Mini Milling Machine

[schmeky]

gwillys,

Thanx for your effort, I really do appreciate it. I understand the mini-mills are a lot like shooting. You start with an out-of-the-box pistol, modify, customize, then. . . holy moly. . . there's reloading, dies, powders, scales, powder tricklers, etc.

It's the same with mills, just different.

 

[44-henry]

Skip the coolant pump and buy yourself some more useful accessories. You shouldn't be taking real deep cuts with that mill and a squirt or two with a spray bottle will give you enough for most jobs.

You can find a lot of accessories at www.littlemachineshop.com and they are a good company to work with. I have used table top machine tools in the university classes I teach at UND for the last several years and students generally like them. I find that they work great to teach the basics and make an ideal stepping stone to the bigger machines that we also use in our program. Enjoy your new machine.

 

[madcratebuilder]

Congrats on the new mill. I well second the belt drive as the first thing you do. I would not waste the money on a true inch conversion. Just put a three axis DRO on it. You never read those damn dials again, besides they are covered by swarf or your work anyway!
E-bay is an excellent place for end mills, several guys sell fresh re-sharps that are 20-30 cents on the dollar of new. These are top of the line made in USA carbide cutters as cheap as HHS Chinese. Unless your running CNC you could care less if your .375 cutter is now .371.
You don't need a flood coolant system, just a hand spray pump is fine, your doing small stuff remember.

 

[Rex B]

I concur

+17 (or whatever) on the minimill

I have had one for years, along with a bigger milldrill.
The minimill gets all the work that fits the envelope, usually slides.
It works just fine - carbide always. Watch your feeds and speeds.
DRO is a must, even if it's converted $20 digi-calipers.
You can get by with a couple of strategically mounted dial or digital indicators.

You can do good work out of the box, but fine work requires disassembly and tuning to get it square, smooth and rigid. I haven't done that, and it's fine for slides.

Enjoy your mill It's habit-forming.

 

[krs]

Skip the coolant pump and buy yourself some more useful accessories. You shouldn't be taking real deep cuts with that mill and a squirt or two with a spray bottle will give you enough for most jobs.

Yep, I go along with this too. I have a coolant system on my big mill but almost always just use a spray bottle of WD-40. I buy the stuff by the gallon for about $10. and use it on the lathe, the mill, and even the surface grinder sometimes. I was surprised to find that this is exactly what Darrel Holland advises to use in his video lessons on running a machine shop. Coolant makes a mess so you'll want to only use it continuously if you really need it, and you won't with small cuts.

You'll get a feel for what burns up your bits and you aren't working in a job shop where everything you do is accounted for on the bill to the customer. You can afford low speeds and contemplation . The only boss yelling at you will be your wife at about dinnertime.

Definitely do whatever it takes to make sure the table and your vise or holding fixtures are perfectly square with the spindle. This will screw up nice things more than most anything you can do. A half thousandths (.0005") out of square will cause an x-axis cut to be higher or lower on one side than the other in just a couple of inches and it gets worse the wider the piece is, to give just one example.

I doubt anyone needs to ask how I know this, eh?

 

[schmeky]

I'll skip the coolant pump for now, just about everybody can't be wrong. I found some new 1/4" carbide 4FL end mills for $7.50 each, so I ordered 3 for now.

It's reassuring to hear others that have used their mini mills for (pistol) slide work. Should have it in a couple days; got notification it's already shipped out. I'm already finding things to do with it I hadn't planned on.

My son and I are building a 4RW75 series Ford transmission for his street/race car. I'm going to mill the hydraulic aluminum apply pistons so we can increase the number of clutches in the clutch packs.

Should have bought a mill sooner.

 

[krs]

I'm going to mill the hydraulic aluminum apply pistons so we can increase the number of clutches in the clutch packs.

Hmm, that sounds like a job that might best be done in your LATHE....

 

[schmeky]

Hmm, that sounds like a job that might best be done in your LATHE....

Absolutely . . . . if I had one. Had one where I used to work and I turned many a GM TH-350, TH-400, and 700R4 apply pistons. A lathe may happen in the future . . . but the mill will get the job done for now.

 

[madcratebuilder]

My son and I are building a 4RW75 series Ford transmission for his street/race car. I'm going to mill the hydraulic aluminum apply pistons so we can increase the number of clutches in the clutch packs.

That was one of the reasons I bought my mini mill and lathe for in the first place. Cutting up them power glides.
I have a 7X14, go bigger if you can afford it.

Check out smartflix.com, you can rent dvd's on learning milling and lathe operation, some are pretty good, some suck.
There is a ton of on-line info about the mini's.

 

[krs]

Absolutely . . . . if I had one

.

I was teasing you, Schmeky, just in case you didn't know that.

Flycutters are pretty cheap but the trick to milling an apply piston will be to hold it. When you're milling it matters a lot which side of the work a cutter runs on. One way, a "climb" cut can exert a lot of force - enough to take your workpiece right out of your holding device and fling it across the room if you haven't got it well set up or try too much cut.

That's the worst case but any movement of your work while it's being cut will do damage to the piece, maybe to the machine, and possibly even to you as quick as a blink. A small machine will exert a smaller force, of course, but the effects are the same big or small. I'd bet that something like this is the reason for the recommendation of a conversion to the belt drive in mini-mills.

