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

Hi Chris,

This has to be one of the easiest machines to convert to CNC. We did
ours over the weekend.
http://www.embeddedtronics.com/
under metalworking, their are pictures of our conversion. We made the
motor mounts out of plywood since it has no effect on accuracy. We
are milling up to the tolerance of what the mill is capable of. We
created our own micro stepper drives and they have worked out great.
The mill has been quite useful for making electronic enclosures and
we are currently using it to mill parts for a larger gantry mill. We
have done some useful mods to the mill to improve it's performance as
well.

Sincerely,

Kin Fong

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Chris Cowley
<rotorheads@e...> wrote:

> i really like your conversion. nice machine.
>
> didn't plug it in either... just started chopping the fat...
>
> haven't had much time to work on it. but i got the X stiction down

from

> 85.30 in/oz to 17.44in/oz, Y did not give up nearly as much.

started at

> 34.34in/oz down to 33.28in/oz. bearings should help considerably..
>
> those motor mounts are quite impressive, did you cast them? or hog

em

> out of square bar? or are they something off the shelf?
>
> belt drive is high on the list too. you wouldn't happen to have a
> drawing of those pulleys?
>
> my Z has a .005 high spot at the top of the column. thats a lot of
> sanding. i just started taking measurements of everything, after i

get

> all the numbers, ill come up with a plan.
>
> im planing to draw up the whole machine in cad before i do anything
> else. i need the practice and it should be a good exercise.
>
> thanks for the reply
>
>
> C Cowley
>
>
> On Mon, 2003-10-13 at 23:40, Chris Baugher wrote:
> > 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|
> >
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