Re: [CAD_CAM_EDM_DRO] HF micro mill (part no. 47158) suitability for CNC

On Mon, 13 Oct 2003, Chris Cowley wrote:

> just bought one today... and its already completely stripped down for
> re-machining.

I did the same. Didn't even plug it in.

> check out
> http://groups.yahoo.com/group/hf47158toCNC

There are some pictures of my conversion there.

> i would not recommend it if you don't have access to larger machine
> tools or would not be willing to drop the coin to farm out the work, as
> you could probably cut better dovetails with an axe...... and this will
> make life hard for motors, drivers, screws, tooling and you.

As with any cheap Asian too quality varies widely. Mine was fairly decent
out of the box although not outstanding. It was better than the
mini-mill.

> here is a short list of bad news:
> the lead screws come pre-bent.

Mine aren't too bad, but they do have couple tight spots.

> the screws are supported on plain bearings not taper roller or even ball
> bearings.

Yeah, that part kinda sucks. Fortunately it's way easy to make new blocks
with bearings of your choice.

> the nuts are iron.

They are, but they work better than I thought they might. Soak 'em up
with oil and adjust 'em just right, and they work fine. I was able to get
mine down to .0025" of backlash without too much friction.

> the gibs are iron.

The gibs are kinda weak. Had to a get some sandpaper and a surface plate
after mine.

> needs counterweight of some kind

Yup. A 25lb. gas spring from McMaster Carr works good.

> need to chop about 10 pounds off the headstock

The best thing to do is scrap the cheesy gearbox and convert to belt
drive. It's SO easy. The hardest part is making the pulleys.

> consider it a rough casting.

For the price of the machine it's fine. I found that swiping a piece of
coarse sandpaper over the dovetails a few times to smooth out the milling
marks did wonders.

> otherwise. yeah, it will be an excellent desktop machine IMHO.
> i really like mine already, in case you could not tell......

For the price you can't beat it.

> > The Z-axis looks strange, having a handle
> > at the top of the column, and two quill feeds (coarse and fine). I'd
> > be interested in hearing from anyone who has one.

The Z is kinda wierd, but it makes for an interesting machine. For CNC
conversion use the fine feed on the dovetailed column. Then just lock the
quill in place.

You could however use it like a precision drill press. Use the column
feed for general hight adjustment and the quill feed for drilling.

C|