I'm lousy at describing what I mean with this but Madcratebuilder's recommendation of the tapes from Smartflix http://smartflix.com/ would be worth your time if you don't already know what I'm talking about.

 

[schmeky]

krs,

I would be more comfortable if you just outright made fun of me instead of just mere teasing

I eatin' up everything you're putting down. All the input here has been from those that have been there. I fully intend to check out the instructional links provided.

The more I learn, the more I realize just how little I know.

 

[schmeky]

Maybe the last post on this topic, but the mill arrived today at my home. Look forward to setting it up.

 

[krs]

You're gonna' have a ball, Schmeky, and so are we seeing your creations and new ideas.

Just bolt the machine down and remember that it could hurt you.

edit: That was quick! Did the driver refuse to do any more than lower it to the street on his liftgate?

 

[madcratebuilder]

A good mod is installing this switch You can change direction of rotation with just a twist of the knob, great for running taps.
This is about as big of vise you can use.
This gets rid of that damn torsion arm and gives you almost two more inches of usable height.

http://www.frets.com/HomeShopTech/hstpages.html

 

[gwillys]

this is a good vise - Vise, 3" Screwless. eliminates slop/shifting you'd get with the screw type.

 

[madcratebuilder]

this is a good vise - Vise, 3" Screwless. eliminates slop/shifting you'd get with the screw type.

I have a 2" and 1" screwless, I do like it for small work items.

 

[Alchymist]

I have the HF micro mill, and have found that a set of collets are a wonderful thing. Beats trying to hold an end mill in a Jacobs chuck by far. But the one thing I found really handy was a 3" Palmgren vise, mounted to a piece of 1/2" aluminum. The vice was carefully positioned on the plate and held with flathead screws countersunk in the plate. The plate was drilled with three holes that aligned with the t slots in the table., allowing the vice to be positioned in either a froward position next to the column or back by one row of slots. By using only two bolts in the T slot, the plate can be positioned at an angle if needed. The biggest advantage though, is that the plate can be slipped on the table with the three bolts loose, and a machinist square used against the plate, and the bolts tightened. The vise fixed jaw is automatically square with the table. Quick on, quick off. Naturally care must be taken to start with a truely square plate (you have the mill right there!), and to make sure the fixed jaw of the vise is square to the plate. I used a dial indicator against the plate to initially clamp it to the table, and then against the fixed jaw as the vise was positioned on the plate. Can't count how much time is saved when a vice is needed and no kludge of hold downs is needed. Of course if you have a dedicated milling vise...different story.


Oh yeah, your second purchase should be a rotary table..... and then the indexing plates, and then......well you get the idea....

 

[schmeky]

Here it is temporarily set up in my shop. Nothing is attached or assembled yet. I checked the Hi-Lo range out for function. Overall, seems to be a pretty solid machine for the money. Don't worry, I plan on moving it away from my Dillon press. Thanx to all.

 

[gwillys]

welcome to the swarf rat consortium

 

[krs]

Schmeky, I'm not sure, but you might be able to get good money for that welding helmet.
It's such a relic that some fool's bound to think it's collectible! LOL!

The machine looks good.

Don't even think about running an end mill or dovetail in that drill chuck. Mill loads are sideways to the spindle - a drill chuck isn't designed to hold anything from moving sideways. And look how much of your working room it takes away.

 

[schmeky]

krs,

So what do I need to get started? I have a little milling project lined up soon.

 

[madcratebuilder]

Clamping kit
parallels
vise
Edge and center finder and T-slot cleaner
R8 collets
end mills
2" brush-several
center drills

Here's a kit from littlemachineshop.com

 

[schmeky]

I have a clamping kit on the way, ordered it with mill, but hasn't arrived yet. The R8 collets are obviously used with end mills. Can I get started without the vise by clamping an item (in this case a 1911 bare slide) down using some spacing blocks and the clamping kit?

Simply don't have $300.00 right now to order the kit.

 

[44-henry]

I would suggest starting simple and adding tools as you have a need for them. I would suggest a good vice would be at the top of the list. You will not want to hold end mills in the drill chuck as it was never designed for side loads and can be very dangerous when used in this manner. On the other hand you probably will use more 1/4 and 3/8 shank end mills than any other so you could save some money by just buying collets (or solid holders) for these two sizes in the beginning. Parallels are nice, but you can make these yourself with some care. It looks like you have a reloading press so you should already have a caliper, if not you need to get one. A dial indicator is also important for dialing in your machine and some other setups, inexpensive ones can be purchased for around $10 and are well worth it. You can spend a lot of money on the latest laser edgefinder; however, a wiggler is really all you need. Beware of the addiction of buying additional tools and accessories until you have a real need for them. Have fun.

 

[snommittj]

Mini Mill

I traded a SA XD 45 for a HF mini mill about 6 months ago. I didn't have any prior experience with a mill but there are alot of great videos available that will walk you through the basics and make learning pretty easy. My first projects were a couple of mini 1911 slides(kinda) to practice different cuts. I apprentice for a gunsmithing and he told me to take some 3/4" stock and start making chips. It's been alot of fun and very educational. Now, I can do most any 1911 mod I need to do. These machines might not be as fast as some, but with proper set up, they'll do the job and do it nicely. I'm addicted.