multi-machine as 14x14 lathe?

[X2cnc]

Now that my CNC mini-mill conversion is almost finished I'm looking ahead for a lathe conversion. I've been planning to do one of the 7x10 or 7x12 mini-lathes.

Recently, I've been looking at the Harbor Freight 5980-0VGA "multi-machine." It's $100 more than the 7x12, but it's 14.5x14! That really got my attention, since I seem to always want to do hubcap-shaped parts, not rifle-barrel-shaped parts. The HF web site lists the 7x12 at 89 pounds and the 5980 at 473 pounds. Even with the drill press bits, I can't see where the extra mass is, though generally heavier is better for machine tools.

Even if I toss the apparently-useless "drill press" bits, $599 looks like a good deal for a 14x14 lathe.

Has anyone here used one of those multi-machines? Comments?

[dld]

Hi, I purchased one of these last year, and in order to lift it onto my tiny benchspace without people or much equipment had to disassemble it, put a beam overhead, and lift the heaviest piece (mill column) using a block and tackle. The base looks like it would be heavy, but isn't all that much without the lathe motor and leadscrew attached to it.

Breakdown of weights (rough guesses, total is about right though):

250 - mill column with mill motor and lathe spindle
60 - lathe motor
40 - x-axis base
40 - y-axis table
40 - toolpost assembly/vice
15 - tailstock
10 - lathe chuck
10 - x-axis lead screw, wheel, mount
5 - drill chuck
3 - dead point

The column is held to the base by four large bolts, and two internal pins. It only pulls straight up, so you'll want something to hoist it during both disassembly and reassembly.

The lathe spindle and mill head could probably be disassembled further, but that would have mean more electrical connections broken, and disassembling the rotating column for probably less than 50 pounds shaved off the column.

I'd stay out of the drill head itself - there's a powerful spring in there that provides upward lift to the drill head.

Not many comments on using it yet. The screws are metric, and yet labelled in inches. If milling, you'll probably need an assortment of both endmill holders, collets, and vices, as the mill head itself has only about half the z-axis range of the space it has to span, so you'll need lots of options to get the tool to the workpiece. I spend a lot of time fiddling with the y-axis gib, and haven't gotten it tuned well for both the extremes and the middle.

The lathe's slowest speed is 430 rpm. To go slower (at 14" you might need to) you'd need a new motor or pulleys. There's no gearing to allow thread cutting - and it's too fast anyway. I'm not certain the toolpost or y-axis table it mounts to would really allow turning a full 14" diameter. You'd probably have to build something to reach over from the side, and the mill head might get in the way from above.

It's all belt driven, which I'm sure my neighbors appreciate. When abusing it to route wood it's not all that loud (quieter than when milling metal, quieter than a gear-driven drill press/mill, and quieter than a high rpm router).

Still, in my 7x10 shed, only one machine was going to fit, and this occupies the corner and can mill the ends long workpieces that stick out over the bench or out the door.

-Drake

[sansbury]

The 8x12 or 9x20 lathes are a better candidate. They're nicer machines overall and their practical capacity is going to be the same or better for most purposes. The machine you linked is fairly crude and not in any way the equivalent of a 12-14" swing lathe. I'm sure it works well as a basic machine for some people, particularly a small maintenance shop where the occasional part is needed. Good CNC performance comes from precision parts, precision assembly, and high rigidity. A manual operator can overcome a lot of limitations in these, but they will send a CNC operator into permanent tail-chasing mode.