Mini mills - are they worth it and which ones

[theoldwizard1]

Well, my intro is out of the way, so here is the really reason I came here ! Are there any "mini mills" out there for less than $1,000 that are really worth buying ?

I would be working in plastic, aluminum and some mild steel. Mostly simple things like slots and holes. I want to learn the "traditional" methods. I am concerned that the DC powered minis just don't have enough power. Vee-belts slip and I can't say that I have ever seen a cogged belt drive.

A used Bridgeport or other full sized machine is just not an option. Too much space and no access to 240V. Plus I would have no idea how to check/adjust it to bring it into reasonable tolerances (+/- 0.002-5 is likely all I will ever need).

Of course at my age, it is not going to get a lot of use (good thing I can afford to buy more material after an "Ooppss" !)

What say the experts ? Or how does one go about finding a "garage" machinist in your area ?

 

[pebbleworm]

I'm very happy with the Harbor Freight X-2. For what I paid for it it seems nicely finished, runs true and was easy to clean, set up and get running. I did fill the column with epoxy, which just made sense and sprung for an inexpensive set of collets. At the very least it's a a damn fine drill press. For the hobby stuff I do it works just fine. There are a couple of fettled/improved versions available from Micromark:
http://www.micromark.com/MicroLux-H...CeYBn69BpDfqEtP8zeR2hyAs05cmO_dHF4BoCFQLw_wcB
And the Little Machine Shop:
https://littlemachineshop.com/3900
but both are almost twice the price of the HF unit if you watch for a sale and have one of their perennial coupons. Each one does have useful and valuable improvements. Since they are a Sieg X-2 they are man-portable and fit on a benchtop. I have no regrets about the HF mill, but your mileage may vary. Check out this and other boards for more info, and there is a yahoo group for these mills too.

 

[Baithog]

Motor power is not a problem if you are not doing production work. I have had my X2 for several years and I have never stalled a bit. Rigidity is another mater. It will cut steel, just lighter cuts than a knee mill. Of course the mini mill doesn't have that ton of cast iron the knee mill has, or the costs.

My mill is from Harbor Freight. It has been converted to CNC. I'm finding it hard to justify the cost of the CAD/CAM software. I mostly run it in Semi-auto mode. Grizzly tends to have higher quality machines than HF, and more variety. Both the G8689 and the G0758 are in your price range.

This is a photo of the dovetails for a boring head I'm making. They were cut in 2 inch mild steel with my wimpy X2.

 

[Travis7s]

Don't underestimate the V-belt, even some large-ish knee mills use them, and they don't really slip unless something very bad is happening.

V-belt is actually the upgrade for the X-2 style mills. If you ever crash your stock X2 or leave the spindle locking pin in (guilty) you can kiss the plastic gears goodbye.

You could also look into the Rong Fu mill drills, the RF25 is close to your budget and is a 400lb machine.

Keep an eye on your local craiglist, you may come across a good deal.

 

[theoldwizard1]

This is a photo of the dovetails for a boring head I'm making. They were cut in 2 inch mild steel with my wimpy X2.

Very impressive. I would love to see a video of your X2 in action, especially cutting that dovetail !

 

[Baithog]

I'm impressed with the dovetail, too. I've never cut one before. There is no video. Maybe when I cut the dovetails for the tool grinder that I'll tackle next. I tried to shoot video of cutting the gib slot tonight and almost ruined the part with my camera fiddling. I'll have to try shooting some dog videos to figure out the process.

I cut the male dovetail first, then used it to fit the female. Everything that could be hogged out with an end mill was. I have better luck with this light mill by running cutters as fast as I can get away with, and using 3 or 4 flute mills for steel. The machine seems to damp higher frequencies better. For the dovetail cutter, I ran it at 2200rpm, cutting .02/pass at 3ips. That is excruciatingly slow, especially for someone used to running a ton of cast iron. The power feed capabilities really help with keeping the feeds consistant through the boredom.

My moto is: slow is better than broken tooling and ruined parts when it comes to these little mills.

 

[theoldwizard1]

What is the difference between a mini-mill and a drill-mill ?

 

[12bolts]

A mini mill is just that, a smaller lighter mill, but still a mill.
A mill drill is more of a bench/pedestal type drill with an x-y table to enable some milling applications. Like any combination tool they are generally not suited to "real" work outside of their original design scope. That being drilling holes in this case.

Cheers Phil

 

[jatt]

My unit is just a column mill drill. Machine spends most of it time ruining perfectly good hunks of MS with it and some ally.

Its a manual unit, so lots of hand turning the X-Y table and Z, but it was never intended to be a production machine.

Rigidity, well it weighs in at approx 360 Kg (790 lb), so its hardly a big unit. For myself I wouldnt go any smaller. Seem to use a lot of the table up with what i do with it and am pushing its limitations more than i care to admit.

Like anything work within the limitations of your machine. If its a little one take lite cuts.

 

[theoldwizard1]

I'm getting excited now after a lot of research ! Biggest problem is I need a place to put my new toy ! The garage is too cold and damp in winter and to hot and humid in summer. Looking at build a nice 8x12 shed/man cave, insulated and heated and cooled.

From my research I am leaning toward the LMS 3990 HiTorque Mini Mill with one of their packages. One thing that bothers me, is that using a milling vice and parallels for through hole boring, you loose Z axis space. The obvious solution is 2-4 1" steel spacers mounted under the column and attached with longer bolts. Obviously these would have to be milled and lapped to provide a true flat parallel surface.

Anyone do anything like this ?