Re: mini-mill converson data kit ?

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "turbulatordude"
<davemucha@j...> wrote:

> --- In CAD_CAM_EDM_DRO@yahoogroups.com, ccq@x wrote:
> > On Mon Jun 30 04:03:49 2003 kdntool wrote:
> > >
> > >--- In CAD_CAM_EDM_DRO@yahoogroups.com, "turbulatordude"
> > ><davemucha@j...> wrote:
> > >> Hi,
> > >>
> > >> I am looking for data on converting a mini-mill to steppers.
> > >>
> > >> can anyone offer some links ? or recomendations on stepper
> sizes ?
> > >>
> > >> I was thinking of starting with some NEM34's 150 in-oz because

I

> > >have
> > >> them and could always swap out for larger units.
> > >>
> > >> Also, what is the best way to automate the Z axis ?
> > >>
> > >> Dave
> > >
> > >Dave,
> > >I just finished the conversion on a "Grizzly" type with the R-8
> > >spindle. A ball screw for the Z-axis is the only way to go. I am
> > >running a 180oz NEMA 23 with a 2:1 pulley ratio. Direct drive on
> the
> > >X&Y axis'. Rapid rates are 24 IPM--Z and @13 IPM X&Y.(until I

ball

> > >screw them as well)(would also improve with higher voltage

drives)

> > >Not finished fine tuning EMC yet so they might get even better!

I

> did
> > >a jig for work with it: 1st piece:50 holes .035 DIA, 5/16" THK
> 6061,
> > >w/ 2 .187 dowel holes 2nd piece: 50 holes .024 DIA, 1/8" THK O-

1

> > >flat ground, w/ 2 .187 dowel holes. I used solid

carbide "circuit

> > >board" drills with the spindle running flat out, no broken

drills

> > >even with the "slow" spindle speed. Had to "peck" .015" deltas
> > >through the O-1. Both pieces line up perfect. I will be going to
> > >market with the retro kit soon if you are interested? Just

waiting

> > >for another saddle to arrive so I can finish the ball screws for
> the
> > >X&Y.
> > >Good Luck with your upgrade it yields a nice little cnc for

small

> > >parts.
> > >Ken
> >
> > Yo Ken;
> >
> > Are you talking about a conversion kit for the mini-mill? If so,
> what are the
> > details?
> >
> > Bill
> >
>
>
> Yes let me know when it is available.
>
> I hope you have a site up soon too.
>
>
> Dave

Details Details,
I plan to offer a full range from mechanics only kits right up to
fully assembled and tested closed loop machines.

Basic "Mechanics" Only Kit:

Modified headstock mount casting with pre-installed 5/8" DIA ball
screw & nut. (Non-preloaded nut as there is not enough room in the
casting, however with the weight of the headstock on the ball nut
backlash is not really an issue except on heavy plunge cuts)

Y & Z axis thrust bearing housings w/ 2 ball thrust bearings per axis
(utilize existing stock X axis thrust bearings)

NEMA 23 motor mounts for all three axis' (NEMA 34 available on
request although I am a little concerned about the weight of a NEMA
34 motor on the X axis)

New mounting plate for spindle motor relocation.

Z-Axis pulleys and belt.(haven't tried direct drive)

All necessary installation hardware.

Advanced Kit will include:
All of the above plus
Modified saddle casting with pre-installed ball screws & Nuts.

For Basic electronics I've chosen a Xylotex based driver/controller
w/power supply, packaged in an enclosure with all necessary quick
disconnect cabling, and (3) 180 oz/in double stack NEMA 23's. I will
include the crossover cable to enable the use of EMC software if
desired. Hell I'll include the two CD's with the BDI installation and
all the settings I am using if you want.

I am looking at the MAXNC closed loop package for advanced
electronics until I design my own set-up. (subject to change)

Prices?
I am looking at @ $400.00 for the basic mechanics only kit.
Basic electronics is in the $500.00 ballpark.
Probably add @ $250.00 for the X&Y ballscrew upgrade.
MAXNC Closed Loop is @ $875.00 directly from them.

Harbor Freight Machine $500.00 (chosen for R-8 spindle)
Basic Package $400.00
Basic Electronics $500.00
EMC Software $ FREE
-----------
Complete "MiniMill" CNC $1400.00 If you don't mind getting
your hands dirty. Even less if you supply the electronics.
CAST IRON DOVETAIL CONSTRUCTON WITH R-8 SPINDLE!!!!

Full Basic Machine (stock x&y leadscrews) with basic electronics and
IBM PII 400mhz loaded with EMC all set-up and tested= @$2300.00

I am a Toolmaker by trade, with an extensive industrial automation
background, so this is not some chop and hack kit. It has been well
thought out and tested every step of the way. I am looking for
feedback so please respond.