Re: [CAD_CAM_EDM_DRO] How to convert a Grizzly 1006 Mill to CNC

Your mill (all typical medium milling machines) is about 0.02 mm +/- in
absolute precision, 0.01 mm +/- in resolution unless its damaged. You
probably have about 2-3 x that in backlash.

Expensive ? this depends.
You should use offset mounts and timing belts and pulleys for various
reasons - if you need better your price range and needs are 10x higher,
and you would know it. They are the easiest, best cheapest way unless
you want sub 0.01 mm precision, at which point your costs and
difficulties are 10x higher. They will help with mid-band resonance,
set-up, and hunting. They are the best option, unless you need a very
very stiff set-up. If you do, you will need tighter nuts, and many many
other things, some of which are expensive. I don´t recommend it. Do the
cnc with belts first, when you get experience you can always change it
if you want, the belts were cheap. The only thing wrong with belts, is
if you are looking for less than 0.01 mm backlash and accuracy, in which
case you will want hard mounts.

At that point, you would also like set-up jigs, you need to change the
bearings and bearing mounts in both ends, make a new, stiffer yoke (3x
more mass), preload the bearings, go to bigger motors and direct drive,
probably servos, probably ball-screws, error-map the screws, about 3000
- 4000 $ in parts. This quality bearings will be 100-200 each, mounts
are 400 $ if bought, so 1600 for 4 etc. etc. And you still might use
belts, just bigger and tighter and more accurate.

Whats expensive for you ?
Your cheapest best solution is nema23 hi-quality motors 425 ozin (2 for
110$), 2:1 belts (6$ belts, 50$ pulleys), 24 v psu (surplus),
non-isolated basic breakout board (12$), surplus pc (free), mach3 trial
(free), kit drivers about 2 amps 24 volts (30$ each, 60$) change nothing
else.
About 1 week to fab motor mounts etc, use surplus flexible ethernet for
cabling.
It will work, quite well, for 240 $. Not expensive, imho.

You can use it to do work as good as the machine is capable of, 10x
faster than manual, with excellent repeatability.

If you want a recommendation for whats the best choice, how much to you
want to spend, ballpark ? If you can possibly afford it, isolated bob
(120), gecko 201s drivers (180) and you are good to go. Total 360 $.
Still not expensive.
If you want a very good choice, 48 psu (100), gecko 203v drivers (260),
newer pc (2.5 ghz plus, 300), total mach3 w. wizards (230), total 1060.
This would be for "real " production use, easy and very reliable.

If you need specific reasons, ask, but you can take it as a given that
the cheapest solution is already really good and will work. When I
started, 5 years ago, there were, and still are, people saying they
build everything for under 100 $. Just let them say it, and ignore the
fact that a decent chuck (m2 precision) is 40$, and decent endmill 3 mm
10$ with collet etc...

The one thing most people don´t do, is turn the motors around, and then
put them under the axes to save space, which costs nothing extra and
works better and they are less in the way. I recommend it, if possible.

FWIW - Today I built a cnc rotary table as a lathe (mill?) accessory
(heavy 12 kg, 6", strong, about 120) with kit driver (30), sonceboz
swiss modern motor (20$) for 190 $. I will now go hook it up and hope
for no smoke ...

> Hello,
>
> I spent the better part of 2 hours looking for a kit or HOWTO on this
> subject and I found out that it is very expensive, not an easy
> project and or simply very little information about it.
>
> I am looking information of others that have done this conversion
> with this machine or like machines/clones etc. Let me also say that I
> can make all the motor mounts, motor coupling etc and I have motors
> and a controller and some software products to drive it.
>
> I recall a mod that was done that simply coupled the motors in place
> of the cranks and others use offset mounts with drive belts. Pros and
> cons would good information to have too.
>
> I dunno for sure how accurate the mill is in a manual process is in
> the first place, so that is a concern going that route. I personally
> do small projects like motor mounts, transmission mounts etc for
> motorcycles. However I would like to perform pocketing too for things
> like right angle gear boxes etc. So eventually I would think ground
> precision screws are in order. I am no expert at this so I wanted to
> drop a few lines to the experts.
>
> Many thanks in advance.
>
> Todd
>
>
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