
Center finders, for finding the exact location of a hole's centerpoint or to exactly follow a scribed line. Likewise, an edge finder; mine's biggest use is tramming up the vice. Any machinist can teach you how to use these, if yours don't include instructions.

Optional, suggested:
3/8" or 1/2" hogging mill. Removes lots of material quickly.
Tap and die set. Very recommended.
A set of angle plates. They're triangular steel plates that make it possible to set a piece in the vice at a specific angle.
A clamping kit. Great for large, flat, or oddly shaped pieces.
Layout dye("engineer's blue") and scriber. Leave hair-thin lines on metal. Much easier to work with for rough cutting, and to within anything larger than an airtight seal once you're used to it. I'd just give up and die without mine. Dye's cheap, and a 4 oz. bottle will last you roughly until the sun collapses upon itself and we alert the nearest advanced galactic neighbors to our existence with the spectacular blast of our parent star going nova.

And anything else that you feel might be important.

1) You will spend more on tooling than on the machine, in the long run. Find a vice you wouldn't be ashamed to use on something bigger, and I suggest the R8 spindle because the tooling will work on larger mills if or when you upgrade.

2)The Sieg (the ones on LMS) are great bang-for-the-buck for rough hobbyists, but they're not an 'unpack and cut' mill, or heavy-duty or production-grade. I love mine, but it's the same type of love all these old Jewish couples get--they're there, but they're always bargaining and arguing.

Continuing on that, the Sieg machines take some work. Unpacking accounts for that first day. These things are packed with shipping grease. It's not a lubricant, and it traps girt like flies on honey, so you really need to strip it down to the bolts and clean it all off with WD40.

Putting it back together isn't a hassle, but adjusting the gibs and mainscrews and tramming the head and everything to proper working order from scratch is another half-day if you know about what it's supposed to feel like.

The cranks are the biggest pain. The X axis is fine--tighten it down a tad, and the thrust bearing makes it smooth. The Y axis is bearingless, and it's a compromise between smooth and tight until it's spot-on.

WD40 (everywhere), Lithium grease/Teflon(PTFE) lube (gibs), and Blue Loctite(various screws) are a must.

3)Light cuts. You're not going to get the whole 5/8" cutting length of that 1/2" end mill through in one pass. Try neatly milling a 1x1x2.5 block away from a larger piece at +/-.002" tolerance, for a good way to pass half an hour. 1/8" is a deep cut for a standard end mill on these. If possible, cut slots with a size smaller than the finished slot, and mill it to about .025"-.05" undersized on every size, and make one or two finishing passes with the appropriate mill.

4)--and this is good advice--if you'll use it and not tire of it quickly, or if it will be on anything larger than a Spyder body, and/or if there's any posibility you can fit a larger machine in your space, do. Save up a bit and check out the Grizzly line.

I like my Sieg, but if you have the space go larger.


EDIT: Moved calipers to the must-haves. Slight changes to list.

[ih8cornnuts]

Ahh i just went through all of this about 2 months ago. I was considering the same mills but also the taig and the sherline. I ended up buying a sherline 2000 because of the larger work surface and adjustablility.

Of the mills your looking at I was going to get the Micro-mark. After working on bridgeports for 7-8 years I didnt think I could deal with the handwheels. When I machine I'm always thinking in thousands of inches so each turn being 50 thousanths makes it easier.

Basically what Deus said about your questions nailed it

Theres some school type textbooks by Walker, Machining Fundementals thats packed with info.

[kidneythief]

Nothing to add here that Deus hasn't...

-Jake

[Deus Machina]

We need a 'bow' smily. :P

Between here and half a dozen other places I've answered, I really should save this just to cut-and-paste.

[amcfall]

DM pretty much said it all... If you plan on upgrading later (to a used Bridgeport at least) get R8. This is part of the whole spending more on tooling than on the machine part of the deal (and let me add it's just not more, but when you're talking about a $500 mill a LOT more). My cheap boring head was not that cheap, and good ones approach (and probably exceed) the price of the cheap mill. If this is a hobby that you will do for years keep that in mind. After a few years it's scary how much you can spend on tooling. It was easier when I was single :-)

Avery

[B]

MT3 is basic standard drill chuck taper if you are going to drill a lot get this if you are going to mill get a R8. If you do decide on the MT3 dump the stock chuck and get the best one you can afford Jacobs, Rhom,Albrecht, etc get a name brand that machinist trust.

[Deus Machina]

Like B said, it's relatively easy to find drill chucks with MT3 tapers integrated or attached. Me, I buy the chucks without the tapers, and attach them myself. Not hard, and still easy to get. They're just a bit bulkier.

I've actually had some really nice results from a couple $7 unbranded 1/2" chucks from Wholesale Tools, but I would hardly expect that to be the rule.

[joelrf600r]

adding to the list: A set of edge finders. quite cheap and with practice will help improve accuracy and consistency.

--J

[Deus Machina]

I meant to include hat with the center finders, but yes. Good stuff to have.

Also:

A center finder for round pieces.