Re: [CAD_CAM_EDM_DRO] Re: X-Y Table, Rotary Table for CNC INFO

Dave,

Yes of course the height mechanism would have to
be anti-backlash. I think I mentioned a heavy spring
preload (several hundred pounds). A preloaded inclined
"channel" would require two bearings rather than one.
That would add cost, but not from the bearings.
They are almost free.

The whole exercise is to get the cost and complexity
down while keeping the profile very low. Stacking
x on y on z could get out of hand!

I agree that just articulating the mill z could be easier.
In my opinion BY FAR the easiest cheapest way
for a hobbyist to get quality cnc is to aquire an old
Bridgeport (perhaps stepper) with burned out
controls and retrofit it. I said aquire rather than
buy, because the combined effects of recession
and deindustrialization means often one can find
these hulks for free if they look around enough.
Steel "dumping" depressed the scrap metal market
so much that the things often just sit there.
It's a great time to get surplus big iron!

But with this thread we are talking exclusively about
a "bolt on and go" device that would work with any machine
that has a spindle- and whether or not it is practical.

Les

Leslie Watts
L M Watts Furniture
Tiger, Georgia USA
http://www.alltel.net/~leswatts/wattsfurniturewp.html
engineering page:
http://www.alltel.net/~leswatts/shop.html
Surplus cnc for sale:
http://www.alltel.net/~leswatts/forsale.html

----- Original Message -----
From: <david_mucha@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Friday, January 17, 2003 9:30 AM
Subject: [CAD_CAM_EDM_DRO] Re: X-Y Table, Rotary Table for CNC INFO


> Hi guys,
>
> murphreys law will show up pretty soon.
>
> if you are threading, the part/table will lift if not held in place.
> ditto for drilling thru holes or uplifitng milling cutters. so now
> you would also need antibacklash on your inclines. It would be much
> easier to make the Z move.
>
> Dave
>